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2. BUREAU OF SOILS AND WATER MANAGEMENT invites tenders for Provision for Procurement of Heavy Duty Paper Shredder
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Soils ,News, opinion and commentary - Abstract
BUREAU OF SOILS AND WATER MANAGEMENT, Philippines has invited tenders for Provision for Procurement of Heavy Duty Paper Shredder. Tender Notice No: AMP 134 BSWMPR 2024-1058 Deadline: July 15, 2024 [...]
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- 2024
3. Variation of Collapse Potential with Initial Suction Pressure for Natural and Treated Unsaturated Gypseous Soil.
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Jassam, Mahmood G. and Hussein, Israa S.
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SOILS ,SILICA fume ,SOIL particles ,FILTER paper ,SOIL stabilization - Abstract
An experimental program is used to look at the impact of different parameters on the collapsibility of treated and untreated gypseous soil which is one of the most intricate soils. It is experiencing a high strength when it dry, but when subjected to wetting, it experiences a high collapse and volume change. A single odometer test was utilized to specify the collapsibility of soil. Lime and silica fume were utilized to detract the collapsibility of gypseous soil at a percent from 0 to 8%. The soil compacts at its field dry unit weight. Hence, while applying treatment material to stabilize the soil, it is crucial to specify the beginning ratio of saturation (So) that yields a satisfactory compaction result and optimal connection among soil particles. These factors were examined to determine the effects of varying starting suction amounts and starting saturation ratios on the collapsibility of both treated and untreated gypseous soil. Furthermore, a saturation-effective ratio that achieves the lowest collapse potential would be defined. The filter paper method was utilized to specify the initial matric suction to examine how it affects the soil's ability to collapse. The primary findings indicate that for both natural and treated soils, compacting the soil at a starting saturation ratio of 10, 20, and 30 percent results in a reasonably high collapsibility. Between 40 and 50 percent was the effective saturation ratio that yielded the lowest collapsibility. Soils' collapsibility was seriously affected by suction pressures. The disparity in the matric suction of the compressed specimens during the soaking had less of an influence on the collapsibility of the treated gypseous soil (particularly treated with silica fume) than untreated soil. To imitate the collapsibility of both natural and treated gypseous soil, an empirical equation is expected. [ABSTRACT FROM AUTHOR]
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- 2024
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4. A Simple, Affordable, Do-It-Yourself Method for Measuring Soil Maximum Water Holding Capacity.
- Author
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Nelson, Jessica T., Adjuik, Toby A., Moore, E. Britt, VanLoocke, Andy D., Ramirez Reyes, Alam, and McDaniel, Marshall D.
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SOIL moisture ,SOIL structure ,FILTER paper ,SOILS ,SOIL testing - Abstract
There is an increasing need for accessible methods to monitor soil health. Our primary objective was to evaluate an accessible, do-it-yourself method for measuring the maximum water holding capacity – we call this the funnel, filter paper, and drainage (MWHC
FFPD ) method. First, we compared MWHCFFPD to the water desorption method via pressure cells (WHCPC ), routinely used for generating soil water retention curves, using 10 soils from a wide range of textures (4–55% clay). Second, we tested the sensitivity of the MWHCFFPD to methodological variations likely encountered by citizen scientists. The two methods were quite comparable in precision, with mean coefficient of variances of 3.5% and 4.4% for the FFPD and water desorption method, respectively. The MWHCFFPD and WHCPC methods were comparable, with MWHCFFPD best correlating to WHCPC at −2.45 kPa (R2 = 0.98). The MWHCFFPD method is somewhat sensitive to some methodological modifications, most notably variation in water source, but with standardized protocols could be scientifically robust. Overall, MWHCFFPD can be used as a simple and affordable test of sieved soil structure and organic matter, and thus has potential to expand soil health monitoring. [ABSTRACT FROM AUTHOR]- Published
- 2024
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5. Geospatial Variability of Soil Properties of the Different Villages in Arajiline Block of Varanasi District of Uttar Pradesh.
- Author
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Maurya, Shivam Kumar, Bharteey, Prem Kumar, Singh, G. R., Bahuguna, Ayush, Luthra, Nidhi, Pal, Sudhir, Pradhan, Surajyoti, and Rai, Sumit
- Subjects
SOIL sampling ,SOILS ,FILTER paper ,AGRICULTURAL productivity ,CROP management - Abstract
The current study was conducted at the different villages of the Arajiline block of Varanasi district, Uttar Pradesh, India during November, 2022-June, 2023 to evaluate the variability of soil properties and nutrient indexof soils. The random sampling technique was used to collect 40 soil samples at different locations with the help of GPS at 0-15 cm depth. The collected soil samples were air-dried in shade at room temperature, passed through a 2 mm filter paper, and analyzed for different physico-chemical properties. The result revealed that the TS (range 8.2-81.3%), VFS (range 4.2-35.5%), Silt (range 10.1-54.2%), Clay (range 7.7-38.8%), BD (range 1.08-1.45 g cm-3), PD (range 2.04-2.33), Porosity (range 30.24-51.56%) pH (range 6.4-7.8), EC (range 0.1-0.3 dS m-1), OC (0.2-0.6%), and available N, P, K, S, Ca, and Mg varied from 130.12-260.30 kg ha-1, 14.2-23.2 kg ha-1, 145.0-240.0 kg ha-1, 7.5-17.6 kg ha-1, 3.8-8.2 cmol(P+)/kg, and 2.1-4.1 cmol(P+)/kg, respectively. The findings indicated that the studied soils were slightly acidic to moderately acidic and free from salinity hazards; 70% of the soil samples were low in organic carbon, 30% were medium in organic carbon, and 100% of the soil samples were low in available N and medium in available P, K, and S. 100% of soil samples were found to be sufficient in exchangeable Ca and Mg. The findings of this research could help in crop nutrient management, fertilizer recommendation, and decision-making for increasing agricultural production and farmer profitability. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Corrigendum to "Spatial and temporal detection of root exudates with a paper-based microfluidic device" [Soil Biol. Biochem. 195 (2024), 109456].
- Author
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Patko, Daniel, Gunatilake, Udara Bimendra, Dupuy, Lionel X., Basabe-Desmonts, Lourdes, and Benito-Lopez, Fernando
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PLANT exudates , *MICROFLUIDIC devices , *SOILS - Published
- 2024
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7. Stability Analysis of a Shield Tunnel in Unsaturated Soil Considering the Soil Arch Effect.
- Author
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Cui, Xiaopu, Li, Pengfei, Wu, Jie, and Wei, Yingjie
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EARTH pressure ,SOILS ,PERSONAL protective equipment ,TUNNELS ,COMPUTER simulation - Abstract
This paper aims at proposing a calculation model to deal with the face stability of shield tunnels in unsaturated soil. Based on the existing results of centrifugal test and numerical simulation, a new failure mechanism is proposed, which combines the logarithmic spiral with upper loosening arch mechanisms. The failure mechanism considers the influence of the soil arching effect and the logarithmic spiral height coefficient. Formulas for calculating the loosening earth pressure of unsaturated soil are deduced. Subsequently, this model of loosening earth pressure is introduced into an analytical model to compute the limit support pressure on the tunnel face. Compared with other height coefficients and the degree of soil arching effect, when the height coefficient is 0.95 and the degree of soil arching effect is 10%–30%, the limit support pressure proposed in this paper is in good agreement with the centrifugal test results. Finally, comparisons are performed with the proposed model and classical models as well as typical centrifuge model tests. The comparative analysis shows that the proposed theoretical model is in good agreement with the numerical simulation. The outline of the failure zone by the theoretical model in this paper is in good agreement with the centrifuge results. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Yangshao Village site, archaeological soil, soil properties, soil development, paleoenvironment.
- Author
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Su Zhang, Qing Yan, Xin Huang, and Bin Yan
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SOIL formation ,GREENHOUSE gases ,ENVIRONMENTAL regulations ,ENVIRONMENTAL responsibility ,SOILS - Abstract
More attention has been paid to environmental regulation of greenhouse gas emissions in the energy industry under the transformation of industrial structure. This paper takes microdata of Chinese energy enterprises from 1998 to 2012 as a sample to build a duty-sharing model, analyzes the effect of environmental regulations on the industrial chain, and explains the "double growth" phenomenon that occurred in China, which is nothing short of miraculous in terms of the environment and economy. In the industrial chain, the environmental obligations and responsibilities will be shared between upstream and downstream enterprises due to trade linkages. This paper finds that environmental responsibilities will move forward through the industrial chain when environmental regulations are strengthened. Downstream companies will loosen "relative" control constraints, thereby expanding output but increasing demand for upstream products. Different from the existing research, we claim that, since environmental regulation has a differential effect on the industrial chain, it will promote the growth of output in the entire chain, in contrast to the theory of "cost compliance", which claims that environmental regulation will inevitably lead to the output. Based on this research, this paper puts forward some suggestions and insights on how the government implements environmental regulations. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Call for papers: 25th anniversary special issue - Impacts of Wildfires on Soil and Sediment Systems.
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WILDFIRES ,SOILS ,SEDIMENTS ,WILDFIRE prevention ,LANDSCAPE ecology ,WATER security ,FUEL reduction (Wildfire prevention) - Abstract
The Journal of Soils & Sediments is calling for papers for a special issue on the impacts of wildfires on soil and sediment systems. The increase in severe wildfires due to human actions and climate change has led to various effects on soil and sediment, including changes in properties, ecosystem health, biodiversity, runoff, erosion, and water and chemical fluxes. These modifications have significant consequences for terrestrial and aquatic ecosystems, water resources, food and water security, and human well-being. The special issue welcomes research on all aspects of wildfires' impact, including conceptual, modeling, and field-based studies, with a particular emphasis on review articles. Expressions of interest should be sent to the designated email addresses by July 1, 2024. [Extracted from the article]
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- 2024
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10. Performance of Some Organic Mulch Materials for Weed Suppression, Soil Conditions and Yield in Capsicum annuum L. Cultivation.
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GÜRBÜZ, Ramazan, ALMA, Mehmet Hakkı, ALTEKİN, Harun, and TÜLEK, Cemal
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CAPSICUM annuum ,WEEDS ,MULCHING ,WATER efficiency ,SOILS ,WHEAT straw ,PLATEAUS - Abstract
The aim of this study was to investigate the effectiveness of different organic mulch materials and thicknesses in controlling weeds, improving soil temperature and moisture, and increasing crop yield in Capsicum annuum L. cultivation. The experiment was conducted in 2022, using three types of mulch materials (grass, chopped paper, wheat straw) and three different thicknesses (5 cm, 10 cm, 15 cm). A total of 22 weed species were identified in the experimental area, and statistical analysis revealed significant differences in all parameters between the mulch treatments and the control group. The use of organic mulch resulted in better weed control, with an increase in mulch thickness corresponding to greater suppression of annual weed species. The highest effect on weed dry weight was observed in the 15-cm paper mulch, which also produced the highest yield (3940.48 kg/da). The study also showed that soil temperature was lower and soil moisture was higher in all mulch treatments compared to the bare soil control group, with some fluctuations observed at times. Overall, the findings suggest that the use of organic mulch is crucial in arid and semi-arid regions for effective weed control, water conservation, improved water efficiency, reduced soil evaporation, and increased pepper yield. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Thermal Effects on the Soil Water Retention Curves and Hydraulic Properties of Benggang Soil in Southern China.
- Author
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Yang, Yuke, Yang, Lu, Zhao, Dongfeng, Guo, Yongjia, Lin, Jinshi, Jiang, Fangshi, Huang, Yanhe, and Zhang, Yue
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SOIL permeability ,SOIL moisture ,SOILS ,RED soils ,HYDRAULIC conductivity - Abstract
Soil hydraulic properties significantly affect the occurrence and development of collapsing gully walls. The effect of temperature on the hydraulic properties of soil in collapsing gully walls remains unclear. In this study, the hydraulic properties of the red soil layer, the sandy soil layer and the detritus layer in a collapsing gully wall were investigated using the filter paper method, and the soil water retention curves of the different soil layers at 25 and 40 °C were determined. The aim of this study was to investigate the impact of temperature on the soil hydraulic properties of different soil layers in collapsing gully walls. The study found that when the water content in the red soil layer and sandy soil layer exceeded 20% and in the detritus layer exceeded 10%, the soil's matric suction significantly decreased as the temperature increased from 25 to 40 °C. Additionally, the parameters of θ s , α , n and m all exhibited a decreasing trend, and the soil water content in the detritus layer was primarily influenced by the temperature change, which resulted in a decrease of 38.10%. The unsaturated hydraulic conductivity of the detritus layer exhibited higher values than that of the sandy layer and red soil layer under identical temperature conditions. Moreover, the unsaturated hydraulic conductivity of the red soil layer, sandy soil layer and detritus layer increased with increasing temperature. It was observed that the unsaturated hydraulic conductivity of the detritus layer increased by 0.18 cm h
−1 at a soil water content of 44%. This increase in conductivity was more pronounced than the corresponding changes in the red soil layer and sandy soil layer. An elevated temperature caused the water-holding capacity of the different soil layers of the collapsing gully wall to decrease and the unsaturated hydraulic conductivity to increase. However, the influence of the clay particle content within the soil of the collapsing gully wall rendered the temperature effect more distinct. Therefore, the destabilizing deformation of the soil in the collapsing gully wall during the summer under high temperatures and precipitation may have played a key role in its collapse. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. A Novel Multiple Linear Regression Approach for Predicting the Unconfined Compressive Strength of Soil.
- Author
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Mahmoudi, Mohammadreza, Toufigh, Vahab, and Ghaemian, Mohsen
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COMPRESSIVE strength ,SOILS ,SOIL classification ,BINDING agents ,GRAIN size - Abstract
This paper proposes a precise and general multiple linear regression (MLR) model to predict the unconfined compressive strength (UCS) of various soil types. The study used a wide range of data sets, including 952 data points considering 39 soil types with varying grain sizes. The model inputs were soil physical properties, grain size, age, mixture proportion, and chemical composition of binder materials. An innovative and novel approach was developed to enhance the accuracy of the MLR model, a randomized exploratory algorithm. The model demonstrated significant accuracy with a 0.921 R
2 in the testing data set. The Bayesian model averaging (BMA) method was employed for feature reduction, focusing on important variables. Alternative models were also developed based on the significant variables highlighted by the BMA approach, all showing high accuracy in predicting the UCS. The proposed models demonstrated superiority over traditional approaches based on the data set size and statistical metrics. The paper provides instances of predicting soil UCS and determining the mix design corresponding to the target UCS. [ABSTRACT FROM AUTHOR]- Published
- 2024
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13. Study on soil pressure of loose soil in cohesive soil tunnel considering soil arch effect.
- Author
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Hongtao Dai, Yang Sun, Yao Rong, Junping Yu, Jiangpeng Wu, Yongjun Zhang, Wei Guo, and Zhanping Song
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ARCHES ,CLAY soils ,TUNNELS ,SOILS ,INTERNAL friction ,EARTH pressure - Abstract
Soil pressure in clay formation tunnels is closely related to soil arch effect and the development of slip surfaces. Firstly, numerical simulation software is used to simulate the actual situation of tunnel excavation, and the change rule of the slip-cracking surface of cohesive soil is analyzed. Secondly, based on the numerical simulation results and the ellipsoid theory, the pressure formula of Terzaghi loose Earth is modified considering that the principal stress trace is catenary. Finally, the calculation results are compared with the finite element calculation results to verify the rationality of the formula in this paper. The relationship between the internal friction angle, cohesion force c, eccentricity ε, looseness coefficient β, and the pressure of loose Earth is further studied. The results show that there is a gap between the sliding crack angles with or without dilatancy angle and it will affect the development form of soil arch. The slip angle decreases gradually with the increase of the buried depth ratio H/D and becomes stable when the buried depth ratio H/D≥3. Compared with deep-buried tunnels, the increase of internal friction angle in the shallow-buried tunnel is more conducive to reducing the overlying soil pressure. The loose soil pressure decreases with the increase of eccentricity ε and loose coefficient β, and the influence of eccentricity ε on loose soil pressure is significantly greater than that of loose coefficient β. Therefore, the change of eccentricity ε should be paid close attention in the project. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Closure to "Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils".
- Author
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Jala, Sudheer Kumar, Rawat, Saurabh, and Gupta, Ashok Kumar
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LIGHTWEIGHT concrete ,CONCRETE columns ,SOILS - Abstract
This document is a closure to the article titled "Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils" by Sudheer Kumar Jala, Saurabh Rawat, and Ashok Kumar Gupta. The closure expresses gratitude to the discusser for their valuable comments on the original paper, which prompted the writers to reevaluate their work. The closure provides responses to specific cases and includes graphs illustrating the effects of different factors on excess pore-water pressure and consolidation. The closure also mentions the initial geotechnical assessments of the pond ash material and notes that the specific aspect of radial consolidation was not examined in the study. [Extracted from the article]
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- 2024
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15. Discussion of "Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils".
- Author
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Diyaljee, Vishnu
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LIGHTWEIGHT concrete ,CONCRETE columns ,PORE water pressure ,SOILS - Abstract
This document is a discussion of a research paper titled "Effect of Underreamed Pervious Concrete Columns on Load-Carrying Capacity of Loose Cohesionless Soils" by Sudheer Kumar Jala, Saurabh Rawat, and Ashok Kumar Gupta. The authors conducted an experimental and analytical study on circular and underreamed pervious concrete columns to determine their impact on the consolidation and bearing capacity improvement of loose pond ash fill. The findings suggest that these columns can increase bearing capacity and expedite consolidation of loose soil deposits. However, there are some aspects of the original paper that are difficult to understand, particularly when referring to associated figures. The authors recommend addressing these issues and exploring the influence of radial consolidation on the dissipation of excess pore-water pressure and consolidation of the pond ash fill. [Extracted from the article]
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- 2024
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16. Precise soil coverage in potato planting through plastic film using real-time image recognition with YOLOv4-tiny.
- Author
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Lu, Huiqiang, Liu, Kaiyuan, Sun, Wei, and Simionescu, P. A.
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PLASTIC films ,IMAGE recognition (Computer vision) ,PLASTICS plants ,POTATOES ,SOILS - Abstract
Planting potatoes through plastic film with incomplete or excessive soil coverage over seed holes significantly impairs yield. Existing covering methods rely solely on mechanical transmissions, leading to bulky and inconsistent soil coverage of the seed holes. This paper reports an innovative method using a precise soil covering device based on the YOLOv4-tiny real-time object detection system to accurately identify potato plastic film holes and cover them with soil. The system adopts a lightweight and high-precision detection scheme, balancing increased network depth with reduced computation. It can identify holes in the plastic film in real-time and with high accuracy. To verify the effectiveness of YOLOv4-tiny real-time object detection system, a precise soil covering device based on this detection system has been designed and applied to a double crank multi-rod hill-drop planter. Field tests revealed that the system's average accuracy rate for detecting holes is approximately 98%, with an average processing time of 15.15 ms per frame. This fast and accurate performance, combined with the device's robust real-time operation and anti-interference capabilities during soil covering, effectively reduce the problems of soil cover omission and repeated covering caused by existing mechanical transmission methods. The findings reported in this paper are valuable for the development of autonomous potato plastic film precise soil covering devices for commercial use. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Model Test Study on the Bearing Mechanism of Inclined Variable Cross-Section Piles Using Transparent Soil.
- Author
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Ma, Qiang, Li, Jianyu, Liu, Lin, and Lu, Xuesong
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PARTICLE image velocimetry ,SOILS ,FRICTION ,ANGLES - Abstract
In view of the influence of the inclination and variable section on the pile stability and bearing capacity, this paper introduces particle image velocimetry (PIV) technology, and designs a transparent soil visualization model test. The experimental results show that, when the pile has a variable cross-section and inclination angle, the friction resistance on both sides of the pile increases. The vertical-load-carrying capacity of the 2% and 4% inclined piles with a variable cross-section is greater than that of the piles with inclinations greater than 8%. For model piles with the degrees of inclination of 2% and 4%, the variable-section inclined piles with diameters of 17 mm and 15 mm show significantly less settlement than the equal-section inclined piles. For the model pile with an inclination of 8%, the settlement of the inclined piles with a variable cross-section diameter of 17 mm is slightly smaller than that of the equal cross-section inclined piles. The change in variable cross-section and inclination angle has a large effect on the soil displacement around the pile, and the conclusions of this paper can provide guidance for the engineering application of variable cross-section piles. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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18. Stability Analyses of Shallow Rectangular Tunnels in Anisotropic and Nonhomogeneous Soils Using a Kinematic Approach.
- Author
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Zou, Jin-Feng and Peng, Zhong-Zheng
- Subjects
PORE water pressure ,TUNNELS ,SOIL permeability ,SOILS ,CONFORMAL mapping - Abstract
Conducting soil stability assessments around tunnels has always been a concern. However, most existing studies have regarded soil as an isotropic and homogeneous material. To overcome this limitation, within the framework of upper bound theory, this paper proposes a novel rotational–translational failure mechanism where the velocity discontinuity surfaces are derived numerically. This theoretical mechanism includes two cases according to the positions of the velocity discontinuity surfaces. An analytical solution for pore water pressure is obtained using the conformal mapping method, which involves solving the two-dimensional (2D) Laplace equation and considering the soil and shotcrete permeability. Then, upper bound expressions for the limit supporting pressure are derived by computing work equations with and without pore water pressure. Comparisons with previous work and numerical results illustrate that the presented approach offers improvements and could be applicable for stability analyses of shallow rectangular tunnels in anisotropic and nonhomogeneous soils. Finally, this paper discusses the effects of the anisotropy and nonhomogeneity of soil properties on the normalized limit supporting pressure and the collapsing domains of rectangular tunnels with different geometric shapes. In addition, the impact of pore water pressure on the changed water levels is assessed. The results demonstrate that for rectangular tunnels that are excavated in water-bearing zones, the width-to-height ratio plays a significant role in the stability of the surrounding soils. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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19. Soil Modeling and Prediction Methods in Dredging Construction Areas.
- Author
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Guo, Qi, Wang, Wangming, Yuan, Zihao, Wang, Zhenjie, Wei, Wei, and Jiang, Pan
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DREDGING ,PREDICTION models ,SOILS ,DREDGES ,SOIL testing - Abstract
In the current implementation process for dredging projects, due to the lack of an accurate understanding of underwater soil characteristics, construction teams often find it difficult to accurately understand the soil condition. Not only does this lead to a reduced dredger operation efficiency, but it may also cause delays to the project's progress, as well as increasing its cost. Therefore, there is an urgent need to closely integrate soil analysis technology with dredging construction to ensure that projects can be completed efficiently and to a high standard. Therefore, this paper proposes a soil modeling and prediction method based on a three-dimensional point cloud model. The research objective is to propose a new method of soil mass identification with a strong generalization ability and function, which can not only be applied to dredging engineering but can also identify and analyze statistics of land soil and its mass. The accuracy of this method, based on a convergent grid, can reach 95%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. Review of the Impact of Permafrost Thawing on the Strength of Soils.
- Author
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Ajmera, Beena and Emami Ahari, Hossein
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LANDSLIDES ,SHEAR strength of soils ,PERMAFROST ,FROZEN ground ,SOIL cohesion ,SOILS ,GLOBAL warming ,TUNDRAS - Abstract
Global warming is causing unprecedented changes to permafrost regions with amplified effects in the Arctic through a phenomenon known as Arctic amplification. This intensified climate warming thaws both the discontinuous and continuous permafrost resulting in changes in the mechanical properties of the soils found in these regions. Since permafrost regions constitute nearly 24% of the Northern Hemisphere, understanding the strength of soils in thawed conditions is essential to analyze the stability of existing structures, and to design safer and more economical infrastructure in these regions. Specifically, thawing of the permafrost is causing considerable reductions in its strength of soils, which may lead to massive landslides, foundation failures, and so forth. Since frozen soil is a multiphase structure that consists of soil particles, unfrozen water, ice, and air, each constituent will influence the mechanical properties. This paper reviews the current state of knowledge of the impact of temperature, volumetric ice content, unfrozen water content, and frozen density on the compressive strength, peak shear strength, residual shear strength, undrained shear strength, and tensile strength of soils. The undrained shear strength of soil is said to have a linear correlation with temperature. In addition, the undrained cohesion of soil was found to depend on the temperature, whereas the undrained friction angle of soil was significantly influenced by volumetric ice content. An increase in the volumetric ice content up to 80% to 90% will cause a reduction in the peak and residual deviatoric stresses. In addition, an increase in volumetric ice content resulted in an increase in the compressive strength of the soil. The tensile and compressive strengths were found to be functions of the unfrozen water content. Global warming is causing the temperature of the permafrost, which is permanently frozen ground, to rise. This paper provides valuable insights into the impact of the changes in this ambient temperature on the strength of frozen soils in permafrost regions for a wide range of applications. Such insights are crucial for the design of resilient and stable infrastructure, such as foundations, embankments, and retaining walls, in which consideration of the reduced strength of thawed soils due to climate change will be necessary. In addition, the knowledge will allow for better management of vulnerable areas prone to landslides and erosion caused by the weakened soil strength permitting the implementation of mitigation measures before lives are lost and costly economic damages are incurred. Finally, this information will aid in early warning systems, emergency planning, and decision making to minimize the impact of hazards on human settlements and infrastructure. In this paper, a review of the current state of knowledge regarding the strength of frozen soils and the associated fluctuations in these strengths because of a rise in temperature are presented. Guidelines on the best practices for sample preparation and testing along with correlations to estimate various strength parameters are also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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21. Soil sampling and sensed ancillary data requirements for soil mapping in precision agriculture I. delineation of management zones to determine zone averages of soil properties.
- Author
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Kerry, Ruth, Ingram, Ben, Oliver, Margaret, and Frogbrook, Zoë
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SOIL mapping ,SOIL sampling ,PRECISION farming ,KRIGING ,SOILS ,CONTOURS (Cartography) - Abstract
Sensed and soil sample data are used in two main approaches for mapping soil properties in precision agriculture: management zones (MZs) and contour maps. This is the first of two papers that explores maps of MZs. Management zones based on variation in sensed data that are related to the more permanent soil properties assume that the zones are multi-purpose. Soil properties are then often sampled on a grid to provide the average values of each property per zone. This paper examines the plausibility of this approach by examining how the number of samples taken on a grid and the application of kriging affect mean soil property values for MZs. The suitability of MZs based on ancillary data for managing several agronomically important properties simultaneously is also considered. These concepts are examined with historic soil data from four field sites in southern UK with different scales of spatial variation. Results showed that when the grid sampling interval is large, there is less difference in the means of properties between MZs, but kriging the soil data increased the differences between zones when the sampling interval was large and sample small. Sensed data are used increasingly to aid the identification of MZs, but these could not be considered multi-purpose at all sites. The MZs produced were most useful for phosphorus (P), pH and volumetric water content (VWC) at the Wallingford site and useful for most properties at the Clays and Y215 sites. For the latter site this was true only when the most dense data were used to calculate MZ averages. The results show that sampling interval for MZ averages should relate to the scale of variation or the size of the MZs at a site. The sampling density could be based on the variogram range of ancillary data. This research suggests that there should be 6–8 samples per zone to obtain accurate averages of soil properties. Nutrient data for more than one year were examined at two sites and showed that patterns remained consistent in the short term unless variable-rate management was used, but also the range of values changed in the short term. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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22. Effects of random heterogeneity of soil on VH failure envelopes of the torpedo anchor.
- Author
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Xu, Shi Jie, Yi, Jiang Tao, Yi, Jin Wen, Li, Xiao Bin, Tian, Ye, Xie, Qiang, and Liu, Fei
- Subjects
MONTE Carlo method ,HETEROGENEITY ,SOIL mechanics ,SOILS ,ANCHORS - Abstract
Torpedo anchor is one offshore anchoring which has been gaining popularity recently for floating structures. The torpedo anchor was expected to resist the environmental loading transferred from the floating platform. Thus, the understanding of the holding capacity of torpedo anchors under vertical and horizontal combined loading is the key concern of its design. Nonetheless, most of the previous studies are deterministic without considering the common existing random heterogeneity nature of marine soil. In light of this situation, this paper reports a large deformation random finite element study under the framework of the Monte Carlo method. VH failure envelopes of torpedo anchors in heterogeneous soil were obtained by conducting simulations of continuous extraction procedures along different directions. Furthermore, the strain-softening behaviour of the soil was also accounted for considering the server deformation of the soil. The results show that both the size and shape of the VH failure envelope are significantly affected by random heterogeneity of soil. A series of VH failure envelopes of various probabilities of failure was thus given to guide the design. Results in this paper may be constructive for the safety design of the torpedo anchor. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Numerical Study on the Shear Failure and Load Transfer Mechanism of Helical Piles in Cohesionless Soils under Axial Compressive Loading.
- Author
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Pratama, Ignatius Tommy, Lestari, Anastasia Sri, and Oktavianus, Ivan
- Subjects
AXIAL loads ,COMPRESSION loads ,FAILURE mode & effects analysis ,SOILS ,STRAINS & stresses (Mechanics) - Abstract
The methods employed to calculate the axial bearing capacity of a helical pile depend on the shear failure model around the pile, which is also influenced by the spacing and diameter of the helical plates. However, studies on the transition of the failure mode and the load transfer mechanism with the change of helical plate spacing and diameter in cohesionless soil subjected to axial compressive load were limited. Thus, this paper investigated the effects of helix diameter and spacing on the axial compressive load-bearing capacity, shear failure model, and load transfer mechanism of helical piles with two helical plates embedded in the homogeneous medium and dense sands, as well as in the stratified medium to very dense sand. Axial loading tests on helical piles with various helix diameters and spacings were simulated using a two-dimensional finite element program with axisymmetric modeling to obtain the load-settlement curve, which was later used to estimate the ultimate bearing capacity of the helical piles. The ultimate bearing capacity of the helical piles was also computed using the conventional methods, i.e., the individual bearing and cylindrical shear methods, and then compared to the numerical-based axial bearing capacity. The stress-strain behaviors of pile and soil were modeled using the Linear Elastic and Mohr-Coulomb material models, respectively. The results show that the numerical-based ultimate bearing capacity of a helical pile increased with increasing the diameter and spacing of the helix. However, the ultimate bearing capacity computed using conventional methods did not show this trend. Then, the transition from the cylindrical shear to the individual bearing failure mechanism occurred at a spacing ratio (i.e., helical plate spacing divided by its diameter) of about two. Ultimately, the load transfer curves indicate that the helical plates mainly supported the applied load. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. RESEARCH ON HEAT PIPE AIR-CONDITIONER WITH SOIL HEAT EXCHANGER FOR BASE STATION.
- Author
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Ying ZHANG, Luqi JIN, Xiaowei FAN, and Zhuming ZHANG
- Subjects
HEAT pipes ,HEAT exchangers ,SOILS ,ENERGY consumption - Abstract
The refrigeration system accounts for 40-60% of the total energy consumption of the base station, so an effective energy-saving technology is much needed. This paper proposes a heat pipe air-conditioner with an additional soil heat exchange unit. When the indoor and outdoor temperature difference is small, the indoor heat can be scattered to the soil to achieve energy-saving effect. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Effects of slope and tree position on soil properties in a temperate deciduous forest.
- Author
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TOMÁŠOVÁ, GABRIELA, VICHTA, TOMÁŠ, ŽIŽLAVSKÁ, NIKOLA, DEUTSCHER, JAN, HEMR, ONDŘEJ, BRYCHTOVÁ, MARTINA, PAVLŮ, LENKA, and BAJER, ALEŠ
- Subjects
DECIDUOUS forests ,TEMPERATE forests ,SOILS ,FOREST management ,SOIL formation - Abstract
This paper examines changes in soil physical and chemical properties in relation to tree proximity on different slopes. Topsoil and subsoil were sampled at 12 research plots on four slope types, the soil pits being placed at the base of a tree (near tree, NT) and between the test tree and an adjacent tree (between trees, BT). We observed a significant decrease in vertical topsoil response to slope on lower, middle and upper slopes, and a decrease in fine roots (R < 2 mm) on flat ground. Overall, middle and lower slopes showed the highest similarity, and upper slopes and flat ground the least, with the greatest subsoil changes observed mainly on middle slopes and least on lower slopes. There was clear topographic dependence between subsoil water stable aggregates (WSA) and C dynamics, with BT total carbon (Ctot) higher on flat ground and lower on middle slopes; unlike topsoil, where the strongest WSA correlation was with distance from the tree. The highest N: OM (organic matter) ratios occurred on middle slopes facing north-west, and lowest on lower slopes facing north and flat ground. Our findings confirm the influence of slope type on soil characteristics, with NT soil supporting soil formation by transporting water to deeper layers, especially on slopes > 5°. These observations contribute to a better understanding of the dependence of soil properties on slope type and tree position when planning sustainable forest management. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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26. AGROPRODUCTIVE DIFFERENCES BETWEEN TWO LUVOSOL UNITS AT THE PREAJBA GORJ EXPERIMENTAL CENTER, ROMANIA.
- Author
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BĂLAN, Mihaela, POPESCU, Cristian, and NIȚU, Oana Alina
- Subjects
SOIL profiles ,CHEMICAL properties ,TOPSOIL ,EROSION ,SOILS - Abstract
This paper presents the agroproductive differences between two luvisol units at the Preajba Experimental Center, Gorj, Romania, under the influence of surface erosion. Thus, two soil profiles were comparatively executed, one on the plateau on a slope of 2-5%, on a typical luvisol characterized by an Aţel, Ao, AE, El, Bt1, BC, C profile, and another in the lower third of the slope on a 10-15% where a stagnic eroded luvisol was identified. The latter had gradually removed its upper horizons due to slow surface geological erosion, exhibiting a shorter profile with the AoEl, El, Bt1w, Bt2w sequence. By washing the fertile topsoil year after year, the physical and chemical properties of the soil worsened. In this regard, the bonitation sheets were drawn up, the potential yields achieved under natural conditions were determined, and following the application of specific hydro-ameliorative measures and the execution of enhanced bonitation based on them, it was observed that the bonitation scores increased, the favourability classes decreased, and the yields increased directly proportional to the value of the enhanced bonitation score. [ABSTRACT FROM AUTHOR]
- Published
- 2024
27. Application of ray methods to one-dimensional site response of inhomogeneous soil deposits.
- Author
-
Garcia-suarez, Joaquin, Seylabi, Elnaz, and Asimaki, Domniki
- Subjects
THEORY of wave motion ,SOILS ,GEOMETRICAL optics ,SEISMOLOGY ,OPEN-ended questions - Abstract
The technique referred as ray approximation treats wave propagation in a heterogeneous medium at the infinitely small wavelength limit. This classic simplification allows useful approximate analytical results to be obtained in cases where complete description of the waveform behaviour is virtually unattainable, hence its wide use in physics. In seismology, this approximation has been widely applied. This paper presents an application in one-dimensional site response (1DSR) analysis: it is used herein, first to explain and elucidate the generality of some previous observations as to the use of the harmonic mean of a shear-wave velocity profile to represent the global behaviour of a site; and second to partially settle an open question in 1DSR, namely 'What are the equivalent homogeneous properties that yield the same response, in terms of natural frequencies and resonance amplitude, for a given inhomogeneous site?', providing a few assumptions are met – chiefly, that excitations of sufficiently high frequency are considered. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Bearing Capacity Estimation for Strip Foundation under Transient Flows.
- Author
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Chen, B. H., Liao, H., Liu, L. L., and Yang, X. L.
- Subjects
HYDRAULIC conductivity ,SANDY soils ,SILT ,SOIL permeability ,SOILS ,FLUIDS - Abstract
A new model was first proposed to estimate the ultimate bearing capacity of strip foundations under transient flows on the basis of the kinematic approach of limit analysis. To describe the collapse process, a symmetrical collapse mechanism was generated by discretization technique following the associated flow rule. A layer-wise summation method was developed to calculate the internal dissipation rate. The theoretical results of this paper are given in terms of some assumptions: (1) both soils and fluids considered in this study were regarded to be noncompressible; (2) the hydraulic conductivity in an unsaturated state was equal to that in a saturated state; and (3) the slope of the soil–water characteristic curve was assumed to be constant through the whole transient infiltration process. A series of comparisons with the theoretical results and experimental data were established to verify the reliability of the new approach proposed by this paper. Based on the numerical results and discussions, the key conclusion can be drawn as follows: the ultimate bearing capacities saw a relatively large decrease under transient flows, especially for strip foundations embedded in silt soil, however, the bearing loads for foundations in sandy soil tended to be steady throughout the whole infiltration process. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Numerical Investigation of the Capacity of Anchor Chain Links in Clay.
- Author
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Liu, Wenlong, Tian, Yinghui, Cassidy, Mark J., O'Loughlin, Conleth, and Watson, Phil
- Subjects
CLAY soils ,THREE-dimensional modeling ,OCEAN bottom ,CLAY ,SOILS - Abstract
Offshore floating systems are held in position with chains that connect the floater to anchors embedded in the seabed. An essential component for calculating the overall mooring capacity is an accurate assessment of the holding resistance from the anchor chains. Existing studies generally simplify the (complex) chain geometry to that of a cylindrical bar, which does not account for the intricate geometry of the connected chain links. This paper reports on three-dimensional finite-element modeling that defined the capacity of a link of anchor chain in clay soil with consideration of the geometry of the chain links, including the influence from adjacent links. Both stud link and studless links were considered, along with the effect of embedment depth, link direction angle, and interface condition. The soil resistance acting on the chain links, represented by uniaxial bearing capacity factors Nn,max , Ns,max , and Nt,max along the normal, lateral, and axial directions of the chain link, respectively, were derived, and the soil failure mechanisms for these conditions are discussed. Equivalent bearing capacity factors Nq and Na were derived by converting the soil resistance to normal and tangential resistances (q and f) acting on an equivalent cylindrical bar. Ultimately, f/q was calculated to represent the friction coefficient, μ , which ranged from 0.2 to 0.4. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
30. Bond–Slip Behavior of Concrete Pile–Cemented Soil Interface Considering Thermal–Temporal Effect: Experimental Study and Constitutive Modeling Based on Disturbed State Concept.
- Author
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Cai, Huan, Chen, Changfu, Zhang, Jiarui, and Li, Wei
- Subjects
EARTH temperature ,CEMENT mixing ,SHEAR strength ,CURING ,SOILS - Abstract
The bond–slip behavior of concrete pile–cemented soil interface is crucial for load transfer analysis of stiffened deep cement mixing piles, which is greatly influenced by ground temperature and age during long-term curing. However, the thermal–temporal effect on the frictional characteristics of this interface remains unclear. In this paper, an element-scale specimen of concrete pile–cemented soil interface was first designed. Then interfacial shear tests were performed on batches of samples subjected to varied curing temperatures (T) and ages (t) to obtain interfacial bond–slip (τ‒s) curves. The test results showed that the interfacial peak shear strength (τ
u ) increased with the growth of T and t. Based on the experimental observations, a strength development model for τu considering the thermal effect was established. Subsequently, a disturbed state concept (DSC)-based constitutive model incorporating the thermal–temporal effect was proposed for the investigated interface. Both prepeak and postpeak stages of the τ‒s curves can be effectively described by the developed DSC model, exhibiting robust performance in fitting and predicting experimental results. Finally, the DSC model was cross-validated by the interfacial τ‒s data sets collected from reported experimental publications. Across all data sets, the coefficient of determination (R2 ) exceeded 0.9, and the mean absolute percentage error of τu remained below 10% when comparing predictions with measurements, which strongly highlights the generalization capability of the DSC model. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
31. Calculation Method for Bearing Capacity of Bottom‐Supported Anti‐Pull Piles in Layered Foundation.
- Author
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Zeng, Jianming, Wang, Zhengzhen, Chen, Xuwei, Lian, Na, Li, Feng, and Vieira, Castorina S.
- Subjects
UNDERGROUND areas ,ELASTIC modulus ,FRICTION ,ENGINEERING ,SOILS - Abstract
In recent years, with the rapid development of cities, the utilization rate of underground space has gradually increased, and anti‐pull piles have also been widely used in practical engineering. In this paper, the failure surface form of the anti‐pull pile was assumed, the soil parameters of each soil layer in the layered foundation and the Poisson effect generated by the anti‐pull pile under the action of the uplift force was considered, and the calculation formula for the bearing capacity of the anti‐pull long pile in the layered foundation was obtained, which was verified by on‐site test data. Finally, the parameter range of the calculation method was analyzed. The results show that when the aspect ratio of the anti‐pull pile is large, and the elastic modulus of the anti‐pull pile is small, the Poisson effect of the anti‐pull pile is obvious, and the increment of pile side friction caused by the Poisson effect is also large. When the value range of parameter N is 50 ≤ N ≤ 100, the calculation results are more reasonable. The average error of the lower limit N = 50 is 11.7%, and the average error of the upper limit N = 100 is 5.3%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Centrifugal Model Test of Multi-Level Slope under Combined Support of Pile-Anchor and Frame-Anchor.
- Author
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Yang, Kuibin, Zhu, Yanpeng, Guo, Hong, Xie, Yongbin, and Wang, Zhiqiang
- Subjects
SLOPES (Soil mechanics) ,PILE anchors (Foundation engineering) ,MULTILEVEL models ,SURFACE potential ,SOILS - Abstract
The combination support structure of pile-anchor and frame-anchor is widely used in multi-level slope engineering, but the relevant theoretical research lags behind engineering practice. To make up for this deficiency, this paper takes the multi-level slope under combined support of pile-anchor and frame-anchor as the research object, conducts a model test using the geotechnical centrifuge, analyzes the most relevant structural force and slope deformation in engineering, and provides some reinforcement suggestions. The test results show that the combination support structure of pile-anchor and frame-anchor has a good reinforcement effect on multi-level soil slopes, but the deformation range of the slope is greatly affected by the anchoring structure and the anchor rods located within the deformation zone. The structural force condition is significantly different from traditional structures that place the anchor rod anchoring section in a stable soil layer. According to the structural force characteristics, it is recommended that the support design fully consider the positional relationship between the anchor rods and the sliding surface. The design of the frame-anchor support section should strictly control the anchoring depth, so that the potential sliding surface of the slope can be moved backward, thereby increasing the difficulty of sliding. The design of pile-anchor support should ensure that the anchor rods have sufficient length to provide greater anchoring force, thereby improving the bearing capacity of the pile. These research results can enrich and improve the support design theory of multi-level soil slopes, providing guidance for engineering practice. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. Graph-Analytical Method for Calculating Settlement of a Single Pile Taking into Account Soil Slippage.
- Author
-
Ter-Martirosyan, Armen Z., Sidorov, Vitalii V., and Almakaeva, Anastasiia S.
- Subjects
BEARING capacity of soils ,BUILDING sites ,ULTIMATE strength ,TEST design ,SOILS - Abstract
Most of the existing methods of pile settlement calculation, including normative methods, do not fully take into account the processes occurring in the soil when loads are transferred to them and the changes in the properties of the contact zone soils. This leads to underutilisation of the bearing capacity of the soil, and the calculated settlement value may differ several times from the real values. In this paper, a graph-analytical solution to the problem of interaction of a single pile with a three-layer soil foundation is proposed to determine the settlement, taking into account the complex nature of the pile operation and the processes occurring in the soil when loads are transferred to them. The proposed method allows to use the non-linear behaviour of the soil on the lateral surface and under the tip of the pile, the possibility of its detachment and slippage after reaching the ultimate strength of the soil, changes in the properties of the contact zone soils, and the load distribution on the pile between its lateral surface and the tip. To verify the proposed graph-analytical solution, a comparative analysis was performed with the numerical method in the Plaxis 2d software (version 21.00.01.7) and with the results of static tests of piles at the construction site. To determine the strength reduction factor at the contact of soils with concrete, laboratory tests were carried out on a direct shear apparatus. Based on the results of the performed calculations, graphs of the dependence of settlements on loads were plotted, conclusions were drawn about the possibility of using the graph-analytical method, and prospects for further development and improvement of the graph-analytical method were proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Assessing the Features of PV System's Data and the Soiling Effects on PV System's Performance Based on the Field Data.
- Author
-
Al Humairi, Ali, El Asri, Hayat, Al Hemyari, Zuhair A., and Jung, Peter
- Subjects
PHOTOVOLTAIC power systems ,SOLAR panels ,CLIMATE change ,SOLAR system ,SOILS - Abstract
This paper assesses the features/characteristics of a photovoltaic system's data, investigates the relationship between the soiling and solar panel performance, and leverages real-world data obtained from a solar site in Shams Solar Facility located at the German University of Technology in Oman. Through an experimental approach, different parameters were scrutinized to unravel the dynamics at play. Due to the lack of studies on how to assess the features of a PV System's data, and in order to model the PV System's data, extensive analyses were conducted based on a big dataset containing 36,851 observations of each parameter (environmental factors) of the study. In addition, diverse environmental factors, operational conditions, and the collected data were analyzed by various mathematical/statistical measures, and inferential statistical measures were applied to obtain accurate and significant results that explain the level of each parameter (environmental factors), and are developed to examine the features/characteristics and performance of PV Systems and reveal the influence of soiling accumulation on the energy output. The research findings do not only deepen the understanding of the features of PV Systems data and the impact of soiling on solar panels, but also underscore the significance of considering geographical and climatic variations. This research contributes significantly to advancing knowledge within the realm of solar energy systems and provides actionable insights for optimizing the performance and reliability of PV installations in real-world settings. The discussion, conclusions, limitations, and future directions have been discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Drained Cavity Expansion–Contraction in CASM and Its Application for Pressuremeter Tests in Sands.
- Author
-
Li, Guo-Yao, Mo, Pin-Qiang, Lu, Zhao, Yuan, Ran, Yang, He, and Yu, Hai-Sui
- Subjects
EULERIAN graphs ,SAND ,STRESS concentration ,LOADING & unloading ,SOILS ,TEST interpretation - Abstract
The contraction behavior of monotonically expanded cavities is intriguing as it offers insights into certain geotechnical scenarios, especially for pressuremeter tests, where the unloading data is equally informative as the loading data. Despite many solutions for cavity expansion, attempts for the analyses of cavity contraction from an expanded state were rarely made. To extend previous solutions to include contraction, this paper presents a novel semianalytical solution for drained contraction of spherical and cylindrical cavities from an initially expanded state in soils characterized by a unified state parameter model for clay and sand (CASM). Given the nonself-similar nature of the contraction after expansion problems, the hybrid Eulerian-Lagrangian (HEL) approach is employed to derive distributions and evolutions of stresses and strains around the cavities during the unloading process. Combined with the previous expansion solution, the complete loading-unloading cavity pressure curves and stress paths at the cavity wall are presented and verified against numerical simulations. Following validation through comparisons with calibration chamber pressuremeter tests conducted in Stockton Beach sand, a new method for the interpretation of pressuremeter testing data is developed based on the proposed solution. This method demonstrates its capability in the back-calculation of the effective horizontal stresses and state parameters for four distinct types of sands. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Reliability analysis of pile group in spatially variable unsaturated expansive soil based on load transfer method.
- Author
-
Dong, Xiaole, Tan, Xiaohui, Guo, Wei, Zhong, Kai, Hou, Xiaoliang, and Ma, Haichun
- Subjects
SWELLING soils ,FAILURE mode & effects analysis ,GEOTECHNICAL engineering ,SUPPLY chain management ,SOILS - Abstract
Accurate assessment of pile group's performance in spatially variable unsaturated expansive soil has long been a challenge in geotechnical engineering. This paper presents a methodology to perform reliability analysis for vertically loaded pile group, where the modified load transfer method (LTM) is utilised to investigate the load–displacement response considering the pile–pile interaction and the non-linear relationship of the pile–soil interface under the influence of matric suction reduction and the swelling of expansive soil; the Karhunen–Loève (KL) expansion method is adopted to simulate the spatial variability of soil parameters; the first–order reliability method (FORM) is utilised to perform reliability analysis of each pile in the pile group; and the reliability analysis of pile group is then performed using the sequential compounding method (SCM) by considering the pile group as a parallel system. By applying the proposed methodology to a 3 × 3 pile group under different vertical loads and infiltration times, the relative magnitudes of reliability indices for different piles in the pile group and the pile group system under two failure modes of uplifting and sinking are identified. The effects of soil's spatial variability and pile spacing on the reliability of pile group are also analysed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Advances in remote sensing based soil moisture retrieval: applications, techniques, scales and challenges for combining machine learning and physical models.
- Author
-
Abbes, Ali Ben, Jarray, Noureddine, and Farah, Imed Riadh
- Subjects
SOILS ,SOIL moisture ,ARTIFICIAL intelligence ,REMOTE sensing ,EARTH sciences - Abstract
Soil Moisture (SM) monitoring is crucial for various applications in agriculture, hydrology, and climate science. Remote Sensing (RS) offers a powerful tool for large-scale SM retrieval. This paper explores the advancements in RS techniques for SM estimation. We discuss the applications of these techniques, along with the advantages and limitations of traditional physical models and data-driven Machine Learning (ML) based approaches. The paper emphasizes the potential of combining ML and physical models to leverage the strengths of both approaches. We explore the challenges associated with this integration and future research directions to improve the accuracy, scalability, and robustness of RS-based SM retrieval. Finally, the paper also discusses a few issues such as input data selection, data availability, ML complexity, the need for public datasets for benchmarking, and analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Investigating the Reliability of Ground Motion Intensity Measures.
- Author
-
Jafari, Ali, Rajabi, Elham, Ghodrati Amiri, Gholamreza, and Castaldo, Paolo
- Subjects
GROUND motion ,EARTHQUAKE engineering ,TECHNICAL literature ,SOIL classification ,SOILS - Abstract
The uncertainty and unreliability in the probabilistic seismic demand models (PSDMs) can be addressed in the framework of performance‐based earthquake engineering (PBEE). Some characteristics have been introduced and extensively investigated in the earthquake engineering literature for appropriateness (i.e., optimality) of various intensity measures, such as efficiency, effectiveness, sufficiency, practicality, and hazard computability. The reliability of the intensity measures can also be considered as another important criterion for intensity measure (IM) selection, which has not been investigated extensively. In this paper, a framework has been developed and implemented to investigate the reliability of various intensity measures alongside the number of adopted earthquake records. In this regard, the inverse of the mean coefficient of variation (IMCV), which is detected to be in a direct and linear relationship with the number of earthquake records, is adopted as the main criterion to compare the reliability of ground motion intensity measures. A simple relation has been proposed and calibrated for the studied IMs that provide the required number of earthquake records to satisfy an intended level of reliability. As a case study, a significant number of recorded ground motions at Zagros and non‐Zagros zones (two major seismic regions in Iran) with rock and soil conditions are selected, and the most reliable ground motion intensity measure is introduced at various seismic regions and soil types by exploiting the developed framework and the proposed relationship. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. An approach based on P-wave velocity for grouting effectiveness evaluation in earthen sites.
- Author
-
Li, Weihao, Zhang, Jingke, Wang, Nan, Zhang, Yichen, Qi, Bojia, Chen, Jiayi, and Yin, Xingduo
- Subjects
NONDESTRUCTIVE testing ,GROUTING ,EVALUATION methodology ,VELOCITY ,SOILS - Abstract
Grouting technology is the primary method for repairing cracks in earthen sites. However, there has been a long-standing lack of effective methods for evaluating grouting effectiveness. This paper proposes a field evaluation method based on P-wave velocity. This method explicitly discusses two scenarios where the P-wave velocity of the grout is either higher or lower than that of the soil, using the depth ℎ of the "hypothetical crack" as the evaluation indicator. The experimental results indicate that specimens with 20% and 40% defects show increases in ℎ values of 0.0113 m and 0.0166 m, respectively. Laboratory tests have demonstrated that this method can accurately evaluate grouting effectiveness and is not affected by the P-wave velocity of the soil. The application of this evaluation method to three typical earthen sites resulted in more reliable and easily quantifiable evaluation outcomes. By considering the width of grout, the method provides a more intuitive comparison of reparation effectiveness. The study demonstrates the feasibility of the proposed method, thereby facilitating effective crack reparation in earthen sites. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Determination of the geographical coordinates of the aboveground nuclear tests epicenters.
- Author
-
Monayenko, Valeriy, Krivitskiy, Pavel, Abisheva, Mariya, Lukashenko, Sergey, and Larionova, Natalya
- Subjects
RADIOACTIVE contamination ,SURFACE area ,SOILS ,MAPS ,DENSITY - Abstract
This paper presents the determination method of the exact geographical coordinates of aboveground nuclear tests (NT) epicenters based on the radioecological study results the example of the Semipalatinsk Nuclear Test Site. By testing the NT Epicenter software for determining the exact geographic coordinates of the NT centers, it was established that it is indeed possible to determine the exact coordinates of most of the aboveground NTs. Their locations are currently determined by the presence are currently determined by the presence of technogenic disturbance of the soil surface in the area of the alleged epicenter (the presence of a crater), as well as by comparing maps of radioactive contamination and a space image. The accuracy of the precise coordinates of the NT is highly dependent on the density of the auxiliary grid: the smaller the pitch of the auxiliary grid, the higher the accuracy of the NT epicenter. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. The 1st Hanrahan Lecture: Geotechnical properties of Irish glacial and interglacial soils.
- Author
-
Farrell, Eric Raymond
- Subjects
SLOPE stability ,SETTLEMENT of structures ,SOILS ,GEOLOGISTS ,CLAY - Abstract
This paper reviews the current state of the art in relation to geotechnical design in unsorted till deposits, commonly called boulder clays by engineers or diamictons by geologists, generally taking the topics discussed by Professor Eamon Hanrahan in his seminal work of 1977 on Irish tills. These topics include the permeability, stiffness and consolidation characteristics of these deposits, together with their undrained and drained behaviour. The geological background to the deposition of these tills is discussed and the available information on the presence of interglacial soils around the country is presented. Where possible, practical experience from working with these deposits is compared with predictions made from field or laboratory test results: for example, in settlement assessment of foundations, slope stability and in earthworks. Whilst most of Ireland is covered with stony boulder clays, which is the main topic of this paper, the geotechnical parameters of a fine-grained till encountered on the east coast, known as Irish Sea Till or colloquially as Macamore Clay, are discussed and the implications of this on slope stability is investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. "You can't manage what you can't measure": Regenerative agriculture, farming by numbers, and calculability in soil microbiopolitics.
- Author
-
Krzywoszynska, Anna
- Subjects
ORGANIC farming ,AGRICULTURE ,ENVIRONMENTAL psychology ,SOIL microbiology ,SOILS - Abstract
Microbes are increasingly central to visions of sustainable and healthy futures, including in farming movements such as regenerative agriculture. In social science and environmental humanities scholarship, (re)connecting with microbes is seen as a way to challenge, conceptually and practically, the very ontology of human-nature separation which underpins the destruction and violence in human relations with other living beings and with environments. The crux of this onto-ethical potential is a shift towards relational modes of knowing microbes, rooted in localised, proximate, and sensuous practice, and expressed in embodied expertise. This paper engages critically with this promise by calling attention to persistence of calculability to people's self-governance within current microbiopolitics. Through a case study of regenerative agriculture in the United Kingdom, I argue that while embodied expertise of soil microbes is seen as crucial to soil health-oriented farming, it is also dismissed as an insufficient in guiding farmers and shaping future practice, including by farmers themselves. Regenerative agriculture continues to function within "farming by numbers", an agri-biopolitical regime in which farmers' and advisors' subjectivity is that of calculating managers situated in calculable environments. As a result, calculability acts as a 'break' on the development of alternative microbial onto-ethics, and regenerative agriculture practitioners look for ways to bring soil microbes into the realm of calculability (e.g., through metagenomics). Consequently, the way microbes are being incorporated into future agri-environmental relations reinforces rather than threatens existing structures of biopolitical power. Overall, I argue that human-microbe research, potentially due to its empirical focus on alternative practices, has underplayed the importance of calculability to people's self-governance in relations with microbes. The struggle for a new microbiopolitics, especially in agriculture and environmental management, will require addressing the continued importance of calculability, and a creative and socially relevant experimentation with alternative forms of expertise. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. A Study of Single Stone Column Bearing Capacity from a Full-Scale Plate Load Test in Long Son Project.
- Author
-
Hong Lam Dang
- Subjects
STONE columns ,PETROLEUM chemicals ,SOILS ,SONS ,DIAMETER - Abstract
The ultimate bearing capacity of stone columns is very important in the design of soil improvement. The bulging failure mechanism is the most common failure mechanism reported. However, it depends on the surrounding soil at the site, necessitating a site-specific study of single-stone column bearing capacity. The current paper presents the full-scale plate load test of the single stone column in the Long Son Petrochemical Project, Vietnam in order to verify the bearing capacity of single stone column. A single stone column of 800 mm diameter was installed at the site by vibroflot. An 800 m circle full-scale plate test was carried out on site. The stone properties followed the Vietnamese standard TCVN 7572. The settlement result of the plate load test verifies the single stone column bearing capacity of 882.5 kPa. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Permeation grouting in soils: numerical discussion of a simplified analytical approach.
- Author
-
Boschi, K., Grassi, D., Castellanza, R. P., and di Prisco, C. G.
- Subjects
GROUTING ,SOIL permeability ,ANALYTICAL solutions ,SOILS ,CAPILLARITY - Abstract
Permeation grouting – injections at low-pressure values of either microfine cements or chemical products – is frequently adopted to increase the mechanical/hydraulic properties of soils, and standard design approaches are currently either empirical or based on simplified analytical solutions. In this paper, some fundamental hypotheses of these analytical solutions are discussed by carrying out a campaign of finite-element numerical analyses, in which the injection phase in a water-saturated soil is analysed, a Newtonian rheology for the grout is implemented and the hypothesis of immiscibility for the two liquids is assumed. The effect of injection source geometry is discussed, as well as the role of gravity and capillarity. The authors analyse the conditions, in terms of injection flow rate, grout viscosity, soil intrinsic permeability and retention curve, under which the analytical solutions provide reliable results. The numerical results have been compared with the simplified analytical solution herein derived for a one-dimensional spherical geometry, in terms of the 'characteristic curves' for the system: the relationship between injection pressure/grout front advancement and injection time. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Mitigation of lateral slope movement and soil improvement using the vacuum-PVD scheme.
- Author
-
Soralump, S., Koirala, N., and Phakdimek, S.
- Subjects
SHEAR strength ,SOILS ,SLOPE stability ,CLAY - Abstract
This paper interprets the results from field monitoring which was carried out during vacuum-PVD improvement in a site located near an actively moving slope. Interestingly, the monitoring results showed, among other things, mitigation in the outward lateral movements during and after the preloading process indicating relative stability in the slope and the efficiency of vacuum to mitigate lateral movements during the preloading period. Analyses were made on other field parameters such as pore pressure and settlement, as well as back-calculation of flow parameters to be considered during vacuum preloading design, such as permeability ratio (k
h /ks ) and horizontal consolidation coefficient (Ch ) due to vacuum-PVD, were carried out. Post improvement, appropriate geotechnical properties were obtained from laboratory tests of clay specimens from borehole samples and undrained shear strengths were measured from unconfined compression and field vane shear test. The obtained properties indicated improvement in soft soil properties with a reduction in water content and an increase in maximum past pressure, OCR and undrained shear strengths. The prediction made for final shear strength using past literature, where applied additional incremental stress was reduced with depth, matched well with the shear strengths recorded from field testing. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
46. Multifidelity Data Fusion for the Estimation of Static Stiffness of Suction Caisson Foundations in Layered Soil.
- Author
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Suryasentana, Stephen K., Sheil, Brian B., and Stuyts, Bruno
- Subjects
MACHINE learning ,MULTISENSOR data fusion ,OFFSHORE wind power plants ,CAISSONS ,SOILS - Abstract
The static stiffness of suction caisson foundations is an important engineering factor for offshore wind foundation design. However, existing simplified design models are mainly developed for nonlayered soil conditions, and their accuracy for layered soil conditions is uncertain. This creates a challenge for designing these foundations in offshore wind farm sites, where layered soil conditions are commonplace. To address this, this paper proposes a multifidelity data fusion approach that combines information from different physics-based models of varying accuracy, data sparsity, and computational costs in order to improve the accuracy of stiffness estimations for layered soil conditions. The results indicate that the proposed approach is more accurate than both the simplified design model and a single-fidelity machine learning model, even with limited training data. The proposed method offers a promising data-efficient solution for fast and robust stiffness estimations, which could lead to more cost-effective offshore foundation designs. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. 3D Numerical Modeling of the Inertial and Kinematic Interactions of Inclined Pile Groups in Liquefiable Soils.
- Author
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Zheng, Gang, Zhang, Wenbin, Zhou, Haizuo, Forcellini, Davide, Zhao, Jihui, and Zhang, Tianqi
- Subjects
BUILDING foundations ,BENDING moment ,EARTHQUAKE intensity ,SOILS ,SURFACE structure - Abstract
Previous earthquake events indicate that pile foundations in liquefiable soils are vulnerable to damage due to the coupling of inertial and kinematic effects. Inclined piles are widely applied in structures located in liquefiable soils, but few investigations of the coupling of the superstructure–pile inertial and soil–pile kinematic effects have been conducted. To address this gap, this study adopted a three-dimensional (3D) numerical model to investigate the coupling of inertial and kinematic effects in pile foundations with different inclination angles. The pile head bending moment was employed to represent the pile response, while the soil surface displacement and structure acceleration were utilized to quantify the kinematic and inertial effects. The role of the inclination angle on the interactions between inertial and kinematic effects is herein considered for pile groups. In particular, the inertial effect significantly influences the behavior of pile groups with larger inclination angles, whereas the kinematic effect predominates the pile head moment in vertical pile groups. In this paper, the influence of the pile inclination angle, superstructure configuration, and earthquake intensity on the interactions was investigated. The principal findings revealed that the kinematic effect dominates in the vertical pile group irrespective of the properties of the superstructure, while the inertial effect plays a significant role in the response of the inclined pile groups, especially for superstructures with considerable heights. Practical Applications: Inclined piles are vulnerable to damage due to the interaction of inertial and kinematic effects during earthquakes. This study conducted a series of three-dimensional (3D) finite-element simulations to investigate the interaction of inertial and kinematic effects in pile foundations with different inclination angles. The influence of pile inclination angle, superstructure height, and earthquake characteristics was investigated. In current practices, various codes and pseudostatic methods have been adopted to sum a percentage of the inertia-induced bending moment and another percentage of the kinematic-induced bending moment. This study indicates that under certain conditions, the simple summing of the bending moment induced by the inertial and kinematic effects could be inaccurate. The present study identified several factors that influence the interaction of inertial and kinematic effects on piles with different inclination angles. The inclined piles in liquefied soil, especially for supporting tall and heavy superstructure, attention should be given to the influence of inertial effect on the pile head bending moment. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Experimental Study on Shear Creep Characteristics of Residual Soil with Different Stone Content.
- Author
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Dong, Jinyu, Wang, Tanyu, and Zhao, Yawen
- Subjects
SOIL creep ,ELASTICITY (Economics) ,SOIL testing ,SOIL structure ,SOILS ,LANDSLIDES - Abstract
The residual soil on a slope can slowly move downward under the influence of gravity, forming a creep landslide. These types of landslides are known for their extensive coverage, significant magnitude, and prolonged duration of hazard. A systematic study of the creep properties of creep landslide geotechnical bodies is essential for the analysis of the deformation process and long-term safety evaluation of landslides. This paper focuses on studying a creep landslide involving residual soil in western Henan Province. The creep characteristics of residual soil with different stone content are investigated through direct shear creep experiments. The findings reveal that stone content has a profound impact on the creep behavior of residual soil. As the stone content of the soil increased, the structure of the test soil changed significantly, resulting in a gradual decrease in its shear creep. The Burgers model can effectively fit the deceleration creep and steady-state creep stages of the residual soil. With the increase in stone content, the four parameters of the Burgers model show a significant increase, with the instantaneous elasticity coefficient G
1 and the viscosity coefficient η1 experiencing more noticeable changes. The average long-term strength of specimens with different stone content is only 54% of their instantaneous strength. Additionally, as the stone content increases, the ratio of long-term strength to instantaneous strength also increases. Notably, the long-term strength of specimens with 10–30% stone content is significantly lower than that of specimens with 50–70% stone content. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
49. Effect of Incorporating Cement and Olive Waste Ash on the Mechanical Properties of Rammed Earth Block.
- Author
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Ghanem, Hassan, El Bouz, Chouk, Ramadan, Rawan, Trad, Adrien, Khatib, Jamal, and Elkordi, Adel
- Subjects
SOIL density ,WASTE products ,SOILS ,CONSTRUCTION materials ,COMPRESSIVE strength - Abstract
Rammed earth blocks have recently gained substantial popularity in construction materials due to their environmental benefits, energy saving, and financial effectiveness. These benefits are even more pronounced if waste materials such as olive waste ash (OWA) are incorporated in rammed earth blocks. There is limited information on the use of OWA in rammed earth blocks. This paper investigates the use of OWA and cement in improving rammed earth block characteristics. OWA was incorporated to partially replace the soil by 10, 20, 30 and 40% of its weight and cement was added in percentages of 2, 4, 6 and 8% by the dry weight of the composite soil. Proctor, unconfined compressive strength (UCS), and California Bearing Ratio (CBR) tests were performed at 7, 28, and 56 days. Results indicated that OWA inclusion decreased the maximum dry density while it increased the optimum moisture content. However, cement addition improved the maximum dry density of soil. The UCS results revealed that OWA possessed cementitious and pozzolanic behavior, and soil mechanical properties improved by up to 30% due to OWA inclusion, after which there was a significant drop of 40%. The trend in the CBR results was similar to those of UCS. To further clarify the experimental results, a mathematical model was proposed to determine the variation in strength as a function of time. Furthermore, correlations between soil mechanical properties were conducted. Predicted equations were developed to determine the properties of rammed earth block. All in all, the inclusion of OWA in cement stabilized earth block suggests the potential to improve the properties of rammed earth blocks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Introducing exceptional growth mining—Analyzing the impact of soil characteristics on on-farm crop growth and yield variability.
- Author
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Mulders, Puck J. A. M., van den Heuvel, Edwin R., Reidsma, Pytrik, and Duivesteijn, Wouter
- Subjects
CROP growth ,CROP yields ,SUSTAINABLE agriculture ,POTATOES ,AGRICULTURAL intensification ,SOILS ,IRON fertilizers ,FARM size - Abstract
Sustainable intensification of agriculture requires understanding of the effect of soil characteristics and nutrient supply on crop growth. As farms are increasing in size by acquiring small fields from various farmers, the soil characteristics and nutrient supply might be very different from field to field, while at the same time specific soil properties might limit the nutrient uptake. As a result, there might be a large number of heterogeneous reasons why crop growth varies significantly. New data analysis techniques can help to explain variability in crop growth among fields. This paper introduces Exceptional Growth Mining (EGM) as a first contribution. EGM instantiates the data mining framework Exceptional Model Mining (EMM) such that subgroups of fields can be found that grow exceptionally in terms of three growth parameters (high/low maximum growth, steep/flat linear growth and early/late midpoint of maximum growth). As second contribution, we apply EGM to a case study by analyzing the dataset of a potato farm in the south of the Netherlands. EGM consists of (i) estimating growth curves by applying nonlinear mixed models, (ii) investigating the correlation between the estimated growth parameters, and (iii) applying EMM on these growth curve parameters using a growth curve-specific quality measure. By applying EGM on the data of the potato farm, we obtain the following results: 1) the estimated growth curves represent the variability in potato tuber growth very well (R
2 of 0.92), 2) the steepness of the growth curve has a strong correlation with the maximum growth and the midpoint of maximum growth, and the correlation between the midpoint of maximum growth and maximum growth is weak, 3) the subgroup analyses indicate that: high values of K correspond to high maxima; low values of K correspond to low maxima, steep growth curves', and a late midpoint of halfway growth; Mg influences the midpoint of the growth curve; values of B are higher on dry soils with high tuber growth, while low values of B are found on wet soils with high tuber growth; high values of Zn, Mn, and Fe are found in subgroups with low tuber weight, probably related to the soil's low pH. In summary, this paper introduces EGM to obtain understanding in crop response to soil properties and nutrient supply. In addition, EGM provides a way to analyze only small parts of a large dataset, such that the impact of soil factors on growth can be analyzed on a more detailed level than existing methods. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
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