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This study establishes a theoretical framework for analyzing the lateral oscillation of marine pipe piles. The additional mass model is introduced herein to consider the inertial fluctuation effect of the soil plug. Analytical mathematical methods are used to determine the complex impedance variation of the pile over a range of frequency effects. An investigation is performed to determine how the presence of soil plugs changes the lateral complex stiffness and natural frequency of pipe piles. Additionally, comparisons of the applicability of the plane strain model and continuous medium model have been conducted to enable the easy use of the theoretical model. The main conclusions can be drawn as (1) if the fluctuation inertia effect of the soil plug is not taken into consideration, the dynamic active length and the dynamic stiffness of the pipe pile will be underestimated; (2) for the soft soil, the plane strain model may give rise to substantial calculation errors attributed to them regardless of the vertical continuity of the soil, nevertheless, the calculation error decreases rapidly with the increase of soil shear modulus and vibration frequency. [ABSTRACT FROM AUTHOR]

Poultry litter (PL) can be used as a viable alternative to phosphate fertilizers. However, there is a lack of information about phosphorus (P) distribution in inorganic (Pi) and organic (Po) forms and its transformation in soils amended with PL of varying age (based on litter clean‐out frequency) and application rate. This study aimed to determine the effect of PL age and application rate on soil P forms and their bioavailability. Soils were amended with 5 and 10 Mg ha−1 PL using 6‐, 18‐, and 30‐month‐old litter and incubated for 6 months. Soil P fractionation was performed following the Hedley protocol. Soil P availability and soil P storage capacity (SPSC) were determined using Mehlich 3 (M3) extraction. Results indicated that P transformation from labile to stable P forms occurred over 150‐day incubation. Litter age had no significant effect on the distribution of soil P forms. However, the highly reactive Pi (HRPi) form was higher for treatments with 10 Mg ha−1 PL on Day 0, indicating a risk for P loss, which was also revealed by negative SPSC for those treatments. At Day 0, M3‐P was positively correlated to HRPi. However, from Day 30 to 150, M3‐P was strongly correlated to both HRPi and moderately reactive Pi (MRPi) forms, indicating MRPi contribution to soil P availability. The negative relationship between HRPi and SPSC further confirms that high HRPi on Day 0 may be an environmental concern. [ABSTRACT FROM AUTHOR]

The soil moisture (SM) balance is affected by afforestation. In this study, the CiteSpace software was used to review the literature on the impact of afforestation on SM, and we further present research findings on the Loess Plateau (LP) as follows: (1) the spatio-temporal heterogeneity of SM varies depending on the research scale; (2) the presence of a dried soil layer significantly hinders deep SM recharge; (3) the accumulation of net primary productivity (NPP) may be occurring at the expense of SM. The following research topics are discussed: (1) the recharge and consumption of deep SM in LP; (2) the green water footprint and its shortage of non-crop greenery for evaluating SM allocation and use; (3) the development of inclusive models encompassing different spatial scales to assess the limits of soil water carrying capacity for vegetation (SWCCV). [ABSTRACT FROM AUTHOR]

Clarifying the response relationship between soil radon gas anomalies and active fault tectonic geomorphology, and to explore a rapid prediction method for concealed fractures, soil radon gas measurements and unmanned aerial vehicle micro-geomorphic scanning were carried out in the basin section of the Aba South Fault in western Sichuan. The areas of radon gas anomalies and tectonic features formed by fracture activities are highly consistent with the distribution areas of hidden fractures. It is concluded that the combination of soil radon gas measurements and tectonic geomorphologic analysis can rapidly and accurately predict hidden fractures covered by Quaternary sediments. [ABSTRACT FROM AUTHOR]

Radioactive cesium rich microparticles (CsMPs) could partially increase 137Cs concentration of the samples collected from the environment after the Fukushima Daiichi Nuclear Power Plant accident. In this study, we investigated the vertical distribution of CsMPs in soils collected from Fukushima Prefecture, Japan. The distribution of CsMPs was relatively large in the soil surface layer. However, the proportion of CsMPs in the RCs concentration at each soil depth was not large, less than 10%. [ABSTRACT FROM AUTHOR]

The activity concentrations of 238U, 232Th, and 40K were determined at 56 sites along the East Coast of India, near the Bay of Bengal, with 31 sites in Odisha and 25 in Andhra Pradesh. In Odisha, average concentrations were 109 ± 13 Bq kg−1 for 238U, 296 ± 27 Bq kg−1 for 232Th, and 450 ± 33 Bq kg−1 for 40K, while in Andhra Pradesh, they were 51 ± 13 Bq kg−1, 149 ± 16 Bq kg−1, and 236 ± 21 Bq kg−1, respectively. Absorbed dose rates and annual effective doses were higher outdoors and indoors in Odisha compared to Andhra Pradesh. The calculated radiological parameters exhibited elevated values at certain sampling locations; however, overall, the values generally complied with regulatory standards. [ABSTRACT FROM AUTHOR]

The relationship between humanity and the soil is an increasingly important topic in social theory. However, conceptualisations of the soil developed by anticolonial thinkers at the high point of the movement for self-determination between the 1940s and the 1970s have remained largely ignored. This is a shame, not least because theorists like Eric Williams, Walter Rodney, Suzanne Césaire and Amílcar Cabral were concerned with the soil. Building on recent work on human-soil relations and decolonial ecology, we argue that these four thinkers conceptualised the connection between soil, empire, and anticolonial revolt. Williams and Rodney ground understanding of soil degradation in global relations of economic power, while Césaire and Cabral reconceptualise postcolonial nationhood in terms of the mutability and diversity of the soil. The article concludes by suggesting that these two anticolonial counterpoints, global connectivity and more-than-human identification, anticipate and deepen contemporary attempts to decolonise ecological thinking. [ABSTRACT FROM AUTHOR]

Quantifying the process of particle breakage is essential whenever a macroscopic investigation into the phenomenon is addressed. Some authors relate an indicator of the evolution of particle breakage, usually the surface created, to a measure of the mechanical loading. Others refer to the evolution of the particle size distribution (PSD) to better understand the problem. In this study, a shape factor of the PSD curve is used as a breakage parameter. The slope of the linear trendline of the PSD in a log-log plot was found to be reasonably representative of the shape of the PSD, for engineering granular materials. It was shown that the new breakage parameter is adapted to both well graded and uniformly graded materials, but cannot be used to describe gap-graded soils. This parameter is first studied from a micromechanical point of view, before being compared to three widely used breakage parameters: Hardin, Marsal and Einav's breakage parameters. The transition between these three parameters and the proposed parameter is provided. The main objective of this study is to allow the operation and utilisation of experimental results, which are reported in the literature through one of the available breakage parameters, or through PSD plots. [ABSTRACT FROM AUTHOR]

The impact of non-linear soil behaviour on seismic hazard in low-to-moderate seismicity areas is often neglected; however, it may become relevant for long return periods. In this study, we used fully non-linear 1-D simulations to estimate the site-specific non-linear soil response in the low seismicity area, using the city of Lucerne in Switzerland as an example. The constitutive model considers the development of pore pressure excess and requires calibration of complex soil models, including the soil dilatancy parameters. In the absence of laboratory measurements, we mainly used the cone penetration test data to estimate the model variables and perform inversion for the dilatancy parameters. Our findings, using Swiss building code-compatible input ground motions, suggest a high probability of strong non-linear behaviour and the possibility of liquefaction at high ground motion levels in the case study area. While the non-linearity observations from strong-motion recordings are not available in Lucerne, the comparison with empirical data from other sites and other methods shows similarity with our predictions. Moreover, we show that the site response modelled is largely influenced by the strong pore pressure effects produced in thin sandy water-saturated layers. In addition, we demonstrate that the variability of the results due to the input motion and the soil parameters is significant, but within reasonable bounds. [ABSTRACT FROM AUTHOR]

To evaluate the seismic performance of a prestressed concrete-steel hybrid (PCSH) wind turbine tower, the seismic fragility curves based on incremental dynamic analysis (IDA) and multiple stripe analysis (MSA) on a two-scale model are presented and compared. The peak ground acceleration (PGA) and peak lateral drift on the top of the tower are adopted as the intensity measure (IM) and engineering demand parameter (EDP) of analysis, respectively. Finally, the seismic performance of the PCSH tower subjected to seismic action at different soil is investigated. The fragility curves obtained by IDA and MSA methods are compared. [ABSTRACT FROM AUTHOR]

The large particle sizes of railway ballast and rock fill have meant that conventional techniques used to measure the small-strain stiffness of finer geomaterials have not been adopted, with the consequence that their stiffnesses are poorly defined. In a series of tests on a UK railway ballast, simple adaptations were made to existing local strain measuring systems to account for the larger particle sizes. The study showed that the small-strain stiffnesses are different in second loading compared to virgin loading, but multiple cycles had little further effect on the stiffness. The large particle size was found rarely to have any detrimental effect on the quality of the strain measurements and the two independent measurements of axial strain taken at diametrically opposite locations were generally as consistent as for finer grained soils. As for other soils, the 'external' measurements of strain across the apparatus platens were of little use in determining stiffness. The presence of water did not have a significant effect on the behaviour, and this was confirmed by inter-particle loading tests on single particle contacts. Despite the use of lubricated end platens, there was a significant barrelling of the sample at large shear strains so that the internal measurement of the volumetric change diverged from the external measurement at large strains. The very small volumetric strains that occurred during isotropic loading meant that each sample could only be used to obtain one measurement of the virgin loading stiffness. [ABSTRACT FROM AUTHOR]

This paper forms part of the SINEW (sinkhole early warning) project and continues the work conducted by Möller and co-workers in 2022, where 1g experiments demonstrated the feasibility of using distributed fibre-optic sensing (DFOS) for sinkhole early warning. Their experimental campaign highlighted an order of magnitude difference in the strain between the soil and the cable that remains unexplained and weakens confidence in the technology and/or the experimental method. This paper uses three-dimensional finite-element analyses to examine further this discrepancy and the soil–cable interface. The results support the experimental findings and demonstrate that the DFOS signature strain profile is induced by the horizontal movement of the ground, and enhanced when sufficient coupling at the soil–cable interface is achieved. This result holds when modelling is scaled to realistic confining pressure, and its significance is twofold. First, this needs to be accounted for in the DFOS laying technique. Second, particles of cohesionless soils undergo relatively high horizontal displacement away from the centre of the sinkhole, and this means that DFOS cables are able to detect subsidence away from the centre of the sinkhole. The paper illustrates this result and the signature strain profile expected in this case. [ABSTRACT FROM AUTHOR]

The analytical solution of the steady-state seepage field of a circular cofferdam in nonhomogeneous layered soil of finite depth is derived, including the head function, exit hydraulic gradient formula, and seepage flow formula. The head function is obtained by dividing the circular cofferdam seepage field into regions and then using the separated variable method combined with the Sturm–Liouville theory, and the unknown coefficients in the head function are determined by constructing a system of equations through the integral transformation of the Bessel function. Based on the head function, an analytical equation is also given for the exit hydraulic gradient and seepage flow. The accuracy of the proposed analytical solution is verified by a comparison with numerical results as well as with the results of other methods. The proposed analytical solution is a display analytical solution without singularities and can be used as an effective tool for the analysis of circular cofferdam seepage problems. [ABSTRACT FROM AUTHOR]

Mechanical response of soils under simple shear conditions has long been a subject of significant interest in the field of geomechanics. When subjected to simple shear loading, soils experience rotations of the principal stress directions. To provide a unified description for the simple shear behavior of clay and sand, this paper proposes a novel critical state model that accounts for the influence of principal stress rotation (PSR), based on the unified critical state model for overconsolidated clay and sand with subloading surface (CASM-S). The novelty of the newly proposed model, which is named as CASM-SP, lies in its ability to consider the influence of direction of the stress increment when establishing the plastic flow rule that is suitable for both clay and sand. Therefore, the model can capture the mechanical response of soils resulting from the PSR loading mechanism, such as noncoaxial behaviors. Then, the newly proposed model is validated through the comparisons with a series of experimental data of clay and sand under both drained and undrained simple shear conditions. Results predicted by the CASM-SP model agree well with those from the experiments, demonstrating that CASM-SP can reasonably describe the simple shear behavior of both clay and sand. [ABSTRACT FROM AUTHOR]

• Thermal treatment alters soil properties, and then influences Cd and As transformation. • The calcinating process exhibits distinct volatilization behaviors for Cd and As. • TCLP-extractable Cd and As contents demonstrate adverse leaching tendencies following the calcination. Thermal treatment can effectively decontaminate soils but alter their properties. Previous research mainly focused on volatile organic compounds and metals, i.e. Hg, neglecting non-volatile metal(loid)s. This study aimed to investigate Cd and As transformation during aerobic and anaerobic calcination. The results showed that both aerobic and anaerobic calcination increased soil pH by reducing soil organic matter (SOM) content, which also influenced the cation exchange capacity (CEC) and the leaching behavior of Cd and As in the soil. The total concentrations of Cd and As in the calcined soils varied depending on the calcination temperature and atmosphere. When the aerobic calcination temperature exceeded 700 °C, Cd volatilized as CdCl 2 , while anaerobic calcination at relatively low temperatures (600 °C) involved reductive reactions, resulting in the formation of metallic Cd with a lower boiling point. Similarly, As volatilized at 800 °C aerobically and 600 °C anaerobically. The formation of As-based minerals, particularly Ca 3 (AsO 4) 2 , hindered its gasification, whereas anaerobic calcination promoted volatilization efficiency through the generation of C-As(III) based gaseous components with lower boiling points. Contrasting trends were observed in the TCLP-extractable Cd and As contents of the calcined soils. Over 70% of TCLP-extractable Cd contents were suppressed after thermal treatment, attributed to the elevated pH and reduced CEC of the soil, as well as volatilization. However, TCLP-extractable As contents increased with elevated temperatures, likely due to the desorption of AsO 4 3− and re-adsorption of gaseous As 2 O 3 during cooling. These findings have implications for assessing the environmental impact of thermal treatment and provide insights for remediation strategies concerning Cd and As-contaminated soils. [Display omitted] [ABSTRACT FROM AUTHOR]

Rammed earth techniques have a long history and are widely used in the Mediterranean and China. These traditional techniques developed independently in the two regions, producing differences and similarities. Tools and materials as two essential aspects are compared in this paper. For ease of movement and secure fixing, formworks comprise forms, end-stops, and retaining devices. The latter determines how the formwork is used. The formwork size represents the main difference and influences various aspects. Although the choice of the earth for construction is similar, the different local soil components and materials constitute essential differences in reinforcing rammed earth in the two areas. [ABSTRACT FROM AUTHOR]

This study presents the effects of moisture variation and the influence of matric suction on the permanent deformation (PD) of three tropical soils with different geological-geotechnical characteristics used in road subgrades in southern Brazil. The experimental programme consisted in determining the soil-water characteristic curves and in dynamic triaxial tests to obtain the PD in different compaction and post-compaction moisture contents. The variation of compaction moisture content caused microstructural changes, influencing the plastic behaviour of soils: the higher the initial moisture content, the greater their accumulated permanent deformations. As expected, the post-compaction moisture variation (wetting process) tended to increase the plastic deformation of materials, evidencing the influence of the suction variation on the performance of the soils studied. In addition, matric suction proved to be the best variable to represent the effects of moisture variation on the plastic behaviour of soils subjected to cyclic loading. Thus, a PD prediction model for tropical soils with the inclusion of this parameter was proposed. The model proved to be highly predictive and may become an important tool to be incorporated into current mechanistic-empirical design methods. [ABSTRACT FROM AUTHOR]

Research on the SSI effect on flat sites has yielded many valuable conclusions. However, current research on the impacts of various special local terrains on structural dynamics remains limited. For mountainous areas, it is common to construct houses in a multi-step, climbing, and laterally staggered architectural form that follows the mountain terrain. Only through the analysis of the combined action of the upper and lower parts can the seismic performance of this type of structural form be better revealed; considering the influence of SSI effects will be closer to the actual seismic effects. Therefore, to identify the damage factors of the mid-story isolated stilted structures under earthquakes and provide optimized design plans for the structures, six models are established considering three slopes and two types of foundations based on the engineering case in Chongqing, China. Through the elastic-plastic time-history analysis under earthquakes in the down and transverse-slope directions, concludes, compared with not considering SSI, the seismic response of the mid-story isolated stilted structures considering SSI in mountainous areas is amplified. With the increase of the mountain slope, the seismic response of the structures considering SSI increases, and the amplification coefficients are between 1–1.8. The amplification coefficients of the structures without SSI are concentrated around 1, which is less influenced by the slope. The damage to the stilted isolated layer is mainly concentrated in the column and the beam end, and the maximum seismic response appears in the short columns. The foundation soil stress increases with the increase of the mountain slope. [ABSTRACT FROM AUTHOR]

This research article outlines a provocation for diverse and experimentally open, situated approaches to exploring care and caring. The diversely positioned authors discuss this idea using the subject of soil, in the place and context of Aotearoa New Zealand. Little is known about the diversity of ways that everyday people value, or, have caring relationships for/with soil, among a plethora of research that positions soil ‘care’ around, for example, commercial food production, waste‐sinking, or property land value. To study diverse care in relation to soil, as with many relational subjects, requires equivalent diversity in the ways in which we might explore it. Here we outline the basis for diverse, situated methodologies that necessarily lead to a diversity of methods. This paper looks at the methodological imperatives that lead to exploring care, and discusses a variety of methods that generate different forms of ‘data’ with different forms of representation of that care. We observe that to holistically observe care relations with soil requires a diversity of methodologies, inherently ontological and epistemological – worldmaking. We discuss situated and enactive, affective approaches of Kaupapa Māori enquiry, monitoring and arts‐based approaches to ‘measure’ soil care taking place, in place, and contextualise this with our own author positionality. We discuss this suite of experimental, reflexive, affective and responsive ways to measure soil care that are contingent on that being cared about, for, with and by, and which reciprocally give care. [ABSTRACT FROM AUTHOR]

Since Artificial ground Freezing (AGF) appeared in the 1880s in the mining sector in Europe, it has been used for various construction applications worldwide. In recent years, it has been increasingly popular in urban projects due to its versatility and applicability to complicated site conditions. So far, it has been used to stabilize substrata to nearly 1,000 m below the ground surface, which is considered not possible for many other ground improvement technologies. Due to the growth in field applications, the practice and theories related to AGF have become more mature in the most recent two decades. The improvement in understanding of this topic is a result of lessons that have been learned through numerous projects, as well as a variety of comprehensive studies that have been completed. This paper reviews the existing practice, the recent development on AGF and the challenges of AGF. [ABSTRACT FROM AUTHOR]

Background: Tetanus is a clinical rarity due to the successful globally adopted childhood vaccination programme. The rising elderly population in the United Kingdom creates a subset of individuals whom are prone to develop Tetanus as they preceded this vaccination drive. Case summary: A 76 year old Caucasian lady presented with a soil contaminated laceration injury on her knee following a fall. Though she received urgent assessment and wound care, the relevance of the injury in the backdrop of her age was not appreciated and her tetanus post exposure prophylaxis was overlooked. She readmitted seeking further management 1 week later with an infected wound with Trismus and clinical features favoring Generalized tetanus. During her stay she developed Takotsubo-cardiomyopathy with congestive cardiac failure and required prolonged care in the intensive unit with mechanical ventilation and rehabilitation before being discharged home. Conclusion: First contact physicians should have a greater appreciation of the types of injuries and at-risk individuals who are more prone to develop tetanus upon exposure to ensure early and appropriate identification. There should be greater situational awareness with regard to the elderly in view of their heightened risk of development of tetanus specially those born before the vaccination drive. Knowledge regarding post exposure prophylaxis measures for tetanus should be regularly updated using local guidance to ensure awareness, so as to despite its rarity Tetanus remains an adequately appreciated disease. [ABSTRACT FROM AUTHOR]

The mobility of arsenic compounds in the soil-plant system and its interaction with biogenic macroelements K, P, Ca, Mg, Si, S, Na in plants under conditions of toxic stress have been studied. This is illustrated by the wheatgrass Elytrigia repens. It has been established that the root system is responsible for protecting the aerial part of wheatgrass from excess arsenic, and it is of great importance for phytostabilisation of arsenic pollution therefore indicating the increased tolerance of this plant. The intensity of As accumulation in plants depends on its speciation in the soil. Antagonism of the main essential elements (K, P) to the accumulation of As in wheatgrass shoots is observed. It can lead to disruption of metabolic processes in plant cells. It has been shown that changes in the K+/Na + values may lead to violation of osmotic processes in the aerial plant organs and contribute to their degradation not only under salt stress but also under the influence of higher concentrations of As in the plants. In areas intensively contaminated with arsenic, a decrease in the K/Na value in the above-ground organs of wheatgrass can be used as a criterion for the degree of phytotoxicity. [ABSTRACT FROM AUTHOR]

AbstractThe Bekker apparatus is an important tool for measuring soil bearing capacity; however, it is not entirely suitable for deep-sea sediments, and the size of the loading plate can affect the accuracy of the Bekker bearing parameters. This paper employs the Coupled Eulerian-Lagrangian (CEL) method to explore how different conditions impact Bekker bearing parameters. As the size of the loading plate gradually increases, the soil compression mechanism and load path reach a relatively stable state, leading to the stabilization of Bekker bearing parameters. The study proposes a range of plate sizes for deep-sea soils with varying strengths, noting that the physical mechanisms of low-strength soils are relatively simple, making them more consistent with the ideal conditions described by Bekker’s theory. Furthermore, an analysis of the relationship between Bekker bearing parameters and penetration depth reveals that the parameters corresponding to different strength soils vary almost parallel with depth. This is attributed to the same settlement path, where the distribution of loads and the geometrical shapes of the supporting structures remain unchanged, resulting in a similar trend in the variation of Bekker parameters. The research findings provide a theoretical basis for analyzing the bearing capacity characteristics of soft deep-sea soils. [ABSTRACT FROM AUTHOR]

The Three Gorges Reservoir Area (TGRA) has often suffered the most serious soil erosion in recent years. Soil erosion control still remains on the purple soil, the main soil type for the sloping farmland in this area. Among them, enzyme- induced carbonate precipitation (EICP) can rely on the urease enzymes to catalyze urea. Specifically, the urea can be decomposed into ammonium and carbonate anions, and then precipitated the calcium carbonate (CaCO3) with the presence of carbonate anions and external calcium sources. EICP has been proven to efficiently strengthen the soil for less infiltration, in order to restore the rock and heritage. A promising approach can be regarded to effectively control soil erosion. However, the effect of EICP on the soil detachment capacity is still far from clear, especially for the response of soil detachment to the EICP concentration and maintenance time. Therefore, this study aims to clarify the effect of EICP solution concentration and maintenance duration on the soil detachment capacity of purple soil in the Three Gorges Reservoir Area. The purple soil in the TGRA was taken as the research material. The scouring experiments were conducted under five EICP solution concentrations (0 (for control check), 0.5, 1.0, 1.5, and 2.0 mol/L) at six maintenance durations (1, 7, 15, 30, 60, and 120 d), in order to estimate the soil detachment capacity. Also, the apparent cohesion and calcium carbonate content were measured at different experiment conditions. Moreover, the SEM was employed to reveal the micro-mechanism of erosion reduction by EICP. The results indicated that the soil detachment capacity of purple soil significantly decreased with the application of EICP solution. Compared with the CK, the soil detachment capacity decreased by 19.63%-86.92%, 38.79%-89.41%, 48.13%-89.91%, and 31.78%-84.49%, respectively, at the EICP solution concentration of 0.5, 1.0, 1.5 and 2.0 mol/L, with the most pronounced effect at the concentration of 1.5 mol/L. Additionally, the soil detachment capacity decreased rapidly, whereas, the subsequent slowly decreased as maintenance duration increased. Compared with the maintenance for 1 d, the decreases at 7, 15, 30, 60, and 120 d were 19.79%-84.08%, 33.81%-87.80%, 87.27%-94.21%, 91.41%-93.18%, and 91.18%-92.77%, respectively. Moreover, the reduction amplitude in the soil detachment capacity accounted for 85.79%-92.21% of the total reduction amplitude at the maintenance duration of 7 d under the application of the EICP solution. The apparent cohesion and calcium carbonate content of purple soil showed a trend of increase followed by a decrease with the increase of EICP solution concentration. Compared with the CK, the apparent cohesion increased by 43.70%-77.43%, 58.54%-101.21%, 77.06%-135.68%, and 64.08%-87.86%, respectively, at the EICP solution concentration of 0.5, 1.0, 1.5 and 2.0 mol/L, while the calcium carbonate content increased by 10.29-17.35 times, 11.12-23.00 times, 12.00-29.59 times and 10.88-24.35 times, respectively. Additionally, the apparent cohesion increased by 10.46%-36.38%, 21.98%-46.46%, 35.12%-55.41%, 45.15%-65.49%, and 48.61%-72.76%, respectively, at the maintenance for 7, 15, 30, 60 and 120 d, compared with the maintenance for 1 d. The content of calcium carbonate increased by 54.17%-133.48%, 60.94%-134.39%, 61.98%-134.84%, 61.46%-134.84%, and 62.50%-135.29%, respectively, at the maintenance for 7, 15, 30, 60 and 120 d under the application of EICP solution, compared with the stable content in the CK. The increase amplitude in the apparent cohesion and calcium carbonate content accounted for 37.59%-59.56% and 78.26%- 98.66% of the total increase amplitude, respectively, at the maintenance duration of 7 d. Additionally, the microscopic analysis exposed that the soil detachment capacity was reduced to aggregate the calcium carbonate in the soil surface under the application of EICP solution. Furthermore, the soil detachment capacity was better described by the apparent cohesion and calcium carbonate content with an exponential function. The findings can provide theoretical guidance to promote erosion control in the application of EICP on soil detachment of purple soil in the TGRA. [ABSTRACT FROM AUTHOR]

Soil thermal conductivity is one of the most important parameters to determine the heat transfer performance of the soil layer, leading to the ground temperature distribution, soil environment, and crop growth. The composition of organic matter is directly related to the thermal conductivity of high organic soil. However, the current model of soil thermal conductivity cannot consider the organic matter content and decomposition degree. This study aims to analyze the influence of the undisturbed turfy soil on the thermal conductivity in the different layers. Additionally, more than 10 improved models of soil thermal conductivity were proposed and then compared on the turfy soil. The results indicate that: 1) The thermal conductivity in each layer of unfrozen turfy soil was similar (0.51~0.66 W/(m∙K)). There was a significant difference in the thermal conductivity among the layers (1.00~1.62 W/(m∙K)) after freezing, indicating that the freezing altered the composition of the soil. The higher proportion of components was found with the low heat transfer performance, due to more organic matter components and pores in turfy soil. The thermal conductivity of unfrozen turfy soil was lower than that of other organic soil with higher dry density. Most water in the soil was turned into ice after freezing, indicating the greatly improved thermal conductivity. The high content of water greatly contributed to the thermal conductivity of frozen turfy soil. Furthermore, a correlation analysis was carried out between the fundamental physical properties of turfy soil and the thermal conductivity. The soil particle size distribution, organic matter content, and decomposition degree depended mainly on the thermal conductivity of unfrozen turfy soil. 2) Most prediction models of soil thermal conductivity (Campbell, Johansen, and their derived models) failed to directly consider the proportion of organic matter components in the turfy soil, leading to overestimation of the thermal conductivity of organic matter in the solid phase. Alternatively, the soil thermal conductivity model was used to consider the dry density (Nikoosokhan model) and component weight (Tian model), indicating the excellent applicability to predict turfy soil. It indirectly quantified the low performance of heat transfer in the organic matter components and pores, according to the density differences after the calculation of soil thermal conductivity. The high level of accuracy was still difficult to achieve (RMSE>0.07 W/(m∙K) for unfrozen soil; RMSE>0.28 W/(m∙K) for frozen soil). 3) According to the soil properties, the parameters were introduced to characterize the turfy soil, including organic matter content (Oc) and decomposition degree (Dd), in order to improve the model of thermal conductivity. The improved model was obtained to comprehensively consider the low dry density, high water content, and high organic matter of turfy soil. The parameters were modified to reduce the overestimation of the thermal conductivity of organic matter components. Furthermore, a better prediction (R² > 0.75) of the soil thermal conductivity model was achieved for both unfrozen and frozen turfy soil with high organic matter, in terms of applicability and accuracy. The research findings can provide a strong theoretical reference for the thermophysical properties of seasonal frozen turfy soil with high organic matter in agricultural cultivation and engineering construction. [ABSTRACT FROM AUTHOR]

Two pedotransfer functions (PTFs) are available in the literature enabling the soil water retention function (WRF) to be estimated from knowledge of the soil particle-size distribution (PSD), oven-dry soil bulk density (rb), and saturated soil water content (qs): i) the Arya and Heitman model (PTF-AH), and ii) the Mohammadi and Vanclooster model (PTF-MV). These physicoempirical PTFs rely on the hypothesis of shape similarity between PSD and WRF, and do not require the calibration of the input parameters. In the first stage, twenty-seven PSD models were evaluated using 4,128 soil samples collected in Campania (southern Italy). These models were ranked according to the root mean square residuals (RMSR), corrected Akaike information criterion (AICc), and adjusted coefficient of determination (R2adj). In the second stage, three subsets of PSD and WRF data (DS-1, DS-2, and DS-3), comprising 282 soil samples, were used to evaluate the two PTFs using the best three PSD models selected in the first stage. The hypothesis of shape similarity was assumed as acceptable only when the RMSR value was lower than the field standard deviation of the WRFs (s*), which is viewed as a tolerance threshold and computed from the physically based scaling approach proposed by Kosugi and Hopmans (1998). In the first study area (DS- 1), characterized by a fairly uniform, loamy textured volcanic soil, the PTF-AH outperformed the PTF-MV and both PTFs provided reasonable performance within the acceptance threshold (i.e., RMSR < s*). In the other two heterogeneous field sites (DS-2 and DS-3, characterized by soil textural classes that span from clay and clay-loam to loam and even sandy-loam soils), the PTF-MV (with 3% to 6% RMSR surpassing s*) outperformed the PTF-AH (with 8% to 30% RMSR surpassing s*) and the majority of RMSR values were larger than those obtained in the original studies. The mean relative error (MRE) revealed that the PTF-MV systematically underestimates the measured WRFs, whereas the PTF-AH provided negative MRE values indicating an overall overestimation. The outcomes of our study provide a critical evaluation when using calibration-free PTFs to predict WRFs over large areas [ABSTRACT FROM AUTHOR]

Rayleigh wave isolation using metamaterials is a research hotspot in the engineering community, yet the development of relevant mitigation methods remains an open and challenging problem. Herein, we propose a new type of metasurface, known as an engineered metagrating, which is a special metasurface buried in soil and plays a role in shielding surface Rayleigh waves. Moreover, the total omnidirectional reflection characteristics and subwavelength properties exhibited by the proposed metasurface provide a more flexible reference for surface Rayleigh wave mitigation measures in practical engineering applications. This work can open new avenues for controlling the propagation of seismic surface waves. [ABSTRACT FROM AUTHOR]

In this research, experimental studies and numerical analyses were carried out to investigate how the usage of geotextile and geopolymer coated geotextile as a hybrid method changes the uplift behavior of the screw piles in cohesionless soil. In this context, traditional pile behavior, the effect of different number of helixes and embedment depths on screw piles, the mechanism of geotextile and the effects of geopolymer coating process were investigated. In addition, experimental studies were modeled by using Plaxis 3D and parametric studies were carried out after verification between the results of experimental study and numerical analysis. In the numerical analysis, a segmented helix model consisting of four 90-degree slices was developed instead of the planar helixes commonly used in the literature. For further investigation of the effectiveness of hybrid method, parameters such as improvement ratios and breakout factors were calculated. When the results obtained within the scope of the study were evaluated, the geopolymer coating process increased the bearing capacity of the geotextile by 24 % at 27 % less elongation. It was also seen that uncoated and geopolymer coated geotextile increased the screw pile performance in terms of improvement ratios by 294 % and 364 %, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper presents a new type of large-diameter multi-disc soil anchor and its cavity-forming tool. The large-diameter multi-disc soil anchor is obtained by adopting a toothed chain, centrifuging holes to form cavities, forming multiple cavities, placing a steel strand with centering support, injecting cement mortar, and curing. In order to study the uplift bearing characteristics and creep property of the large-diameter multi-plate soil anchor, the equal-diameter soil anchor was taken as the control group. The ultimate pull-out bearing capacity, vertical displacement, axial force, anchor plate bearing load, and side friction resistance were simulated and analyzed by FLAC3D 5.0 64-bit software, and the creep property test of the anchor bolt was carried out. The results show that under the same conditions, the ultimate pulling capacity of the large-diameter multi-disc soil anchor is 125% higher than that of the same-diameter soil anchor. The vertical displacement of the large-diameter multi-disc soil anchor decreases by 51.74% compared with that of the equal-diameter soil anchor when the ultimate uplift capacity is reached. The side friction resistance of the large-diameter multi-disc soil anchor is small and its growth rate is slow. When the ultimate pulling capacity is reached, the load sharing of the anchor disc accounts for 76.54% of the total load applied. The creep rate of the large-diameter multi-plate soil anchor bolt is 0.91 mm, and the creep rate of the equal-diameter soil anchor bolt is 1.69 mm. By fitting the data, it is found that the large-diameter multi-disc soil anchor provides a method to increase the anchorage force of the soil anchor, and the research on its bearing characteristics and creep property provides a theoretical basis for the application of the soil anchor. [ABSTRACT FROM AUTHOR]

In the field of tunnels, the stability of tunnel faces is generally considered in dry, saturated and homogeneous soils. However, the actual condition of some soils has been found to be inhomogeneous, with unsaturated seepage. In this paper, an analytical method is applied to estimate the safety factor when the supporting force at the tunnel face is zero under steady unsaturated seepage and inhomogeneous conditions. This method combines kinematic limit analysis techniques with strength reduction techniques; an efficient stress formulation utilizing suction stress is employed to determine the apparent cohesive force to obtain the solution of the steady unsaturated seepage problem, and indicators of soil inhomogeneity are attributed to the effect on cohesion. A 3D log-spiral collapse mechanism is used to find the zero supporting pressure and determine the safety factor through an iterative method. This paper analyzes the effect of variations in the unsaturated parameters, inhomogeneity parameters and tunnel dimensional parameters on the stability of the tunnel face. [ABSTRACT FROM AUTHOR]

Due to its simple design and cost-effectiveness, Bromhead ring shear apparatus is widely used to assess the drained residual strength through various testing procedures such as single stage, preshearing, and multistage. However, when compared to back-calculated case histories, values obtained through these testing procedures were found to be higher due to wall friction. To address this, Stark and Vettel (Geotech Test J 15:24–32, 1992) have introduced the "Flush testing procedure" which involves adding remolded soil to the specimen and reconsolidate it, in order to minimize the wall friction. Although the procedure yielded satisfactory results, it is more time-consuming. This paper presents a comparison between a proposed preconsolidated presheared flush (P.P.F) and flush testing procedures. The test results showed that this procedure has successfully minimized the effect of wall friction, providing values lower than those obtained using the flush procedure in shorter time. [ABSTRACT FROM AUTHOR]

The design of large-scale pile foundation systems is routinely assisted by finite element simulations. To a large extent, both the modeling and the computational effort of such analyses are governed by the adopted pile modeling technique. The traditional approach to this problem fully resolves the pile and soil domain employing solid elements, resulting in considerable meshing constraints and high simulation runtimes that may be regarded as unbearable for many practical purposes. As an attractive alternative to circumvent these obstacles, embedded FE models have become increasingly popular in solving this modeling task, mainly due to their flexible meshing procedure and significantly enhanced runtime efficiency. In a preceding contribution, the authors have proposed an extended formulation that provides a rigorous framework to capture soilstructure interaction effects at the physical soil-pile contacts. As a key feature, the implemented combined soil-pile coupling scheme explicitly accounts for endpoint interaction. However, validation studies have been constrained to single pile analyses to date. The present work expands this validation scope to largescale boundary value problems involving multiple piles and investigates the model performance based on three different case studies. The results are compared to both, measurements and numerical benchmark solutions and provide exclusive insight into the numerical fidelity of the developed embedded FE model, with a view to increasing its potential for take-up in engineering practice. [ABSTRACT FROM AUTHOR]

Soil structure is a standard component of pedon descriptions collected to characterize the nature and function of soils as a natural body. Soil structure is an important indicator of soil development and a predictor of water, air, and root movement throughout the profile. However, inconsistencies exist within the current standardized methodologies used to describe soil structure in the field, making soil structure data difficult to use and often confusing to students encountering these concepts for the first time. Therefore, we propose an updated method of soil structure description to add an interpretive component that clearly distinguishes geogenic, pedogenic, and human‐induced structures. This method employs terminology that communicates both observable morphology and the mechanism of formation. The updated method herein differentiates three classes of structure: (a) geogenic structural formation (GS), (b) natural pedological structural formation (current nomenclature), and (c) significant human‐induced structure changes from natural pedological structure. This updated approach improves the documentation of scientifically relevant soil morphology and communicates the processes involved in the formation of all forms of soil structure. As a result, this change eases description challenges around soil structure and interpretations common in soil science classes, including soil judging. [ABSTRACT FROM AUTHOR]

The main chemical, ecotoxicological, and environmental fate characteristics of cyanide, along with its treatment methods for cyanide-contaminated wastewater, were thoroughly examined. A global biogeochemical cycle of cyanide is proposed, covering the key physicochemical processes occurring in aqueous, soil, and atmospheric environments. The principles, advantages, and disadvantages of various treatment methods—including chemical, physicochemical, electrochemical, photochemical, and biological approaches—are evaluated. Finally, the feasibility of reusing cyanide waste is explored. [ABSTRACT FROM AUTHOR]

Phosphorus (P) application can enhance soil P availability and alter P fractions. However, the P accumulation and transformation of different P sources in low-phosphorus red soil remain unclear. Two-year (2018–2019) field experiments were conducted to investigate the effects of five P source treatments (CK—no phosphorus; SSP—superphosphate; MAP—calcium–magnesium phosphate; DAP—monoammonium phosphate; and CMP—diammonium phosphate) on the P accumulation of maize and soil P fractions in low-P red soil using the Hedley Sequential Method. The results showed that P application significantly increased P uptake, Olsen-P, total phosphorus, and most of the soil P fractions. Compared to the CMP, MAP, and DAP treatments, SSP had a relatively higher P accumulation and labile P pool, with a slightly lower moderately labile P pool. The SSP treatment mainly increased soil-available P content and crop P uptake by increasing the labile P pool (resin-P and NaHCO3-Pi) and reducing the moderately labile P pool and non-labile P pool. The P activation coefficient (PAC%) and Olsen-P were positively correlated with labile P (resin-P, NaHCO3-Pi, and NaHCO3-Po) and moderately labile P (NaOH-Pi and 1 M HCl-Pi) and negatively correlated with Fe2O3 and Al2O3. The results suggest that SSP has a priority effect on the crop P uptake and soil P availability in low-P red soil. [ABSTRACT FROM AUTHOR]

This study investigated the adsorption-desorption characteristics of tembotrione in four different types of soils using the oscillating equilibrium method, explored the primary factors influencing its adsorption properties, and assessed the impact of biochar addition on its adsorptive behavior. The experimental results indicated the following: Adsorption kinetic tests revealed that the adsorption equilibrium time for tembotrione in various soils was 24 hours. The adsorption thermodynamic tests showed that the Freundlich model could effectively fit the adsorption curves of tembotrione in all four soil types. The adsorption intensity of tembotrione in these soils followed the order: red soil > paddy soil black soil fluvo-aquic soil. Desorption tests demonstrated that the hysteresis coefficients (H) of tembotrione in different soils were all less than 1. The lower the soil pH value, the stronger the adsorption of tembotrione in the soil. Additionally, there was a positive correlation between the content of organic matter and cation in the soil and the adsorptive properties of tembotrione. The adsorption capacity of tembotrione in the four different soil types ranged from 2.1 to 20.2 mg/kg. After the addition of rice husk biochar at varying ratios, the adsorption capacity increased to 8.3-21.0 mg/kg. This research provides a scientific basis for the rational and scientific use of tembotrione. [ABSTRACT FROM AUTHOR]

This article presents an analytical technique for determining the free vibration response of a rectangular tank. It is assumed that this structure has a flexible foundation and rigid walls. The effects of beneath soil are considered by using Winkler and Pasternak foundations. To verify the authors' responses, the finite element solutions are also compared with the analytical results. Additionally, a closed-form approximate relationship is provided in this research work to determine the first natural frequency of the tank resting on a deformable foundation. In order to find the effect of various parameters, such as the stiffness of the elastic foundation and tank dimensions, on the natural frequencies of this system, a sensitivity analysis is also carried out. [ABSTRACT FROM AUTHOR]

Soil arching is one of the main load transfer mechanisms of geosynthetic‐reinforced and pile‐supported (GRPS) embankments. This study established a numerical spring‐based trapdoor model that can consider the coupling effect between embankment filling, horizontal geosynthetic, piles, and soft soil between piles by the discrete element method (DEM). The effects of multiple factors on the deformation pattern, load transfer, and the settlement at the top surface of GRPS embankments were analyzed, such as soft soil stiffness, geosynthetic stiffness, fill height, and pile clear spacing. The multiple spring‐based trapdoor (MS‐TD) model effectively replicated the actual deformation of soft soil between piles in engineering practice by elucidating the nonuniform settlement of the fill on the trapdoor. Although the geosynthetic indirectly reduces the load transferred to the pile top by weakening the soil arching, it can directly increase the load transferred to the pile top by the membrane effect, thereby increasing the total load transferred to the pile top. The effect of the geosynthetic on reducing settlement decreases with the increase of soft soil stiffness, and the displacement reduction ratio at the top surface remains unchanged when it exceeds a certain value. In addition, the shape of the soil arch evolves rather than unchanged during the growth of pile clear spacing. [ABSTRACT FROM AUTHOR]

This paper proposes an improved discretization‐based kinematic approach (DKA) with an efficient and robust algorithm to investigate slope stability in nonuniform soils. In an effort to ensure rigorous upper‐bound solutions which may be not satisfied by the initial DKA based on a forward difference method (DKA‐FD), a central and backward difference "point‐to‐point" method (DKA‐CD and DKA‐BD) is proposed to generate discretized points to form a velocity discontinuity surface. Varying (including constant) soil frictional angles along depth are discussed, which can be readily considered in the improved DKA‐CD. Work rate calculations are performed to derive upper‐bound formulations of slope stability number, and critical failure surface is correspondingly obtained at limit state. The comparison with forward and backward difference methods clearly reveals that the improved DKA‐CD could significantly reduce the mesh‐dependency issue and enhance efficacy of slope stability analyses in nonuniform soils. [ABSTRACT FROM AUTHOR]

This paper presents an elastoplastic model to estimate the hydromechanical behavior of unsaturated soils based on state boundary hypersurface. Through mechanical hypersurface, the influence of saturation on yield stress can be expressed in a full form rather than an incremental form. Two hydraulic hypersurfaces and one mechanical hypersurface are proposed to establish the model. Two hydraulic hypersurfaces, composed of degree of saturation, void ratio and matrix suction, define the plastic hydraulic boundary. The elastic hydraulic behavior of unsaturated soils can be represented by scanning lines between these two hydraulic hypersurfaces. The mechanical hypersurface, composed of degree of saturation, void ratio and effective stress, defines the plastic mechanical boundary. The elastic mechanical behavior of unsaturated soils can be represented by scanning lines below the mechanical hypersurfaces. A large number of laboratory tests are used to validated the proposed model, showing that it can reasonably capture important features of the hydromechanical behavior of unsaturated soils. [ABSTRACT FROM AUTHOR]

Helical piles can be classified as partial displacement piles in terms of moderate advancement rate. However, its installation effect on surrounding soil is unclear. This study presented four field tests on the installation of helical piles with various dimensions in silty clay. The radial earth pressure and excess pore water pressure were measured during the installation processes. The installation effect of helical pile embedded in silty clay was comprehensively discussed and evaluated from multiple dimensions of time and space, based on the cavity expansion method (CEM) and Randolph and Wroth's elastic–plastic method verified by field data. The research reveals that as the length of the helical pile increases by 1.0 time, the maximum variations in radial earth pressure and pore water pressure by a remarkable 25.0 times and 7.8 times, respectively. Additionally, when the shaft diameter of the helical pile expands by 20%, the maximum alterations in radial earth pressure and pore water pressure swell by approximately 18.6 and 5.7%, respectively. Comparing the radial earth pressure at various embedment depths at the same penetration stage, it is found that the radial earth pressure induced by helices is slightly greater than that induced by pile shaft. The estimated radial earth pressure and pore water pressure agree with the measured maximum data, and the pore water pressure generated by the installation of helical pile completely dissipates after 10–12 days of installation in this work. [ABSTRACT FROM AUTHOR]

The stubby root nematode, Paratrichodorus allius, is one of the most important plant-parasitic nematodes. Besides root feeding, P. allius also transmits the Tobacco rattle virus in potatoes, which causes corky ringspot disease. Rapid detection of P. allius is key for efficient management. This study was conducted to develop a real-time recombinase polymerase amplification (RPA) assay that is capable of detecting P. allius directly in DNA extracts from soil using a simple portable device in real time. A fluorophore-attached probe was designed to target the internal transcribed spacer (ITS)-rDNA of P. allius and was used along with primers designed previously. The real-time RPA assay had the ability to detect P. allius DNA extracted directly from infested soil with a sensitivity of one-sixteenth portion of a single nematode. This RPA assay was specific, as it did not produce positive signals from non-target nematodes tested. The real-time RPA was found to be rapid as it could even detect P. allius in as little as 7 min. Testing with 15 field soil samples validated the RPA assay developed in this study. This is the first report of P. allius detection directly from soil DNA using real-time RPA and is the fastest method for P. allius detection in soil to date. [ABSTRACT FROM AUTHOR]

Nanomaterials (NMs) have unique properties and control processes relevant to the fate of contaminants in soils, air, and aquatic systems and within the carbon cycle. Many NMs often occur in association with larger mineral grains, organic matter, or living organisms such as microbes, plants and fungi. The preservation of the spatial, textural, chemical, and mineralogical relations between NMs and minerals, organic matter, and organism (NM‐associations) is of fundamental importance as it provides information about the origin and formation mechanisms of NMs. Here we review analytical approaches and techniques to study NM‐associations at the bulk‐, micro‐, nano‐ and atomic‐scale. We will focus on (a) X‐ray diffraction and mass‐spectroscopy techniques; (2) automatisms within software packages that permit the search of features without operators; (3) preparation and analytical techniques such as the focused‐ion beam technology, transmission electron microscopy and atom probe tomography; (4) nano‐spectroscopic techniques such as tip‐enhanced Raman spectroscopy, synchrotron infrared nanospectroscopy, and nano‐X‐ray fluorescence spectroscopy; (5) ptychographic X‐ray computer tomography. This review paper concludes with selected new perspectives such as (a) the characterisation of NM‐precursors, (b) the role of NM‐associations in the stabilisation of soil organic matter and (c) the interaction of NM‐associations in wildfire smoke with contaminants from other sources. [ABSTRACT FROM AUTHOR]

The response of tunnels subjected to seismic loading is a complex mechanism and depends not only on the seismic nature but also on tunnel structure and surrounding soil properties. The individual behavior of circular, rectangular, and sub-rectangular tunnels subjected to seismic loadings has already been studied in the literature. In the present research, two case scenarios of circular, rectangular tunnels and four sub-rectangular shaped tunnels, with similar cross-section areas, were adopted to perform a comprehensive numerical investigation. The purpose of the study was to determine the mechanical behavior of tunnels of different shapes, depending upon seismic conditions. Analyses were performed by considering the influence of soil-lining interaction, soil parameters, and lining thickness, as well as lining rigidity. Computations were performed for no-slip and full-slip conditions. The results indicate that the tunnel shape design is of great importance when regarding the mechanical behavior of the surrounding soil. This concerns no-slip as well as full-slip soil-lining interaction, especially when the lining is subjected to seismic loading. Moreover, it is shown that changes in incremental bending moments for circular, rectangular and sub-rectangular tunnels that depend upon the soil-lining interaction conditions differ significantly. [ABSTRACT FROM AUTHOR]

ABSTRACT Stem growth responses to soil and atmospheric drought are critical to forecasting the tree carbon sink strength. Yet, responses of drought‐prone forests remain uncertain despite global aridification trends. Stem diameter variations at an hourly resolution were monitored in five Mediterranean tree species from a mesic and a xeric site for 6 and 12 years. Stem growth and dehydration responses to soil (REW) and atmospheric (VPD) drought were explored at different timescales. Annually, growth was determined by the number of growing days and hours. Seasonally, growth was bimodal (autumn growth ≈ 8%–18% of annual growth), varying among species and sites across the hydrometeorological space, while dehydration consistently responded to REW. Sub‐daily, substantial growth occurred during daytime, with nighttime‐to‐daytime ratios ranging between 1.2 and 3.5 (Arbutus unedo ≈ Quercus faginea < Quercus ilex < Pinus halepensis in the mesic site, and Juniperus thurifera < P. halepensis in the xeric site). Overall, time windows favourable for growth were limited by soil (rather than atmospheric) drought, modulating annual and seasonal growth in Mediterranean species, and stems maintained non‐negligible growth during daytime. These patterns contrast with observations from wetter or cooler biomes, demonstrating the growth plasticity of drought‐prone species to more arid climate conditions. [ABSTRACT FROM AUTHOR]

To improve the probability analysis efficiency of slope, this paper proposes an improved particle swarm optimization (IPSO) method to determine the critical sliding surface (CSS) and its corresponding minimum safety factor, which is used to calculate the failure probability of slope. Based on the random fields generated by using Karhunen-Loève (KL) expansion method, the simplified Bishop's method combined with the entry and exit method, the particle swarm optimization (PSO) method, and the IPSO method is used to determine the CSS and its corresponding minimum factor of safety. Then, Monte Carlo simulation is used to estimate the failure probability of slope. The application potential of the IPSO method is demonstrated by re-analyzing two examples. Meaningful comparisons are made to demonstrate the calculating accuracy and calculating efficiency of the IPSO method in searching for the minimum safety factor of slope. Results show that the IPSO can accurately and efficiently determine the minimum safety factor in slope probability analysis considering the spatially variable soils. The IPSO method provides a promising tool for an efficient slope probability analysis. [ABSTRACT FROM AUTHOR]

Dredged soils are often considered as waste and pose significant environmental challenge. The objective of this study is to find the feasibility of utilizing dredged soil from Vizhinjam (MH soil) and Vallarpadam (CH soil) sites for land-filling applications through Chemical-Physical Combined Method (CPCM). Lime and fly ash were used as chemical stabilizers. The optimum percentage of the lime is determined as 6 (wt.%) and fly ash is 10 (wt.%) and 15 (wt.%) for MH and CH soil, respectively. The California Bearing ratio (CBR) increased by 55 and 60%, and Unconfined Compressive Strength (UCS) was enhanced by 61 and 53% for MH and CH soil, respectively. The chemically treated soil is then subjected to various physical treatments. The CPCM effectiveness was evaluated by determining shear strength by fall cone test. Curing by geobags enhanced 77 and 69% increase in shear strength for MH and CH soil, respectively, while vacuum preloading resulted in two times increase over the curing method. Among the physical methods, surcharge using geo-bags was found to be the most effective, as it improved the shear strength by 20–30% when compared to other approaches, making them suitable for reuse as an increase in shear strength contributes to the enhancement of bearing capacity. [ABSTRACT FROM AUTHOR]

An earthquake of Mw = 7.0 occurred on October 30, 2020, in the Aegean Sea near Samos Island, which caused severe structural damage in Bayraklı, Izmir (Türkiye), located around 70 km from the epicenter. To investigate the source, path, and site effects, ground motions recorded in Western Anatolia are simulated using the stochastic finite-fault method based on a dynamic corner frequency approach. The input model parameters are calibrated using the recorded motions at selected 10 stations within an epicentral distance of less than 100 km. The soil amplifications are modeled using horizontal-to-vertical spectral ratios and generic amplification factors. At most stations, including a few within Izmir Bay, amplitudes and frequency contents are modeled closely. Minor discrepancies within particular frequency bands can be attributed to insufficient representation of the local site effects. Finally, distributions of observed and simulated felt intensities are found to be consistent. [ABSTRACT FROM AUTHOR]