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This study investigates the quasi-static bearing stress-settlement response of shallow foundations in monolithic tire derived aggregate (TDA) layers having a total thickness of 3 m using a large-scale container and loading system. Tests were performed on footings having a range of widths, embedment depths, shapes, and loading inclinations. In tests where tilting was restricted, a clear bearing capacity was not observed for settlements up to 1.2B, where B is the footing width, but in tests where tilting was permitted bearing capacity was observed between settlements of 0.2B to 0.7B. Surface settlements indicate a dragdown response of the TDA adjacent to the footing extending out to more than 3B from the footing center, while settlement plates beneath the footing indicate a zone of influence of induced settlements of 14% at a depth of 4B. While bearing capacity theories for frictional geomaterials provided a reasonable prediction of the bearing capacity of footings in TDA for most tests, the corresponding settlements may be excessive for engineering applications. Accordingly, a correlation was developed between the theoretical bearing capacity and bearing stress at a settlement of 0.1B. A test with sustained loading indicates slight creep settlements with some stress dependency with magnitudes consistent with past studies.

Village classification is an important foundation for preparing village planning and formulating development strategies. This study takes a typical plateau mountain area-Yulong County, Yunnan Province as the research object. First, the analytical hierarchy process is used to build a “three evaluations” (ecological sensitivity, development potential, and construction suitability)indicator system. Second, spatial correlation analysis of the “three evaluations” was carried out to obtain the initial village classification results. Finally, the state space method was used to calculate the village bearing capacity, which could be used to correct the initial village classification. Thus, the final village classification could be obtained. The results show that a significant plateau mountain space distribution of heterogeneity was shown in the villages of the research area, and the spatial autocorrelation coefficients of the “three evaluations” were 0.343, 0.253, and 0.110, respectively; more than 60% of the villages were in a bearing state and the higher bearing capacity was concentrated in the southeast, northwest, and central regions of the research area. After the comprehensive carrying capacity was calculated and corrected, the special protection category accounted for 23%, the suburban integration category accounted for 4%, the relocation and withdrawal category accounted for 15%, the agglomeration and promotion category accounted for 40%, and the temporary unclear category accounted for 18%. For different types of villages, the layout optimization strategy should be proposed according to the carrying capacity calculation results. The results of this research can provide a reference and basis for the formulation of township(town)-level territorial spatial planning and the implementation of “multi-planning” practical village planning. [ABSTRACT FROM AUTHOR]

Load‐bearing capacity tests on large scale test specimens for modular polygon tower sections of wind turbines The verification for stability and fatigue of steel towers for onshore wind‐turbines require large dimensions due to the high static and dynamic loads. Since, the rated power as well as the hub height will further increase for wind turbines in the future, also the dimensions of the tower must be increased. Some kind of turbines will require a tower base diameter of > 4.5 m. Tubular steel sections with this dimensions cannot be transported (economically) by road. Therefore modular construction methods have been developed, whereby the tubular steel sections consist of longitudinally divided segments, which will finally assembled on site. Furthermore, the detail design of the connections between the structural components is also a challenge when planning wind turbines for the next generation. As a technical alternative to the existing tower configurations, a concept for a modular polygon tower made of steel is presented, where single plate segments can be connected along the longitudinal edges using extruded profiles so that no further bolted or welded connections are required for the final assembly on site. This technical proposal allows a longitudinal manufacturing of tower segments with steel plates but without any formwork with rolling and bending machines. As part of a research project, the technical feasibility of a modular polygon tower for a hub height of 200 m and a wind turbine class with 10 MW rated power was analysed to offer technical solutions for the next generation of onshore wind turbines. Load cases were generated for a fictitious reference wind turbine to carry out a pre‐design for the tower sections. A test programme was created on the basis of the calculated tower dimensions and ultimate load bearing tests were carried out on test specimens at a scale of 1 : 10. This paper presents the results of the experimental investigations, comparing the load‐bearing capacity of the various tower configurations and the observed failure mechanisms are explained. [ABSTRACT FROM AUTHOR]

Large seabed trenches have recently been found adjacent to suction caissons with taut and semi-taut moorings. Seabed trenching leads to loss of soil support and additional caisson rotation, and can therefore significantly decrease geotechnical capacity. In this paper, upper-bound solutions are presented that enable calculation of the reduction in ultimate load-carrying capacity of a suction caisson in a trenched seabed compared to optimal capacity in an intact seabed. Failure mechanisms for caissons embedded in an intact seabed are augmented to incorporate a kinematically admissible mechanism for a trench extending from the mudline. The rate of work dissipation is calculated to determine the optimised solution of the inclined capacity of suction caissons. Comparisons of the results of the upper-bound solutions with finite-element analyses show that the failure mechanisms and the calculated load-carrying capacities derived from the two methods agree well. Therefore, the analytical upper-bound method presented in this paper can be employed for efficient routine calculations of suction caisson capacity under inclined load considering seabed trenches, which are increasingly encountered in engineering practice. [ABSTRACT FROM AUTHOR]

This study presents a new solution algorithm to calculate the bearing capacity coefficient Nγ for a fully rough strip footing located on an infinite slope considering different soil friction angles φ and ground slopes β° using the stress characteristics method. The results showed that Nγ coefficients decreased with an increase in slope inclination, and roughness contribution prevented further reduction, particularly for higher φ values. The higher contribution of the upside-sloping ground for footing laid on the infinite slope led to a lower reduction of the Nγ coefficients compared with the footing placed at the slope vicinity in terms of a larger area affected by the stress field, and a larger plastic region of the downface slope. The reduction value was more eminent for steeper slopes β ≥ 20° due to the tendency for nonsymmetrical failure pattern, especially for higher φ values. The findings of the current research and those described in the literature were in good agreement, so much so that the lower-bound limit analysis and the current solution technique virtually reflect the same trend. The load inclination values for footings located adjacent to the slope with β ≤ 30° were not meaningful, whereas for footing resting on an infinite slope with β ≥ 25° it exceeds 15°, which reflects the fact that its effect should not be neglected, especially for ground slopes greater than 20°. By increasing β°, the maximum values of plastic length and plastic depth on the left and right sides of the footing decrease and increase, respectively. The maximum depth of the plastic region for β ≥ 20° from around the right side of the footing shifts toward the downward-sloping face. The maximum width of the elastic wedge gradually reduces, and the intersection point of the left and right plastic regions slowly shifts to the left and upside of the footing. [ABSTRACT FROM AUTHOR]

The strength anisotropy and strain softening of natural soil can significantly impact the bearing capacity of shallow foundations on clay. In this article, we present a nonlocal numerical method to study the coupled rotation of the maximum normal stress axis and strain softening on the bearing capacity of shallow foundations on clay through a Cosserat strain softening constitutive model. The strength anisotropy and strain softening characteristics were numerically implemented into a finite-element (FE) program by dynamically updating the anisotropic cohesion in global Newton–Raphson iterations. Due to its nonlocal feature, the proposed nonlocal numerical method can overcome the mesh dependence in simulating the progressive failure of clay through the classical FE method. We first validated the efficacy of this method against the results of the plane strain test and numerical results in the literature. We then study the bearing capacity of a strip footing over anisotropic and strain-softening clay through the implemented numerical method. The results indicated that the deposition angle has an important effect on the bearing capacity and failure mode. The effects of the degree of anisotropy and strain softening on the ultimate bearing capacity are quantified through the numerical method. It is found that (1) the proposed method can effectively reflect the characteristics of the maximum normal stress axis rotation on the failure surface of the footing; (2) the ultimate bearing capacity of a footing (Pu) on anisotropic clay could increase linearly with an increase in the anisotropy ratio k (i.e., k is the ratio between C1 and C2) and decreases with an increase in the softening modulus; and (3) the strength anisotropy and strain softening are strongly coupling factors impacting the bearing capacity of anisotropic clay. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Current research has shown a nonlinear trend in the failure of soil, and the single tangent method is commonly adopted when coping with nonlinear problems of soil failure. However, the method equates a nonlinear criterion to an optimizable linear criterion, which may differ from the actual situation, resulting in conservative results. In this paper, two types of piece-wise log-spiral failure mechanisms for bearing capacity estimations, including symmetrical and unilateral mechanisms were proposed with the nonlinear Mohr-Coulomb criterion. The static bearing capacity of foundations was evaluated using the symmetric failure mechanism, while the seismic bearing capacity of foundations was evaluated adopting a modified pseudo-dynamic method based on the unilateral failure mechanism. The result shows that the bearing capacity calculated in the paper is smaller compared to the result using the linear Mohr-Coulomb criterion. For London clay, the static bearing capacity is reduced by about 45% at a foundation width equal to 1m. From the comparisons, it is found that the proposed approach of piece-wise log-spiral failure mechanism for bearing capacity estimation is effective. In addition, parametric studies show that the nonlinear parameters, the initial factor of seismic acceleration, the normalized frequency, and the damping ratio all have obvious effects on the seismic bearing capacity. A significant reduction in the seismic bearing capacity of the foundation occurs when the normalized frequency ωsH/Vs is equal to (0.5 + n)π (n = 0, 1, 2, ...). Considering that the approach proposed provides a strict upper bound to the bearing capacity, the result imparts confidence in the approach of analysis presented. [ABSTRACT FROM AUTHOR]

It is reported in the literature that the load-carrying capacity of the reinforced sand bed increases with increasing the footing settlement. However, the nature of settlement plays a critical role in shallow foundation designs due to the conditional allowable settlement of the footings. In this present study, laboratory model tests have been performed on a model jute geotextile reinforced sand bed under 1g condition. The associated scaling laws are adopted for the geometrical parameters of the model footing and reinforcements as proposed in the literature. On the other hand, a new approach has been developed for the model reinforcements for scaling down of geosynthetic materials under 1g condition to simulate the condition of geosynthetic reinforcement layers as in the field or Ng conditions. The test results revealed that based on the scaling factors the model footing can be allowed to settle according to the criteria of footing settlement and allowable reinforcement tensile strains. Finally, the suitable guidelines have also been developed as per the safety considerations in order to understand the effect of reinforcement layers on the improvement of soil bearing capacity ratio (BCR) up to a certain settlement ratio (s/D) of the footing. [ABSTRACT FROM AUTHOR]

Shallow foundations are usually built above the groundwater table. In such cases, this soil is considered dry in analysis and design, while it is actually an unsaturated soil. This unsaturated soil can lead to many geotechnical issues, such as swelling when wet and collapsing when dry. It can also change the soil's shear strength, which in turn affects the bearing capacity of the soil. The classical principles of saturated soil are often not suitable for explaining these phenomena. Limited studies dealt with a large scale model close to the field conditions for such soil and therefore, there is much more room for improvement. The study reveals that compacting the expansive soil on the wet side of optimum is capable of reducing swelling pressure and the expansion index for both the bentonite–sand mixture and kaolin soil. The bearing capacity of a footing resting on both swelling and non-swelling soils decreases noticeably with the increase in the soil degree of saturation due to the effect of matric suction which increases the soil stiffness. The results show that the measured bearing capacity is (1.1–3.3) higher than that estimated by Terzaghi equations. [ABSTRACT FROM AUTHOR]

The foundation is the lower part of a structure used as a load distributor for the loads generated by the upper structure, which are then transmitted into the hard soil layers. The selection of foundation types in building construction must consider the type and characteristics of the soil at the construction site to avoid construction failures. This analysis is conducted to determine the bearing capacity of pile foundations using analytical and finite element methods. The type of foundation used in this analysis is a pile foundation with a pile length of 8 meters and a pile diameter of 0.4 meters. For the analytical calculation, Standard Penetration Test (SPT) data obtained from PT. Adhi Karya (Persero) for the Infrastructure Green House Biodiversity LIPI Cibinong-Bogor project are used, employing the analytical method (Alpha Method) and the finite element method with the assistance of Plaxis 2D V.8 software. The results of the analysis show that the bearing capacity of the group pile foundation (Qg) for a pile diameter of 0.4 meters and a pile length of 8 meters on clayey soil, based on SPT data using the analytical method (Alpha Method), is 60.432 tons. Meanwhile, the bearing capacity of the horizontal pile foundation using the Broms method is 6.03 tons. The bearing capacity obtained using the Finite Element Method yields an ultimate load on the group pile (Qq) of 57.89 tons. The bearing capacity of the group pile foundation (Qg) from both sets of data, with a difference of 2.5%, meets the requirement, being greater than the axial load (P) of 42.6 tons that must be supported. [ABSTRACT FROM AUTHOR]

The section K0 +785 -K0 +988 on the north shore of the Dalian Bay immersed tunnel, which is higher than the original seabed surface, is susceptible to ship collision risks and requires anti-collision measures. Taking into account factors such as construction difficulty, environmental protection, and cost, a permeable gravity pier foundation composed of circular caissons, column piles, and cast-in-place piers was proposed as the anti-collision structure, while meeting the requirements of the construction period. Combined with the structural form and main loads of the anti-collision pier, the overall stability of the anti-collision pier structure and the bearing capacity of the column piles were analyzed and calculated using finite element method and specification method. The results show that the permeable gravity pier anti-collision structure can meet the requirements of engineering use in all aspects, and can provide design reference for the construction of similar structures in the future. [ABSTRACT FROM AUTHOR]

The state of meadow vegetation in areas with different ages of experimental spring burnout (from 1 to 12 years ago) was studied in the Tomsk region for 3 years. On experimental plots of 1 m2 and 100 m2 (small- and middle-scale levels, respectively), the dynamics of species richness, total projective cover of vegetation, and aboveground phytomass reserves were characterized, and the structure of communities was analyzed. It was revealed that a single fire in the spring significantly reduces species richness for small-scale plots and increases the total projective cover for middle-scale plots. Structural differences from control plots can be traced from 1 to 4 years for different characteristics. The effects of fire are more prominent for small-scale plots. To suppress tree growth and maintain the existence of meadows, grass fires seem to be a less effective practice than mowing. At the same time, the results obtained potentially allow us to consider prescribed burning as a tool for maintaining the stability of meadow plant communities in the south of Western Siberia, preventing them from becoming overgrown with tree undergrowth, in cases with a controlled frequency of burning and the use of appropriate fire safety measures. [ABSTRACT FROM AUTHOR]

To investigate the flexural performance of Steel-FRP Composite Bars (SFCBs) reinforced Ultra-High Performance Concrete (UHPC) beams, eight concrete beams with different reinforcement ratio, types of concrete were designed and fabricated. Flexural performance tests were conducted to examine the effect of various parameters on bearing capacity, deflections, crack patterns, ductility, and failure modes. The results indicate a significant enhancement in the flexural capacity of tested beams with UHPC. The bearing capacity of SFCB–UHPC beam is higher than that of steel-reinforced UHPC beams, but less than that of FRP (Fiber-Reinforced Polymer) reinforced UHPC beams. The deformation and crack resistance ability of SFCB–UHPC beams fall between those of steel-reinforced UHPC beam and BFRP-reinforced UHPC beam. Increasing the concrete strength and SFCB reinforcement ratio can significantly enhance the deformation and crack resistance ability of SFCB–UHPC beam. All tested specimens exhibited ductile failure. At the serviceability limit state controlled by deflection/crack, the steel-reinforced UHPC beams and BFRP-reinforced UHPC beams exhibit the highest and lowest utilization factors of flexural capacity, respectively, and that of SFCB–UHPC beams falling in between. High-ductility UHPC enhances energy absorption, ductility, initial and secant stiffness. The reinforcement type has a minor impact on the energy dissipation of flexural beams. SFCB, on the other hand, enhances the ductility, initial and secant stiffness of specimens. Based on a simplified material constitutive model and fundamental assumptions, three failure modes for the SFCB–UHPC beam under bending were defined, along with their respective criteria. This enables the establishment of a simplified load capacity calculation formula. With reference to ACI440.1R-03, a stiffness calculation formula was developed to predict the deformation of SFCB–UHPC beams. This research can provide a technological reference for the design and analysis of SFCB-reinforced UHPC beams. [ABSTRACT FROM AUTHOR]

Stronger granular layers are often placed as working platforms over weaker sand subgrade. The design of a working platform involves the calculation of a two-layer bearing capacity under rectangular loading. Existing design methods are either overly simplified, based on infinitely long strip loads and validated by a small number of small-scale 1g model tests, or rely on numerous or empirically derived charts that are difficult to use or implement into design software. In this paper a new and highly practical design method is proposed in which the bearing capacity is determined simply from the shear strengths and unit weights of the two soil layers. The method was derived from extensive finite-element analysis and finite-element limit analysis (FELA) parametric studies in both plane strain and axisymmetric geometries. It was validated against published physical model tests, other FELA analyses and existing design methods. It can be applied to all rectangular shape ratios with dry and saturated layers. [ABSTRACT FROM AUTHOR]

In order to study the effect of high temperatures on the thermomechanical properties of reinforced concrete (RC) beams, fire and mechanical tests were carried out on four fully dimensioned simply supported beams. A numerical analysis model based on the measured information was developed, and validated through experimental tests and theoretical calculations. The effects of fire exposure time, different physical parameters and concrete spalling parameters on the thermodynamic properties were further analysed. The results show that the measured vibration frequencies exhibit a fluctuating trend of decay with increasing fire exposure time. The simulated frequency decays as a power function of fire exposure time. The frequency decreases with increasing span-to-height ratio and increases with section width, elasticity modulus of the concrete and reinforcement ratio. Cross-sectional temperature field is most significantly affected by spalling depth, and increases rapidly with an increase in this parameter. With the increase in spalling area ratio, the increase in the temperature field gradually becomes smaller. The effect of spalling area ratio was relatively stable after more than 15%. Flexural bearing capacity shows a linear trend of decrease with increase in spalling depth. With the increase in spalling area ratio, it shows a power function of the decreasing trend. [ABSTRACT FROM AUTHOR]

An experimental and numerical study of hollow reinforced concrete-filled glass-fibre-reinforced polymer tubular beams was carried out. Based on bending tests, the working mechanism and failure modes were studied. A finite-element model was established and the validity was assessed by comparing the experimental and numerical results. The main parameters included the wall thickness of the fibreglass tube, reinforcement ratio, hollow ratio, concrete strength and fibre winding angle. The results indicated that the composite beams failed gradually with considerable ductility. The bending capacity increased by about 12% with every 1 mm increment of the fibreglass tube thickness, increased by about 40% as the reinforcement ratio increased from 2.28% to 4.56%, and increased by about 6% with every 5 MPa increment of the concrete strength. The bending capacity decreased and then increased as the fibre winding angles ranged from 10° to 90°, and a small fibre winding angle was preferable for the flexural member. A hollow ratio of 0.375 is proved to be applicable to obtain lighter member self-weight with minimal decrease in strength. [ABSTRACT FROM AUTHOR]

This paper presents the results of field tests performed to investigate the bearing capacity of Drilling with a prestressed concrete (DPC) pipe pile under different end sealing and side grouting conditions. The High Strain Dynamic Testing (HSDT) was conducted to evaluate the bearing characteristics of full-scale DPC pipe piles. Moreover, base resistance theoretical formula considering end sealing effect and shaft resistance theoretical formula considering side grouting effect are presented. The theoretical results were compared with the recommended values of specification for traditional pipe piles and tested values to demonstrate the rationality of theoretical formulas and the superiority of end sealing and side grouting. Furthermore, the effects of sediment under the sealing concrete and grouting conditions on the bearing capacity of a single pile were discussed in detail to reveal the influencing mechanisms of end sealing and side grouting. The result showed that the presented base resistance theoretical formulas can estimate the effect of end sealing on the ultimate base resistance of DPC pipe piles with good accuracy. For 1 m pipe piles, end sealing increases the base resistance by up to 103.5% at most compared to unsealing pipe piles; total shaft resistance of piles with double or multi-pipe grouting is more than 37% higher than the recommended maximum value of traditional pipe piles in the pile foundation specification. In addition, the base resistance was significantly affected by the sediment thickness under the sealing concrete. The hole wall time-dependent deformation caused by drilling and unloading affected the side grouting significantly. [ABSTRACT FROM AUTHOR]

A new type of UHPC‐NC (normal concrete) structure in the negative moment zone was proposed to improve the bearing capacity of the connection structure in the negative moment zone of prefabricated prestressed concrete (PC) beam bridges. First, the distribution characteristics of the crack, cracking load, ultimate moment, and ductility coefficient of the new structure were obtained by the 1:4 scale model tests. The feasibility of the connection structure is verified. Then, the value ranges of critical structural parameters affecting the bearing capacity of the connection structure based on the plane section assumption analysis, including the reasonable thickness of the UHPC layer, the reinforcement ratio of the longitudinal tensile reinforcement, and the diameter of the reinforcement, are obtained. At the same time, based on the verification of the finite element model, the influence of crucial research parameters on the bending capacity of the connection structure is obtained by using the finite element method. Finally, a theoretical method for the bending moment capacity of the connection structure of the UHPC‐NC structure is proposed, considering the high ductility characteristics of UHPC materials. The average relative error between the calculation results and the finite element method is within 7.2%, which verifies the reliability of the calculation method in this paper and provides a reference for its design and engineering application. [ABSTRACT FROM AUTHOR]

The finite element limit analysis solution presented in this paper offers novel approaches for estimating the ultimate bearing capacity of annular foundations on Hoek–Brown criterion. The study examines the effects of five of dimensionless parameters, including the ratio of internal to external radii, the depth ratio, the adhesive factor, the yield parameter, and the geological strength index, on the findings of bearing capacity as well as the processes of collapse. Furthermore, one of the soft-computing regression methodologies, the multi-objective evolutionary polynomial regression analysis (MOGA-EPR) method, is utilized along with the requirement of the FELA outcomes as input data. This paper provides accurate limit-state predictions for annular footings on diverse rock masses using the MOGA-EPR model. By using the MOGA-EPR approach, the findings are highly precise and trustworthy, empowering designers to choose the best annular foundation design for various Hoek–Brown material varieties. Moreover, this study extends its scope by encompassing the application of multiple linear regression, multiple nonlinear regression, and artificial neural network models for an extensive comparative analysis. The amalgamation of these models widens the evaluative framework, fostering a more comprehensive exploration of predictive capabilities and insights into the stability assessment of annular footings across rock mass conditions. Through this multifaceted approach, a holistic comprehension emerges, thereby enhancing the decision-making process pertaining to the design of annular foundations within diverse Hoek–Brown material contexts. [ABSTRACT FROM AUTHOR]

The reuse of scrap tires to save storage space and lower traditional disposal risks is an environmental challenge. Currently, recycled tires are considered low-cost, lightweight materials that can be used to improve soil, retaining walls, backfills and roadbeds. The present study investigated the effect of the tire-shred aspect ratio and weight percentage on the bearing capacity and displacement of a stabilized mechanical retaining wall with multi-plate anchors under static loading. To this end, sandy soil containing tire shreds with widths of 1 and 2 cm, aspect ratios of 1, 2, 3, 4 and 5 at 5%, 10%, 15% and 20% contents (weight percentage of soil) was examined. Direct shear tests were conducted to determine the shear strength parameters of the mixtures. It was found that an increase in the tire-shred content in the mixture at a fixed aspect ratio, the bearing capacity of the mixture increased. Also at a fixed aspect ratio, the horizontal wall displacement increased with an increase in the tire-shred content. The wall bearing capacity was determined to increase at a fixed tire-shred content with an increase in the aspect ratio of the tire shreds. The results of the particle image velocimetry showed that an increase in the tire-shred aspect ratio increased the strain on the particle slip surface. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the influence of the anisotropic variability in soil on the failure mechanism and the ultimate bearing capacity of foundations that are placed near slopes. A random adaptive finite-element limit analysis (RAFELA) with anisotropic random field modeling and the Monte Carlo simulation technique are combined. The stochastic ultimate bearing capacity for various undrained shear strengths, slope angles, normalized slope heights, distances from the slope crest, and horizontal and vertical correlation distances are analyzed. The quantitative identification and characterization of failure mechanisms, which are determined by the failure slip and passive wedge contribution, are achieved through the digital image processing of realizations from anisotropic random soil. This study showcases the diverse failure mechanisms and sliding surface sizes that arise from distinct soil patterns, which are influenced by alterations in slope geometry and soil anisotropic spatial variability. The quantitative findings highlight that alterations in failure mechanisms and slip surface sizes lead to heightened failure probabilities and significant variations in bearing capacity. [ABSTRACT FROM AUTHOR]

Large stone porous asphalt mixes (LSPMs) have the characteristics of large gaps, large content of coarse aggregate, and large particle size of coarse aggregate. Compared with the traditional asphalt-treated base (ATB), LSPM forms a more obvious skeleton structure in the process of bearing load. In this study, the discrete element method (DEM) model of LSPM is established, and an evaluation method for studying the bearing capacity and high-temperature performance of LSPM through an internal skeleton network is proposed. Firstly, the DEM model of asphalt mixture with different gradations is established, and the virtual uniaxial penetration test is carried out. Then, the performance of the skeleton network inside the asphalt mixture is analyzed, and the contribution of each group of aggregates to the skeleton network is further studied. The experimental results show that the bearing capacity of an asphalt mixture is closely related to the performance of internal skeleton network. The skeleton network inside the asphalt mixture is extracted by the value of the contact force, the angle between the contacts, and the contact continuity. When the skeleton network has better bearing capacity and load-transfer capacity, the asphalt mixture can bear more external load in the virtual penetration test. The contribution of different coarse aggregates to the skeleton network is analyzed from four perspectives: total contact force, vertical work, contact number, and effective coordination number. The aggregates of 19–26.5 and 4.75–9.5 mm constitute the main body of the load-transfer path and play a major role in bearing and transmitting the load in the skeleton network. [ABSTRACT FROM AUTHOR]

In the Chengdu-Chongqing economic circle in China, the recommended bearing capacity of a medium-weathering mudstone foundation is less than the capacity of the rock structure to withstand loads. The aim of this paper was to perform plate loading tests (PLTs) with binocular vision measurement (BVM) to obtain the accurate deformation of the foundation under vertical loading. The results revealed that vertical load–bearing foundations have a failure mode that can be reduced to that of thrust failures for thin bedded structures of mudstone foundations. By analyzing the differences in results between the PLTs and the uniaxial compressive strength tests under the same conditions, a new formalism for calculating foundation-bearing capacity was proposed; there is only a 5% difference compared to in situ tests. The results of this research provide theoretical support and a practical benchmark for the full development of the load-bearing capability of soft red rocks. As the Chengdu-Chongqing economic circle progresses toward the international urban cluster, inevitably, soft rock is used as a foundation retaining layer in the construction of superhigh and super-rise buildings in the region. However, owing to antiquated testing methods and poor intelligibility of the testing equipment, the bearing capacity of such a mass of rock has yet to be fully developed and cannot meet the dual-carbon economic goals and sustainable development of architectural design. Based on this, the study introduces a noncontact method to measure the bearing capacity of soft rock within the traditional method of in situ testing and combines the concept of big data analysis to advance an empirical method for calculating the bearing capacity accurately. Based on the results of this study, the concept of natural foundations can be adopted and the engineering dilemma that the treatment of building foundations cannot be economical and practical can be solved. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive examination of the effects of quicklime (QL) addition on the stabilization of two distinct clayey soils with high (CH) and low plasticity (CL-tuff). The results showed that incorporating QL into the soils substantially improves their stabilization characteristics. Specifically, the addition of QL results in a notable decrease in the final water content of both soils, as shown by a reduction from 23.04 to 19.06% in CH and from 18.07 to 17.1% in CL-tuff at 4% QL addition. Furthermore, this study reveals a transformation in the plasticity properties of soils. Liquid Limit (LL) and Plasticity Index (PI) were reduced, with CH-tuff exhibiting a significant decrease in PI from 48 to 12 and an increase in Plastic Limit (PL) from 21.8 to 55 at 4% QL. CL-tuff also showed reduced plasticity, with PI decreasing to 8.33 at 4% QL. Additionally, the Immediate Bearing Index (IBI) was improved for both soil samples, indicating improved load-bearing capacities. For CH samples, IBI improved from 6.37 to 11.99 at 4% QL addition, while for CL-tuff, it increased dramatically from 4.5 to 23.6 for the same QL percentage. The findings underscore the effectiveness of QL in improving soil properties crucial for chemical stabilization, providing evidence that QL addition can be a key technique in soil stabilization, especially for soils with high plasticity or those requiring increased bearing strength. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper analyzes the bearing capacity of two-layered soil medium using finite element (FE) software ABAQUS/CAE 2023. Although geotechnical engineers design foundations for layered soil, majorly current geotechnical studies emphasize single homogenous soil. So, this research has significant novelty as it focuses on layered soil and adds to the current literature. A nonlinear FE model was prepared and analyzed to determine the ultimate bearing capacity of two-layered soil (sandy soil over clayey soil). The Drucker–Prager and Mohr–Coulomb models were used to represent sandy soil and clayey soil layers, respectively. Strip footing material properties were considered isotropic and linearly elastic. This study performed parametric studies to understand the effects of thickness, unit weight, and the modulus of the elasticity of sandy soil on the ultimate soil bearing capacity. Additionally, it also analyzed the effect of the cohesive strength of clayey soil on layered soil bearing capacity. Results showed that an increase in sandy soil layer thickness strengthens the layered soil, and thus, improves the bearing capacity of soil. Increasing the sandy soil layer thickness over footing width (h1/B) ratio from 0.15 to 2.0 improved the ultimate bearing capacities with elastic settlements of 350 mm and 250 mm by 145.62% and 101.66%, respectively. Additionally, for a thicker sandy soil layer, an increase in the unit weight and modulus of the elasticity of sandy soil led to higher ultimate bearing capacity. Furthermore, it was concluded that an increase in clayey soil's cohesive strength from 20 kPa to 30 kPa resulted in a 24.31% and 3.47% increase in soil bearing capacity for h1/B = 0.15 and h1/B = 2.0, respectively. So, the effect of cohesion is prevalent in the case of a thicker clayey soil layer. [ABSTRACT FROM AUTHOR]

A grouting pad is the key structure for the construction of water inrush grouting on the shaft working surface. Previous methods of calculating the bearing capacity have limitations due to a lack of understanding of the failure mode. To investigate the bearing capacity of a concrete grouting pad on the working surface of a shaft, this paper establishes a mechanical model for the punching shear failure of a grouting pad under symmetrical loading conditions. A unified solution for the bearing capacity is derived, and the influence of parameters is discussed. In addition, a new method for designing the plastic limit thickness is proposed based on this research. The results show that the reason for the grouting pads' punching shear failure resulted from the formation of peripheral grouting holes "weak ring" caused by the reduction of the bearing capacity. When the thickness of B0 remains constant, the bearing capacity qu of the grouting pad is inversely proportional to the ratio of the diameter and the area of the bottom load. Therefore, following the method of "dividing, interval, and jumping holes" during grouting construction is recommended. The greater the thickness of the grouting pad, the greater the bearing capacity qu will be. When the grouting pad diameter is 2r2 and the thickness B0 is constant, the bearing capacity qu increases with the material tensile strength ft. When designing grouting pads, following the principles of "large thickness, uniform strength theory, high strength materials" will improve bearing performance. The findings have been implemented in the design of the grouting pad thickness for the Tianshan Shengli Tunnel shaft project, which can successfully solve the problem of frequent cracking caused by the weak bearing capacity of a grouting pad. The findings can provide a theoretical basis and reference for the design and construction of grouting pads in a highway tunnel shaft. [ABSTRACT FROM AUTHOR]

The need for practical and economical solutions to increase the stability of embankments and reduce their settlement is a significant issues in geotechnical engineering. An effective approach to improve the overall performance of embankment systems is using structural elements such as piles. In recent years the use of helical piles has gained consideration due to their proper performance under compressive and tensile loads, quick and easy installation, and elimination of concreting problems. This study investigates the performance of embankments supported by helical piles through a 3D numerical study using the Abaqus software. The validation was performed according to the experimental and field data provided by other researchers. Then, 3D numerical models were developed to investigate the effects of pile caps, the ratio of helix diameter to shaft diameter, the number of helices, and the optimum spacing of helices. The finite element modeling results indicated that increasing the number of helices and changing their spacing had no significant impact on controlling the settlement. It was also found that the load transfer mechanism parameters had a direct relationship with the helix dimensions and shaft diameter. Adding helices to piles increased their bearing capacity, improving parameters of the load transfer mechanism, such that the arching in a pile with three helices decreased by 40% compared to the one with one helix. The results also revealed that on average, 80% of the load imposed on a pile was sustained by the shaft, and helices had a smaller effect on the settlement of pile-supported embankments. [ABSTRACT FROM AUTHOR]