Soils and Foundations最新文献

{"title":"Optimizing compaction of low-grade embankment soils with non-plastic fines under cyclic traffic loading and seasonal moisture variations","authors":"Bhargavi Chowdepalli ,&nbsp;Kenji Watanabe ,&nbsp;Hiroyuki Kyokawa","doi":"10.1016/j.sandf.2026.101729","DOIUrl":"10.1016/j.sandf.2026.101729","url":null,"abstract":"<div><div>In many developing countries in Asia, the scarcity of high-quality natural sands poses a major challenge to the cost-effective construction of road and railway embankments. As a result, there is an increasing need to utilize locally available sandy soils with higher fines contents. These embankments are typically compacted under unsaturated conditions and subsequently subjected to vehicle-induced cyclic loading and saturation fluctuations over time due to seasonal rainfall. However, the long-term performance of such materials under these combined effects remains insufficiently understood.</div><div>The cyclic and post-cyclic behavior of compacted sandy soils with varying fines contents was investigated in this study to better understand the soils’ mechanical response and suitability for embankment applications, specifically when subjected to seasonal rainfall and long-term cyclic loading. A comprehensive testing program was conducted, including suction-controlled drained cyclic triaxial tests followed by post-cyclic monotonic loading under both unsaturated and soaked conditions. The results showed that, under unsaturated conditions, increasing compaction significantly reduces the accumulated axial strain while enhancing post-cyclic strength and stiffness. Lower saturation levels lead to higher initial suction, which improves stiffness and post-cyclic strength, especially in soils with higher fines. While soils with higher fines contents display increased post-cyclic strength due to improved suction and interparticle friction, they also experience greater axial strain during cyclic loading, particularly when compacted at low saturation levels due to reduced skeletal stability.</div><div>Soaking leads to a notable reduction in post-cyclic strength, especially in soils initially compacted at low saturation levels with high fines contents, despite having higher initial stiffness and suction. This highlights the critical role of suction and fabric stability in maintaining a long-term soil performance. These findings provide practical guidance for optimizing compaction and moisture control in the field, and for supporting the sustainable use of locally available fine-grained soils for embankment construction under cyclic loading and environmental changes.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 3","pages":"Article 101729"},"PeriodicalIF":3.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of water immersion on the mechanical properties and hydrochemical characteristics of cemented calcareous soil","authors":"Peng Feng ,&nbsp;Juntao Li ,&nbsp;Pan Cao ,&nbsp;Jin Ren ,&nbsp;Yuanfeng Dong ,&nbsp;Guanzhong Wu ,&nbsp;Ran Tang ,&nbsp;Xuanmei Fan","doi":"10.1016/j.sandf.2026.101759","DOIUrl":"10.1016/j.sandf.2026.101759","url":null,"abstract":"<div><div>The mechanical response of cemented calcareous soils to water immersion is critically influenced by the complex architecture of their particulate framework and cementing materials. Understanding the mechanical and hydrochemical properties of these soils under saturated conditions is crucial for assessing the stability of geoengineering structures. The research detailed in this manuscript evaluates the influences of water immersion on the mechanical and hydrochemical characteristics of cemented calcareous soil collected near the Jinsha River. Additionally, the study discusses the implications of these soil properties for geological phenomena located in proximity to the sampling area. The results showed that prolonged immersion precipitates substantial alterations in the hydraulic conductivity of cemented calcareous soil, accompanied by extensive ion dissolution that modifies its hydrochemical properties. The soaking solution exhibits alkalinity with high concentrations of Ca²⁺ and HCO₃⁻. Initial short-term immersion augments the strength of cemented calcareous soil, while a progressive decline in strength occurs as the immersion period extends, with the natural state displaying markedly greater strength relative to the dried state. Long-term immersion facilitates the moisture infiltration into the interstitial spaces between particles, dissolving the cementing material and undermining the interparticle bonds, which critically impairs the mechanical properties and stability of the soil. Furthermore, localized seepage facilitates the migration and precipitation of soluble salts in moisture-prone environments, exacerbating the weathering and degradation processes. Such long-term immersion results in structural transformations within the soil, undermining the cementation structure and potentially precipitating soil collapse.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 3","pages":"Article 101759"},"PeriodicalIF":3.3,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on creep mechanical properties and damage mechanisms of water-saturated coal-bearing sandstone under freeze-thaw cycles","authors":"Peng Wu ,&nbsp;Lianying Zhang ,&nbsp;Shuai Guo ,&nbsp;Yiwen Mao ,&nbsp;Fuqiang Zhu","doi":"10.1016/j.sandf.2026.101743","DOIUrl":"10.1016/j.sandf.2026.101743","url":null,"abstract":"<div><div>To reveal the long-term instability mechanism of rock slopes in open-pit coal mines in cold regions, this study takes water-saturated coal-bearing sandstone from the Antaibao Open-pit Coal Mine as the research object. Systematic uniaxial compression creep tests were conducted under different freezing temperatures (−5°C, −10°C, −15°C, −20°C) and freeze–thaw cycles (5, 10, 15, 20 times). Combined with longitudinal wave velocity measurements, porosity tests, and scanning electron microscopy (SEM) <em>meso</em>-analysis, the coupled damage evolution law under freeze–thaw-creep conditions was elucidated. The results show that: With decreasing freezing temperature and increasing freeze–thaw cycles, the reduction rate of longitudinal wave velocity and the increment of porosity significantly increase (e.g., wave velocity reduction rate reached 29.58% at −20°C/20 cycles). The number of freeze–thaw cycles exhibits higher sensitivity to damage than freezing temperature. The creep failure stress significantly attenuates (decreased by 21.8% at −20°C compared to −5°C, and by 53.0% after 20 cycles compared to 5 cycles). The ratio of long-term strength to peak strength remained stable at approximately 80%. Microscopically, a sequential damage mechanism is identified, initiating with ice-expansion cracking, progressing to thermal fatigue accumulation, followed by pore networking, and culminating in particle spalling. This process leads to a transition in the macroscopic failure mode from pure shear to a tensile-shear composite. This study provides a theoretical basis for stability assessment and prevention of coal mine slopes in cold regions.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101743"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-model feature-importance analysis of soil properties for predicting optimum moisture content and maximum dry unit weight of fine-grained soils","authors":"Harish Paneru,&nbsp;Netra Prakash Bhandary","doi":"10.1016/j.sandf.2025.101728","DOIUrl":"10.1016/j.sandf.2025.101728","url":null,"abstract":"<div><div>This study evaluates the influence of routine soil index properties on the prediction of optimum moisture content (w_opt) and maximum dry unit weight (γ_dmax), which are the primary outcomes of the Proctor compaction test, using machine learning (ML) methods. A curated database of fine-grained soils (n = 465, drawn from 15 sources) included gravel content (GC), sand content (SC), fines content (FC), liquid limit (LL), plastic limit (PL), plasticity index (PI), specific gravity (Gs), w_opt, and γ_dmax. After correlation-based feature filtering, three models were developed: Generalized Additive Model (GAM), Random Forest (RF), and Extreme Gradient Boosting (XGBoost). The training used nested cross-validation with Bayesian optimization, corresponding to an overall 80–20 train-test split. The model performance was evaluated using R², RMSE, MAE, MAPE, r, and the overfitting ratio calculated for the test set. For w_opt, the best GAM model achieved R² = 0.84 and RMSE = 2.16%, outperforming RF and XGBoost. For γ_dmax, the best GAM and XGBoost models reached R² = 0.79 and RMSE = 0.76 kN/m³, respectively. SHapley Additive exPlanations (SHAP), model-based importance scores, and single ablation analyses consistently identified LL and PL as the most influential predictors, and FC provided secondary contributions, while GC and Gs added little once LL and PL had been included. Moreover, paired-feature ablation confirmed the joint influence of LL and PL on the prediction. Overall, all three models predicted compaction parameters with good accuracy; however, GAM models achieved comparable or better predictive metric values than the ensembles (RF and XGBoost) while offering interpretability through plots linking soil indices with the predicted outcomes. This balance of accuracy and interpretability supports GAM as the preferred model for prediction modeling.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101728"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of supporting soil during construction of 330-m supertall building on spread foundation in Tokyo","authors":"Youhao Zhou ,&nbsp;Takatoshi Kiriyama ,&nbsp;Yoshiharu Asaka","doi":"10.1016/j.sandf.2026.101746","DOIUrl":"10.1016/j.sandf.2026.101746","url":null,"abstract":"<div><div>The Mori JP Tower is a newly constructed 330-m supertall building located in Tokyo, Japan. As the tallest building in Japan, as of 2025, it is directly supported by the Kazusa Group, which is a Pleistocene stratum with a shear wave velocity of more than 400 m/s via a spread foundation. The building was constructed using a combination of the bottom-up and top-down methods. Owing to the unprecedented scale of buildings in Japan and the complexity of the construction process, the supporting soil may exhibit complex behaviors that are difficult to predict accurately. Therefore, it is crucial to monitor the movement of the supporting soil to ensure construction quality. This paper reports on the monitoring methods, vertical displacement, and changes in stiffness of the supporting soil during the construction process. The following results were obtained: (1) The supporting soil at the center of the tower showed a rebound of 35 mm by the end of the excavation and then settled 42 mm by the end of the construction. (2) The vertical displacement of the supporting soil was affected by changes in the groundwater level. (3) The shear wave velocity of the supporting soil showed a confining-pressure dependency, particularly in the sandy sand–clay mixture strata. (4) The rebound and settlement during the construction, as well as the confining-pressure dependency of the soil, were generally in line with previous reports.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101746"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic response of end-bearing piles in nonhomogeneous unsaturated soils subjected to seismic P-waves","authors":"Wenjie Ma ,&nbsp;Koichi Isobe ,&nbsp;Eng-Choon Leong ,&nbsp;Bolin Wang ,&nbsp;Xu Wang ,&nbsp;Changdan Wang","doi":"10.1016/j.sandf.2026.101752","DOIUrl":"10.1016/j.sandf.2026.101752","url":null,"abstract":"<div><div>This study proposes an analytical model to investigate the kinematic response of end-bearing piles in nonhomogeneous unsaturated soils subjected to vertically propagating seismic P-waves. The soil profile exhibits continuous heterogeneity characterized by power-law variations in Lamé constants, density, porosity, and bulk modulus of three-phase along the pile shaft, while the pile is modeled as a standard beam with fixed-base boundary conditions. Governing equations for the coupled soil-pile system are derived employing the three-phase poroelastic theory within a continuum mechanics framework. The mathematical formulation utilizes Laplace transforms combined with operator decomposition techniques to decouple wave propagation equations, with potential functions employed to address compressional wave interactions. Frequency-domain solutions are obtained through rigorous enforcement of displacement-stress continuity conditions at the pile-soil interface and predefined boundary constraints under P-wave excitation. Validation through degenerate case comparisons demonstrates consistency with classical solutions for homogeneous saturated and single phase soils profiles. Parametric analyses systematically explore how gradient variation patterns, soil saturation, air-entry value, pile slenderness ratios, and pile-soil modulus ratios on seismic response characteristics.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101752"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the vertical bearing characteristics and influencing factors of threaded piles","authors":"Lina Xu ,&nbsp;Peng Zhang ,&nbsp;Chenhui Qi ,&nbsp;Lei Niu ,&nbsp;Junjie Zheng","doi":"10.1016/j.sandf.2026.101731","DOIUrl":"10.1016/j.sandf.2026.101731","url":null,"abstract":"<div><div>This study investigated the mechanism by which thread height affects the load-bearing performance of threaded piles, as this is a critical factor influencing their vertical bearing capacity. Laboratory half-pile model tests combined with Digital Image Correlation (DIC) were used for this investigation. Concurrently, numerical simulation analysis was used to systematically examine the influence of thread height, thread pitch, thread shape and thread thickness on the load-bearing capacity of threaded piles. The findings suggest that the threaded parameters primarily influences the bearing capacity of individual threaded piles by increasing the contact area between the pile and the soil and enhancing the mechanical interlocking effects, compared to straight piles. As thread height increases, the pile’s bearing capacity increases, though at a gradually diminishing rate. Concurrently, the pile body’s material utilisation rate reaches a peak, with optimal performance observed when the thread height is between 8 and 10 mm. When the pitch ratio (i.e. the ratio of thread pitch to main pile diameter) is 1.0, the threaded pile demonstrates superior bearing capacity. In terms of thread geometry, trapezoidal threads correspond to the highest ultimate bearing capacity. Furthermore, under identical settlement values for threaded piles, trapezoidal threads maximise material utilisation efficiency. Additionally, thread thickness has a relatively minor influence on pile bearing performance.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101731"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced diesel removal from contaminated soil: A coupled approach of negative-pressure extraction and subzero-temperature-induced migration","authors":"Liyu Yi ,&nbsp;Jielong Rao ,&nbsp;Yong Wan ,&nbsp;Yaoqiang Chen ,&nbsp;Zhixiang Chen","doi":"10.1016/j.sandf.2026.101742","DOIUrl":"10.1016/j.sandf.2026.101742","url":null,"abstract":"<div><div>To reduce the energy demand of conventional high-temperature thermal desorption and related technologies for remediating organic-contaminated soils, and to elucidate the evolution of liquid-phase contaminants in soils subjected to coupled temperature–pressure fields, this study develops a remediation process that couples negative-pressure extraction with subzero-temperature-induced migration of diesel in porous media. The method exploits the depression of liquid boiling points under reduced pressure and the acceleration of fluid transport driven by temperature gradients in porous media. Saturated diesel-contaminated soils with different initial dry densities (<em>ρ</em>_d) were treated under low-temperature negative-pressure conditions, and diesel removal tests were conducted. The results show that, for all <em>ρ</em>_d considered, the removal efficiency exhibits a characteristic three-stage temporal evolution. Under subzero temperature and negative pressure, the residual diesel mass fraction in the samples stabilizes at approximately 10–12%, approaching the residual liquid content of the soil and indicating that late-stage removal is controlled by high-boiling fractions and strong sorption. Post-test energy-dispersive X-ray spectroscopy further confirms that the carbon content in the soil decreases from about 35% to 13%, demonstrating a substantial reduction in organic contamination. Overall, the proposed approach achieves stepwise, high-efficiency removal of high-boiling organic pollutants at moderate to low energy input, and provides quantitative criteria for the scale-up design and energy optimization of subzero negative-pressure remediation processes.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101742"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing the shearing strength of compacted Qiantang River silty clay from a state-dependent perspective","authors":"Xiao Wei ,&nbsp;Hongliang Liu ,&nbsp;Lisha Zhang ,&nbsp;Kaiyuan Han ,&nbsp;Xin Liu ,&nbsp;Zhongxuan Yang","doi":"10.1016/j.sandf.2025.101727","DOIUrl":"10.1016/j.sandf.2025.101727","url":null,"abstract":"<div><div>Compacted clay is widely used in geotechnical projects involving road embankment, subgrades, backfillings, etc. The shearing strength of saturated compacted clay is an important parameter in the analysis of the stability of these structures, and it is affected by states of soil, fabric, stress history, etc., making the characterization of the shearing strength remain difficult. This study investigated the shearing behaviors and shearing strength of a saturated and compacted Qiantang River silty clay using undrained triaxial compression tests. The specimens were compacted to different void ratios and saturated, followed by consolidation to different effective confining pressures for triaxial compression. The shearing behaviors are found to be state-dependent, namely, dependent on the void ratio and effective confining pressure before shearing. Several characteristic states, such as the undrained instability state, quasi-steady state, phase transformations state, and critical state, have been identified for each specimen. The deviatoric stresses at these states were characterized in the framework of critical state soil mechanics. The state parameter can be used to characterize the state-dependent shearing strength, while a modified state pressure index was proposed and found to be a better state variable for characterizing the state-dependent shearing strength of the compacted clay.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101727"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145941342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel settlement calculation method and engineering application of strength composite piles","authors":"Heng Liu,&nbsp;Peng Xi,&nbsp;Xihao Yan,&nbsp;Zhengwei Wang,&nbsp;Mingjie Xu,&nbsp;Lei Guo,&nbsp;Ning Zhang","doi":"10.1016/j.sandf.2026.101749","DOIUrl":"10.1016/j.sandf.2026.101749","url":null,"abstract":"<div><div>As a novel type of pile foundation structure, the strength composite (SC) piles lack a settlement calculation method that accurately reflects the stress diffusion state within the composite soil mass. In this study, based on the multilayer theory, a settlement calculation formula for strength composite (SC) piles is proposed for homogeneous foundations, which accounts for the evolution of the plastic zone in the surrounding soil. This method is then extended to the settlement calculation of SC piles in layered foundations encountered in practical engineering. A corresponding calculation program is also developed. Through comparison with static load tests, recommendations are provided for the form of the soil modulus distribution around the pile and the value of the soil disturbance radius. Finally, the proposed method is applied to case studies of typical engineering sites. The results show that the calculated values agree well with the measured values in both trend and magnitude, reflecting the nonlinear bearing characteristics of the SC pile. The proposed method demonstrates broad applicability and satisfactory engineering accuracy.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"66 2","pages":"Article 101749"},"PeriodicalIF":3.3,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}