Acta Geotechnica最新文献

{"title":"Insight into nonlinear thermal consolidation of saturated clay under coupled thermo-mechanical loading: a unified one-dimensional model","authors":"Mengmeng Lu, Jinxin Sun, Minjie Wen, Kang Yang, Kuo Li","doi":"10.1007/s11440-024-02382-0","DOIUrl":"https://doi.org/10.1007/s11440-024-02382-0","url":null,"abstract":"<p>The evaluation of thermo-hydro-mechanical (THM) coupling response of clayey soils has emerged as an imperative research focus within thermal-related geotechnical engineering. Clays will exhibit nonlinear physical and mechanical behavior when subjected to variations in effective stress and temperature. Additionally, temperature gradient within soils can induce additional pore water migration, thereby resulting in a significant thermo-osmosis effect. Indeed, thermal consolidation of clayey soils constitutes a complicated THM coupling issue, whereas the theoretical investigation into it currently remains insufficiently developed. In this context, a one-dimensional mathematical model for the nonlinear thermal consolidation of saturated clay is proposed, which comprehensively incorporates the crucial THM coupling characteristics under the combined effects of heating and mechanical loading. In current model, the interaction between nonlinear consolidation and heat transfer process is captured. Heat transfer within saturated clay is investigated by accounting for the conduction, advection, and thermomechanical dispersion. The resulting governing equations and numerical solutions are derived through assuming impeded drainage boundaries. Then, the reasonability of current model is validated by degradation and simulation analysis. Subsequently, an in-depth assessment is carried out to investigate the influence of crucial parameters on the nonlinear consolidation behavior. The results indicate that increasing the temperature can significantly promote the consolidation process of saturated clay, the dissipation rate of excess pore water pressure (EPWP) is accelerated by a maximum of approximately 15%. Moreover, the dissipation rate of EPWP also increases with the increment of pre-consolidation pressure, while the corresponding settlement decreases. Finally, the consolidation performance is remarkably impacted by thermo-osmosis and neglecting this process will generate a substantial departure from engineering practice.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 fabric anisotropy on the small-strain shear modulus of granular materials","authors":"Xiao-Tian Yang, Yan-Guo Zhou, Qiang Ma, Yun-Min Chen","doi":"10.1007/s11440-024-02381-1","DOIUrl":"https://doi.org/10.1007/s11440-024-02381-1","url":null,"abstract":"<p>Granular soil generally exhibits an anisotropic stiffness in engineering but challenging to quantify in situ and laboratory condition, due to a lack of the appropriate factor and quantitative research. In this paper, discrete element method is employed to create two typical types of soil fabric and conduct shear wave measurement in double direction, with the microscopic parameters monitored to investigate the connection with macroscopic stiffness anisotropy. The results show that the reference fabric increases as fabric anisotropy increases first and then decreases with further increase in the <i>XZ</i> stress plane, while always decreases approximately linearly in the <i>XY</i> stress plane. The reference fabric is determined by the contact density in the direction of wave propagation and particle perturbation under microscale examination. The results also reveal a linear relationship between the macroscopic stiffness anisotropy and microscopic fabric anisotropy, which could be used as an effective method to reflect the degree of anisotropy in situ by wave measurement. And the applicability of the expression of small-strain shear modulus is also discussed.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landslide susceptibility mapping using physics-guided machine learning: a case study of a debris flow event in Colorado Front Range","authors":"Te Pei,&nbsp;Tong Qiu","doi":"10.1007/s11440-024-02384-y","DOIUrl":"10.1007/s11440-024-02384-y","url":null,"abstract":"<div><p>Landslides are common geohazards worldwide, resulting in significant losses to economies and human lives. Data-driven approaches, especially machine learning (ML) models, have been widely used recently for landslide susceptibility mapping (LSM) by extracting features from geospatial variables based on their contribution to landslide occurrences using known distributions of landslides as the training dataset. However, challenges remain in applying ML models for LSM models due to the scarcity and uneven spatial distribution of landslide data coupled with the spatial heterogeneity of hillslope conditions. Moreover, ML models developed with limited data often exhibit unexpected behaviors, resulting in poor interpretability and predictions that deviate from intuitive expectations and established domain knowledge. To overcome these challenges, this study proposes a physics-guided machine learning (PGML) framework that integrates landslide domain knowledge into ML models for LSM. The PGML framework was developed and assessed using a detailed debris flow inventory from a storm event in the Colorado Front Range. Based on the infinite slope model, the factor of safety for the study area was first determined and was subsequently used to constrain the prediction of ML models through a modified loss function and measure the physics consistency of model predictions. To evaluate the robustness and generalizability of the models, this study uses geographical sample selections for model performance evaluation, where ML models are trained and tested across heterogeneous ecoregions. The results of this study demonstrated the efficacy of both physics-based and data-driven methods in determining landslide susceptibility in the study area; however, pure data-driven ML models produced physically unrealistic results and poor generalization performance in new ecoregions. With the incorporation of physical constraints, the PGML model demonstrated notable enhancements in physics consistency and generalization capability, along with reduced model uncertainties across various ecoregions, surpassing the performance of benchmark ML models.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of stress conditions on concentrated leak erosion resistant of fine-grained soils with different characteristics","authors":"Sadettin Topçu, Hasan Savaş, Hasan Tosun","doi":"10.1007/s11440-024-02376-y","DOIUrl":"https://doi.org/10.1007/s11440-024-02376-y","url":null,"abstract":"<p>Internal erosion is one of the most important factors that cause earth structures that retain water, such as embankment dams, to collapse. Concentrated leak erosion, one of the forms of internal erosion, occurs in cracked fine-grained soils and pressurized flow conditions. To evaluate the concentrated leak erosion risk of cracks/voids, it is necessary to ascertain the erosion resistance of these materials. The erosion rate and critical shear stresses determine internal erosion resistance in concentrated leak erosion. This study determined soil’s concentrated leak erosion resistance using test equipment that allowed the flow to pass through a hole with stress-free (no loading), anisotropic-compression stress, anisotropic-expansion stress, and isotropic stress conditions. The stresses that developed in the samples’ hole wall where erosion occurred were determined with numerical modeling as pre-experimental stress conditions. The experiments were performed under a single hydraulic head on four selected cohesive soils with different erosion sensitivity. Time-dependent flow rates obtained from the test system can be used to determine hydraulic parameters, such as energy grade lines, with the help of basic theorems of pipe hydraulics in theoretical hydraulic models. Moreover, the erosion rates were quantitatively determined using the continuity equation, while critical shear stresses were qualitatively compared for concentrated leak erosion developed by the dispersion mechanism. As a result of the experiments, stress conditions influence the concentrated leak erosion resistance in the soil samples with dispersive erosion. Moreover, the shear strength in the Mohr–Coulomb hypothesis can explain the erosion resistance in these soils under stress conditions depending on the sand/clay ratio.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142214269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of granular materials at crushing-dominant stage","authors":"Yaolan Tang,&nbsp;Chunshun Zhang,&nbsp;Congying Li,&nbsp;Weiru Zhou,&nbsp;Junfeng Qian,&nbsp;Jian Zhao","doi":"10.1007/s11440-024-02383-z","DOIUrl":"10.1007/s11440-024-02383-z","url":null,"abstract":"<div><p>Granular crushing significantly changes mechanical behaviours, especially under elevated stress levels. Therefore, this study aims to develop a model to simulate the constitutive behaviours of granular materials at the crushing-dominant stage. Firstly, the contour of elastic potential energy is demonstrated and employed to derive the yield surface or function, acknowledging that the stored elastic energy dominates the breakage yield criterion. The versatility of the proposed yield function in accurately capturing the features of yield surfaces is verified with three cases, including Cam-clay models, test results, and an empirical yield function. Next, a hardening parameter, <i>H</i>, is formulated, considering the extent of crushing, <i>B</i>, and the void ratio, <i>e</i>, to reflect the expansion of the yield surface during hardening. The proposed simple hardening formulation favourably represents compression characteristics under elevated stress levels. Combining the above results of yield and hardening functions, a new elastic–plastic-crushing constitutive model is developed; the model’s capability to describe crushable granular material behaviours is validated against experimental counterparts.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grouting mechanism of quick-setting slurry in fracture with random fracture opening considering time–space characteristics of viscosity","authors":"Shu Zhu,&nbsp;Jianfu Shao,&nbsp;Hexuan Zhu,&nbsp;Zhende Zhu,&nbsp;Feiyang Wang,&nbsp;Junyu Wu","doi":"10.1007/s11440-024-02378-w","DOIUrl":"10.1007/s11440-024-02378-w","url":null,"abstract":"<div><p>The coupling effect between the spatial variability of slurry diffusion and the time-varying viscosity of quick-setting slurry is the time–space characteristics of slurry viscosity (TSCSV). The TSCSV is the governing factor for the complex and uncontrollable flow of slurry in fractures. In this regard, the flow pattern of quick-setting slurry is considered as a Bingham fluid with viscosity spatiotemporal characteristics. Using the fractal function with random parameters (W-M function), a single fracture with random fracture opening (RFO) is drawn, and a theoretical model on grouting diffusion in fractures is established considering the TSCSV. The RFO is corrected for head loss, and the spatiotemporal distribution equation of the RFO grouting pressure is derived. The relationship between grouting pressure, grouting time, and slurry diffusion distance is obtained. Additionally, the effects of the RFO, the fractal dimension of the fracture curve, the horizontal movement distance of the lower end face of the fracture, and the effects of viscosity and grouting rate on the viscosity and grouting pressure in the slurry diffusion space are discussed. Finally, by predefining the spatial distribution function of slurry viscosity for a single fracture in the numerical calculation model, a numerical simulation of random fracture distribution grouting considering viscosity spatiotemporal characteristics is achieved. The rationality of the model is validated through a comparison of theoretical analysis and numerical simulation, providing reference for the determination of grouting parameters in practical grouting projects.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141941898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Important considerations in machine learning-based landslide susceptibility assessment under future climate conditions","authors":"Yi Han, Shabnam J. Semnani","doi":"10.1007/s11440-024-02363-3","DOIUrl":"https://doi.org/10.1007/s11440-024-02363-3","url":null,"abstract":"<p>Rainfall-induced landslides have caused a large amount of economic losses and casualties over the years. Machine learning techniques have been widely applied in recent years to assess landslide susceptibility over regions of interest. However, a number of challenges limit the reliability and performance of machine learning-based landslide models. In particular, class imbalance in the dataset, selection of landslide conditioning factors, and potential extrapolation problems for landslide prediction under future conditions need to be carefully addressed. In this work, we introduce methodologies to address these challenges using XGBoost to train the landslide prediction model. Data resampling techniques are adopted to improve the model performance with the imbalanced dataset. Various models are trained and their performances are evaluated using a combination of different metrics. The results show that synthetic minority oversampling technique combined with the proposed gridded hyperspace sampling technique performs better than the other imbalance learning techniques with XGBoost. Subsequently, the extrapolation performance of the XGBoost model is evaluated, showing that the predictions remain valid for the projected climate conditions. As a case study, landslide susceptibility maps in California, USA are generated using the developed model and are compared with the historical California landslide catalog. These results suggest that the developed model can be of great significance in global landslide susceptibility mapping under climate change scenarios.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141884481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compression and critical-state behaviors of calcareous sand–diatom mixtures","authors":"Yang Xiao, Haoran Yang, Shuang Liu, Qingyun Fang, Hao Cui, Hanlong Liu","doi":"10.1007/s11440-024-02365-1","DOIUrl":"https://doi.org/10.1007/s11440-024-02365-1","url":null,"abstract":"<p>Calcareous sand–diatom mixtures are found naturally in the coral reef sediments, where the diatom potentially affects the mechanical behaviors of the mixtures. We performed a series of isotropic compression and triaxial drained shear tests to investigate the effect of diatom on the compression and critical-state behaviors of the mixtures. We found that the diatom and effective confining pressure can considerably affect the compression index, swelling index, coefficient of volume compressibility, compression modulus, secant modulus, peak-state deviatoric stress, peak-state axial strain, and peak-state frictional angle. In addition, the critical-state friction angle is independent of the diatom content, while the critical-state line (CSL) in the compression plane is affected significantly by the diatom content. We proposed modified equations for compression modulus and CSL considering the influence of diatom content, and the two equations could reasonably predict the compression deformation and critical-state behaviors of the mixtures. This study provides experimental basis for understanding critical-state behavior for the calcareous sand–diatom mixtures.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141862703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of non-erodible particle content on the mechanism of suffusion and the evolution of permeability of sandy soil","authors":"Jie Kang, Jie Ren, Songtao Hu, Hengle Guo, Kaixuan Chen, Ting Zhuang, Shenghao Nan, Jiaheng Sui","doi":"10.1007/s11440-024-02375-z","DOIUrl":"https://doi.org/10.1007/s11440-024-02375-z","url":null,"abstract":"<p>Suffusion is a typical type of internal erosion that is an important factor leading to the failure of dams and dikes. In this paper, fine particles are divided into erodible particles and non-erodible particles, and the soil suffusion mechanism is investigated by laboratory tests and CFD_DEM simulations when the content of erodible particles (<i>F</i>_c) and non-erodible particles (<i>F</i>_z) is 15% and 5%, 10% and 10%, and 5% and 15%. The global mean permeability coefficient (<i>k</i>_av) and local permeability coefficient (<i>k</i>_i–j) were calculated by monitoring the water head in the seepage path of the sample. The results show that with increasing non-erodible particle content, the difficulty of soil suffusion increases gradually. When soil suffusion occurs, the loss of fine particles starts from the seepage outlet area and the influent area, and the non-erodible particles have little influence on the particle loss process in these two areas. After the occurrence of suffusion, the number of weak contact chains is obviously reduced, while the strong contact chains are basically stable. When <i>F</i>_z = 5% and <i>F</i>_z = 10%, the average permeability coefficient of the soil after suffusion expands to 2.21–1.60 times that of the initial state, and the corresponding values of the CFD_DEM simulation are 2.14–1.86 times.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.7,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 gradation-dependent hypoplastic model for crushable sands","authors":"Yaolan Tang,&nbsp;Shun Wang,&nbsp;Chunshun Zhang","doi":"10.1007/s11440-024-02372-2","DOIUrl":"10.1007/s11440-024-02372-2","url":null,"abstract":"<div><p>A gradation-dependent hypoplastic model is developed to capture the mechanical behaviours of crushable sands. First, a gradation evolution law is proposed to describe the variation of the grain size distribution (GSD) and the development of the extent of crushing during the loading process. Second, the family of CSLs under different gradations is formulated. Combining the developed CSL function and GSD evolution leads to well-modelling the unique critical state features of crushable sands. Subsequently, critical state features are incorporated into a well-established hypoplastic framework, such that the gradation-dependent hypoplastic model for crushable sands is developed. The accuracy and efficiency of the developed hypoplastic model in capturing the mechanical behaviours of crushable sands are validated against experimental counterparts.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141775641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}