Computers and Geotechnics最新文献

{"title":"An improved local coarsening method for discrete element simulation on cracking propagation in rock and rock-like materials","authors":"Guansheng Han ,&nbsp;Shaoqi Wang ,&nbsp;Yu Zhou ,&nbsp;Bo Li ,&nbsp;Wenjun Lv ,&nbsp;Weiqiang Chen ,&nbsp;Qiongqiong Tang","doi":"10.1016/j.compgeo.2024.107002","DOIUrl":"10.1016/j.compgeo.2024.107002","url":null,"abstract":"<div><div>One key aspect of optimizing numerical techniques is balancing accuracy with computational cost. However, the traditional local coarsening method (LCM) used in the discrete element method (DEM) always overlooks size-dependent characteristics, which can lead to nonnegligible error compared to homogenous model. This study first quantitatively analyzed the resulting errors in macroscopic mechanical properties and deviation in cracking behavior. The results indicate that mechanical property errors can even reach up to around 20–30 %, with cracks tending to propagate into local coarsening regions. Further investigation revealed that these unrealistic phenomena are primarily due to reduced contact stiffness resulting from enlarged particle size. To address this issue, an improved local coarsening method (ILCM) for DEM was then proposed, focusing on coordinating the stiffness difference between fine and coarse regions. The effectiveness of the proposed ILCM was finally validated through a series of uniaxial compression and Brazilian numerical tests.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107002"},"PeriodicalIF":5.3,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145715","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":"Laser rock-breaking mechanism considering rock inhomogeneity and the temperature effect","authors":"Zhengkuo Ma ,&nbsp;Chunshun Zhang ,&nbsp;Congying Li ,&nbsp;Wei Wei ,&nbsp;Jie Dong","doi":"10.1016/j.compgeo.2024.107029","DOIUrl":"10.1016/j.compgeo.2024.107029","url":null,"abstract":"<div><div>While experimental research on laser rock-breaking is extensive, numerical simulations, especially for thermal fractures, are limited, and the thermal rupture mechanism remains poorly understood. This study addresses these gaps by introducing a novel approach that combines Voronoi diagrams and Weibull distributions with the coupled cohesive zone model and thermomechanical damage (CZM-TMD) approach. The developed numerical model accurately predicts the temperature and stress distributions, as well as the formation and propagation of thermal cracks and craters. Validation against theoretical analyses and past experiments confirms its accuracy. Thermal cracks originate at the interface between irradiated and nonirradiated areas and propagate bidirectionally. Shear damage is prominent at the crater, whereas tensile damage is more common in cracks. With continued irradiation, the crater diameter increases rapidly before stabilizing, and the depth follows an S-shaped curve after a rapid increase, similar to the water cushion effect in water jet rock-breaking. These insights enhance the theoretical understanding of laser rock-breaking and provide a key reference for future simulations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107029"},"PeriodicalIF":5.3,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145737","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":"Developing a memory-efficient GPGPU-parallelized contact detection algorithm for 3D engineering-scale FDEM simulations","authors":"Yiming Lei ,&nbsp;Quansheng Liu ,&nbsp;He Liu","doi":"10.1016/j.compgeo.2024.107031","DOIUrl":"10.1016/j.compgeo.2024.107031","url":null,"abstract":"<div><div>Despite FDEM’s superior advantages in modeling solid deformation and fracturing behaviors for engineering-scale analysis, it has been restricted to two-dimensional (2D) scenarios, with three-dimensional (3D) scenarios remaining relatively unexplored due to excessive memory constraints and computational overheads, especially in contact-related computations. This study proposes a GPGPU-parallelized contact detection algorithm to address memory constraints in 3D FDEM engineering-scale simulations. The search domain is initially divided into equally sized search cells (subCells). Through an initial element mapping procedure, subCells containing at least one solid element (realCells) are identified. RealCells are dynamically pinpointed through hashing, forming subCell-realCell lists, which allows directly allocating GPU’s memory to useful realCells instead of all subCells. Then, a second element mapping operation populates realCells with element IDs, followed by a broad search at the CUDA block level for potential contacts and a narrow search to determine actual contacts. The algorithm’s effectiveness is first verified through three benchmark tests, and then further highlighted by two engineering-scale simulations showcasing a significant decrease in GPU memory consumption with the comparable computational time. We demonstrate that the proposed algorithm reduces memory usage of the contact detection phase by 85% compared to the conventional algorithm in a 3D engineering-scale simulation involving over 8.5 million tetrahedral and 17.6 million cohesive elements.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107031"},"PeriodicalIF":5.3,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145736","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":"Progressive failure analysis of axially loaded single pile embedded in unsaturated soils based on LTM coupling with SDM","authors":"Gengyun Liu ,&nbsp;Jingpei Li ,&nbsp;Chang Liu ,&nbsp;Panpan Li","doi":"10.1016/j.compgeo.2024.107036","DOIUrl":"10.1016/j.compgeo.2024.107036","url":null,"abstract":"<div><div>An analytical framework to analyze the progressive failure behavior of axially loaded single pile embedded in unsaturated soils is presented by means of the load transfer method (LTM) coupling with shear displacement method (SDM). In this study, the proposed DSC-based interface constitutive model and modified small-strain stiffness model undertake the role of load-transfer mechanism for the pile shaft and pile end, respectively, and the shear displacement method is adopted to take the soil deformation surrounding the pile shaft in consideration. This study adopts a stress loading approach in the solution process, differing from traditional strain loading methods, which involves assuming a segment of displacement at the pile end. By successively applying loading increments, the entire load–displacement relationship of the pile is accurately determined, effectively reproducing the authentic stress process of pile foundation, and analyzing the gradual failure processes of friction-dominated piles and end-bearing friction piles under varying suction conditions in unsaturated soil. Customized model piles with smooth, rough and ribbed surfaces and a stress-controlled servo system were developed to conduct static load tests on pile foundations in unsaturated sand-clay mixture and grey clay. Model parameters were calibrated through suction-controlled unsaturated ring shear tests. Finally, the validity of the solutions proposed in this study was verified by comparing the results of static load tests on smooth, rough and ribbed model piles. Subsequently, the effects of suction, interface dilation, and environmental factors on the load–displacement response were analyzed. The research findings of this study can provide a theoretical basis for the design of pile foundations with displacement control in unsaturated soil.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107036"},"PeriodicalIF":5.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145717","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":"Fast and interpretable prediction of seismic kinematics of flexible retaining walls in sand through explainable artificial intelligence","authors":"Francesco Pistolesi ,&nbsp;Michele Baldassini ,&nbsp;Evelina Volpe ,&nbsp;Francesco Focacci ,&nbsp;Elisabetta Cattoni","doi":"10.1016/j.compgeo.2024.107007","DOIUrl":"10.1016/j.compgeo.2024.107007","url":null,"abstract":"<div><div>Assessing the response of earth-retaining walls to seismic loading is key for safety. Nonlinear dynamic analyses using the finite element method (FEM) calculate the permanent displacements (PDs) the soil–wall system accumulates during an earthquake, but are computationally intensive. Simplified dynamic displacement-based methods that obtain PDs based on a failure mechanism (FM) and critical acceleration are faster. Still, they require geotechnical expertise, e.g., in strength, failure criteria, and stability under pseudo-static conditions. This paper presents a new method using eXplainable Artificial Intelligence (XAI) to predict the FM and <span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> (critical acceleration as a fraction of gravity) of flexible retaining walls in dry, coarse-grained soil, based on geometry and soil/wall properties. We created a large dataset (<span><math><mo>∼</mo></math></span>1000 samples) via FEM simulations based on plasticity limit theorems, with 7 types of FMs affecting 3 types of walls: propped, cantilever, and anchored. Each sample contained geometrical parameters, soil/wall properties, and FEM-derived FM and <span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. Trained on these data, our system has a weighted F1-score of 97.28% and an <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> above 0.987 for FM and <span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> predictions, respectively. Shapley explanations (SHAP) and a new coherence model help experts interpret the results and check explanation consistency. Its high accuracy and millisecond-level inference make our method ideal when assessing the seismic response of numerous structures within short timeframes. Also, its interpretability promotes AI-expert collaboration, enhancing decision-making.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107007"},"PeriodicalIF":5.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiscale Examination of the Unified Form of UCS Model for Bimrocks","authors":"Minghui Ren ,&nbsp;Guangsi Zhao ,&nbsp;Hai Pu ,&nbsp;LuLu Liu","doi":"10.1016/j.compgeo.2024.107034","DOIUrl":"10.1016/j.compgeo.2024.107034","url":null,"abstract":"<div><div>Understanding failure mechanisms in a multiscale context is essential for enhancing predictive models of bimrock. This study introduces a multiscale mechanical framework (MMF) to establish the mechanical scaling relationships of bimrock, enabling the derivation of generalized failure criteria for uniaxial compressive loads. Using the discrete element method (DEM), this study elucidates the various failure mechanisms of bimrocks with different block forms, thereby validating the unified failure criteria. Additionally, a generalized model of uniaxial compressive strength (UCS) applicable to various constituent conditions of bimrock is proposed. An extensive analysis of different block-matrix interface strengths reveals that in bimrock with strong blocks, when the cementation strength of the matrix-block interface exceeds 0.5 times the matrix strength, the stress field significantly influences the UCS of bimrock (UCS_bimrock). By contrast, the UCS_bimrock is primarily determined by the interaction between the matrix strength and the volumetric block proportion (VBP) for bimrock with weak interphaces. Finally, the impact of the interface strength on UCS_bimrock is investigated across a range of VBP values for bimrocks with strong blocks. By comparing these findings with the reports in the literature, various observations are reinterpreted through the combined use of matrix strength and normalized matrix stress. The generalized UCS model established in this study provides new insights for advancing the mechanical modeling of bimrock under complex conditions in future research.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107034"},"PeriodicalIF":5.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144986","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 novel insight into the transition from plasticity to elasto-damage modelling in intact rocks","authors":"Vahid Azamipour ,&nbsp;Hamid Roshan ,&nbsp;Daniela Boldini ,&nbsp;Hossein Masoumi","doi":"10.1016/j.compgeo.2024.107021","DOIUrl":"10.1016/j.compgeo.2024.107021","url":null,"abstract":"<div><div>This study developed a coupled elasto-damage constitutive model for predicting the transition from brittle to ductile behaviour in quasi-brittle rocks. By integrating the bounding surface framework with damage evolution hardening, the model can accurately simulate the stress–strain behaviour under various loading conditions. Unlike traditional elastoplastic criteria, the proposed model incorporated the inelastic strain from the initial stage of loading and accounts for the associated damage evolution, enabling a smooth transition from elastic to inelastic zones. It can also consider the nonlinear deformation of quasi-brittle rocks with different geological origins under various loading conditions through highlighting the importance of considering damage factor in rock materials modelling. The proposed framework introduced damage-induced permanent deformation as an alternative to plasticity in stress–strain modelling by combining damage and shear effects. Finally, a comparative analysis was performed between the scenarios with and without damage function to highlight the significance of having damage parameter in modelling of quasi-brittle rocks. It is noteworthy that such a model was mainly developed to account for the triaxial loadings and to capture the complex relationship between inelastic hardening/softening and damage progression.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107021"},"PeriodicalIF":5.3,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of compound bio-inspired cone pressuremeter probe mechanisms with Material Point Method","authors":"Harsha Vardhan Kurugodu ,&nbsp;Debayan Bhattacharya ,&nbsp;Prashanth Vangla ,&nbsp;J. David Frost","doi":"10.1016/j.compgeo.2024.107013","DOIUrl":"10.1016/j.compgeo.2024.107013","url":null,"abstract":"<div><div>Bio-inspired probes have emerged as a promising solution for in-situ site characterisation, particularly in challenging terrains and extraterrestrial exploration. This study presents a viable and computationally efficient Material Point Method (MPM) framework for studying Bio-Inspired Cone Pressuremeter (BICP) probe mechanism. With its inherent advantage of particle and continuum frameworks, MPM allows seamless simulation of multi-staged BICP probe propulsion that involves large deformation. A novel implementation strategy was developed for this study to simulate the complex movement of the BICP probe in three sequential stages, including penetration, pressuremeter module expansion, and tip advancement. Sensitivity analysis was conducted to achieve an objective solution and determine the optimum mesh size and mass scaling factor for the BICP probe within the realms of current state-of-the-art MPM formulation. Furthermore, investigations were performed on the established MPM framework to study the influence of probe geometry, material state, and layered soil strata. The findings reveal that in probes with longer pressuremeter modules, larger zone of stress relaxation was observed around the cone tip during module expansion stage than their shorter or double-module counterparts. Meanwhile, the BICP probe’s response during all stages in different material states corroborates its sensitivity to the soil’s mechanical properties. Although the layered strata significantly influenced the BICP probe’s response during the penetration and module expansion stages, it had minimal impact during the tip advancement stage.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107013"},"PeriodicalIF":5.3,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145185","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":"Hydromechanical properties of unsaturated compacted loess considering initial structural strength attenuation under undrained conditions","authors":"Biao Qin ,&nbsp;Xi-An Li ,&nbsp;Hao Chai ,&nbsp;Li Wang ,&nbsp;Qian Liu","doi":"10.1016/j.compgeo.2024.107037","DOIUrl":"10.1016/j.compgeo.2024.107037","url":null,"abstract":"<div><div>The hydromechanical characteristics of unsaturated loess determine the engineering performance such as bearing capacity and stability of compacted loess structures. In this study, the volume change equation is constructed in the effective stress-saturation space by correlating soil compressibility with saturation. Meanwhile, a hydraulic model considering the influence of volumetric strain is introduced to develop a hydraulic-mechanical elastoplastic model for unsaturated loess. Furthermore, a stress ratio sensitivity parameter is developed to describe the initial structural strength attenuation of unsaturated loess under loading, introducing the sensitivity parameter to modified effective stress to characterize the hydromechanical behaviors under initial structural strength attenuation. The proposed model can well describe the coupling effect of hydraulic and mechanical wetting. Using the constraints of the saturation and volumetric strain relationship under undrained conditions, predictions of soil–water change are achieved via net stress and deviatoric stress driving. And then the excellent performance of the proposed model in predicting the hydromechanical behavior of unsaturated compressed loess under undrained conditions is verified.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107037"},"PeriodicalIF":5.3,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145187","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":"Efficient reliability analysis of slopes in spatially variable soils with active learning-assisted bootstrap polynomial chaos expansion","authors":"Kang Liao ,&nbsp;Xiaoyan Zhao ,&nbsp;Yiping Wu ,&nbsp;Fasheng Miao ,&nbsp;Yutao Pan ,&nbsp;Michael Beer","doi":"10.1016/j.compgeo.2024.107022","DOIUrl":"10.1016/j.compgeo.2024.107022","url":null,"abstract":"<div><div>Evaluating the reliability of slopes with spatial variability is a challenging issue, especially when the failure probably of the target event is at a low level, because of unaffordable computational cost required in such cases. In this context, an adaptive surrogate model-based approach, namely active learning-assisted bootstrap polynomial chaos expansion, is proposed to alleviate the above computational burden. The proposed approach extends the traditional polynomial chaos expansion by introducing the bootstrap resampling method so that it can deal with reliability issues smoothly and provide a feasible configuration environment to support the active learning algorithm. The computational efficiency can thus be greatly improved by adaptively searching for the most informative samples to train the surrogate model through iterative program. Two spatially varying soil slopes are studied to illustrate the validity of the active learning-assisted bootstrap polynomial chaos expansion. The results show that the proposed approach has superior advantages in terms of efficiency and accuracy, and it is also suitable for handling problems with complex parameter configurations, including high dimensionality and cross-correlation. Besides, the proposed approach has potential in addressing geotechnical engineering problems with low probability levels.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"179 ","pages":"Article 107022"},"PeriodicalIF":5.3,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145186","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}