Computers and Geotechnics最新文献

{"title":"Investigating the effects of non-uniformity of mixing on the shear behavior of soft-rigid mixtures with DEM","authors":"","doi":"10.1016/j.compgeo.2024.106794","DOIUrl":"10.1016/j.compgeo.2024.106794","url":null,"abstract":"<div><div>Soft-rigid mixtures (SRMs) are typically pre-mixed before backfilling in engineering applications. However, the properties of soft materials make it particularly challenging to achieve uniform mixing with soils. This study is a pioneer in the exploration of non-uniform mixing in SRMs. A total of 76 quasi-static cubic compression tests were conducted with various mixing forms, mixing degrees, soft particle contents, and confining pressures under a standardized initial state. Based on the numerical results, the macroscopic responses were first quantitatively analyzed to reveal the effects of non-uniform mixing on the micromechanical behaviors of soft-rigid mixtures from compressibility, stress, and volumetric deformation perspectives. Then, the evolution of micro-scale properties, including the internal structure, stress network, internal stability, and fabric anisotropy, was investigated. It was found that the effects of non-uniform mixing on SRMs are considerably more pronounced than on traditional geotechnical binary mixtures. From a macroscopic perspective, non-uniform mixing greatly impacts the critical strength and void ratio of SRMs, with effects comparable to a 10% change in soft content. On a microscopic level, SRMs with higher uniformity exhibit a more stable internal structure, stress network, and enhanced internal stability. The results also show that layering should be avoided during construction. Additionally, the mixing index without considering stress direction is unsuitable for engineering applications. This paper underscores the paramount importance of considering the uniformity in soft-rigid mixtures, providing a robust foundation for further studies in this field.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357769","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":"Deciphering how the particle shape modulates the elastic anisotropy of granular media","authors":"","doi":"10.1016/j.compgeo.2024.106773","DOIUrl":"10.1016/j.compgeo.2024.106773","url":null,"abstract":"<div><div>Anisotropy is a quintessential property of granular materials, in large part stemming from the complex interparticle interactions modulated by particle shape, orientation, and contact properties. This paper delves into the microscopic underpinnings of elastic anisotropy within granular solids composed of non-spherical particles. Employing the Discrete Element Method (DEM), incremental probes have been imposed on packed configurations of ellipsoidal particles generated through a clumping strategy. The synthetic specimens were deliberately designed to prevent permanent rearrangements, thereby ensuring fully reversible granular structures. Through a comprehensive blend of analytical and numerical approaches, the study establishes scaling relationships that shed light on the intertwined influence of particle orientation and contact curvature on elastic anisotropy, effectively disentangling their individual contributions. The results enabled a clear mathematical identification of two coexisting forms of elastic anisotropy: one of microstructural type, stemming from the directional properties of the initial particle arrangement (which in an elastic context is here referred to as <em>inherent</em>) and another stemming from mechanical processes, such as contact interaction promoted by the imposed stress path (here referred to as <em>induced</em>). Specifically, it is found that each of these anisotropy contributions can be linked to distinct fabric variables, namely the shape fabric (here associated with particle orientation and aspect ratio of the particles) and the contact area fabric (here associated with the local normal force and curvature of the particles at contact points). Inherent elastic anisotropy is revealed to be predominantly governed by the microstructural characteristics of shape fabric, whereas, induced elastic anisotropy is shown to be primarily driven by the contact area fabric. By underscoring the critical role played by microstructural fabrics in determining macroscale elastic anisotropy, the DEM simulations also enabled the calibration of the fabric components of a nonlinear anisotropic hyperelastic model, thereby paving the way for enhanced predictive capabilities of constitutive laws for granular materials harnessing the profound connection between grain-scale processes and continuum-scale mechanical properties.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357677","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":"Thermo-hydro-mechanical behavior of soft soils beneath energy shallow foundations subjected to thermal and mechanical loads","authors":"","doi":"10.1016/j.compgeo.2024.106790","DOIUrl":"10.1016/j.compgeo.2024.106790","url":null,"abstract":"<div><div>Energy shallow foundations represent an innovative technology that can simultaneously support structural loads and harvest geothermal energy. During geothermal operations, the underlying soils are subjected to structural loads and temperature fluctuations. Despite the potential, knowledge regarding the thermo-hydro-mechanical behavior of the multilayered soils beneath the energy foundations remains scarce. This study proposed an analytical approach to investigate the thermo-hydro-mechanical response of soft fine-grained soils beneath energy shallow foundations. The analysis focused on the evolutions of the temperature, pore water pressure, and vertical displacement of the underlying soils. The results indicate that the generation and development of the thermally induced excess pore pressure are controlled by thermal transfer processes and soil hydraulic properties. Furthermore, the mechanical load-induced ground settlement decreases upon heating and increases upon cooling, primarily due to the development of thermally induced pore pressure and the thermal volume changes of the soil skeleton. Under the considered conditions, ignoring the thermally induced mechanical effects could result in a settlement prediction error of nearly 120%. Therefore, the thermo-hydro-mechanical interactions within the soils should be appropriately considered in the analysis and prediction of the displacement behavior of the energy foundations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357768","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":"One-dimensional consolidation analysis of layered unsaturated soils: An improved model integrating interfacial flow and air contact resistance effects","authors":"","doi":"10.1016/j.compgeo.2024.106791","DOIUrl":"10.1016/j.compgeo.2024.106791","url":null,"abstract":"<div><div>Layered unsaturated soils exhibit complex mechanical and physical properties. Owing to the roughness between unsaturated soil interfaces and the presence of irregularly distributed micro-pores, this study explores the laminar flow of pore water and counter-cyclonic flow of pore air through these channels at low velocities. In response to the complex consolidation behavior of unsaturated soils influenced by the flow and air contact resistance, an improved model is developed. The model incorporates the flow contact transfer coefficient <span><math><mrow><mo>(</mo><msub><mi>R</mi><mi>ω</mi></msub><mo>)</mo></mrow></math></span>, flow partition coefficient <span><math><mrow><mo>(</mo><msub><mi>η</mi><mi>ω</mi></msub><mo>)</mo></mrow></math></span>, air contact transfer coefficient <span><math><mrow><mo>(</mo><msub><mi>R</mi><mi>a</mi></msub><mo>)</mo></mrow></math></span> and air partition coefficient <span><math><mrow><mo>(</mo><msub><mi>η</mi><mi>a</mi></msub><mo>)</mo></mrow></math></span>. Semi-analytical solutions for pore water pressure, pore air pressure and settlement in layered unsaturated soils are derived by employing the Laplace transform and its inverse transform. The rationality of the model is validated through comparative analysis with existing solutions. Analysis of the improved model yields critical insights: the presence of flow and air contact resistance leads to the development of relative pore pressure and air pressure gradients at interfaces, which diminishes the influence of the permeability coefficients of the water phase <span><math><mrow><mo>(</mo><msub><mi>k</mi><mi>ω</mi></msub><mo>)</mo></mrow></math></span> and air phase <span><math><mrow><mo>(</mo><msub><mi>k</mi><mi>a</mi></msub><mo>)</mo></mrow></math></span> on the consolidation process. Moreover, neglecting the flow and air contact resistance effects may lead to an overestimation of settlement.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357676","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":"Nonlinear distinct element modeling of the microstructural compression-hardening effect on the progressive failure and associated acoustic emission of brittle rock","authors":"","doi":"10.1016/j.compgeo.2024.106787","DOIUrl":"10.1016/j.compgeo.2024.106787","url":null,"abstract":"<div><div>The linearly bonded particle model (LBPM) and moment tensor method (MTM) have been combined and applied to simulate the progressive failure of rock and associated acoustic emission (AE). However, LBPM-MTM cannot characterize the compression-hardening response of a rock microstructure or its effect on progressive failure and AE. We propose a nonlinear bonded particle model (NBPM) to address this with MTM. Results revealed that NBPM could reproduce the compression-hardening response of Xinzhuang sandstone far better than LBPM. For the LBPM case, the proportion of the tensile force and concentration zones changed slightly during compression, while the results of the NBPM significantly increased. Microcracks in the NBPM case emerged later than in the LBPM case. Compared to the LBPM-MTM case, the NBPM-MTM case has more microcracks and AE events, and more energy is released near the peak stress. The correlation between the accumulative AE event count and magnitude via NBPM-MTM complied with the Gutenberg-Richter law much better than via LBPM-MTM. Overall, the magnitude of a single AE event with NBPM-MTM is greater than with LBPM-MTM. Our NBPM-MTM was proven to be more feasible and accurate in characterizing the progressive failure of rock and its associated AE than the traditional LBPM-MTM.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357772","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 the frost cracking behavior in clayey soils: A peridynamic approach","authors":"","doi":"10.1016/j.compgeo.2024.106765","DOIUrl":"10.1016/j.compgeo.2024.106765","url":null,"abstract":"<div><div>Frost cracking is one of the primary causes of deterioration in frozen soil structures, yet few relevant numerical studies have been reported, and the simulation of frost cracking in soils remains challenging due to inadequate consideration of reasonable simulation algorithms. Numerous experimental studies have identified frost heave and desiccation shrinkage as the principal cause of frozen soil cracking. On this basis, this study presents a peridynamic (PD) model that considers the coupled effects of frost heaving and desiccation shrinkage for simulating frost cracking in soils during freezing process. The heat conduction equation is reformulated using the peridynamic differential operator (PDDO). The variation of thermal parameters for soils is addressed using the thermal enthalpy method, equivalent homogeneous method, and linear release assumption of latent heat. The frost-heaving load induced by pore water is represented using an equivalent displacement load. The multiphysics solution using PDDO and bond-based peridynamics (BBPD) considering freezing heave and desiccation shrinkage is developed for the first time. By simulating the frost cracking of a two-dimensional soil strip after model validations, the resulting crack pattern closely resembles the experimental observation. It indicates that the present model can capture the phase transition interface (PTI) and cracking behaviors of frozen soils.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357770","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":"Bayesian Updating for Prediction of Scour Depth Using Natural Frequency of Monopiles","authors":"","doi":"10.1016/j.compgeo.2024.106793","DOIUrl":"10.1016/j.compgeo.2024.106793","url":null,"abstract":"<div><div>Scour is a non-negligible issue of monopiles that profoundly threatens the safety of monopile for offshore wind turbines (OWTs). Accurately predicting the scour depth is essential for the design and operation of OWTs. This study introduces a model aimed at predicting scour depth from the aspect of the natural frequency of monopile. The model is developed using uniform design samples to ensure its applicability across a wider range of OWT monopiles and soil properties. To enhance the model accuracy, a Bayesian framework is employed, incorporating prior information. The three main model coefficients are updated iteratively, allowing the predicted scour depth to converge with the observed values. The Monte Carlo Markov chain (MCMC) simulation is utilized to generate the posterior distribution. The model accuracy is validated through 48 representative samples, and the effectiveness of Bayesian updating in improving the model precision is demonstrated by comparing the results prior to and following Bayesian updating. Additionally, the numerical simulations and monitored data confirm the validity of the proposed prediction model.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327022","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":"Analytical prediction of displacement-dependent lateral earth pressure against stabilizing piles in sandy slopes considering arching effect","authors":"","doi":"10.1016/j.compgeo.2024.106776","DOIUrl":"10.1016/j.compgeo.2024.106776","url":null,"abstract":"<div><div>Accurate prediction of the magnitude and distribution of lateral earth pressure is essential for reliable structural design of stabilizing piles. Although there have been many analytical studies of the lateral load response of these piles, they inadequately quantify the pressure distribution under working conditions and primarily neglect the soil arching effect. This study proposes a novel analytical method for displacement-dependent analysis of the lateral earth pressure against piles in sandy slopes by considering soil arching effect. A shear resistance mobilization model was proposed to characterize the relation between the soil displacement and mobilized friction angle of soils. This was then incorporated within the slice element method to solve the profile of sliding wedge between two adjacent piles and the associated active lateral earth pressure. An improved arching model, capable of analyzing the noncircular arch shape, was combined with the active lateral earth pressure to calculate the lateral load transferred on the piles. Comparison of analytical results with experimental and numerical observations demonstrated that the proposed method can reliably predict the progressive development of nonlinear pressure distribution with soil displacement. Neglecting shear resistance mobilization and soil arching effect results in an overestimation of external forces applied to the piles. Meanwhile, parametric studies indicated that surcharge pressure exerts the greatest influence on resultant lateral force, followed by internal friction angle of soils, while slope angle and pile spacing have lower influences. Furthermore, the proposed method allows the capture of the influence of soil displacement profile and spatial arching behavior on the pressure distribution. This study facilitates a performance-based assessment of the lateral load response of piles in slopes, particularly in scenarios with scarce design parameters.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357771","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":"Investigating the effects of diverse cavity morphologies on the mechanism of tensile crack-induced collapse: A phase field method approach","authors":"","doi":"10.1016/j.compgeo.2024.106774","DOIUrl":"10.1016/j.compgeo.2024.106774","url":null,"abstract":"<div><div>Tensile crack-induced collapse is widely distributed in major mountainous areas of China, often result in sudden and catastrophic consequences due to the rapid movement of the falling bodies. To better understand the development of tensile crack-induced collapses, the phase field method, originally used for studying brittle fracturing, has been further applied in this research. Firstly, the application of the phase field method in modeling rock tensile failure is validated, demonstrating its effectiveness. The rationality of applying the phase field method for analyzing tensile crack-induced collapses has been thoroughly investigated, and solutions to address phase field disorder have been proposed. By incorporating heterogeneity features and implementing a prefabricated crack, both approaches can effectively address the issue of phase field disorder. However, the latter method aligns more closely with engineering practices. The present study provides a comprehensive investigation into the development of tensile crack-induced collapses with varying cavity morphologies. The corresponding change laws of tensile crack-induced collapses are systematically analyzed and summarized. Moreover, novel stability evaluation parameters, including reduction coefficients and safety points, are proposed and successfully applied in calculations. Our research on different cave morphologies has shown that the depth and shape of a cave, as well as the thickness and center of gravity of protruding rock masses, significantly influence the development process of tensile crack-induced collapse. This approach facilitates a comprehensive examination of the fracture process and yields valuable insights into the mechanics underlying tensile crack-induced collapses.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322556","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":"Large strain radial thermo-consolidation model for saturated soil foundation","authors":"","doi":"10.1016/j.compgeo.2024.106788","DOIUrl":"10.1016/j.compgeo.2024.106788","url":null,"abstract":"<div><div>Based on the piecewise-linear approach, a large strain nonlinear radial thermo-consolidation model for saturated soil foundation, called RTCS1, is established. The model uses the finite difference method to solve the governing equations of radial heat transfer in the soil layer and couples it with large strain radial consolidation. RTCS1 accounts for thermal effect, thermal expansion, time-dependent load increment and time-dependent heat source temperature, unload/reload effects, radial and vertical flows, equal strain and equal stress, and the nonlinear changes of soil parameters during thermo-consolidation process. Validation of the model is conducted through laboratory and field test of thermo-consolidation from existing literature, and the RTCS1 numerical solution for settlement is in good agreement with the test values. Computational examples are presented to explore the effect of strain condition, strain magnitude, and heating mode on the thermo-consolidation of saturated soil foundations. The findings indicate that the consolidation rate under equal strain condition is greater than that under equal stress condition, the lager strain leads to faster heat transfer. Under the cyclic heating modes, the excess pore pressure cannot be completely dissipated, and the soil settlement, temperature and excess pore pressure fluctuated with time.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":null,"pages":null},"PeriodicalIF":5.3,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322553","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}