Acta Geotechnica最新文献

{"title":"Response to Comment on “Undrained shear strength prediction of clays using liquidity index”","authors":"Qiusheng Wang,&nbsp;Songnan Qiu,&nbsp;Hong Zheng,&nbsp;Ruitao Zhang","doi":"10.1007/s11440-025-02540-y","DOIUrl":"10.1007/s11440-025-02540-y","url":null,"abstract":"<div><p>O’Kelly et al. critique the Wang et al. undrained shear strength prediction model paper in terms of its utility and accuracy. Both criticisms suffer from the miscomprehension of the model comparison method. Utility of the three-parameter liquidity index (<i>I</i>_<i>L</i>)—undrained shear strength (<i>S</i>_<i>u</i>) models has been enhanced through optimizing some empirical equation.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1499 - 1501"},"PeriodicalIF":5.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571013","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 poromechanical framework for hydraulic fracturing processes in transversely isotropic rocks","authors":"Weihong Yuan,&nbsp;Yang Zhao,&nbsp;Bingyin Zhang","doi":"10.1007/s11440-025-02541-x","DOIUrl":"10.1007/s11440-025-02541-x","url":null,"abstract":"<div><p>We present a poromechanical framework for hydraulic fracturing processes in transversely isotropic rocks. We derive the conservation laws and effective stress formulation for the coupled solid deformation, damage evolution, and fluid flow processes in porous rocks based on the mixture theory and continuum thermodynamics. For the modeling of hydraulic fracture propagation in transversely isotropic rocks, a recently developed double-phase-field model is adopted that considers fracture initiation through the rock matrix and along the weak bedding planes. The finite element framework for the coupled processes is introduced in detail as a <span>(u-p-d)</span> formulation, and the staggered numerical solution scheme is adopted that updates the displacement and pore pressure fields first and then the phase-field variables. We then conduct element-level simulations to verify the proposed framework. Lastly, we investigate the hydraulic fracturing processes for both isotropic and transversely isotropic rocks. The impact of bedding plane orientations, strength ratios between the rock matrix and bedding planes, strength anisotropy levels of the rock matrix, and tectonic stress conditions on the initiation and propagation of hydraulic fractures in transversely isotropic rocks are studied.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"2049 - 2073"},"PeriodicalIF":5.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919312","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 biostimulation treatment methods on mechanical properties and microstructure characteristics of biocemented soil","authors":"Wenjun Fan,&nbsp;Yang Xiao,&nbsp;Baofeng Cao,&nbsp;Shifan Wu,&nbsp;Hao Cui,&nbsp;Jian Chu,&nbsp;Hanlong Liu","doi":"10.1007/s11440-025-02548-4","DOIUrl":"10.1007/s11440-025-02548-4","url":null,"abstract":"<div><p>The objective of the current study is to explore the effect of biostimulation treatment methods on the mechanical properties and microstructure characteristics of biocemented soil. Biostimulated microbially induced carbonate precipitation (MICP) is an eco-friendly and economical soil reinforcement measure. It relies on the stimulation of the urease-producing bacteria (UPB) in situ for the MICP process. Different biostimulation treatment methods involve different oxygen availability, stimulation solution content and distribution, and number of biostimulation treatments. There may be differences in the effect of UPB stimulation and biocementation when different biostimulation treatment methods are used. In this study, four biostimulation treatment methods, i.e., unsaturated single biostimulation treatment (USBT), unsaturated multiple biostimulation treatments (UMBT), saturated single biostimulation treatment (SSBT) and saturated–unsaturated-combined single biostimulation treatment (CSBT), were used to stimulate native UPB in soil columns, and then, the same cementation treatment was applied to the soil columns. Subsequently, the mechanical behavior and microstructural properties of the biocemented soil were investigated. The results indicated that the saturated single biostimulation treatment was more conducive to stimulating native UPB to induce CaCO₃ precipitation. Samples subjected to the saturated single biostimulation treatment exhibited higher CaCO₃ precipitation content (<i>CCP</i>), dry density, unconfined compressive strength (UCS) and lower permeability within the same cementation treatment cycle (<i>N</i>_<i>C</i>). However, UCS was not only determined by <i>CCP</i>, but was also regulated by CaCO₃ spatial distribution and precipitation pattern. This study could help guide the selection of biostimulation treatment methods.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"2163 - 2184"},"PeriodicalIF":5.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919309","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 automatic estimation of soil constitutive model parameters via particle swarm optimization","authors":"Takayuki Sakai,&nbsp;Masaki Nakano","doi":"10.1007/s11440-024-02454-1","DOIUrl":"10.1007/s11440-024-02454-1","url":null,"abstract":"<div><p>In this study, we automatically estimated the parameters of the modified Cam-Clay model, a representative constitutive model for soil. The estimation was carried out by minimizing the objective function using the dynamic multiswarm particle swarm optimization (DMS-PSO) algorithm, which is an improvement over the original PSO. The objective function was newly defined by quantifying the discrepancy between the targeted results and the model calculations in <i>q</i>-<i>p</i>′-<i>v</i> space. DMS-PSO divides particles into several islands to search globally and prevent local solutions, and even particles that fall into a local solution can be relocated. To evaluate the automatic estimation performance of DMS-PSO, we examined whether model parameters could be correctly estimated from the calculation results (Consideration (1)) and whether the DMS-PSO algorithm could consistently obtain the same parameter values when reproducing the experimental results (Consideration (2)). Regarding Consideration (1), the objective function was consistently smaller than 1.0 × 10^–6 when the number of particles was greater than 400 and the number of islands was greater than 40. At this time, the parameter values could be estimated to the fifth decimal place. When two experiments were conducted, the estimation was obtained approximately 1.5 times faster than when only one was conducted. Regarding Consideration (2), the coefficient of variation of the parameters obtained from 100 estimations was at most 1%, and the parameter values were estimated to be approximately the same each time. In addition, narrowing the solution search range based on soil physical properties could reduce the variation in parameters by approximately 10%. Additionally, the parameters could be accurately estimated by data from at least two mechanical experiments.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1001 - 1017"},"PeriodicalIF":5.6,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02454-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570969","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":"Dynamics of particle segregation and its impact on mechanical properties","authors":"Shaoheng Dai,&nbsp;Feng Gao,&nbsp;Gang Niu,&nbsp;Xuzhen He,&nbsp;Sheng Zhang,&nbsp;Daichao Sheng","doi":"10.1007/s11440-025-02547-5","DOIUrl":"10.1007/s11440-025-02547-5","url":null,"abstract":"<div><p>Particle segregation is a widespread phenomenon in nature. Vertical vibration systems have been a focal point in studying particle segregation, providing valuable insights into the mechanisms and patterns that influence this process. However, despite extensive research on the mechanisms and patterns of particle separation, the consequences, particularly the mechanical properties of samples resulting from particle segregation, remain less understood. This study aims to investigate the segregation process of a binary mixture under vertical vibration and examine the consequences through monotonic and cyclic triaxial drained tests. The results reveal that large and small particles segregate nearly simultaneously, with more thorough separation observed for large particles. The segregation index, <i>D</i>_<i>s</i>, effectively describes this evolution process, offering a quantitative metric for both mixing and segregation. Granular temperature analysis unveils three distinct states during segregation: solid-like, fluid-like, and solid–liquid transitional phase, corresponding to varying activity levels of particle segregation. Drained triaxial shear tests demonstrate the sensitivity of stress–strain relationships to the degree of segregation. Interestingly, ultimate strength is found to be essentially unrelated to the degree of segregation. When the segregation index approaches zero, signifying particles approaching a uniform distribution, the granular system reaches a harmonic state. This state exhibits optimal mechanical performance characterised by maximum peak stress, friction angle, and the highest elastic modulus. These findings underscore the potential impact of segregation on the mechanical response of granular mixtures and emphasise the necessity of a comprehensive understanding of particle segregation in soil mechanics.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"1991 - 2007"},"PeriodicalIF":5.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-025-02547-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919004","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":"A coupled hydro-mechanical field-enriched finite element method for simulating the hydraulic fracture process of rocks subjected to in situ stresses","authors":"Linyuan Han,&nbsp;Xiaoping Zhou","doi":"10.1007/s11440-024-02518-2","DOIUrl":"10.1007/s11440-024-02518-2","url":null,"abstract":"<div><p>A coupled hydro-mechanical field-enriched finite element method (HM-FE-FEM) is developed for simulating the hydraulic fracture process of rocks subjected to in situ stresses. The staggered iterative scheme based on the Newton–Raphson iterative algorithm is utilized to address the coupled hydro-mechanical problems. The opening process of the hydraulic fracture and natural fracture subjected to in situ stresses can be reproduced by the proposed method. The accuracy of the proposed method is verified through stress intensity factor, fracture opening and experiment results. For coalescence patterns between hydraulic and natural fractures, the influences of horizontal stress difference and intersection angle are analyzed and discussed. Additionally, for coalescence patterns between hydraulic fracture and natural karst caves, the influences of cave location, cave radius and horizontal stress difference are investigated and discussed. The numerical results illustrate the effectiveness of HM-FE-FEM in handling the complex coalescence behaviors in the hydraulic fracture process of underground rock reservoirs with different defects. This study has a certain guiding significance for optimizing the fracturing operation parameters.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1315 - 1339"},"PeriodicalIF":5.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570922","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":"Packing fraction effect on dynamic creep deformation of granular materials","authors":"Lihong Tong,&nbsp;Li Fu,&nbsp;Bingni Wu,&nbsp;Changjie Xu,&nbsp;C. W. Lim","doi":"10.1007/s11440-024-02459-w","DOIUrl":"10.1007/s11440-024-02459-w","url":null,"abstract":"<div><p>The rheological properties and creep dynamical behavior of the granular materials are significantly influenced by the packing fraction. The granular materials with a low packing fraction tend to transit from a solid-like to liquid-like state. The strain evolution and deformation characteristics of granular materials under different packing fractions are investigated by triaxial creep tests. The result indicates that a critical packing fraction exists for the granular system under specific external loading conditions, below which the system will be broken in a short period of time. Conversely, for packing fraction that exceeds the critical value, the granular material system exhibits logarithmic creep dynamics and eventually reaches a steady state. To characterize the creep behaviors of granular materials under dynamic loading, a state evolution model is introduced. The model is verified by combining the theoretical predictions with the experimental observations. Furthermore, parametric analysis is also implemented based on the introduced model. The results demonstrate that the model can capture the fundamental spatiotemporal evolution characteristics of granular materials which are subjected to dynamic loading conditions.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"2135 - 2144"},"PeriodicalIF":5.6,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919114","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":"Field and 3D numerical investigation on bearing characteristics of the long-core SDCM piles under vertical load in sandy soil","authors":"Zhiyu Gong,&nbsp;Guoliang Dai,&nbsp;Weiwei Xu,&nbsp;Xinsheng Chen,&nbsp;Hongbo Liu","doi":"10.1007/s11440-025-02533-x","DOIUrl":"10.1007/s11440-025-02533-x","url":null,"abstract":"<div><p>The stiffened deep cement mixing (SDCM) pile is a new composite pile type, which is a stiffened core inserted into the cemented soil, compared to the DCM pile structure. The SDCM pile not only combines the advantages of DCM piles, but also improves the corresponding bearing capacity<b>.</b> In this paper, the bearing characteristics (the ultimate bearing capacity, the pile end resistance and the pile side friction) of PHC pipe pile and the long-core SDCM piles with number of different piles are investigated through field tests. The ultimate bearing capacities of PHC pipe pile, the long-core SDCM pile and the double long-core SDCM pile are 5.82, 8.23 and 14.67 MN. Combined with finite element analysis, it was found that the long-core SDCM pile is a friction pile in sandy soil, the cemented soil can provide lateral friction resistance and its role in bearing the vertical load is cannot be ignored. Parametric analyses were carried out for parameters: the length ratio of the cemented soil and PHC pipe pile (<i>L</i>_C/<i>L</i>_P), the radius ratio of the cemented soil and PHC pipe pile (<i>R</i>_C/<i>R</i>_P) and the modulus of elasticity of PHC pipe pile (<i>E</i>_P) on the long-core SDCM pile with the objective of ultimate bearing capacity. The ultimate bearing capacity will be increased with increasing in <i>L</i>_C/<i>L</i>_P and <i>R</i>_C/<i>R</i>_P, and changes in <i>E</i>_P will not affect the ultimate bearing capacity. Finally, the bearing capacity equations of the long-core SDCM pile were adjusted with the results of the study.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1341 - 1362"},"PeriodicalIF":5.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571156","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":"Mesoscale simulation of the compression and small-strain elastic shear behavior of illite nanoparticle assemblies","authors":"Hejian Zhu,&nbsp;Andrew J. Whittle,&nbsp;Roland J.-M. Pellenq","doi":"10.1007/s11440-024-02440-7","DOIUrl":"10.1007/s11440-024-02440-7","url":null,"abstract":"<div><p>The mechanical properties of clay minerals are largely dependent upon the chemical compositions and the mesoscale fabrics of the constituent particles. This paper describes results of a series of mesoscale molecular dynamics simulations of the hydrostatic compression and shear strain behavior for initially randomly oriented assemblies of 10³ illite primary particles. The particles are simulated as rigid-body ellipsoids that interact through the single-site, Gay–Berne potential function. This corresponds to a coarse-grained model based on prior atomistic scale computation of the potential of mean force for water-mediated interactions between pairs of particles through free energy perturbation method. We investigate the mesoscale fabrics of the NPT-equilibrated assemblies for confining pressures ranging from 1.0 to 125 atm, including path dependence associated with unloading and reloading. We analyze and quantify the geometric arrangement including particle orientation, specific surface area, properties of particle stacks/aggregates, and interstack pair correlation functions. The compression of each particle assembly is associated with large irrecoverable changes in void ratio, while unloading and reloading involves much smaller, largely recoverable volumetric strains. The results are qualitatively similar to macroscopic compression behavior reported in laboratory tests. We simulate the uniaxial and shear behavior at each of the equilibrated pressure states through a series of strain-controlled steps, allowing full relaxation of the virial stresses computed at each step. The simulations investigate directional and path dependence of the shear behavior for strain deviations up to 0.2%. The results show the onset on nonlinear stiffness properties at strain levels <span>(sim)</span>0.01% and hysteretic behavior upon unloading and reloading. Small-strain stiffness properties of the particle assemblies are qualitatively in good agreement with quasi-static, elastic stiffness properties reported for illitic clays.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"781 - 802"},"PeriodicalIF":5.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362109","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":"Assessment of Young’s modulus of small-sized rock samples based on macroindentation testing","authors":"Yujie Luo,&nbsp;Yang Zhang,&nbsp;Qian Wang,&nbsp;Jinliang Song,&nbsp;Dawei Hu,&nbsp;Hui Zhou","doi":"10.1007/s11440-024-02520-8","DOIUrl":"10.1007/s11440-024-02520-8","url":null,"abstract":"<div><p>Assessing the Young’s modulus of deep rock formations is essential for deep rock engineering. However, obtaining high-quality cores remains challenging. This study introduces a macroindentation method to evaluate the Young’s modulus of small-sized rock samples, which are easier to obtain. Comprehensive experiments were conducted on fused quartz, shale, sandstone, limestone, and granite, and the <span>(Phi)</span>1 mm and <span>(Phi)</span>2.5 mm Brinell indenters were found to provide consistent results. Numerical simulations demonstrated the influence of substrate effect on indentation depth, and system compliance was defined to account for the combined effects of machine deformation and substrate effect. An improved five-step loading method was developed to calibrate system compliance, yielding results comparable to those from uniaxial compression tests. This method offers a practical alternative for evaluating the mechanical properties of rocks in deep engineering applications.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"2257 - 2278"},"PeriodicalIF":5.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919142","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}