Acta Geotechnica最新文献

{"title":"Avalanches and failures in bio-stimulated soils","authors":"Yang Xiao,&nbsp;Bingyang Wu,&nbsp;Xiang Jiang,&nbsp;Wenjun Fan,&nbsp;Hao Cui","doi":"10.1007/s11440-024-02500-y","DOIUrl":"10.1007/s11440-024-02500-y","url":null,"abstract":"<div><p>Bio-stimulation is a popular method to improve the engineering properties of soils because it treats the soils by using native bacteria which is environmentally friendly. However, the failure mechanism of bio-stimulated soils has not been studied. In this work, we apply avalanche dynamics which has been used in the investigation of bio-augmented sands to analyze the avalanche characteristics and failure mechanisms of bio-stimulated soils. We find the average relative magnitude, waiting time distribution and aftershock distribution are independent of the degree of cementation when the calcium carbonate precipitation content ranges from 14% to 27%. Additionally, the exponents in the mean-field thory indicate the failure of bio-stimulated soils is not brittle. Furthermore, we find the failure mechanism of bio-stimulated soils is a mixture of fracture and intergranular movement. During the failure process of bio-stimulated soils, the fracture behavior becomes more obvious with an increase in degree of cementation. At the pre-peak stage, the proportion of intergranular movement gradually increases in the mixture of fracture and intergranular movement with the loading process. The main failure mechanism at the whole stage and post-peak stage is intergranular movement. The findings may contribute to the further investigation of the mechanical behavior exhibited by bio-stimulated soils.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1911 - 1920"},"PeriodicalIF":5.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716963","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":"New simplified stability analysis method of structuralized cemented slopes","authors":"Sujia Liu,&nbsp;Fangyue Luo,&nbsp;Ga Zhang","doi":"10.1007/s11440-024-02495-6","DOIUrl":"10.1007/s11440-024-02495-6","url":null,"abstract":"<div><p>In recent years, structuralized cementation method has become a novel and promising method for reinforcement of coarse-grained soil slope, which has been proved by practical application. Nevertheless, structuralized cemented slopes with gradient material properties cannot be analyzed using the current methods. The structuralized cemented slope is divided into pure soil zone, variation zone, and solidification zone. The constitutive models of cemented soil in the three zones are proposed, respectively. Slip surfaces of structuralized cemented slopes are all assumed as circular arc shape. It is proved that the displacement compatibility rule is valid for the structuralized cemented slope. A new simple approach is proposed through extension of simplified Bishop slice approach for analyzing structuralized cemented slope stability degree with different cement distribution under various conditions. Our proposed approach involves few parameters examined by element tests. Through analyzing structuralized cemented slopes based on vertical loading and excavation conditions, our proposed method is validated, showing agreement with centrifuge model test analysis. Application of this approach to an actual slope based on excavation conditions reveals that an expanded solidification zone enhances slope safety and reduces shear deformation. Stability remains relatively constant once the solidification zone reaches a certain size. This result underscores the practical value of the proposed method in predicting and optimizing the stability of structuralized cemented slopes.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"23 - 36"},"PeriodicalIF":5.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963150","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":"Super-large-scale triaxial tests to study the effects of particle size on the monotonic stress–strain response of rockfill materials","authors":"Fanwei Ning,&nbsp;Jingmao Liu,&nbsp;Degao Zou,&nbsp;Xianjing Kong,&nbsp;Gengyao Cui","doi":"10.1007/s11440-024-02471-0","DOIUrl":"10.1007/s11440-024-02471-0","url":null,"abstract":"<div><p>Owing to the lack of super-large-scale triaxial apparatuses, the prediction of field behaviour involving rockfill materials is commonly based on laboratory test data, which are often unreliable due to size scaling. In this work, a newly developed super-large-scale triaxial apparatus able to accommodate a sample diameter of up to 1000 mm was introduced to analyse the effects of particle size on the monotonic stress–strain response of rockfill materials. A series of triaxial tests was conducted with maximum particle sizes <i>d</i>_max of 200 mm, 160 mm, and 60 mm in parallel grading to investigate the effects of particle size on the strength and deformation behaviour of Rumei rockfill materials. The results indicated that the peak friction angle<i> ϕ</i>_p, peak dilation angle <i>ψ</i>_p and secant modulus at 50% of the peak strength <i>E</i>₅₀ decreased with increasing <i>d</i>_max and the particle breakage was enhanced as <i>d</i>_max increased. A unified linear relationship between <i>ϕ</i>_p and <i>ψ</i>_p was observed, regardless of <i>d</i>_max, and an equation considering <i>d</i>_max and the confining pressure was proposed to simulate <i>E</i>₅₀. These rare super-large-scale triaxial data can provide a valuable reference for assessing the effects of particle size on the strength and deformation behaviour of rockfill materials.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1847 - 1858"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716939","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 burgers model for sliding zone soil subjected to cyclic seepage pressure and its applications to the deformation analysis of landslide","authors":"Yabo Li,&nbsp;Xinli Hu,&nbsp;Haiyan Zhang,&nbsp;Hongchao Zheng,&nbsp;Chu Xu","doi":"10.1007/s11440-024-02488-5","DOIUrl":"10.1007/s11440-024-02488-5","url":null,"abstract":"<div><p>Numerous incidents and failures of bank slopes are caused by the creep behavior of sliding zone soil. During reservoir regulation, the pore water pressure in the sliding zone undergoes cyclic changes. Under such complex cyclic hydraulic conditions, the creep behavior may differ from that under the monotonic seepage condition, which is still poorly understood. In this paper, the Majiagou landslide in the Three Gorges Reservoir area is taken as a case study. Triaxial creep tests were first carried out to study the creep behavior of the sliding zone soil specimen under cyclic seepage pressure. Then, the nonlinear Burgers creep model was proposed to characterize the observed creep behavior of the sliding zone soil specimen, and the secondary development was performed based on FLAC3D software. Finally, the proposed model was applied to the Majiagou landslide to simulate its deformation under fluctuating reservoir water levels. The following results were obtained: (1) Under low deviatoric stress levels, cyclic seepage pressure causes the creep strain curve to fluctuate significantly. The decrease of seepage pressure leads to a reduction in pore pressure, resulting in a sharp increase in the strain rate of sliding zone soil. (2) The proposed model can well reflect the creep characteristics of sliding zone soil under cyclic seepage pressure. (3) During reservoir operation, the landslide deformation exhibits a step-like growth, and the proposed creep model can effectively simulate the retrogressive deformation characteristics of the Majiagou landslide. The research results provide the theoretical basis for the long-term stability of reservoir landslides under fluctuating water levels.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"743 - 763"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361898","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":"Rev assessment of granular materials with varied grading based on macro- and micro-mechanical statistical data","authors":"Paula Quiroz-Rojo,&nbsp;David Cantor,&nbsp;Mathieu Renouf,&nbsp;Carlos Ovalle,&nbsp;Emilien Azéma","doi":"10.1007/s11440-024-02498-3","DOIUrl":"10.1007/s11440-024-02498-3","url":null,"abstract":"<div><p>To assess the mechanical behavior of granular materials in triaxial tests, a mandatory condition is to guarantee a representative elemental volume (REV) sample. This is achieved by limiting the minimum sample size and the coarsest particle in the sample (<span>(d_textrm{max})</span>). The common geotechnical practice is based on the sample scales <i>H</i>/<i>D</i> and <span>(alpha = D/d_textrm{max})</span>, where <i>D</i> is the sample diameter and <i>H</i> is its height. While, it is widely accepted that <i>H</i>/<i>D</i> should be between 2 and 2.5, international standards do not agree on the minimum <span>(alpha)</span>, and the recommended values vary widely between 5 and 20. Moreover, the impact of particle size distribution on REV is not well understood and is consequently overlooked by most standards. In this paper, we present a study of the effects of <span>(alpha)</span> and grading on the critical shear strength of granular materials. We conducted DEM simulations of triaxial tests on samples with values of <span>(alpha)</span> ranging from 5 to 20 and grading that varied from mono-size particle assemblies to samples, where the ratio between the coarsest and finest particle was <span>(d_textrm{max}/d_textrm{min} = 4)</span>. The results show that the minimum <span>(alpha)</span> required to obtain an REV depends on grading. While, for mono-size particle assemblies REV conditions are obtained for <span>(alpha ge 12.5)</span>, better graded samples behave as REV once <span>(alpha ge 8)</span>. A detailed analysis of macro and microscopic parameters reveals that <span>(alpha)</span> is not necessarily the most suitable parameter to assess REV scales. We discover that, in our samples, a unique relationship between critical shear strength and the number of grains carrying interparticle forces (<span>(N_p^*)</span>) exists independently of grading. In effect, REV can be systematically defined as long as <span>(N_p^* ge 3000)</span>. The physical source of this observation is linked to the evolution of contact arrangement and force transmission mechanisms, which evolve according to the number of particles engaged in load bearing.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1585 - 1598"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716940","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":"On rotational hardening in soil elastic-plasticity","authors":"Giuseppe Mortara,&nbsp;Claudio di Prisco","doi":"10.1007/s11440-024-02458-x","DOIUrl":"10.1007/s11440-024-02458-x","url":null,"abstract":"<div><p>In this paper, a new approach for rotational hardening in elastic-plasticity is formulated. After discussing the standard yield criteria employed for geomaterials and the rotational hardening models proposed in the past, the authors introduce the concept of pure rotational hardening, that is a rigid rotation of the yield surface not implying any distortion of it. In the second part of the paper, a new approach for rotational hardening, based on Householder transformations, is proposed. The method, that allows to reflect vectors with respect to a given hyper-plane, is briefly described since not usually employed in geomechanics. Moreover, the authors clarify that any yield surface or plastic potential rotation, not being a rolling, is a transformation keeping unaltered first and second invariants, but not the third. As a consequence, when rotational hardening is introduced, the use of the third mixed invariant, for defining in the deviatoric plane the yield surface shape, is not appropriate. Finally, the application of the proposed approach in the formulation of anisotropic elastic–plastic strain hardening constitutive models is briefly discussed for the classes of <i>uncoupled</i> and <i>hybrid</i> yield criteria that include a dependence of the yield surface on Lode angle.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"197 - 210"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963053","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":"An efficient image processing methodology for rapid 3D size and shape parameter extraction of multiple particles","authors":"Kun Fang,&nbsp;Jiefei Zhang,&nbsp;Huiming Tang,&nbsp;Honghui Yuan,&nbsp;Xiaolong Hu,&nbsp;Pengju An,&nbsp;Xiaotao Wang","doi":"10.1007/s11440-024-02497-4","DOIUrl":"10.1007/s11440-024-02497-4","url":null,"abstract":"<div><p>Accurate, fast, and automatic measurement of 3D size and shape parameters for multiple particles is essential for understanding their characteristics and behavior across different site conditions. This study proposes an efficient methodology for determining particle size and shape parameters using image processing techniques. The approach allows for quick measurement of multiple particles, with an easy setup for automatic segmentation and extraction the 3D parameters, while also exploring influencing factors and optimal setting. The method involves four key processes: image capturing, 3D models reconstruction, single-particle segmentation, and data acquisition. It combines computer vision algorithms and point cloud processing technology to extract 3D data from multiple particle images captured using a smartphone camera. By comparing the results from a 3D laser scanner, the method for 25 particles is assessed using error percentage in the laboratory under various influencing factors, including particle size, shooting angle, object-to-camera distances, and the number of captured images. Additionally, a site investigation of the methodology is executed and contrasted with sieve analysis. The results show an error percentage of less than 10% when using a 12-megapixel smartphone camera at a 45° capturing angle with 36 images. With rapid data acquisition, semi-automatic analysis, a simple, low-cost setup, and minimal error, the method proves efficient in capturing 3D size and shape parameters for multiple particles.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1891 - 1909"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716883","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":"Soybean-urease-induced CaCO3 precipitation as a new geotechnique for improving expansive soil","authors":"Mingdong Li,&nbsp;Wei Liu,&nbsp;Jingwu Zhang,&nbsp;Chaopeng Lang,&nbsp;Guizhong Xu,&nbsp;Liping Zhu,&nbsp;Qiang Tang","doi":"10.1007/s11440-024-02481-y","DOIUrl":"10.1007/s11440-024-02481-y","url":null,"abstract":"<div><p>In this study, soybean-urease-induced CaCO₃ precipitation (SICP) was proposed as a new geotechnique for improving expansive soil without precedent. SICP-reinforced expansive soil (SRES) specimens, as well as unreinforced expansive soil specimens as control samples were prepared following standard proctor tests at various moisture contents (20, 23, 26, 29, and 32%). Differential free swell tests, expansive potential tests, swelling pressure tests, shrinkage tests, compression tests, direct shear tests, unconfined compression tests, particle size analysis tests, and scanning electron microscope tests were carried out on the specimens. The results reveals that SICP reinforcement prompts distinct increases in compacted dry density, UCS, cohesion, and internal friction angle of expansive soil, while induces a remarkable reduction in DFS, swell potential, swelling pressure, and shrinkage of expansive soil. For instance, the compacted maximum dry density increases from 11.5 kN/m³ for UES to 12.5 kN/m³ for SRES and the optimum moisture content decreases correspondingly from 26.4% for UES to 23.6% for SRES. Furthermore, the reinforcing mechanics of SICP for expansive soil are analyzed and graphically presented. In conclusion, this research identifies SICP reinforcement to be an effective solution to problematic expansive soil and provides fundamental data for engineering practices.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1877 - 1890"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716884","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":"Quantifying water adsorption ability of unsaturated soil by soil water isotherm","authors":"Yijie Wang,&nbsp;Zhen-Yu Yin,&nbsp;Liming Hu","doi":"10.1007/s11440-024-02490-x","DOIUrl":"10.1007/s11440-024-02490-x","url":null,"abstract":"<div><p>Adsorption plays a crucial role in governing soil water retention and significantly effects the hydromechanical behavior of unsaturated soil, which is, however, often overlooked. This study proposes that a thorough evaluation of soil adsorption ability should be undertaken by considering two perspectives: the specific surface area (SSA) and adsorption strength per unit area (soil sorptive potential, SSP). To achieve this, a soil water isotherm (SWI)-based method is developed to determine them, which considers the temperature effects and allows SWI measured at arbitrary temperatures as input. It solves the SSA and SSP coupling from the SWI, avoiding inaccurate SSA results caused by ignoring SSP. Experimental and simulated data validate the generality and accuracy of the method. The analyses reveal that sorption energy plays a pivotal role in the spatial variation and temperature dependence of SSP. Moreover, it is evident that SSA and SSP are independent quantities that can describe the soil adsorption ability and determine the adsorbed water content together. In comparison with existing methods, the proposed method exhibits higher accuracy, requires fewer fitting parameters, and is applicable across a wider temperature range. This study provides a new approach for comprehensively assessing the adsorption ability of soil under various environmental conditions.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 4","pages":"1723 - 1742"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716941","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":"Lateral capacity and failure mechanisms of skirted foundation resting on slopes","authors":"Khalid Bashir,&nbsp;Ravi S. Jakka","doi":"10.1007/s11440-024-02486-7","DOIUrl":"10.1007/s11440-024-02486-7","url":null,"abstract":"<div><p>While the effect of combined loading on the load carrying capacity of skirted foundations on horizontal ground surfaces is well documented in the literature, comprehensive studies for skirted footings situated on or near slopes remain lacking. This study aims to investigate the influence of various factors, including slope angle (<i>β</i>), angle of internal friction (<i>ϕ</i>), setback distance (<i>B′</i>/<i>B</i>), and skirt length (<i>L</i>/<i>B</i>), on failure loads and capacity envelopes for skirted foundations. The performance of a skirted footing system under combined vertical and lateral loadings in cohesionless soils was analysed using finite-element limit analysis (FELA) and small-scale experimental tests. The results indicate that the optimal skirt length depends on the specific conditions of the slope and setback distances. As the setback distance increases, the optimal skirt length tends to decrease, while an increase in slope steepness corresponds to an increase in the optimal skirt length. Furthermore, this study presents integrated capacity envelopes that incorporate a wide range of realistic soil slopes. The calculated capacity envelopes are subsequently compared to those on flat ground, highlighting that the unique characteristics of these envelopes are based on different combinations of vertical load (<i>V</i>) and combined vertical and lateral load (VH). Skirted footings on slopes exhibit distinct behaviour compared to those on level ground, with multiple factors influencing their capacity envelopes. Specifically, skirted foundations demonstrate lower capacity than equivalent block foundations, particularly when placed near steep slopes due to the formation of an inverted circular scoop failure surface for larger <i>L</i>/<i>B</i> ratios. In contrast, the formation of an inverted circular scoop is less pronounced for moderate slopes and footings with a smaller <i>L</i>/<i>B</i> ratio. The numerical study provides a comprehensive explanation of the failure mechanisms associated with the design of skirted footings located in close proximity to slopes, especially when subjected to lateral loads. Based on the results obtained, capacity envelope diagrams are proposed for estimating the capacity of skirted footings on slopes. Small-scale experiments were also conducted to explore the effects of varying skirt lengths placed on both level and sloping ground within a testing tank. The outcomes of this study yield valuable insights into the behaviour of skirted foundations on slopes, as well as their overall response to both vertical and lateral loadings.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"89 - 117"},"PeriodicalIF":5.6,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963054","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}