Acta Geotechnica最新文献

{"title":"Coupling effects on class C predictions of soft soil settlements","authors":"Shan Huang,&nbsp;Jinsong Huang,&nbsp;Richard Kelly,&nbsp;Shui-Hua Jiang,&nbsp;Merrick Jonse,&nbsp;A. H. M. Kamruzzaman","doi":"10.1007/s11440-024-02422-9","DOIUrl":"10.1007/s11440-024-02422-9","url":null,"abstract":"<div><p>In uncoupled consolidation analysis, settlement and pore water pressure are solved independently, whereas in coupled analysis, they are solved simultaneously to ensure continuity (i.e., the volume change in soil due to compression must equal the water volume change caused by dissipation). This study investigates the coupling effects of soil deformation and pore water pressure dissipation in the back analysis of soft soil settlements. It further evaluates the suitability of both coupled and uncoupled constitutive models with different types of monitoring data, providing practical guidance for selecting consolidation models and achieving reliable long-term predictions. The one-dimensional governing equations for soft soil consolidation, incorporating prefabricated vertical drains and creep deformation, are first reviewed. A case study of a trial embankment in Ballina, New South Wales, Australia, is then used to demonstrate the impact of coupling effects and monitoring data on settlement predictions. The results show that considering coupling effects not only improves long-term settlement predictions but also reduces uncertainties in the updated soil parameters, especially when both settlement and pore water pressure data are used.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"723 - 742"},"PeriodicalIF":5.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02422-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362106","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":"Experimental study on the mechanical behavior of artificially prepared stratified soil in triaxial compression tests","authors":"Lisha Luo,&nbsp;Yang Yang,&nbsp;Zhifu Shen,&nbsp;Wangcheng Zhang,&nbsp;Zhihua Wang,&nbsp;Xudong Wang,&nbsp;Hongmei Gao,&nbsp;Qier Xu","doi":"10.1007/s11440-024-02426-5","DOIUrl":"10.1007/s11440-024-02426-5","url":null,"abstract":"<div><p>Stratified soil is a type of widely distributed special soil, consisting of alternating interlayered soils with distinct properties in both terrestrial and marine sedimentation conditions. It is endowed with anisotropic physical properties and mechanical behavior by its unique laminar structure features. So far, its mechanical behavior has not been fully understood. To systematically investigate the laminar structure effects of stratified soil, artificially prepared stratified soil samples of silty clay interlayered by silty sand were studied. First, the laminar structure features of stratified soil in Yangtze River floodplain deposits at Nanjing, China, were summarized. Then, based on the laminar structure features, preparation method for stratified soil samples was proposed by stacking soil layers one by one, which was basically an integration of <i>soil paste plus consolidation method</i> for silty clay layer preparation and <i>water pluviation plus freezing method</i> for silty sand layer preparation. After verification of the sample preparation method, a series of consolidated-undrained triaxial compression tests were carried out to study the mechanical behavior of stratified soil. The effects of thickness of constituent layers, consolidation conditions (isotropic or anisotropic consolidation), and loading paths (conventional triaxial compression, constant-<i>p</i> compression, and lateral extension) were investigated. The results show that the mechanical behavior of stratified soil (including stress–strain curves, excessive pore pressure accumulation, sample failure modes, and strength index) generally falls in between the behavior of the two constituent layers of soil, i.e., a normally consolidated silty clay and a medium-dense silty sand. The silty clay layer thickness (with fixed silty sand layer thickness), consolidation conditions, and loading paths together determine the stratified soil behavior, either silty sand dominant or silty clay dominant. Laminar structure can improve volumetric dilation trend and thus increase undrained shear strength of stratified soil. The presence of silty clay layer would suppress shear banding development in stratified soil. The strength of stratified soil can be underestimated by experiments using disturbed or remolded samples where the laminar structure is partially or completely lost.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"543 - 562"},"PeriodicalIF":5.6,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361801","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":"Experimental investigation of fracture permeability reduction process by MICP technology with Sporosarcina pasteurii cultured by different mediums","authors":"Lei Shi,&nbsp;Haiyang Qiao,&nbsp;Xiao Yang,&nbsp;Bin Zhang,&nbsp;Jianwei Zhang","doi":"10.1007/s11440-024-02425-6","DOIUrl":"10.1007/s11440-024-02425-6","url":null,"abstract":"<div><p>This study conducted a detailed investigation on the influence of the culture medium type on the permeability reduction effect through microbial-induced calcium carbonate precipitation (MICP) technology in a single rough fracture. The differences between the Sporosarcina pasteurii cultured by two mediums were compared in terms of bacterial growth properties, permeability treatment effects, distribution characteristics of induced CaCO₃, and microscopic crystal characteristics. The study revealed that the culture medium did indeed impact the permeability reduction effect when treated with MICP technology, primarily related to whether urea is added in the culture medium. Two distinct permeability reduction modes were proposed for the treatment process using Sporosarcina pasteurii cultured by different mediums through one-phase injection (mixing bacterial solution and cementing solution). The permeability decreased rapidly, and the distribution of induced CaCO₃ was uneven after treatment with Sporosarcina pasteurii cultured in medium containing urea, while the permeability decreased relatively slowly and the induced CaCO₃ distribution was relatively uniform when treated with Sporosarcina pasteurii cultured in medium without urea. Additionally, differences in crystal morphology were observed due to variations in seepage characteristics during the treatment process with the Sporosarcina pasteurii cultured by different mediums. Finally, some investigations were given to the treatment effect optimization for the treatment process of Sporosarcina pasteurii cultured in medium containing urea. This study gave an insight to the regulation mechanism of culture medium and treatment method for the process of permeability reduction by MICP technology in the rock fracture.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7349 - 7368"},"PeriodicalIF":5.6,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595312","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":"Visual experimental investigation on the performance of grouted gravel pile during construction process in clay","authors":"Lingzhi Zhang,&nbsp;Hanlong Liu,&nbsp;Xuanming Ding,&nbsp;Qiang Ou,&nbsp;Chunyan Wang","doi":"10.1007/s11440-024-02423-8","DOIUrl":"10.1007/s11440-024-02423-8","url":null,"abstract":"<div><p>The grouted gravel pile is a new method of pile foundation, which has been widely used in engineering fields in recent years. However, the grout diffusion characteristics and full-field displacement response of soil during grouting have not been fully revealed and systematically studied in previous publications. This paper employed a transparent soil model test system to explore the effects of the grouting pressure (GP), soil pre-consolidation pressure (SPCP), and initial viscosity of grout (GIV) on the grouting performances and load-bearing characteristics of grouted gravel piles. The development laws of the grouting duration, displacement field of the soil, and ultimate load-bearing capacity of the pile were analyzed. The results show that the total grouting duration decreases with a higher GP, increases with the increasing GIV, initially increases and then decreases as SPCP increases. Both the range of horizontal and vertical displacements of the soil around the pile and the distribution of vertical displacements of the soil at the pile end were obviously enlarged with GP as well as with GIV. However, with the increasing SPCP, they showed a decreasing tendency. The vertical ultimate load-bearing capacity of the grouted gravel pile increases with GP, SPCP, and GIV to varying degrees. The findings of this study contribute to the understanding of the pile-soil interaction during grouting process of the grouted gravel pile, which may improve the design of construction parameters.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7369 - 7387"},"PeriodicalIF":5.6,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595475","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":"Experimental and 3D numerical analysis of embankment on soft soil improved with cement bottom ash columns","authors":"Arshad Ullah,&nbsp;Azman Kassim,&nbsp;Ahmad Safuan A. Rashid,&nbsp;Yu Huang,&nbsp;Muhammad Junaid,&nbsp;Mohammad Jawed Roshan","doi":"10.1007/s11440-024-02412-x","DOIUrl":"10.1007/s11440-024-02412-x","url":null,"abstract":"<div><p>Bottom ash (BA) is a byproduct produced during coal combustion and can be utilized in mortar as a column material to conserve natural resources and promote sustainable ground stabilization. In this paper, the load-carrying capacity performance of the embankment resting on cement bottom ash columns (CBAC) improved ground was examined. Physical model tests and numerical analysis were conducted for the soft soil improved with three columns spacing to diameter ratios (<i>s</i>/<i>d</i>) of 1.8, 2.4, and 3.6 and two columns length to diameter ratios (<i>L</i>/<i>d</i>) of 6 and 8. Three earth pressure transducers, load cell, and pore water pressure transducer were employed to measure the applied vertical stress on the bottom and top of the column and surrounding clay, embankment surface, and excess pore water pressure (<i>u′</i>), respectively. The findings obtained from both physical and numerical models demonstrated that ultimate bearing capacity (<i>q</i>_ult) increased by reducing the <i>s</i>/<i>d</i> and increasing the <i>L</i>/<i>d</i> values. The <i>q</i>_ult increased by almost 1.15, 1.39, 1.70 times and 1.18, 1.44, and 1.77 times as compared to the unimproved soil for the <i>s</i>/<i>d</i> of 3.6, 2.4, and 1.8 with <i>L</i>/<i>d</i> values of 6 and 8, respectively. The maximum improvement was achieved for the model with CBAC having <i>L</i>/<i>d</i> of 8 and <i>s</i>/<i>d</i> of 1.8. In addition, a mathematical equation with <i>R</i>² of 0.999 was established for the determination of the predicted <i>q</i>_ult. The results of this paper can lead to the usage of BA as a green material in the column for ground stabilization.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7727 - 7745"},"PeriodicalIF":5.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595237","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":"Analysis of thixotropy of cement grout based on a virtual bond model","authors":"Haizhi Zang,&nbsp;Shanyong Wang,&nbsp;John P. Carter","doi":"10.1007/s11440-024-02417-6","DOIUrl":"10.1007/s11440-024-02417-6","url":null,"abstract":"<div><p>Thixotropy of cementitious materials is a crucial intrinsic property that determines the flowability and workability of cement-based grout. A novel virtual bond model of cement particles is developed in this paper to depict the thixotropy of cement grout. A particulate description of the reversible and erasable interparticle bonds is established based on experimental observations with a focus on the non-contact interactions mainly contributed in practice by calcium silicate hydrates (C–S–H). The structural breakdown of the cement network is realized through bonds breakage under applied motion, and the bonding network recovers with regeneration of interparticle connections that involve reversible hydrate reactions in the mixture. The balance between bond rupture and rebuilding can be tuned by assigning different strength limits for bond breakage. We have implemented this model in the open-source code Yade to carry out 3D discrete element method simulations of a rotational vane system filled with spherical particles, and the results show good agreement with experimental data. The modelling results reveal the transition from a solid-like structure to a fluid-like medium within cement suspensions caused by the evolution of broken interparticle bonds. The results also provide a distinct view of thixotropic variation upon disturbance. This model is extendable to other cohesive materials providing an explicit physical definition of the interparticle interactions. It also provides a theoretical explanation for the empirical estimations of thixotropy common in engineering industries and a potential means of measuring cementitious granular flow that may be useful in future studies.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7427 - 7450"},"PeriodicalIF":5.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02417-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595530","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":"Influence of bio-cementation on gas permeability of unsaturated soils in landfill cover system","authors":"Longjian Huang,&nbsp;Weiling Cai,&nbsp;Bogireddy Chandra,&nbsp;Ankit Garg,&nbsp;Yanning Wang","doi":"10.1007/s11440-024-02416-7","DOIUrl":"10.1007/s11440-024-02416-7","url":null,"abstract":"<div><p>Landfill cover systems should exhibit low gas permeability to minimize the overflow of greenhouse gases and subsequent air pollution. Microbially induced carbonate precipitation (MICP), a biocementation technique, has been applied for subsurface soil stabilization by improving the shear strength of the soil. However, the impact of MICP on the gas permeability of unsaturated soils remains unknown. Considering the role of biocementation in the modification of soil interpores, this study investigated the feasibility of using the MICP technique to reduce the gas permeability of granite residual soils in response to unsaturated conditions. The biocemented soil samples were prepared by mixing soils with MICP chemical solutions at different chemical concentrations. Water retention tests and measurements of gas permeability were performed, in which suction, volumetric water content and gas permeability were continuously monitored. Additionally, energy-dispersive X-ray spectroscopy and X-ray diffraction analyses were performed to investigate the formation of CaCO₃ precipitates; scanning electron microscopy was used to study the impact of MICP on the soil interpore structure, and the acid washing method was used to determine the CaCO₃ content. The results showed that soils treated with higher concentrations of MICP chemical solutions had higher air entry pressures and residual water contents. This indicates the improvement of water retention due to the presence of MICP, which increases the microstructural porosity and enhances the capillarity, as observed via microscopy. Furthermore, the results revealed that biocementation significantly reduced the gas permeability of the soil and that the change in the maximum gas permeability strongly correlated with the MICP chemical solution concentration and the CaCO₃ content. This study highlights the role of MICP in soil–water–air interface studies and the potential application of this biocementation technique to minimizing gas emission issues in landfill cover systems.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7389 - 7405"},"PeriodicalIF":5.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595531","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":"Economic impact analysis for steel piles driven in intermediate geomaterials using machine learning algorithms","authors":"Nafis Bin Masud,&nbsp;Shaun S. Wulff,&nbsp;Kam Ng","doi":"10.1007/s11440-024-02406-9","DOIUrl":"10.1007/s11440-024-02406-9","url":null,"abstract":"<div><p>To mitigate the existing challenges with piles driven in intermediate geomaterial (IGM), this study presents an economic impact assessment for steel piles in IGMs based on the newly developed and existing static analysis (SA) methods using 149 test pile data from seven US states. The assessment determines the differences in the number of piles and the equivalent steel pile weight. The proposed SA methods yield, on average, a smaller difference in steel weight based on states, pile types, and bearing IGM layers. Three machine learning (ML) algorithms: random forest, support vector machine (SVM) and neural network are applied to predict the difference in steel weight. Three percentage-based variables are employed in the ML algorithms as inputs: total pile penetration, total shaft resistance and end bearing in IGM. Based upon 31 testing data, SVM with the lowest RMSE, MAD and highest pseudo-<i>R</i>² is identified as the best algorithm. The predicted difference in steel weight from SVM is optimized to zero using a novel application of the genetic algorithm, and various contour maps are generated. These contour maps can be used to predict the difference in steel weight graphically based on the three percentage-based variables for future driven steel piles in IGMs.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7407 - 7425"},"PeriodicalIF":5.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595385","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 physical model test on a seepage-initiation-braking-type (SIBT) landslide under the coupling of rainfall and water level fluctuation","authors":"Qianyun Wang,&nbsp;Huiming Tang,&nbsp;Pengju An,&nbsp;Kun Fang,&nbsp;Sha Lu,&nbsp;Ding Xia","doi":"10.1007/s11440-024-02403-y","DOIUrl":"10.1007/s11440-024-02403-y","url":null,"abstract":"<div><p>Seepage-initiation-braking-type (SIBT) landslides are the majority of reservoir landslides in the Three Gorges Reservoir Area in China that involve gradual deformation in response to water level (WL) and rainfall rather than experiencing an abrupt failure and sliding directly into the river, highlighting the complex nature of this landslide. Here, a physical model test with the rainfall and the fluctuation of WL was conducted on a representative SIBT landslide, Huangtupo Linjiang No. 1 landslide (HTPLJ1). The changes in pore water pressure, earth pressure, and overall displacement of the landslide model were monitored by a monitoring system. The results revealed distinct stages in the landslide model: impoundment-induced deformation, preliminary sliding, stagnation and stability, re-initiation, short stability, and accelerated sliding to failure. Combined with monitoring system analysis, the rainfall infiltrations destabilized the shallow landslide by reducing the effective stress, while impoundment increased pore water pressure, leading to buoyancy-driven effects. However, the most notable deformations occurred during the WL drawdown stages, when seepage drag force induced by the low permeability of the sliding mass triggered more pronounced deformations. The deformation mechanism of HTPLJ1 with SIBT is attributed to a bulged slope toe induced by the seepage drag force, leading to increased effective stress along the resisting section and temporary stabilization. The site geological investigations and monitoring data indicated continuous buoyancy-driven effects and a higher sensitivity to seepage-driven effects in HTPLJ1. It can be inferred that the SIBT landslides undergo repetitive deformation characterized by “dragging and compression,” which leads to initiation and stagnation.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"37 - 54"},"PeriodicalIF":5.6,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963044","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":"Deceleration of projectiles in sand","authors":"S. R. Mercurio,&nbsp;M. Iskander,&nbsp;S. Bless,&nbsp;M. Omidvar","doi":"10.1007/s11440-024-02408-7","DOIUrl":"10.1007/s11440-024-02408-7","url":null,"abstract":"<div><p>This study investigates the deceleration dynamics of projectiles during vertical penetration into silica sand targets up till the final depth of burial (DoB). Experiments were conducted with cone cylinder rods launched vertically into sand targets using a compressed air gun. Velocity–time records were obtained using a multichannel homodyne photon Doppler velocimeter (PDV) which tracked the back face of the penetrator as it decelerated, supplemented by high-speed video cameras from two views. A Poncelet framework was employed to describe the velocity–penetration relationship and drag and resistance coefficients were extracted by fitting the experimental measurements. Experiments were performed in dense and loose sand at a nominal impact velocity of 200 m/s, and experimental excursions were conducted with modified launch parameters. Mean drag and bearing resistance coefficients were found for sands under dry and wet pore saturation, as well as loose and dense packing. The work contributes essential insights for predicting the DoB of projectiles, particularly relevant for environmental remediation efforts in formerly used military sites.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"519 - 541"},"PeriodicalIF":5.6,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361842","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}