Acta Geotechnica最新文献

{"title":"DEM investigation on flow instability of particulate assemblies under coupling between volumetric and axial strains","authors":"M. Salimi,&nbsp;A. Lashkari,&nbsp;M. Tafili","doi":"10.1007/s11440-024-02331-x","DOIUrl":"10.1007/s11440-024-02331-x","url":null,"abstract":"<div><p>The discrete element method (DEM) is employed to investigate the impact of coupling between volumetric and axial strains on the flow liquefaction vulnerability of 3D cubic particulate specimens. The virtual testing program conducted here encompasses a wide range of initial states and varying degrees of coupling between volumetric and axial strains. Utilizing data obtained from DEM simulations, the evolution of micro- and macroscale variables, including coordination number, contact fabric anisotropy, redundancy index, strong force networks, invariants of the effective stress tensor, and excess pore-water pressure, is examined. Results from DEM tests indicate that coupling expansive volumetric strain with axial strain leads to a gradual loosening of the load bearing microstructure, a decrease in coordination number, and a faster change in contact anisotropy. DEM simulations demonstrate that the triggering of flow liquefaction instability is followed by a sudden increase in contact fabric anisotropy and abrupt drops in coordination number and redundancy index. Moreover, a detailed analysis of the findings suggests that the stress ratio at the onset of post-peak softening decreases with increasing expansive volumetric strains.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7261 - 7286"},"PeriodicalIF":5.6,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02331-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140935889","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":"Effect of compression and shear on particle\u0000 breakage of silica and calcareous sands","authors":"Andrzej Głuchowski,&nbsp;Linzhu Li,&nbsp;Magued Iskander","doi":"10.1007/s11440-024-02339-3","DOIUrl":"10.1007/s11440-024-02339-3","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Changes in particle granulometry could lead to significant changes in a\u0000 soil’s behavior, making an understanding of micro-scale granulometry essential for\u0000 practical applications. Changes in particle size, shape, and particle size distribution\u0000 could result from a combination of applied normal and shearing stresses, which can in\u0000 turn influence further response of the material. This study explored particle breakage\u0000 during both compressive and shear loading under typical stresses. A deeper understanding\u0000 of the phenomenon requires distinguishing broken and unbroken grains at the particle\u0000 scale. Dynamic Image Analysis (DIA) was therefore employed to quantify changes in\u0000 particle granulometry in two sands, a siliceous Ottawa sand and a calcareous sand known\u0000 as Fiji Pink. Pre-sorted specimens having similar size, granulometry, and particle size\u0000 distributions were tested using both oedometric and direct shear tests having the same\u0000 aspect ratio, facilitating a direct comparison of the effects of shearing and\u0000 compression on similar materials having different mineralogy. A breakage index was used\u0000 for prognosis of particle breakage at key reference diameters. During oedometric tests,\u0000 grain breakage was limited in both sands at stresses up to 1.2 MPa, but it increased\u0000 significantly during direct shear tests. A conceptual model was proposed to explain the\u0000 particle breakage mechanism during shear, at four key phase points representing (1)\u0000 maximum compaction, (2) transition from compaction to dilative behavior, (3) maximum\u0000 shear stress, and (4) peak test strain. In addition, a loading intensity framework was\u0000 adopted to explain the relative roles of normal and shearing stresses on particle\u0000 breakage. An increase of fines in soil during shearing was also observed and related to\u0000 two sources: coarser grain abrasion and finer particle crushing. The vulnerability of\u0000 grains with more anisotropic shapes was also observed. The loading intensity framework\u0000 suggested that attrition of particle diameter could be divided into two phases, with a\u0000 transitional critical loading intensity that appeared constant for each sand. For Ottawa\u0000 sand, abrasion was the primary mechanism observed, causing a significant increase in\u0000 Aspect Ratio (&lt;i&gt;AR&lt;/i&gt;) and Sphericity (&lt;i&gt;S&lt;/i&gt;) for finer grains. For Fiji sand, a transition from\u0000 abrasion to attrition was noted, leading to limited sphericity decrease for the largest\u0000 particles. Finer particles cushioning larger Fiji sand particles are more prone to\u0000 breakage, resulting in increased &lt;i&gt;AR&lt;/i&gt; and &lt;i&gt;S&lt;/i&gt;. Finally, test results were used to propose a simple\u0000 hyperbolic model to predict ","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"1 - 27"},"PeriodicalIF":5.6,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140935912","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":"Influence of wetting and drying cycles on the shear behavior of discontinuities between two different rock types with various surface topographies","authors":"Qiong Wu,&nbsp;Yue Qin,&nbsp;Huiming Tang,&nbsp;Zhen Meng,&nbsp;Changdong Li,&nbsp;Sha Lu","doi":"10.1007/s11440-024-02332-w","DOIUrl":"10.1007/s11440-024-02332-w","url":null,"abstract":"<div><p>Wetting and drying cycles (WDCs) have a significant impact on the shear behavior of discontinuities with different joint wall materials (DDJMs). This influence is crucial for the reasonable evaluation of the long-term stability of soft and hard interbedded rock slopes under water level fluctuations. As the surface topographies of natural discontinuities collected from the field vary, conducting comparative experiments on natural discontinuity specimens with identical surface topographies is challenging. To solve this problem, a 3D surface topography reconstruction technique was employed to obtain DDJM specimens with three types of surface topographies collected from a typical sliding-prone stratum in the Three Gorges Reservoir area, China. A series of experiments, including computed tomography scanning, 3D laser scanning, and direct shear tests, were conducted to investigate the influence of WDCs on the micro- and macroproperties of joint walls, surface topographies, and shear behavior of DDJMs. The experimental results showed that repeated WDC treatments caused the degradation of the microstructures and macroscopic physical properties of the studied joint walls, and the more severely weakened joint wall played a predominant role in reducing the shear strength of DDJMs. The influence of WDCs on the surface topographies of DDJMs was negligible in this study; changes in the shear behavior of DDJMs were closely associated with the weakening of joint walls induced by WDCs; and the impact degree of joint wall weakening on the deterioration of the shear behavior of DDJMs was interactively influenced by and positively correlated with both the joint roughness coefficient and normal stress. These results will contribute to a better understanding of the evolution of the stability of soft and hard interbedded rock slopes induced by water level fluctuations in the Three Gorges Reservoir area and other reservoir regions.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7125 - 7147"},"PeriodicalIF":5.6,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885213","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 advanced ICMV for vibratory roller compaction","authors":"Johannes Pistrol, Mario Hager, Fritz Kopf, Dietmar Adam","doi":"10.1007/s11440-024-02342-8","DOIUrl":"https://doi.org/10.1007/s11440-024-02342-8","url":null,"abstract":"<p>The compaction success of vibratory roller compaction can be assessed by systems for continuous compaction control (CCC) or intelligent compaction (IC) which calculate soil stiffness-proportional quantities based on measurements of the motion behavior of the vibrating drum. However, state-of-the-art intelligent compaction meter values (ICMV) do not only depend on the stiffness of the soil but are also strongly influenced by machine and process parameters. In this paper, the methodology for determining an advanced ICMV is presented, in which the mechanical properties of the soil, the process parameters and geometric relationships in the contact area between the drum and the soil are directly included in the calculation. The methodology is explained on the example of measurement data from a compaction test conducted on sandy gravel with a heavy single-drum roller. The results of the novel ICMV are compared with those of the most widely used IC systems.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"17 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885146","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":"Behavior of model pile in unsaturated soil subjected to cyclic loading","authors":"Hijran Aljanabi, Reza Imam, Mohammad Khorand","doi":"10.1007/s11440-024-02313-z","DOIUrl":"https://doi.org/10.1007/s11440-024-02313-z","url":null,"abstract":"<p>Most previous experimental studies on the behavior of piles subjected to lateral loading have focused on testing model piles embedded in dry or fully saturated soils, and little attention has been paid to the impact of the soil partial saturation on the results. This paper presents results of 1g model tests on a single pile embedded in dry and unsaturated sand subjected to two-way constant displacement amplitude loading. The tests were aimed at examination of the effects of degree of soil saturation and density on the pile internal forces and lateral capacity and the deformation patterns of the adjacent soils. Five degrees of saturation (<i>S</i>_<i>r</i> = 0, 10, 20, 35 and 50%) for loose and medium-dense sand (<i>D</i>_r = 20% and 50%) were chosen and a 65-mm-diameter and 900-mm-long polyethylene model pile was used. Test results indicated that at each soil relative density, the pile head horizontal load, and the maximum bending moment, shear force, and soil reaction in the pile increase with increase in the degree of saturation up to about <i>S</i>_<i>r</i> = 35%. However, further increase in <i>S</i>_<i>r</i> led to decrease in these values. Moreover, the cyclic loading led to depressions in the surface of the dry sand and bulging associated with soil–pile separation in the unsaturated sand. For the model testing conditions used, results indicated that the sand degree of saturation can have a greater impact on the pile behavior than its density.</p>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"29 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885299","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":"Performance evaluation of an ex situ permeable reactive bio-barrier in phenol-contaminated water containment and remediation under a laminar flow regime","authors":"Zohreh Emmarloo, Mohsen Karrabi, Bahar Shahnavaz, Asal Masoumi Khameneh, Philippe Sechet","doi":"10.1007/s11440-024-02301-3","DOIUrl":"https://doi.org/10.1007/s11440-024-02301-3","url":null,"abstract":"<p>Petroleum hydrocarbons (PHCs) including phenolic compounds cause major environmental impacts just the once released into soils or groundwater. Among the core technologies, permeable reactive barriers (PRBs) have been so far exploited to contain and control such contaminants within the subsurface layers of the soil. Against this background, the present study investigated flow-biofilm interactions in a laboratory-scale permeable reactive bio-barrier (PRBB). To this end, an experimental setup was firstly built by embedding pressure measurement ports, at 10 cm intervals, onto a cylindrical column with a diameter of 57 mm and a height of 50 cm, and then filled with a porous medium, made up of sand with an average diameter of 1.78 mm. The bacterium, <i>Pseudomonas putida</i> (<i>P. putida</i>), was also utilized to generate the biofilm. Afterward, phenol-containing water was passed through the column at a rate of 2 L/h under a hydrodynamic laminar flow regime. Experimental evidence showed that the biofilm formed by bacterial growth could shrink the bio-barrier (BB) porosity from 0.35 to 0.07, instigating a drop by 590 and 840 times in the hydraulic pressure across the column at phenol concentrations, 200 and 400 mg/L, respectively. The desired biofilm additionally managed to remove 40 and 30% of phenol at concentrations of 200 and 400 mg/L, in that order. Exploring the variations in hydraulic conductivity in different layers plus the microscopic images further demonstrated that the biofilm created at phenol concentration of 200 mg/L seemed to be much stronger and even more stable, compared to the one at 400 mg/L. This was traceable to the better adaptation of <i>P. putida</i> to lower concentrations of phenol as the carbon source. Furthermore, the study results established that the given PRBB could help decompose only a small portion of phenol, but outperformed in terms of containing and controlling this contaminant through reducing hydraulic conductivity.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":""},"PeriodicalIF":5.7,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140809052","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":"Undrained cyclic responses of biocemented calcareous silty sand","authors":"Yang Xiao,&nbsp;Jian Hu,&nbsp;Jinquan Shi,&nbsp;Lei Zhang,&nbsp;Hanlong Liu","doi":"10.1007/s11440-024-02293-0","DOIUrl":"10.1007/s11440-024-02293-0","url":null,"abstract":"<div><p>Microbially induced calcium carbonate precipitation (MICP) technology is an emerging and environmentally sustainable method for improving the strength and stiffness of soil. Specifically, this innovative approach has gained favor in marine engineering due to the advantaged compatibility between precipitated calcium carbonate induced by MICP and coral sand. Sand containing fines is susceptible to liquefy. Whereas, the impact of fines contents on cyclic behavior of MICP-treated calcareous sand remains uncertain. Consequently, this technical note aims to investigate the liquefaction behavior of biocemented calcareous silty sand by conducting undrained cyclic triaxial shear tests and microscopic analysis. The results revealed the patterns of the excess pore water pressure curves and cyclic deformation characteristics as the fines contents increased. The liquefaction resistance of biocemented sand initially decreases with the addition of fines but subsequently exhibits an increasing trend. Microscopic analysis showed that at the cementation level with the cementation solution concentration of 1 mol/L, the calcium carbonate crystals are mainly attached to the surface of sand grains and this pattern does not directly affect the force chain.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6683 - 6690"},"PeriodicalIF":5.6,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806763","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":"Vertical dynamic impedance of pile groups embedded in soils considering the groundwater level","authors":"Zi Ye,&nbsp;Yonghui Chen,&nbsp;Geng Chen,&nbsp;Jiangwei Shi,&nbsp;Nan Hu,&nbsp;Minguo Lin","doi":"10.1007/s11440-024-02245-8","DOIUrl":"10.1007/s11440-024-02245-8","url":null,"abstract":"<div><p>The groundwater level divides the soils into unsaturated zone and saturated zone, imposing an indispensable effect on the soil–pile interaction behavior. In this work, the groundwater level is introduced into soil–pile group interaction models for advancing the dynamic impedance research of pile groups. The motion equation of pile groups is modeled by the finite element method. The vibration solution of soils considering the groundwater level is solved via the precise integration method, which is utilized as the kernel function to construct the boundary integral equation. The coupled finite element method (FEM) and boundary element method (BEM) establishes the unsaturated soil–pile group interaction equation, which is further solved based on the soil–pile compatibility condition. After confirming the reliability of the above theory, parametric analyses are provided to discuss the effect of a series of key parameters on the impedance function of pile groups.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 9","pages":"6391 - 6405"},"PeriodicalIF":5.6,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140655829","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":"Hydraulic breakthrough of clay smears due to technical and natural actions","authors":"Gerd Gudehus,&nbsp;Christian Karcher","doi":"10.1007/s11440-024-02261-8","DOIUrl":"10.1007/s11440-024-02261-8","url":null,"abstract":"<div><p>We outlined earlier in this journal by means of finite element simulations how patterns of normal faults arise by a synsedimentary tectonic extension, and how clay smears evolve therein. In the present paper, we show how hydraulic breakthroughs of clay smears can arise so that water, gas and mud rise in faults. Mechanical properties of sand and clay are introduced first for the stable range and then for rupture and internal erosion. Our numerical simulations for the evolution of normal faults and clay smears are discussed in light of critical phenomena. Water assembled in an open-cast mine about 20 years ago as the critical hydraulic gradient in a clay smear dropped to the actual one due to the rapid excavation-induced deformation. The latter led to a critical point under an excavation the slope of which was parallel to a nearby normal fault. Clay smears can also break by earthquakes so that the critical hydraulic gradient drops to the actual one caused by methane with an excess pressure. This can lead to hydraulic breakthroughs and cold eruptions at outcrops of faults.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 6","pages":"3283 - 3298"},"PeriodicalIF":5.6,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02261-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140655881","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":"Long-term “memory” of extraordinary climatic seasons in the hysteretic seepage of an unsaturated infinite slope","authors":"Diana Bianchi,&nbsp;Domenico Gallipoli,&nbsp;Rossella Bovolenta,&nbsp;Martino Leoni","doi":"10.1007/s11440-024-02307-x","DOIUrl":"10.1007/s11440-024-02307-x","url":null,"abstract":"<div><p>This paper presents a study of the hydraulic response of an infinite unsaturated slope exposed to a perturbation of the ordinary seasonal climatic cycle. The ground flow is modelled via a simplified one-dimensional finite difference scheme by decomposing the two-dimensional slope seepage into antisymmetric and symmetric parts. The numerical scheme incorporates two distinct hysteretic and non-hysteretic soil water retention laws, whose parameters have been selected after a preliminary sensitivity analysis. Results indicate that, in the hysteretic case, the “memory” of the perturbation takes a long time to fade, and the ordinary soil saturation cycle is only restored after several years of normal weather. Instead, in the non-hysteretic case, the recovery of the ordinary saturation regime is almost immediate after the perturbation. In contrast with the markedly different predictions of degree of saturation, both hysteretic and non-hysteretic slope models predict virtually identical evolutions of negative pore water pressures, with an almost immediate restoration of the ordinary cycle after the perturbation.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7207 - 7227"},"PeriodicalIF":5.6,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02307-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140656065","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}