Acta Geotechnica最新文献

{"title":"Calcium ions and calcium carbonate: key regulators of the enzymatic mineralization for soil dispersivity control","authors":"Guanzhou Ren,&nbsp;Minqiang Meng,&nbsp;Henghui Fan,&nbsp;Jixiang Wen,&nbsp;Jianwei Zhang,&nbsp;Gaowen Zhao,&nbsp;Xiujuan Yang,&nbsp;Zengchun Sun,&nbsp;Xiang He","doi":"10.1007/s11440-024-02304-0","DOIUrl":"10.1007/s11440-024-02304-0","url":null,"abstract":"<div><p>Dispersive soil is a widely distributed problematic soil in arid or semiarid areas of the world and can cause pipe erosion, gully damage and other seepage failures. This study analyzed the effect of environmentally friendly enzyme-induced carbonate precipitation (EICP) on the dispersivity of dispersive soils. This methodology was tested for the stabilization of three dispersive soil types (two high-sodium soils, two low-clay-content soils, and two soils with both high sodium and low clay contents) to examine the impact on dispersivity based on the results of pinhole tests and mud ball tests. Physical, chemical, mechanical, and microscopic tests were also conducted to investigate the effects of the components in the EICP reaction solution on dispersive soil modification. The experiments showed that the concentration of the reaction solution and the curing time required to limit the dispersivity decreased with increasing clay content in the soil. Ca²⁺ limited the dispersivities of dispersive soils via four distinct mechanisms. The first mechanism was ion exchange; Ca²⁺ decreased the percentage of exchangeable sodium ions to less than 7% while reducing the thickness of the diffuse double layer such that the spacings between soil particles were reduced and the chemical dispersivity was limited. Second, Ca²⁺ increased the viscosity of the solution by salting out the organic matter present in the soybean urease. Subsequently, the D1-class physically dispersive soil was converted into an ND2-class nondispersive soil. Third, Ca²⁺ decreased the soil pH by reducing the CO₃²⁻ content, which could hydrolyze to increase the soil alkalinity. Finally, the presence of Ca²⁺ led to the generation of cementitious minerals through the precipitation of CaCO₃ crystals that continuously generated CO₃²⁻, filling and cementing soil particles and thereby limiting their physical dispersivity. These results indicated that a low-concentration EICP reaction solution efficiently controlled the dispersivities of the three dispersive soils.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6661 - 6682"},"PeriodicalIF":5.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141100620","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 load-carrying mechanism of driven battered minipiles","authors":"Sanchari Mondal,&nbsp;Mahdi M. Disfani","doi":"10.1007/s11440-024-02250-x","DOIUrl":"10.1007/s11440-024-02250-x","url":null,"abstract":"<div><p>The lateral load-carrying mechanism of vertically installed and battered minipiles is evaluated using 1<i>g</i>-physical and numerical modelling. Single minipiles with batter angles of 0°, ± 25° and ± 45° are tested under lateral load in medium dense and dense sand. The minipiles are instrumented with fibre Bragg grated optic fibres to obtain a strain profile (two-dimensional) along the minipile shaft. A calibrated numerical model is further adopted to produce <i>p–y</i> curves for battered minipiles at various node deflections. The ratio of soil reaction of battered minipiles to vertically installed minipiles is observed to change with both deflection and depth of the minipile. An analytical solution is developed based on the decomposition of lateral load into skin friction and passive pressure for battered minipiles. A reduction factor is proposed that considers a decrease in passive pressure when the minipile is loaded in the opposite direction of the batter. The analytical solution is capable of accounting for soil properties, pile rigidity and the angle of inclination of battered minipiles. The analytical method is subsequently verified for cohesive soils using full-scale field results. The ratio of the ultimate lateral load of battered minipiles to vertical minipiles presented in the literature corroborated the findings of this study.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 9","pages":"6407 - 6425"},"PeriodicalIF":5.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02250-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141102347","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":"An analytical solution to account for the earthquake body force for twin circular tunnels in elastic media using complex variable approach","authors":"Hemant Jain,&nbsp;Jyant Kumar","doi":"10.1007/s11440-024-02343-7","DOIUrl":"10.1007/s11440-024-02343-7","url":null,"abstract":"<div><p>By using the complex variable approach, an analytical solution for non-uniformly deforming twin circular tunnels has been determined for a linear elastic weighty medium under the influence of earthquake pseudo-static inertial force. The non-uniform radial displacements along both the tunnels’ peripheries have been imposed by using the Gaussian distribution function keeping the ground volume loss (<span>(it {text{GVL}})</span>) as the basic input parameter. By using the Schwarz iterative technique, the effect of interference of the twin tunnels on stresses and displacements’ patterns has been explored. The analytical solution satisfies (i) the prescribed non-uniform displacement boundary conditions along the tunnels’ peripheries, (ii) the existence of buoyant and pseudo-static earthquake inertial forces due to the formation of tunnels, (iii) the geostatic stresses in the presence of horizontal earthquake (inertial) forces in a zone far away from the tunnels, and (iv) the stress-free ground surface. The ground displacements and stresses in the domain have been determined and presented in terms of a number of contour plots showing the effect of spacing, orientation and size of the tunnels for a given magnitude of pseudo-static earthquake acceleration. The results obtained from the analytical approach have been found to compare well with the solution separately determined on the basis of the finite element analysis.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"8023 - 8049"},"PeriodicalIF":5.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107702","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":"Data-driven forward and inverse analysis of two-dimensional soil consolidation using physics-informed neural network","authors":"Yu Wang,&nbsp;Chao Shi,&nbsp;Jiangwei Shi,&nbsp;Hu Lu","doi":"10.1007/s11440-024-02345-5","DOIUrl":"10.1007/s11440-024-02345-5","url":null,"abstract":"<div><p>Employing machine learning algorithms to forecast the behavior of nonlinear spatiotemporal systems, such as soil consolidation induced by land reclamation, has been popular in recent years. Although pure data-driven models demonstrate strong performance within their training domain, i.e., in-sample prediction, they lack interpretability and might have poor generalization outside the training domain, i.e., out-of-sample prediction, particularly when the observed geodata is limited. Moreover, these models often disregard valuable geotechnical domain knowledge. To address these limitations, a novel physics-informed neural network (PINN) is developed for both forward and inverse analyses of two-dimensional soil consolidations when only limited measurements are available. Different random seeds are used to test the robustness of the PINN developed and quantify the associated model uncertainty. Plane strain and axisymmetric consolidation partial differential equations serve as valuable prior domain knowledge to regulate the model training and optimization process in PINN. The performance of PINN is illustrated using both simulated and real consolidation examples. Results indicate that PINN can accurately approximate spatiotemporal pore pressure response and exhibits excellent generalization performance. More importantly, PINN renders an efficient identification of unknown governing parameters from limited measurements with quantified statistical uncertainty, which diminishes as measurement data increase. Furthermore, a real example shows that PINN is capable of discovering the nonlinear decay of horizontal permeability around a prefabricated vertical drain (PVD) based on limited data, tackling the challenge of specifying a smear zone and its permeability distribution in PVD design.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"8051 - 8069"},"PeriodicalIF":5.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103813","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":"Temperature effects on adsorption and capillarity water retention mechanisms in constrained unsaturated soils","authors":"Yu Lu,&nbsp;John S. McCartney","doi":"10.1007/s11440-024-02341-9","DOIUrl":"10.1007/s11440-024-02341-9","url":null,"abstract":"<div><p>This paper focuses on the impact of elevated temperatures on the adsorptive and capillarity water retention mechanisms of unsaturated soils under constrained (constant volume) conditions. This topic is critical for simulating the thermo-hydraulic behavior of soils in hydrogeological or geotechnical applications, including climate change effects on near surface soils, energy piles or soil borehole thermal energy storage systems in unsaturated soil layers, and buffers for geological nuclear waste repositories. A nonisothermal soil water retention curve (SWRC) that separately considers the temperature-dependency of the key parameters governing adsorptive and capillarity water retention mechanisms and soil physical parameters (e.g., surface tension, contact angle, adsorption capacity, cation exchange capacity, mean cavitation suction, air entry value and equilibrium film thickness) was developed to provide insights into the impact of temperature on water retention over the full suction range. The nonisothermal SWRC was validated using experimental data on high plasticity clays, with a good prediction of temperature effects on adsorption and capillarity water retention mechanisms in constrained unsaturated soils.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 10","pages":"6467 - 6482"},"PeriodicalIF":5.6,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02341-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141119420","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":"Controllable hydrophobization of sands with self-healing polymeric microcapsules","authors":"Rui Qi,&nbsp;Ke Chen,&nbsp;Hongjie Lin,&nbsp;Sérgio D. N. Lourenço,&nbsp;Antonios Kanellopoulos","doi":"10.1007/s11440-024-02294-z","DOIUrl":"10.1007/s11440-024-02294-z","url":null,"abstract":"<div><p>Hydrophobized soils have functional hydrophobic coatings to delay or restrict water infiltration and thus prevent infrastructure failure and long-term degradation. Over time, hydrophobized soils will be subjected to degradation under the action of external stresses, leading to the loss of its functional properties. Microencapsulation approaches, initially developed for self-healing applications emerge as a potential solution to enhance, switch (from hydrophilic) or prolong the longevity of hydrophobized soils. The aim of this study is to produce and investigate the effectiveness of microencapsulation to impart hydrophobicity in granular materials in response to external stimuli. In this research, polydimethylsiloxane (PDMS), with hydrophobic properties, is encapsulated in calcium alginate microcapsules with the ionic gelation method. The effectiveness of the microcapsules to induce hydrophobicity is investigated by mixing sand with microcapsules and quantifying the change of the contact angle and water drop penetration time (measures of hydrophobicity) under an external trigger, i.e., under drying and consecutive wetting–drying cycles. The results show that microcapsules release the hydrophobic cargo (PDMS) during shrinkage. After drying, the PDMS content in sand increased to 0.1–0.8% by mass of sand. The released hydrophobic cargo (PDMS) induced hydrophobicity in sands, reflected by a contact angle increase from 29.7° to at least 87.7°. The amount of polydimethylsiloxane encapsulated is a key parameter controlling the release of hydrophobic cargo. In addition, 4% capsule content in sands is identified as an effective microcapsule content in inducing hydrophobicity.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 9","pages":"6427 - 6442"},"PeriodicalIF":5.6,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02294-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059060","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":"Compacted sand–bentonite mixtures for the confinement of waste landfills","authors":"Robeta Proia,&nbsp;Erminio Salvatore,&nbsp;Paolo Croce,&nbsp;Giuseppe Modoni","doi":"10.1007/s11440-024-02335-7","DOIUrl":"10.1007/s11440-024-02335-7","url":null,"abstract":"<div><p>This paper illustrates the results of an experimental study on sand–bentonite mixtures for their use as confinement barriers for solid waste landfills. The mixtures have been prepared parametrically varying the percentage of bentonite. The sample preparation method was established willing to simulate the compaction processes on site. In fact, the compacted samples were tested following two different stress-wetting paths representative of the possible stress and imbibition sequences occurring on a landfill confinement barrier. In the first case, the barrier comes into contact with rainwater before being subjected to the overloading stress induced by waste disposal, while, in the second case, the barrier is overloaded by the waste before being wetted by the leachate. The compressibility and permeability of the sand–bentonite mixtures were determined, in both cases, by oedometric compression tests. The experimental results are analysed and compared in order to evaluate the influence of the bentonite content on the mechanical and hydraulic behaviour of the mixture. Interpretation of the results is also accomplished with a micro-mechanical investigation of the mixtures fabric. Suitable compositions of sand and bentonite are finally proposed for the design of effective confinement barriers.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"8007 - 8022"},"PeriodicalIF":5.6,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02335-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140962335","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 and analytical study on the reinforcement mechanism of in-pipe deep dynamic compaction in loose sandy soil","authors":"Ping Li,&nbsp;Xinfei Sun,&nbsp;Jun Yu,&nbsp;Gangqiang Kong,&nbsp;Junjun Chen","doi":"10.1007/s11440-024-02340-w","DOIUrl":"10.1007/s11440-024-02340-w","url":null,"abstract":"<div><p>Considering that conventional dynamic compaction (CDC) method has limitation in the effectiveness of improvement depth because the improved shallow soil layers prevent the impact energy further transmitted to the deep ground, a new technique of in-pipe deep dynamic compaction (IDDC) is proposed in which the tamper can compact soil from the deep to the shallow soil layers. In this paper, the main objective is to illustrate the work mechanism of IDDC. Firstly, main components of equipment and construction process of IDDC are introduced. Then, model tests of CDC and IDDC were conducted on loose sand to obtain the influence depth using the acceleration of soil particles during impact and the distribution of cone resistance and side friction through static cone penetration tests (CPTs) after impact. Finally, the analytical formulae of superimposed stress and settlement due to IDDC was derived based on the Mindlin’s solution and equation of motion, and verified with model test results and a practical case. The results indicate that with the falling height of 1 m in model tests, the further impacts after the 6th impact of CDC could hardly improve ground, resulting in the improvement depth of around 45 cm, whereas the improvement depth of IDDC was over 80 cm. Moreover, at the falling height of 1 m, the average increment in cone resistance after IDDC is 82% greater than that after CDC. Finally, compared with experimental results, the errors of the predicted settlement and the superimposed stress are less than 26 and 14%, respectively, and the proposed formulae succeed to predict the improvement depth of IDDC applied in a coastal area of China.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"7989 - 8006"},"PeriodicalIF":5.6,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975362","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":"Frozen enzyme EICP method for more effective soil improvement","authors":"Samuel Ng,&nbsp;Jian Chu","doi":"10.1007/s11440-024-02348-2","DOIUrl":"10.1007/s11440-024-02348-2","url":null,"abstract":"<div><p>Enzyme-induced calcite precipitation (EICP) is one of the emerging soil improvement methods. However, when plant-based enzyme is used, the urease enzyme harvested from plants cannot be stored long. This affects large-scale applications of this method. This paper presents a new method that not only enables urease enzyme to be stored for a long duration, but also improves significantly the effectiveness and efficiency of EICP for soil improvement. In this method, the storage duration of soybean derived urease enzyme is prolonged by storing it at negative 20 degrees. The experimental results indicated that the frozen-stored urease enzyme had an activity of 326% higher than that of fresh enzyme. The shear strength of a fine sand treated using the frozen-stored enzyme is 238.8% higher than that using a normal EICP method. Thus, the frozen method not only overcomes the enzyme storage problem, but also offers a much-improved EICP method. The reasons for the higher urease activity and improved strength enhancement are also explained in this paper.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7117 - 7124"},"PeriodicalIF":5.6,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140935744","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":"Progressive yielding/softening of soil–cement columns under embankment loading: a case study","authors":"Jin-chun Chai,&nbsp;Takenori Hino,&nbsp;Yafei Qiao,&nbsp;Wenqi Ding","doi":"10.1007/s11440-024-02346-4","DOIUrl":"10.1007/s11440-024-02346-4","url":null,"abstract":"<div><p>An embankment with a fill thickness of 7.5 m was built on a soil–cement column-slab system improved about 15.8 m thick soft subsoil. The embankment was stable for about 5 months after construction, and then, its settlement rate increased rapidly. To avoid the failure of the embankment, 1.0 m thick fill was removed and the embankment was stabilized again. The results of field investigation using all-core boring through a cement deep mixing (CDM) column under the central of the embankment and 3D finite element analysis (FEA) indicate that the most likely mechanism for the observed field behavior is progressive yielding/softening of the upper part of the columns. In FEA, the yielding/softening of the upper part of columns was simulated using strength reduction option and the start of the softening was triggered manually at the time of observed rapid increase in the settlement rate. This case history indicates that in field quality control of CDM columns, identifying local weak part(s) by continuous measuring the strength of the column samples retrieved from all-core boring is important. It is suggested that combination of unconfined compression test as well as needle penetration tests for the cores retrieved can be an economic and practical way to do this.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 11","pages":"7229 - 7241"},"PeriodicalIF":5.6,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140935747","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}