Géotechnique最新文献_第2页

Use of shells for the mechanical stabilisation of sediments: a valuable geomechanical perspective? 利用贝壳对沉积物进行机械加固：宝贵的地质力学观点？

Géotechnique Pub Date : 2024-03-25 DOI: 10.1680/jgeot.22.00383

Rossella Petti, Claudia Vitone, Maurizio Iler Marchi, Michael Plötze, Alexander Puzrin

{"title":"Use of shells for the mechanical stabilisation of sediments: a valuable geomechanical perspective?","authors":"Rossella Petti, Claudia Vitone, Maurizio Iler Marchi, Michael Plötze, Alexander Puzrin","doi":"10.1680/jgeot.22.00383","DOIUrl":"https://doi.org/10.1680/jgeot.22.00383","url":null,"abstract":"The present study contributes to develop a novel eco-friendly solution for the mechanical stabilisation of dredged marine sediments by using mussel shells, i.e., another highly impacting waste of marine origin, in partial replacement of cements. Which are the underlying chemo-mechanical interactions affecting the evolution of such mixtures? Can the mussel shells replace cement without compromising useful geomechanical and geochemical properties of the stabilized sediments? Can such mixtures still be modelled as soils when it comes to their geotechnical design and analysis? The paper answers these questions by assessing the mechanical performance of the mixtures formed by sediments stabilised with three types of cement and a mussel shell powder and comparing it with that of the same sediments when treated with cement only. Multiple beneficial effects of the use of mussel shell powder, as peculiar source of calcium carbonate for its biogenic origin, have been demonstrated: it acts as a void filler, enhances the electrolytic exchanges between sediment and cement, and increases the contact area between the mineral particles promoting the chemical hydration reactions. As a result, for fixed replacement ratios, the original mixtures still exhibit soil-like behaviour consistent with traditional geomechanics and even better performances than the control mixtures.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140299893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Backward erosion piping in geotechnical infrastructure: a rate process perspective 岩土基础设施中的后向侵蚀管道：速率过程视角

Géotechnique Pub Date : 2024-03-25 DOI: 10.1680/jgeot.23.00259

Zhijie Wang, Caglar Oskay, Alessandro Fascetti

引用次数: 0

Mechanized deep tunnel excavation in saturated clayey soils: a pre-design hydro-mechanically coupled method for the assessment of both spoil and face volume loss 饱和粘性土中的机械化深层隧道挖掘：评估弃土和工作面体积损失的设计前水力机械耦合方法

Géotechnique Pub Date : 2024-03-25 DOI: 10.1680/jgeot.23.00294

Luca Flessati, Claudio di Prisco

{"title":"Mechanized deep tunnel excavation in saturated clayey soils: a pre-design hydro-mechanically coupled method for the assessment of both spoil and face volume loss","authors":"Luca Flessati, Claudio di Prisco","doi":"10.1680/jgeot.23.00294","DOIUrl":"https://doi.org/10.1680/jgeot.23.00294","url":null,"abstract":"Mechanized tunnel excavation in soils causes over-excavations, potentially leading to large amounts of spoil and settlements at ground level. An accurate estimation of over-excavations is crucial in the pre-design phase for assessing costs, determining the appropriate excavation method and choosing the muck management strategy. Currently, the estimation is based on experience and data from similar projects, but it becomes difficult when project conditions are heterogeneous. Alternatively, finite element analyses are time-consuming and not suitable for early design stages and, therefore, simplified tools are needed. In this paper, the authors present a simplified approach putting in relation face extrusion with estimated spoil mass and face volume loss. This approach, conceived for deep tunnels, is the extension to the case of mechanized tunnelling of a hydro-mechanical coupled meta-model derived from finite element numerical analyses for tunnels in clayey soils excavated by using conventional techniques (i.e. without any use of tunnel boring machines). The model has been validated against field data relative to a case study. The approach can be used in the early design process to identify tunnel boring machine characteristics and provide preliminary cost estimates. Additionally, during the construction phase, the method can be employed to interpret monitoring data and pre-design mitigation measures for unforeseen soil profile variations.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic stress analysis of rock joints under railway loading 铁路荷载下岩石接缝的动态应力分析

Géotechnique Pub Date : 2024-03-25 DOI: 10.1680/jgeot.23.00301

Marlisio Oliveira Cecilio Junior, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Rakesh Sai Malisetty

{"title":"Dynamic stress analysis of rock joints under railway loading","authors":"Marlisio Oliveira Cecilio Junior, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Rakesh Sai Malisetty","doi":"10.1680/jgeot.23.00301","DOIUrl":"https://doi.org/10.1680/jgeot.23.00301","url":null,"abstract":"The proper estimation of stresses generated by train passage is of fundamental importance for the serviceability and longevity of railways, and yet very limited knowledge is available where the track substructure is built on a jointed rock mass. The present study introduces an analytical solution for estimating the ground stresses arising from moving wheel loads, causing a change in the three-dimensional stress state in the track formation, in relation to the stress variation with depth and along the longitudinal track section, i.e. the direction of train passage. Based on 21 case histories, an array of field measurements and numerical simulations covering a wide range of freight tonnage, train speeds, and different formation conditions, were considered to validate the proposed analytical solution. The proposed methodology (analytical solution) was then applied to a jointed rock subgrade to determine the normal and shear stresses acting along a specific discontinuity plane. The main analytical outcome demonstrates that the orthogonal vertical and shear stresses present different and phase-shifted history plots for homogeneous ground conditions with principal stresses rotation. However, conversely for a jointed subgrade, the normal and shear stresses along the discontinuity have the same history plot pattern and are in phase. As a practical guide, the results from this study would help to define which cyclic loads should be applied in laboratory tests to simulate realistic traffic patterns of trains travelling over a jointed rock subgrade.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140322312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental study on the influence of cyclic loading frequency on liquefaction characteristics of saturated sand 循环加载频率对饱和砂液化特性影响的试验研究

Géotechnique Pub Date : 2024-03-25 DOI: 10.1680/jgeot.21.00384

Chengshun Xu, Chong Yue, Xiuli Du, Ke Liang, Bing Wang, Guoxing Chen

{"title":"Experimental study on the influence of cyclic loading frequency on liquefaction characteristics of saturated sand","authors":"Chengshun Xu, Chong Yue, Xiuli Du, Ke Liang, Bing Wang, Guoxing Chen","doi":"10.1680/jgeot.21.00384","DOIUrl":"https://doi.org/10.1680/jgeot.21.00384","url":null,"abstract":"A series of undrained cyclic torsional shear tests were conducted to investigate the effect of cyclic loading frequency on the liquefaction characteristics of saturated sand using the hollow cylinder apparatus. The test results show that the dilative and contractive tendencies of various saturated sands are not only related to the physical properties of sand, but also affected by loading frequency. Under low-frequency loading, the saturated sand has a dilative behaviour, excess pore water pressure fluctuates after initial liquefaction and soil maintains the ability to resist liquefaction to some extent after the initial liquefaction. The liquefaction mode in terms of stress-strain relationship generally performs as the “cyclic mobility”. However, under the high-frequency loading, the saturated sand has a contractive behaviour, excess pore water pressure generally keeps stable after the initial liquefaction. The liquefaction mode in terms of stress-strain relationship generally exhibits as “cyclic instability”. The deformation caused by low-frequency loading is significantly larger compared with that caused by high-frequency loading. At higher loading frequencies, the phase transformation stress ratio increases with the increase of loading frequency, and gradually approaches the failure stress ratio.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140299523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of embedded walls on tunnelling-induced sandy ground displacements: a numerical investigation 嵌入墙对隧洞引起的砂质地面位移的影响：数值研究

Géotechnique Pub Date : 2024-03-21 DOI: 10.1680/jgeot.23.00307

Jingmin Xu, Luorui Zheng, Geyang Song, Dingwen Zhang, Brian Sheil, Alec M. Marshall

{"title":"Effects of embedded walls on tunnelling-induced sandy ground displacements: a numerical investigation","authors":"Jingmin Xu, Luorui Zheng, Geyang Song, Dingwen Zhang, Brian Sheil, Alec M. Marshall","doi":"10.1680/jgeot.23.00307","DOIUrl":"https://doi.org/10.1680/jgeot.23.00307","url":null,"abstract":"Urban tunnelling projects pose significant risks to the integrity of nearby structures due to ground movements induced by the excavation process. Embedded walls are commonly employed as a protective measure to mitigate these adverse effects. This paper presents a comprehensive numerical investigation into the effects of embedded walls on tunnelling-induced ground displacements, aiming to provide insights and recommendations for optimal embedded wall design. The study assesses the impact of varying embedded wall length and horizontal distance from the tunnel on soil settlement and horizontal displacements. Results demonstrate the complex interplay between embedded wall length, horizontal distance, and ground movement patterns, and the highly non-linear influence of key parameters on embedded wall efficiency (i.e. its ability to reduce settlements). A preliminary design chart is proposed to guide engineers in determining the appropriate horizontal location and depth of embedded walls to effectively reduce tunnelling-induced ground displacements. The findings contribute to a better understanding of embedded wall performance in the context of tunnelling and provide valuable guidance for the practical design and implementation of protective measures in urban areas.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of vegetation growth on soil microstructure and hydro-mechanical behaviour 植被生长对土壤微观结构和水力机械性能的影响

Géotechnique Pub Date : 2024-03-21 DOI: 10.1680/jgeot.23.00163

Alessandro Fraccica, Enrique Romero, Thierry Fourcaud

{"title":"Effects of vegetation growth on soil microstructure and hydro-mechanical behaviour","authors":"Alessandro Fraccica, Enrique Romero, Thierry Fourcaud","doi":"10.1680/jgeot.23.00163","DOIUrl":"https://doi.org/10.1680/jgeot.23.00163","url":null,"abstract":"Literature studies are evidencing the counterposed effects of vegetation on soil hydraulic behaviour. Besides, root effects at the microscale are rarely quantified for direct correlations with phenomenological observations due to the complexity of adopting up-scaling factors. This study explores the microstructural causes behind the observed changes in vegetated compacted clayey sand's hydraulic and volume change behaviour. To this aim, laboratory experiments were carried out on compacted samples seeded with <i>Cynodon dactylon</i>. Significant changes in soil water-saturated permeability, water retention and shrinkage upon drying were observed after root growth. Laboratory measurements were complemented with quantification of root morphological features and observations at the microscale at different soil hydraulic states. X-ray scans and mercury intrusion porosimetry allowed covering seven orders of magnitude of pore sizes, shedding light on soil fabric changes at the soil-root interface and the clay aggregate scale. The effects of roots on the soil pore size distribution consisted of multi-physics phenomena: fissure generation, void clogging, and soil aggregation due to roots’ chemical interaction. Furthermore, a good correlation was found between the normalised volume of roots and the micro-pores volume. This new expression was included in a framework to predict soil water retention behaviour considering the aggregated structure and soil-root hydro-chemical interactions.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling the piping-assisted erosion of clay barriers 粘土屏障的管道辅助侵蚀建模

Géotechnique Pub Date : 2024-03-14 DOI: 10.1680/jgeot.22.00421

Huaxiang Yan, Majid Sedighi, A. Jivkov, Abdelmalek Bouazza

{"title":"Modelling the piping-assisted erosion of clay barriers","authors":"Huaxiang Yan, Majid Sedighi, A. Jivkov, Abdelmalek Bouazza","doi":"10.1680/jgeot.22.00421","DOIUrl":"https://doi.org/10.1680/jgeot.22.00421","url":null,"abstract":"Recent laboratory and field experiments have provided evidences of the erosion and piping of clay-based barriers. Predicting these phenomena is essential for the performance assessment of bentonite barriers and containments. This paper presents a non-local multi-physics model for bentonite erosion induced by piping flow that includes swelling, detachment of particles and co-transport of detached particles with piping flow. The erosion is controlled by the balance between the cohesive strength, which depends on the swelling, and the shear force, which depends on the water velocity and chemistry. The accuracy of the model is tested by comparison of simulation results with experimental data from pinhole tests and material erosion in boreholes. It is demonstrated that the model predicts accurately the total mass eroded by the piping flow. For example, the results show that the mass loss induced by piping-assisted erosion during the installation of a bentonite plug can reach 10.3% of the original mass, which may significantly reduce the sealing capacity of bentonite plugs in boreholes. The results of simulations show that the eroded mass depends on the borehole diameter and flow rate. The minimum flow rates required to erode 10% of the original mass are 0.8 L/s and 0.045 L/s for db = 56 mm and 160 mm, respectively. These results demonstrate how the proposed formulations can be used to quantify the piping-assisted erosion of clay barriers, such as buffers, backfills, and plugs considered for geological disposal of higher activity waste, and the sealing of investigation boreholes and abandoned geo-energy wells.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140243329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Reducing shallow foundation rotation due to reverse faulting using predefined shear planes 利用预定剪切平面减少反向断层引起的浅层地基旋转

Géotechnique Pub Date : 2024-03-06 DOI: 10.1680/jgeot.23.00221

M. Baziar, Mir Mahdi Rashedi, A. S. Azizkandi

{"title":"Reducing shallow foundation rotation due to reverse faulting using predefined shear planes","authors":"M. Baziar, Mir Mahdi Rashedi, A. S. Azizkandi","doi":"10.1680/jgeot.23.00221","DOIUrl":"https://doi.org/10.1680/jgeot.23.00221","url":null,"abstract":"Permanent ground displacement due to faulting during strong earthquakes threatens stability of civil structures. To protect surface foundations from faulting, several mitigation techniques have been developed. Due to limitations of earlier mitigation strategies for unidentified reverse faulting conditions, this research presents a novel mitigation system, including installing sliders beneath the wings of a V-shaped concrete element, to reduce footing rotation. To evaluate the effectiveness of the suggested mitigation strategy, concrete strength tests, a physical centrifuge test and a comprehensive numerical study for different fault locations and dip angles were conducted for the first time. Results demonstrated that the placement of the sliders beneath the V-shaped wings had a significant effect on dissipating the fault dislocation. Compared to the previous mitigation techniques, the proposed system decreased the foundation rotation from a high value (11o) to a low value (3.2o) for the worst-case scenarios. Furthermore, the friction coefficients among sliders and concrete, the concrete wing inclination angle, length, and thickness were critical parameters to design the optimum proposed system. On the other hand, soil layer thickness and relative density did not significantly affect the footing rotation.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140260997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A closed-form criterion to identify high-mobility flowslides 识别高流动性滑道的闭式标准

Géotechnique Pub Date : 2024-03-06 DOI: 10.1680/jgeot.23.00171

Yanni Chen, G. Buscarnera

{"title":"A closed-form criterion to identify high-mobility flowslides","authors":"Yanni Chen, G. Buscarnera","doi":"10.1680/jgeot.23.00171","DOIUrl":"https://doi.org/10.1680/jgeot.23.00171","url":null,"abstract":"This paper derives a closed-form criterion to assess the risk of flowslide runout in loose frictional soil. The derivations rely on a recently proposed framework to simulate pre- and post-failure motion in infinite slopes. An analytical solution of the coupled differential equations capturing flowslide hydromechanics is obtained by specifying them for a perfectly plastic constitutive law. This result enables a comprehensive examination of the factors that control whether the landslide motion, once triggered, autonomously comes to rest (self-regulating behavior with low mobility) or continues to propagate (self-feeding behavior with high mobility). It is found that the time history of motion is regulated by non-dimensional property groups reflecting the timescale of excess pore pressure dissipation and the inertial properties of the liquefied zone, which are in turn governed by material (e.g., hydraulic conductivity, dilation coefficient, elastic moduli) and slope properties (e.g., thickness, inclination). The solution is used to build charts identifying the critical ranges of soil properties and triggering factors that differentiate between high-mobility and low-mobility flowslides. Most importantly, it is shown that the fate of flowslide motions is predicted by a critical ratio expressed in terms of excess pore pressure and flow velocity, here defined factor of mobility, FM, with values above 1 indicating a self-feeding runout.","PeriodicalId":501472,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140261366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0