Weiping Wang, Xi-An Li, Haoyang Dong, Hao Chai, Wenfu Yang
The vast majority of geological disasters in loess-covered areas are caused by seepage erosion in loess. Therefore, this paper focuses on the microscopic mechanism of loess seepage erosion, and constructs a loess microstructure model based on particle "core+coat". On this basis, the SEM photos are imported into COMSOL to simulate the micro-scale seepage in the pore domain. Through the actual permeability test, combined with the micro-quantitative information obtained by IPP(Image-pro-plus) and Arcgis, the micro-factors affecting loess permeability are quantitatively analyzed by grey relational analysis. The results show that the dry density affects the porosity of loess and ultimately determines the permeability of loess. Different pore types and proportions lead to different seepage erosion of loess. The erosion process mainly occurs at the junction of pores. The sudden increase of velocity, pressure drop and maximum shear rate at the throat indicate that this area is the main action area of loess seepage erosion. The research results of this paper provide an important theoretical basis for the research and prevention of geological disasters and engineering diseases related to seepage deformation and failure in loess area.
{"title":"Micromechanical study of loess permeability and seepage erosion based on microstructure functional basic unit and seepage simulation in pore domain","authors":"Weiping Wang, Xi-An Li, Haoyang Dong, Hao Chai, Wenfu Yang","doi":"10.1139/cgj-2023-0281","DOIUrl":"https://doi.org/10.1139/cgj-2023-0281","url":null,"abstract":"The vast majority of geological disasters in loess-covered areas are caused by seepage erosion in loess. Therefore, this paper focuses on the microscopic mechanism of loess seepage erosion, and constructs a loess microstructure model based on particle \"core+coat\". On this basis, the SEM photos are imported into COMSOL to simulate the micro-scale seepage in the pore domain. Through the actual permeability test, combined with the micro-quantitative information obtained by IPP(Image-pro-plus) and Arcgis, the micro-factors affecting loess permeability are quantitatively analyzed by grey relational analysis. The results show that the dry density affects the porosity of loess and ultimately determines the permeability of loess. Different pore types and proportions lead to different seepage erosion of loess. The erosion process mainly occurs at the junction of pores. The sudden increase of velocity, pressure drop and maximum shear rate at the throat indicate that this area is the main action area of loess seepage erosion. The research results of this paper provide an important theoretical basis for the research and prevention of geological disasters and engineering diseases related to seepage deformation and failure in loess area.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138595893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jun Wang, Guojin Lin, Ning Tian, Kun Feng, Guowne Xu, Xiong-yu Hu, Zi-quan Chen, Chuan He
This paper aims at addressing the face failure of earth pressure balance (EPB) shield tunnels in dry dense sand by model tests and discrete element method (DEM) models. The model tests incorporated a miniature EPB shield which could fully reproduce the real tunnel construction of excavation and support. DEM models simulating the model tests were developed to capture the underlying face failure mechanism. Results show that both the limit support pressure obtained at chamber board and tunnel face increase with increasing C/D (C is tunnel buried depth, D is tunnel diameter). The ratio of the former to the latter approximates 0.60 due to the soil retaining of cutterhead panel, and it is independent of C/D. The local face failure initializes around tunnel face and develops directly to the global failure outcropping the ground surface in one phase with C/D≤1.0, while the local failure develops to the global failure in three phases with C/D=2.0 due to the soil arching evolution. The soil arching gets weaker when it propagates upward, and the horizontal stress concentration in the longitudinal direction is stronger than the transverse direction due to the difference of arch foot.
{"title":"Face failure of EPB shield tunnels in dry dense sand: a model test and DEM study","authors":"Jun Wang, Guojin Lin, Ning Tian, Kun Feng, Guowne Xu, Xiong-yu Hu, Zi-quan Chen, Chuan He","doi":"10.1139/cgj-2023-0072","DOIUrl":"https://doi.org/10.1139/cgj-2023-0072","url":null,"abstract":"This paper aims at addressing the face failure of earth pressure balance (EPB) shield tunnels in dry dense sand by model tests and discrete element method (DEM) models. The model tests incorporated a miniature EPB shield which could fully reproduce the real tunnel construction of excavation and support. DEM models simulating the model tests were developed to capture the underlying face failure mechanism. Results show that both the limit support pressure obtained at chamber board and tunnel face increase with increasing C/D (C is tunnel buried depth, D is tunnel diameter). The ratio of the former to the latter approximates 0.60 due to the soil retaining of cutterhead panel, and it is independent of C/D. The local face failure initializes around tunnel face and develops directly to the global failure outcropping the ground surface in one phase with C/D≤1.0, while the local failure develops to the global failure in three phases with C/D=2.0 due to the soil arching evolution. The soil arching gets weaker when it propagates upward, and the horizontal stress concentration in the longitudinal direction is stronger than the transverse direction due to the difference of arch foot.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138597793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
324 data points on the saturated hydraulic conductivity (k) of various hard rock mine tailings are collected from previous publications. The applicability of existing empirical equations for hard rock mine tailings are assessed based on this database collected. Results show that with a greater exponent of d10, the correlation between the measured and predicted k is greatly improved. An empirically modified version of the Kozeny-Carman equation is then proposed for predicting the saturated k of tailings and compared with the database. The proposed equation gives the best fit with a varying exponent greater than 2 for d10. Finally, the impact of particle shape on k is discussed.
{"title":"An empirical equation predicting the saturated hydraulic conductivity of tailings","authors":"Ji-ying Fan, R. K. Rowe","doi":"10.1139/cgj-2023-0339","DOIUrl":"https://doi.org/10.1139/cgj-2023-0339","url":null,"abstract":"324 data points on the saturated hydraulic conductivity (k) of various hard rock mine tailings are collected from previous publications. The applicability of existing empirical equations for hard rock mine tailings are assessed based on this database collected. Results show that with a greater exponent of d10, the correlation between the measured and predicted k is greatly improved. An empirically modified version of the Kozeny-Carman equation is then proposed for predicting the saturated k of tailings and compared with the database. The proposed equation gives the best fit with a varying exponent greater than 2 for d10. Finally, the impact of particle shape on k is discussed.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138600833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yufei Wang, C. O’Loughlin, Zefeng Zhou, Christophe Gaudin
Accurate quantification of the temporal changes in seabed strength allows for more reliable and less conservative geotechnical design. A recently developed effective stress framework, established within a one-dimensional computational domain to quantify changes in soil strength due to pore pressure generation and dissipation, has been extended to a two-dimensional (2D) computational domain to allow for consideration of boundary value problems that are too complex to be simplified to one-dimensional conditions. The work to implement the 2D framework is reported across two companion papers. The first of the two papers utilises large deformation finite element analyses to quantify the spatial distribution of accumulated plastic shear strain. These distributions are encapsulated within a strain influence function that is used within the new 2D framework in this paper to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength for a number of boundary value problems that represent typical offshore geotechnical processes. The merit of the new 2D framework is explored via retrospective simulations of existing experimental and numerical data. The resulting comparisons demonstrate the potential of the new framework, which is in quantifying the reliability of a range of geotechnical structures under complex loading conditions.
{"title":"A two-dimensional effective stress framework for modelling whole-life soil strength changes due to pore pressure generation and dissipation, Part 2: Applications","authors":"Yufei Wang, C. O’Loughlin, Zefeng Zhou, Christophe Gaudin","doi":"10.1139/cgj-2022-0332","DOIUrl":"https://doi.org/10.1139/cgj-2022-0332","url":null,"abstract":"Accurate quantification of the temporal changes in seabed strength allows for more reliable and less conservative geotechnical design. A recently developed effective stress framework, established within a one-dimensional computational domain to quantify changes in soil strength due to pore pressure generation and dissipation, has been extended to a two-dimensional (2D) computational domain to allow for consideration of boundary value problems that are too complex to be simplified to one-dimensional conditions. The work to implement the 2D framework is reported across two companion papers. The first of the two papers utilises large deformation finite element analyses to quantify the spatial distribution of accumulated plastic shear strain. These distributions are encapsulated within a strain influence function that is used within the new 2D framework in this paper to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength for a number of boundary value problems that represent typical offshore geotechnical processes. The merit of the new 2D framework is explored via retrospective simulations of existing experimental and numerical data. The resulting comparisons demonstrate the potential of the new framework, which is in quantifying the reliability of a range of geotechnical structures under complex loading conditions.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yufei Wang, C. O’Loughlin, Zefeng Zhou, Christophe Gaudin
The undrained shear strength of fine-grained soils changes with time, reducing due to pore pressure generation, and increasing during consolidation. There is an increasing appetite to recognise these temporal soil strength changes in offshore geotechnical design, as it provides a basis for potentially less conservative designs. Contributions to this endeavour are reported across two companion papers. This first paper extends an existing effective stress framework that relates generation of pore pressure to accumulated plastic shear strain, allowing undrained shear strength to be calculated within the context of critical-state soil mechanics. The main development is the extension of the computational domain to two dimensions, allowing calculations to be made for boundary value problems that cannot be satisfactorily simplified to 1D conditions. The magnitude and distribution of accumulated shear strain surrounding objects buried in soil are quantified through a series of large deformation finite element analyses. These spatial distributions are described using a strain influence function in the new 2D framework to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength around the buried object. The performance of the 2D framework is examined in the companion paper through retrospective simulations of experimental and numerical data.
{"title":"A two-dimensional effective stress framework for modelling whole-life soil strength changes due to pore pressure generation and dissipation, Part 1: Formulation","authors":"Yufei Wang, C. O’Loughlin, Zefeng Zhou, Christophe Gaudin","doi":"10.1139/cgj-2022-0331","DOIUrl":"https://doi.org/10.1139/cgj-2022-0331","url":null,"abstract":"The undrained shear strength of fine-grained soils changes with time, reducing due to pore pressure generation, and increasing during consolidation. There is an increasing appetite to recognise these temporal soil strength changes in offshore geotechnical design, as it provides a basis for potentially less conservative designs. Contributions to this endeavour are reported across two companion papers. This first paper extends an existing effective stress framework that relates generation of pore pressure to accumulated plastic shear strain, allowing undrained shear strength to be calculated within the context of critical-state soil mechanics. The main development is the extension of the computational domain to two dimensions, allowing calculations to be made for boundary value problems that cannot be satisfactorily simplified to 1D conditions. The magnitude and distribution of accumulated shear strain surrounding objects buried in soil are quantified through a series of large deformation finite element analyses. These spatial distributions are described using a strain influence function in the new 2D framework to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength around the buried object. The performance of the 2D framework is examined in the companion paper through retrospective simulations of experimental and numerical data.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Upon dynamic loading, saturated soil loses its strength and behaves differently with respect to the excess pore pressure variation resulting in volumetric-induced settlements. Traditionally, these settlements have been evaluated using standard charts based on one soil type and its relative density (RD). To assess these settlements, this study established a unique experimental methodology based on two laboratory tests: triaxial simple shear and piezoelectric ring actuator technique. Fifty-seven tests were performed on Ottawa F65 sand under strain-controlled cyclic and post-cyclic conditions. A chart was generated, revealing a relationship between the dissipated energy from cyclic loading and volumetric strain (v), based on the shear wave velocity as a controlling factor. This study was compared with previous studies to verify the compatibility of the proposed approach. Another novelty was revealed by studying v variation with the dissipated pressure. This variation is presented in a post-seismic chart, in which deformations are tracked based on the initial soil state and maximum excess pore pressure generation ratio (Rumax). For each RD, the soil is divided between liquefied and non-liquefied states according to a specific Rumax (Rumax-trigger point). The calculation of the volume compressibility coefficient is proven to serve as a liquefaction-triggering criterion identifying the liquefied state.
{"title":"Experimental Approach for Assessing Dissipated Excess Pore Pressure Induced Settlement","authors":"A. Bayoumi, M. Chekired, M. Karray","doi":"10.1139/cgj-2022-0063","DOIUrl":"https://doi.org/10.1139/cgj-2022-0063","url":null,"abstract":"Upon dynamic loading, saturated soil loses its strength and behaves differently with respect to the excess pore pressure variation resulting in volumetric-induced settlements. Traditionally, these settlements have been evaluated using standard charts based on one soil type and its relative density (RD). To assess these settlements, this study established a unique experimental methodology based on two laboratory tests: triaxial simple shear and piezoelectric ring actuator technique. Fifty-seven tests were performed on Ottawa F65 sand under strain-controlled cyclic and post-cyclic conditions. A chart was generated, revealing a relationship between the dissipated energy from cyclic loading and volumetric strain (v), based on the shear wave velocity as a controlling factor. This study was compared with previous studies to verify the compatibility of the proposed approach. Another novelty was revealed by studying v variation with the dissipated pressure. This variation is presented in a post-seismic chart, in which deformations are tracked based on the initial soil state and maximum excess pore pressure generation ratio (Rumax). For each RD, the soil is divided between liquefied and non-liquefied states according to a specific Rumax (Rumax-trigger point). The calculation of the volume compressibility coefficient is proven to serve as a liquefaction-triggering criterion identifying the liquefied state.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rigid-wall permeameter testing of two potentially unstable gradations established the critical hydraulic gradient to trigger instability is smaller for upward flow than for downward flow. The experimental finding is explained with reference to the Skempton-Brogan stress reduction factor α in the finer fraction content of the soil. Theory uses the α-factor to define a hydro-mechanical envelope in gradient-stress space that is independent of flow direction, and the experimental results are found in good agreement with the theory. Testing with upward flow is recommended to determine the value of α for an internally unstable gradation because, in contrast to downward flow, there is no requirement for an outflow boundary.
{"title":"Internal Instability of Cohesionless Soils in Upward and Downward Flow: An Experimental Verification of Theory","authors":"Maoxin Li, R. Fannin, Mark Foster, Li Yan","doi":"10.1139/cgj-2023-0011","DOIUrl":"https://doi.org/10.1139/cgj-2023-0011","url":null,"abstract":"Rigid-wall permeameter testing of two potentially unstable gradations established the critical hydraulic gradient to trigger instability is smaller for upward flow than for downward flow. The experimental finding is explained with reference to the Skempton-Brogan stress reduction factor α in the finer fraction content of the soil. Theory uses the α-factor to define a hydro-mechanical envelope in gradient-stress space that is independent of flow direction, and the experimental results are found in good agreement with the theory. Testing with upward flow is recommended to determine the value of α for an internally unstable gradation because, in contrast to downward flow, there is no requirement for an outflow boundary.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139211791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study characterises the effects of naturally varying organic content on the compression and shear behaviour of a marine silty-clay from the Netherlands. Index properties and mechanical properties are determined through laboratory tests, including oedometer and multistage loading-unloading triaxial stress paths. The results indicate a significant impact of the organic content on the compression response, with both the loading and reloading indexes increasing as the loss on ignition increases from 3% to 7%. Additionally, the study suggests a directional response of the compression behaviour, with the loading index increasing with the stress ratio. The influence of the organic content on shear strength appears to be less significant. No brittle response is observed during shearing and a similar ultimate stress ratio is attained by all samples. However, a unique critical state line can only be identified for samples with similar organic content, as its intercept and slope are found to increase with increasing organic content. The experimental results from stress paths at constant stress ratio reveal an anisotropic pre-failure plastic deformation mode, which depends on the previous stress history and loading direction. This suggests that the stress-dilatancy relationship cannot be formulated as a unique function of the stress ratio. The high-quality experimental data presented in the paper enlarge the database on soft organic soils in view of the development of advanced constitutive models.
{"title":"Deformational response of a marine silty-clay with varying organic content in the triaxial compression space.","authors":"Elisa Ponzoni, S. Muraro, A. Nocilla, C. Jommi","doi":"10.1139/cgj-2023-0058","DOIUrl":"https://doi.org/10.1139/cgj-2023-0058","url":null,"abstract":"This study characterises the effects of naturally varying organic content on the compression and shear behaviour of a marine silty-clay from the Netherlands. Index properties and mechanical properties are determined through laboratory tests, including oedometer and multistage loading-unloading triaxial stress paths. The results indicate a significant impact of the organic content on the compression response, with both the loading and reloading indexes increasing as the loss on ignition increases from 3% to 7%. Additionally, the study suggests a directional response of the compression behaviour, with the loading index increasing with the stress ratio. The influence of the organic content on shear strength appears to be less significant. No brittle response is observed during shearing and a similar ultimate stress ratio is attained by all samples. However, a unique critical state line can only be identified for samples with similar organic content, as its intercept and slope are found to increase with increasing organic content. The experimental results from stress paths at constant stress ratio reveal an anisotropic pre-failure plastic deformation mode, which depends on the previous stress history and loading direction. This suggests that the stress-dilatancy relationship cannot be formulated as a unique function of the stress ratio. The high-quality experimental data presented in the paper enlarge the database on soft organic soils in view of the development of advanced constitutive models.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abedalqader Idries, Timothy D. Stark, Lucia Moya, Jiale Lin
Canadian Geotechnical Journal, Ahead of Print. Water infiltration can cause softening of compacted structural fill and a reduction of the shear strength from the peak compacted strength to the fully softened strength (FSS) with an accompanying reduction in drained factor of safety (FoS). This study presents two-dimensional (2D) and 3D stability analyses of a compacted fill slope failure that occurred 6 years after construction due to water leaking from a connection between the main and lateral water pipes in the water supply system. The compacted fill material primarily consists of high plasticity fine-grained soil. The 3D FoS at the end of construction is 2.44 using the peak compacted strength envelope. However, the 3D FoS is close to unity (1.0) when the FSS is assigned to the compacted fill material with the appropriate piezometric surface, which means the 2 H:1 V compacted fill slope softened to the FSS within 6 years. This is an interesting FSS case because the failure surface is 4 m deep and semi-circular, which differs from infiltration cases that exhibit a shallower and more planar surface.
{"title":"Case study: 3D mobilized strength of compacted fill","authors":"Abedalqader Idries, Timothy D. Stark, Lucia Moya, Jiale Lin","doi":"10.1139/cgj-2023-0187","DOIUrl":"https://doi.org/10.1139/cgj-2023-0187","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. <br/> Water infiltration can cause softening of compacted structural fill and a reduction of the shear strength from the peak compacted strength to the fully softened strength (FSS) with an accompanying reduction in drained factor of safety (FoS). This study presents two-dimensional (2D) and 3D stability analyses of a compacted fill slope failure that occurred 6 years after construction due to water leaking from a connection between the main and lateral water pipes in the water supply system. The compacted fill material primarily consists of high plasticity fine-grained soil. The 3D FoS at the end of construction is 2.44 using the peak compacted strength envelope. However, the 3D FoS is close to unity (1.0) when the FSS is assigned to the compacted fill material with the appropriate piezometric surface, which means the 2 H:1 V compacted fill slope softened to the FSS within 6 years. This is an interesting FSS case because the failure surface is 4 m deep and semi-circular, which differs from infiltration cases that exhibit a shallower and more planar surface.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140597860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xuesong Cheng, Linsong Zhao, Shengzhang Han, Yetao Ji, Zhaorong Xu, Lingbo Meng, Jun Pan, Gang Zheng, Ruikun Wang
Multi-row grouting can be used to repeatedly mitigate the deformation of critical structures like tunnels. Nevertheless, no comprehensive investigation into the development patterns of soil deformation and excess pore water pressure, induced by multi-row grouting in soft soil, has been conducted to date. To address this gap, this study carried out a field test of multi-row grouting, systematically exploring the evolution and accumulation of soil horizontal displacement (SHD) and excess pore water pressure (EPWP) resulting from multi-row grouting. The findings demonstrated that the grouting process during multi-row grouting respectively exerted reaction and shielding effects on the subsequent grouting for the behavior of soil surrounding the grouting area. The reaction and shielding effects increased proportionally with the number of grouted rows. To predict the SHD induced by multi-row grouting, considering the reaction and shielding effects, this study provided a theoretical calculation method based on cavity expansion theory and the concept of upper and lower bounds, and proposed an optimal grouting scheme.
{"title":"In-situ Test and Calculation Method for Horizontal Deformation of Soil Induced by Multi-row Grouting","authors":"Xuesong Cheng, Linsong Zhao, Shengzhang Han, Yetao Ji, Zhaorong Xu, Lingbo Meng, Jun Pan, Gang Zheng, Ruikun Wang","doi":"10.1139/cgj-2023-0394","DOIUrl":"https://doi.org/10.1139/cgj-2023-0394","url":null,"abstract":"Multi-row grouting can be used to repeatedly mitigate the deformation of critical structures like tunnels. Nevertheless, no comprehensive investigation into the development patterns of soil deformation and excess pore water pressure, induced by multi-row grouting in soft soil, has been conducted to date. To address this gap, this study carried out a field test of multi-row grouting, systematically exploring the evolution and accumulation of soil horizontal displacement (SHD) and excess pore water pressure (EPWP) resulting from multi-row grouting. The findings demonstrated that the grouting process during multi-row grouting respectively exerted reaction and shielding effects on the subsequent grouting for the behavior of soil surrounding the grouting area. The reaction and shielding effects increased proportionally with the number of grouted rows. To predict the SHD induced by multi-row grouting, considering the reaction and shielding effects, this study provided a theoretical calculation method based on cavity expansion theory and the concept of upper and lower bounds, and proposed an optimal grouting scheme.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139263136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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