{"title":"Estimating Plasticity Index Directly from Piezocone Penetration Tests in Saturated Natural Soils","authors":"N. Ramsey, K. Tho","doi":"10.1139/cgj-2023-0106","DOIUrl":"https://doi.org/10.1139/cgj-2023-0106","url":null,"abstract":"Plasticity Index, Ip, is a relatable parameter for most geotechnical engineers, because Ip can be used to estimate other soil properties, such as internal friction angle, compression index and low strain shear modulus. Consequently, a method for estimating Ip directly from a piezocone penetration test (CPTU) which measures cone resistance, sleeve friction and pore pressure would be useful for many practising geotechnical engineers. This technical note presents a method for estimating Ip profiles entirely from CPTU data. The new method has been calibrated using a case database of 258 complementary measurements taken, in natural soils, at 25 globally distributed marine sites.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"2 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84340930","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}
{"title":"Longevity of Multi-layered Textured HDPE Geomembranes in Low-level Waste Applications","authors":"M. Zafari, R. Rowe, F. Abdelaal","doi":"10.1139/cgj-2023-0039","DOIUrl":"https://doi.org/10.1139/cgj-2023-0039","url":null,"abstract":"The degradation behaviour of five multilayered textured white geomembranes (GMBs) is investigated when immersed in two synthetic low-level waste (LLW) leachates with pH 7 and 9 at a range of temperatures (40-85oC) for 48-55 months. Results are compared to the performance of the GMBs in synthetic municipal solid waste (MSW) leachate. Increasing pH from 7 to 9 gives slightly faster antioxidant depletion in LLW leachate. The estimated time to nominal failure for the GMBs is at least 20% longer in LLW leachate than in MSW leachate containing surfactant that accelerates both antioxidant depletion and stress cracking. Thus, MSW leachate can be used as a conservative proxy to estimate the service-life of a GMB in contact with LLW leachate. Two GMBs are considered very highly likely to meet the required 550-year design life of the near surface disposal facilities even based on the most conservative prediction of the time to nominal failure for the GMBs.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"11 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78286723","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}
{"title":"Displacement-based finite element approach on analysing flexible combined pile–raft foundation in layered soil","authors":"Aniruddha Bhaduri, D. Choudhury","doi":"10.1139/cgj-2021-0310","DOIUrl":"https://doi.org/10.1139/cgj-2021-0310","url":null,"abstract":"The present study proposes a new finite element methodology to analyse the behaviour of flexible combined pile–raft foundation (CPRF) situated in layered soil, in a displacement-based framework. The soil medium is idealised as an advanced elastic Pasternak medium and the piles and raft are modelled as bar and plate element, respectively. The two components of CPRF are analysed simultaneously and displacement compatibility is satisfied at the pile–raft junctions. A number of soil–structure interaction factors, which govern the behaviour of CPRF, are suitably subsumed in the analysis scheme. The proposed method is validated with available analytical and experimental studies. Further parametric studies, investigating the effects of soil layering and raft flexibility on the behaviour of CPRF, are explored. It is observed that the load sharing proportion between the components and the raft deformation pattern depend upon the thickness and position of the soft soil layer in a multilayered soil system. The thickness of the flexible raft plays a pivotal role in determining the behaviour of CPRF, founded in a multilayered soil profile. Thus, this research manifests notable advancement in understanding the behaviour of flexible CPRF in layered soil.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"45 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80963019","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}
{"title":"Partially drained uplift behaviour of plant roots in dilative soils","authors":"Jun Zhu, A. Leung, Yu Wang","doi":"10.1139/cgj-2023-0104","DOIUrl":"https://doi.org/10.1139/cgj-2023-0104","url":null,"abstract":"A large volume of research reporting the pull-out behaviour of root systems is available, but no study has considered the effects of soil drainage. This work implemented a modified three-dimensional embedded beam element model in a finite element platform that solved model equations by using a fully hydromechanically coupled algorithm. The model was validated against published centrifuge pull-out tests on root analogues, and the validated model was then applied to study parametrically the influence of the ratio of uplift rate to soil hydraulic conductivity on pull-out behaviour. The results demonstrated that the model can well capture the prepeak behaviour of the root systems up to the peak pull-out resistance. The generation of negative pore-water pressure (p_ex) owing to soil dilation upon root–soil interfacial shearing was the major reason for increased pull-out resistances under partially drained conditions. Compared with other root systems, root systems with smaller branch angles and deeper branch depths mobilised considerably more significant plastic deviatoric strains in the soil in their vicinity, generating more negative p_ex. Hyperbolic dimensionless backbone curves were derived to explain the transitional pull-out behaviours of root systems of different geometries under drainage conditions that ranged from fully drained to undrained.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"4 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75587899","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}
Deng Zhang, Liming Zhang, Yan Liu, Zai-quan Wang, Faxing Zhang
{"title":"Creep failure characteristics and characterization of constitutive behaviors of jointed sandstone under multi-level loading of seepage pressure","authors":"Deng Zhang, Liming Zhang, Yan Liu, Zai-quan Wang, Faxing Zhang","doi":"10.1139/cgj-2023-0069","DOIUrl":"https://doi.org/10.1139/cgj-2023-0069","url":null,"abstract":"jointed sandstone experiences three creep stages in creep tests under multi-level loading paths of seepage pressure. Jointed sandstone with joint dip angles of 30° and 60° undergoes shear failure, while that with the joint dip angle of 45° is subject to tensile-shear failure. Under the same seepage pressure, the sandstone with the joint dip angle of 45° has a greater creep rate in the steady-state creep stage than that with joint dip angles of 30° and 60°. In the volumetric compression stage, the permeability increases at the instant of applying each level of seepage pressure, followed by gradual reduction and stabilization of permeability. In the volumetric dilation stage, the permeability gradually rises. The theory of memory-dependent derivative reflecting the time memory effect was introduced to establish the memory-dependent nonlinear viscoelastic-plastic seepage-creep model for jointed sandstone. The results obtained using the theoretical model conform to the test data. Moreover, the creep failure criterion of the rock was proposed. The creep acceleration starts to increase from 0 and the critical steady state transitions to a non-steady state, suggesting that the rock will soon be damaged.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"1 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83046317","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}
Guoliang Ma, Xiang He, Yang Xiao, Jian Chu, Han Liu, A. Stuedlein, T. M. Evans
{"title":"Spatiotemporal Evolution of Biomineralization in Heterogeneous Pore Structure","authors":"Guoliang Ma, Xiang He, Yang Xiao, Jian Chu, Han Liu, A. Stuedlein, T. M. Evans","doi":"10.1139/cgj-2022-0496","DOIUrl":"https://doi.org/10.1139/cgj-2022-0496","url":null,"abstract":"A fundamental understanding of the CaCO3 precipitation process in the pore network of geomaterials is important to uncover the mechanism behind the evolution of the engineering properties of geomaterials during the MICP treatment. However, the details about the CaCO3 precipitation process and its interaction with the flow field at the pore scale are not well understood. In the current work, the CaCO3 precipitation process and flow field in a heterogeneous chip composed of two pore bodies, four pore throats of different sizes, and two dead-end pores are presented. The test results show that solutions can percolate through all four pore throats and diffuse into the dead-end pores at the beginning of the tests. As a result, CaCO3 can be precipitated across the chip with some difference in the number, shape, and size of crystals. Fine pore throats are more likely to be clogged, leading to solution percolating through coarse channels, thereby increasing the amount of CaCO3 in coarse channels. Precipitation in coarse channels is also ceased after a certain duration despite the continued injection of the solution. Our work provides insight into the CaCO3 precipitation process in a representative pore element, which can help to understand the mechanism behind the evolution of engineering properties and establish simulation models to predict the engineering properties of geomaterials treated by the MICP method.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"49 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90933150","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}
Yuan‐qin Tao, K. Phoon, Honglei Sun, Yuanqiang Cai
{"title":"Hierarchical Bayesian model for predicting small-strain stiffness of sand","authors":"Yuan‐qin Tao, K. Phoon, Honglei Sun, Yuanqiang Cai","doi":"10.1139/cgj-2022-0598","DOIUrl":"https://doi.org/10.1139/cgj-2022-0598","url":null,"abstract":"This paper develops a hierarchical Bayesian model (HBM) that integrates the physical knowledge and the test data to predict the small-strain shear modulus Gmax for a target sand type. The limited target-specific data is combined with the abundant generic data through a hierarchical structure so that the variability of Gmax within one sand type and across different sand types can be captured. The hyperparameters that characterize the same underlying distribution of physical model parameters across all the sand types are first estimated from the abundant generic data. The model parameters for the new sand type are then updated as the limited site-specific data become available. The approach is illustrated using a generic database and two real examples not covered by the generic database. Multiple possible hierarchical models are compared in terms of model complexity and goodness-of-fit. The results show that the hierarchical modeling of small-strain shear modulus data is reasonable and necessary. The hierarchical model can provide less biased and more accurate predictions of Gmax compared to the commonly used complete pooling model, especially for cases where the site-specific data is quite different from the overall average of the generic database.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"48 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76113594","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}
{"title":"STABILITY OF SLOPE CORNERS: A DISPLACEMENT BASED FEM STUDY","authors":"A. Timchenko, J. Briaud","doi":"10.1139/cgj-2022-0495","DOIUrl":"https://doi.org/10.1139/cgj-2022-0495","url":null,"abstract":"The stability of slopes is typically evaluated by two-dimensional plane strain analysis. However, many slopes exhibit three-dimensional geometries, including slope corners. Several researchers have studied the stability of slope corners but found that the factor of safety (FS) was close to the FS for the plane strain case. The results of a new series of 3D Finite Element Method (FEM) simulating slope corners including slope angle, plan view angle, radius of curvature, and slope height are presented. They confirm that the FS does not vary much for corners compared to the plane strain case. However, 220 cases using an elastic-perfectly plastic soil model together with the FEM shear strength reduction method show that the displacement field is very different at the corners compared to plane strain with differences reaching over 100%. The displacement ratio between corners and plane strain is presented as a function of the plan view angle of the corner. Often failure is defined at a chosen large displacement, as in the ultimate load of foundation elements. If this concept is carried over to slope stability, it would indicate that the FS of corners should be very different from the plane strain case. A possible explanation is discussed.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"39 2 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79808690","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}
T. Shuku, K. Phoon, M. Ishii, T. Kumagai, Y. Yokota, K. Date
{"title":"Probabilistic generic transformation model between two rock mass properties: specific fracture energy and P-wave velocity","authors":"T. Shuku, K. Phoon, M. Ishii, T. Kumagai, Y. Yokota, K. Date","doi":"10.1139/cgj-2022-0235","DOIUrl":"https://doi.org/10.1139/cgj-2022-0235","url":null,"abstract":"This study proposed a probabilistic generic transformation model between two rock mass properties, specific fracture energy, Ev, and P-wave velocity, VP. To build the transformation model, 12 pairwise data sets of Ev and VP were collected from six different construction sites involving construction of mountain tunnels in Japan. This database is labeled as “RockMass/2/350”. A probabilistic transformation model was built based on a bivariate standard normal distribution with these 350 data points. The model is generic, because it is based on a variety of sites. The performance of the constructed transformation model was evaluated through a cross-validation. It was found that 98.2% of the validation data fell within the computed 95% confidence interval of the model estimation, and this result provides a preliminary validation of the probabilistic transformation model. Unlike existing deterministic transformation models for estimating VP from Ev, the proposed model can explicitly evaluate the transformation uncertainty with a quantitative metric such as a percentile. For practical application, a 3D model of the spatial distribution for Young’s modulus, E, was visualized based on the proposed transformation model. Since the proposed model is probabilistic, it can provide the spatial distribution for percentiles of E values. The constructed 3D model presented in this paper can be directly used as an input data for finite element or finite difference analysis, and probabilistic evaluation of excavation simulation is feasible based on the proposed probabilistic model. The quantitative information on such uncertainty can be useful in decision-making for tunnel constructions, such as selection of a cautious characteristic value.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"31 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81751281","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}
{"title":"Reply to the discussion by Shuttle and Jefferies on “Improved cone penetration test predictions of the state parameter of loose mine tailings”","authors":"Juan Ayala, Andy Fourie, David Reid","doi":"10.1139/cgj-2023-0095","DOIUrl":"https://doi.org/10.1139/cgj-2023-0095","url":null,"abstract":"","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135110537","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}