Engineering behaviour of in situ cored deep cement mixed marine deposits subjected to undrained and drained shearing

作     者：Wei Li Chung Yee Kwok Wei Li;Chung Yee Kwok

作者机构：Faculty of EngineeringChina University of GeosciencesWuhan430074China Department of Civil EngineeringThe University of Hong Kong999000Hong Kong SARChina 

出 版 物：《Journal of Rock Mechanics and Geotechnical Engineering》 (岩石力学与岩土工程学报（英文版）)

年 卷 期：2024年第16卷第5期

页      面：1749-1760页

核心收录：

学科分类：081401[工学-岩土工程] 08[工学] 0814[工学-土木工程] 

基　　金：funded by the Environment and Conservation Fund(Grant Nos.2020-170 and 2021-156) the National Natural Science Foundation of China(Grant No.42102327) 

主　　题：Deep cement mixing(DCM) In-situ cored sample Triaxial shearing Drainage condition Confining pressure Computed tomography(CT) 

摘      要：The deep cement mixing(DCM)is used to improve the capacity and reduce the settlement of the soft ground by forming cemented clay *** investigation on the mechanical behaviour of the DCM samples is limited to either laboratory-prepared samples or in-situ samples under unconfined *** this study,a series of drained and undrained triaxial shearing tests was performed on the in-situ cored DCM samples with high cement content to assess their mechanical *** is found that the drainage condition affects significantly the stiffness,peak and residual strengths of the DCM samples,which is mainly due to the state of excess pore water pressure at different strain levels,*** positive before the peak deviatoric stress and negative after the peak deviatoric stress,in the undrained *** slope of the failure envelope changes obviously with the confining pressures,being steeper at lower stress levels and flatter at higher stress *** strength parameters,effective cohesion and friction angle obtained from lower stress levels(c′0 andφ′0)are 400 kPa and 58°,respectively,which are deemed to be true for design in most DCM applications where the in-situ stress levels are normally at lower values of 50-200 ***,the computed tomography(CT)scanning system was adopted to visualize the internal structures of DCM *** is found that the clay pockets existing inside the DCM samples due to uneven mixing affect markedly their stress-strain behaviour,which is one of the main reasons for the high variability of the DCM samples.