The investigation of supporting pressure is of great significance to the design of underground structures.Based on the kinematical approach of limit analysis,an improved failure mechanism is proposed,and the supportin...The investigation of supporting pressure is of great significance to the design of underground structures.Based on the kinematical approach of limit analysis,an improved failure mechanism is proposed,and the supporting pressure is investigated for deep buried cavity.Three failure mechanisms are first introduced according to the existing failure mechanisms of geotechnical structures of limit analysis.A comparison with respect to the optimal failure mechanisms and the upper bound solutions provided among these three mechanisms are then conducted in an attempt to obtain the improved failure mechanism.The results provided by the improved failure mechanism are in good agreement with those by the existing method,the numerical solution and field monitoring,which demonstrates that the proposed failure mechanism is effective for the upper bound analysis of supporting pressure.展开更多
This study focuses on the stress and displacement of a circular opening that is excavated in a strain-softening rock mass under hydraulic-mechanical coupling.It follows the generalized Hoek-Brown(H-B) failure criterio...This study focuses on the stress and displacement of a circular opening that is excavated in a strain-softening rock mass under hydraulic-mechanical coupling.It follows the generalized Hoek-Brown(H-B) failure criterion.Moreover,an improved numerical method and stepwise procedure are proposed.This method considers the deterioration of the strength,deformation,and dilation angle.It also incorporates the hydraulic-mechanical coupling and the variation of elastic strain in the plastic region.Several examples are conducted to demonstrate the validity and accuracy of the proposed solution through MATLAB programming and FLAC software.Parametric studies are also conducted to highlight the influence of hydraulic–mechanical coupling on stress and displacement.Results show that in this case,stress confinement is lower and tunnel convergences are higher than the corresponding stresses and displacements obtained when those factors are not considered.The displacement and plastic radius are also larger than those obtained when hydraulic-mechanical coupling is not considered.展开更多
基金Project(51674115)supported by the National Natural Science Foundation of ChinaProject(51434006)supported by the Key Program of the National Natural Science Foundation of ChinaProject(2015JJ4024)supported by the Natural Science Foundation of Hunan Province,China
文摘The investigation of supporting pressure is of great significance to the design of underground structures.Based on the kinematical approach of limit analysis,an improved failure mechanism is proposed,and the supporting pressure is investigated for deep buried cavity.Three failure mechanisms are first introduced according to the existing failure mechanisms of geotechnical structures of limit analysis.A comparison with respect to the optimal failure mechanisms and the upper bound solutions provided among these three mechanisms are then conducted in an attempt to obtain the improved failure mechanism.The results provided by the improved failure mechanism are in good agreement with those by the existing method,the numerical solution and field monitoring,which demonstrates that the proposed failure mechanism is effective for the upper bound analysis of supporting pressure.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2013CB036004)the National Natural Science Foundation of China(Grant No.51208523)China Postdoctoral Science Foundation(Grant No.2003034468)
文摘This study focuses on the stress and displacement of a circular opening that is excavated in a strain-softening rock mass under hydraulic-mechanical coupling.It follows the generalized Hoek-Brown(H-B) failure criterion.Moreover,an improved numerical method and stepwise procedure are proposed.This method considers the deterioration of the strength,deformation,and dilation angle.It also incorporates the hydraulic-mechanical coupling and the variation of elastic strain in the plastic region.Several examples are conducted to demonstrate the validity and accuracy of the proposed solution through MATLAB programming and FLAC software.Parametric studies are also conducted to highlight the influence of hydraulic–mechanical coupling on stress and displacement.Results show that in this case,stress confinement is lower and tunnel convergences are higher than the corresponding stresses and displacements obtained when those factors are not considered.The displacement and plastic radius are also larger than those obtained when hydraulic-mechanical coupling is not considered.
