Analysis of Cavity Roof Stability Based on Degree of Reliability
LI Wen-tao;TANG Yu-chun;TANG Cheng-tie;YANG Xiao-li;School of Civil Engineering,Central South University;Hunan Province LOU-HENG Expressway Construction and Development Co Ltd;
Aiming at failure mode of cavity roof,energy dissipation was calculated based on fictitious power principle by introducing Mohr-Coulomb failure criterion into the limit analysis,combined with the consideration of the effect of seepage pressure. Due to the uncertainty of soil properties,degree of reliability was used in the determination of support pressure required to maintain the stability of cavity roof,and effects of surrounding soil properties on the support for maintaining the roof safety were analyzed. Results showed that a higher pore water coefficient and higher nonlinear coefficient can result in greater support pressure required for maintaining the roof stability. It is also found that the coefficient of variation of soil properties will also affect the stability of cavity roof. It is suggested that more research shall be conducted on the uncertainty of soil characteristics.