理想弹–塑性岩体的自承载系数

Self-bearing capacity coefficient of ideal elastic-plastic rock mass

针对岩体自身承载能力的评价,修改抗力系数提出了岩体新的自承载系数,给出其物理意义,并以理想弹–塑性围岩中圆孔收缩和扩张为例,推导了岩体缩孔自承载系数Kc和扩孔自承载系数Ke,得出各参数的影响特性。研究结果表明:岩体自承载系数是一个受多因素共同影响的综合评价指标,应力状态和孔壁压力对其具有显著影响;岩体自承载系数随岩体强度参数和统一强度理论参数的增加而增大,随剪胀参数的增加岩体缩孔自承载系数Kc减小,而扩孔自承载系数Ke却增大。应充分考虑岩体强度参数的变化、中间主应力效应和剪胀特性的影响,合理利用岩体的强度潜能和自承载能力。

By revising the resistance coefficient, a new self-bearing capacity coefficient of rock mass is proposed in this study to evaluate the bearing capacity of rock mass, and its physical meaning is also given. A circular opening in the ideal elastic-plastic rock mass is taken as an example to derive the self-bearing capacity coefficients Kc under contraction and Keunder expansion, and parametric studies are discussed. The obtained results show that the self-bearing capacity coefficient of rock mass is a comprehensive evaluation index by multiple factors, which is significantly influenced by stress state and wall pressure, and increases with strength parameters of rock mass and the unified strength theory parameter. With the increase of the dilation parameter, the coefficient Kc decreases, whereas the coefficient Ke increases. The effects of changes in strength parameters of rock mass, intermediate principal stress and dilatancy should be fully considered in order to take full advantage of the latent potentialities of rock mass.