节理岩体圆形隧道滑动区的研究

对于连续介质问题,可以利用Mohr-Coulomb准则很好地解决圆形隧道滑动区问题.但是对于节理岩体问题要复杂得多.由于节理岩体具有复杂的力学特性,因此节理岩体圆形隧道滑动区的确定问题一直都没有很好地解决.节理岩体的力学特性可以很好地用考虑了中间主应力影响的非线性统一强度准则来表达.根据非线性统一强度准则确定了即时摩擦角,进而获得了节理岩体圆形隧道滑动区和支护应力的封闭形式的理论解,并给出了算例.

Study on slip zones around circular cavities on crack-weakened rock masses based on nonlinear unified strength criterion

The jointed rock mass possesses complex mechanical behaviors, the slip zones around circular openings on jointed rock masses has not been studied in detail from a theoretical point of view. An analytic expression has been developed that enables the shear strength to be determined using the nonlinear strength criterion which takes influence of intermediate principal stress on the yield and failure of jointed rock masses into account. The important concept of instantaneous friction angle is defined. This paper presents the theory to estimate the region of joint effect around circular openings located in crack-weakened rock masses based on nonlinear unified strength criterion. An approximate procedure to determine support pressure is established. Several results are given. Results show that the properties of jointed rock masses and intermediate principal stress importantly affect the slip zones around circular openings on jointed rock masses. Magnitude of the slip zones around circular cavities increases with the decrease of the intermediate stress parameter.