基于非线性统一强度理论的裂隙岩体圆形隧道扩张问题的弹塑性研究

Analysis to Slip Zones Around Circular Cavities in Cracked Rock Masses Following General Nonlinear Unified Strength Criterion

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扩张问题的弹塑性解要复杂得多。节理岩体的力学特性可以很好地用考虑了岩体结构的强度参数m,s和α以及中间主应力影响的非线性统一强度准则来表达。本文根据非线性统一强度准则确定了瞬时摩擦角,强度参数m,s和α是瞬时摩擦角的函数,获得了节理岩体圆形隧道扩张问题的弹塑性解和支护应力的封闭形式的理论解,并给出了算例。

An analytic expression of the jointed rock mass is developed to determine the shear strength with the general nonlinear strength criterion considering the influence of intermediate principal stress and strength parameters m,s and α on the jointed rock yield and failure,which are regarded as the functions of instantaneous friction angle. An approximate procedure to determine support pressure is established,it is concluded that the properties of jointed rock masses and intermediate principal stress obviously affect the slip zones around circular openings on jointed rock masses,and the size of slip zones around circular cavities increases with the decreasing intermediate stress parameter.