节理岩体地基极限承载力研究

由于节理岩体具有复杂的力学特性，节理岩体地基的极限承载力问题一直都没有很好解决。利用非线性统一强度准则考虑中间主应力影响和岩性、岩体结构特性可以通过参数m，s和σc 来反映的优点，将非连续介质特性的节理岩体等效为连续介质，在确定即时摩擦角后，结合滑移线场理论获得了节理岩体地基极限承载力的封闭形式的理论解，其解考虑了边界条件和基础的几何形状，举例说明了计算裂隙岩体极限承载力的过程和所需的参数。结果表明：节理岩体的材料特性和中间主应力对极限承载力具有重要影响。

Research on ultimate load bearing capacity of foundation of jointed rock masses

The jointed rock mass possesses complex mechanical behaviors, the ultimate bearing capacity of foundations of 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 defines a methodology for load bearing capacity quantification based on the nonlinear unified strength criterion and by applying the characteristics method for resolving the differential equation systems which govern the stress field. The boundary conditions are defined by the external load system and the geometrical configuration are incorporated. The closed form solution is obtained. To facilitate an overall understanding of the procedure ,an example problem is solved showing how the initial data are used . Results show that the properties of jointed rock masses and intermediate principal stress importantly affect the ultimate load bearing capacity of foundation.