基于零厚度黏聚力单元节理面剪切破坏机理宏细观研究

为了探究不同粗糙度节理岩体剪切过程及破坏类型,利用ABAQUS有限元分析软件,采用全局嵌入零厚度黏聚力单元的方法模拟带节理岩体压剪过程。通过室内压剪试验和数值模拟结果对比确定所建立模型的正确性,从宏细观角度分析节理岩体剪切破坏行为。研究结果表明：采取全局嵌入零厚度黏聚力单元模拟节理岩体压剪过程的方法相对准确,能真实反映节理面细观破坏过程;不同粗糙度节理试样在恒定法向荷载下的剪切峰值强度随着粗糙度增加而递增;节理岩体的剪切过程大致可以分为4个阶段,线弹性强化阶段、带裂纹强化阶段、塑性软化阶段和残余强度阶段;不同粗糙度节理岩体在剪切过程中破坏类型不同,在恒定法向荷载下岩体剪切破坏大致可以分为3种形式,分别是滑移破坏,岩体局部剪断破坏和切齿破坏。

Macro-micro study on shear failure mechanism of rock joint based on zero-thickness cohesive element

In order to explore their shear process and failure types with different roughnesses, the ABAQUS finite element analysis software is used to simulate the shearing process of jointed rock masses under constant normal load by using the method of globally embedded zero-thickness cohesion elements. The correctness of the numerical model is confirmed by comparing the results of laboratory shear tests and numerical simulations, and the shear failure behavior of the jointed rock masses is analyzed from the macro-micro perspective. The results show that the method of global embedded zero-thickness cohesive elements to simulate the shear process of jointed rock masses is accurate and can truly reflect the microscopic process of rock joint failure. The shear peak strength of joint samples with different roughnesses increases with the roughness under constant normal load. The shear process of jointed rock masses can be divided into four stages: linearly elastic strengthening stage, crack strengthening stage, plastic softening stage and residual strength stage. The joints of rock masses with different roughnesses have different types of failure during the shearing process, and the shear failure of rock masses can be roughly divided into three types under the constant normal load, which are slip failure, local shear failure and gear cutting failure.