基于两种颗粒体模型的巷道围岩应力应变分析

Analysis on the stress and strain in surrounding rock of the tunnel based on two kinds of granular models

本文将岩石视为颗粒体材料,采用两种模型对巷道围岩的应力、应变及破坏区的分布规律进行了数值模拟。第一种模型是连续介质模型,其中考虑了颗粒、界面及基体。第二种模型是将第一种模型中的基体去掉。研究结果表明:当基体强度参数降低较少时,巷道围岩中的环向和径向应力在传统结果附近波动;当基体强度参数降低较多时,两种应力的波动幅度提高,而且,基体位置的应力向其周围的颗粒或界面转移。第二种模型结果的波动幅度更大。随着基体强度参数的降低,巷道围岩中的应变集中区向深部转移,形成相互交织的滑移线网,滑移线网的位置主要位于基体和界面中,这与第二种模型的结果有明显的差异(多个环向的应变集中区)。

In the paper,rock is treated as a kind of granular materials.The failure zone,stress and strain in surrounding rock of the tunnel are simulated by using two kinds of models.The first model is a continuum model,where granulae,interfaces and matrixes are considered.The second model is based on the first model and the matrix elements are deleted.Results show that the loop and radial stresses in surrounding rock of the tunnel fluctuate around traditional results as the strength of matrix elements is decreased slightly.As the strength of matrix elements is decreased greatly,the fluctuation amplitude rises;stresses in matrix elements transfer to elements of granulae and interfaces.In the second model,the fluctuation amplitude is even obvious.As the strength of matrix elements is decreased,the higher strain regions propagate toward the depth of surrounding rock of the tunnel and an intersecting slip line network is formed.In addition,it is found that the network is mainly located at the elements of granulae and interfaces.This result is obviously different from the result in the second model in which several loop regions with higher strains are found.