论文部分内容阅读
绿泥石片岩是一种典型的软岩,开挖过程中出现的围岩大变形和塌方对工程安全危害极大。为了深入研究绿泥石片岩的力学特征并建立其合理的力学模型,首先进行了不同围压下的三轴压缩试验,并考虑应力状态对塑性演化的影响,定义了新的内变量;分析了凝聚力和内摩擦角随内变量的演化规律,结果表明,凝聚力先近似呈线性减小,而后近似呈抛物线递减至残余破坏;而内摩擦角一直近似呈抛物线递增;研究了绿泥石片岩的剪胀特性,分析了剪胀角随内变量演化规律,结果表明,剪胀角与内摩擦角呈相反的演化趋势。考虑硬化、软化和剪胀特性,建立了绿泥石片岩的力学模型,对室内三轴压缩试验结果的模拟分析表明,该力学模型可以较好地描述绿泥石片岩的硬化、软化规律和剪胀等性质,为工程安全性分析提供了基本的力学模型,对于类似软岩力学性质的研究也具有重要的参考意义。
Chlorite schist is a kind of typical soft rock, and the large deformation and landslide of surrounding rock appearing during the excavation are very dangerous to project safety. In order to study the mechanical characteristics of chlorite schist and establish its reasonable mechanical model, the triaxial compression tests under different confining pressures were carried out first, and the new internal variables were defined considering the influence of stress states on plastic evolution. Cohesion force and internal friction angle with the internal variables. The results show that the cohesion decreases linearly first and then decreases parabola to the residual failure, while the internal friction angle increases approximately parabolically. The effects of shear of chlorite schist The characteristics of dilatancy angle with internal variables are analyzed. The results show that dilatancy angle and internal friction angle show the opposite evolution trend. Taking into account the hardening, softening and dilatancy characteristics, the mechanical model of chlorite schist was established. The simulation analysis of the results of triaxial compression tests showed that the mechanical model can describe the hardening and softening laws of chlorite schist well and the shear Swelling and other properties, provide a basic mechanical model for engineering safety analysis, and also have important reference significance for the research on the mechanical properties of similar soft rocks.