岩石节理剪切流变特性及其与节理表面形貌参数关联性研究

Based on the tests of rock joints shear rheology, in this project the shear rheological characteristics of joints will be analyzed from many methods, such as tests, theoretical analysis and numerical modeling. The main substances of the project range over establishing the elastic-plastic constructive equation of rock joints shear rheology, influence rules of the thickness and compositions of joint fillings on the shear rheological characteristics of joints, the relationship between negative exponential shear strength model and the elastic-plastic constructive equation, the joint shear rheological time effect and using the fractal dimension and the JRC to descript the joints surfaces roughness. The influence of joint wall roughness on the shear rheological characteristics of joints will be emphasized and its variation in the shear tests will be studied, in order to set up the predictive constitutive model for long-term shear strength and the rock joints shear rheology constitutive model considering the roughness coefficient. The numerical model will be built by numerical analysis software for fitting the shear rheological characteristic curves of rock joints. The research achievement of this project will bring meaningful theoretical and practical influences on the knowledge of joint shear rheological characteristics and long-term shear strengths.

本项目以岩石节理剪切流变试验为基础，从试验、理论分析、数值建模多角度分析节理的剪切流变性质，主要研究节理剪切流变的粘弹塑性本构方程，充填物厚度与成分对节理剪切流变性质的影响规律，负指数剪切强度模型与弹塑性本构模型方程关系，节理剪切流变时间效应，以及用分形维数、JRC定量描述节理表面的粗糙度，着重研究节理表面粗糙度对节理剪切流变性质的影响，分析粗糙度参数在剪切流变试验下的变化，最后建立考虑粗糙度参数的节理剪切流变本构模型、节理长期抗剪强度的预测模型，并用数值分析软件建立节理剪切流变的数值模型，拟合节理剪切流变特性曲线。该课题的研究成果对进一步认识节理的剪切流变性质和长期抗剪强度有较大的理论与实际意义。

岩石节理是岩体断裂后断裂两侧没有位移或仅有微量位移的一种断裂构造。岩石节理的力学和水力学性质影响了岩体工程的稳定性。节理构造的剪切力学行为均受到多种因素的影响，如含水率、接触形态、充填物厚度、壁面粗糙度、岩石种类等。本项目总结了已有研究成果，在进行了大量试验研究和数值分析的基础上，主要对节理表面的定量描述，节理面粗糙度对节理剪切力学性质的影响，填充物对节理剪切破坏过程的影响，水对节理面粗糙度的影响和剪切特性的影响以及岩石流变本构模型的改进等方面进行了研究。通过对自然岩石节理、人工岩石节理和类岩材料节理模型进行剪切试验和节理面精确扫描，提出了能够准确反映节理面粗糙度的节理体积计算方法，得到了水岩作用下的节理表面特征参数及抗剪强度的演化规律，建立了能够描述瞬时变形和加速蠕变阶段的流变节理软岩的本构模型，总结了各种节理面循环剪切作用下的粗糙度演化规律，建立节理表面形态特征与其剪切强度的关系公式。该项目的研究成果对进一步认识节理剪切力学特性和流变性质有较大的理论与实际意义。