考虑结构面切向刚度各向异性效应的岩体等效弹性模量研究

Affected by the rock mass structure, the elastic modulus of jointed rock mass has typical characteristics of anisotropy and weakening. The inaccuracy of elastic modulus of rock mass has given rise to lots of engineering problems. Therefore, it is important and urgent to accurately quantify the elastic modulus of rock mass. However, the anisotropy of shear stiffness has not been appropriately taken into consideration when quantifying the elastic modulus of rock mass, which hence makes it fail to reflect the real mechanical effects of rock mass structure. In view of these issues, we will conduct the following four aspects of researches by combining original measurements, model tests, mechanical analyses and theoretical calculations: (1) establishing the geometrical parameter representation model to describe the shear stiffness of joint; (2) studying the macromechanics effects brought by the anisotropy of shear stiffness of joint; (3) exploring the stress-strain relationship of rock mass considering the effects of anisotropy of shear stiffness of joint; and (4) obtaining and validating the 3-D theoretical analytic solution of equivalent elastic modulus of rock mass. Based on these researches, this project aims to quantify the real mechanical effects of rock mass structure, and obtain the accurate theoretical analytic solution of equivalent elastic modulus and hence the quantitative expression on its anisotropy and weakening characteristics in consideration of the anisotropy of shear stiffness of joint. This project will strengthen our understanding on the deformation characteristics and behavior mechanisms of rock mass.

岩体弹性模量因受岩体结构影响而具有典型的各向异性和弱化特征，对岩体弹性模量把握不准确是许多工程问题的诱因，其准确取值已成为了一个亟待解决的重要科学问题。然而，由于对结构面切向刚度各向异性的影响考虑不足，在获取弹性模量的过程中并不能真实反映岩体结构力学效应。针对这些问题，本项目拟通过原始数据采集、模型试验、力学分析与理论计算，开展四个方面的研究工作：（1）结构面切向刚度的几何形貌参数表征；（2）结构面切向刚度各向异性宏观力学效应研究；（3）考虑结构面切向刚度各向异性效应的岩体应力-应变关系建立；（4）岩体等效弹性模量的三维理论解析与验证。在此基础上，本项目将实现岩体结构力学效应的真实量化表达，并在考虑结构面切向刚度各向异性的条件下准确获取岩体弹性模量的解析解，定量表征其各向异性和弱化，由此进一步加深对岩体变形特性与行为机制的认识。

岩体弹性模量因受结构面影响而具有典型的各向异性和弱化特征。然而，由于对结构面切向刚度各向异性的影响考虑不足，在获取弹性模量的过程中很难真实反映岩体结构的力学效应，从而导致对许多工程问题无法有效预判。针对这些问题，本项目通过原始数据采集、模型试验、力学分析与理论计算，完成了四个方面的研究工作：（1）实现了结构面切向刚度的几何形貌参数表征，提出了考虑微坡度分布特征的新形貌参数；（2）揭示了结构面切向刚度各向异性的宏观力学效应，建立了考虑各向异性形貌特征的结构面刚度计算模型；（3）建立了考虑结构面切向刚度各向异性力学效应的岩体应力-应变关系；（4）实现了岩体等效弹性模量的理论解析解，并进行了验证。在此基础上，本项目发现了结构面粗糙度的对数正态分布规律，提出了结构面剪切破坏特征评价指标，实现了岩体结构力学效应在岩体弹性模量计算中的真实量化表达。由此进一步加深了对岩体变形特性与行为机制的认识，为解决岩体力学参数快速精准取值，提供了理论支撑，体现了显著的理论与实践价值。依托本项目，共发表学术论文12篇，其中SCI期刊收录7篇，EI卓越期刊（梯队期刊）收录2篇，CSCD期刊收录2篇，北大核心期刊收录1篇；已授权实用新型专利2项，登记软件著作权2项。