Complex limit state criterion for rock masses

Abstract

The paper presents a complex limit state criterion, which allows to predict limit states of rock masses and its potential transition to discontinuum state. The idea of the complex limit state criterion is based on the fact that the stress-strain state of the rock mass should be evaluated not by one particular failure criterion, but by a system of criteria taking physical specifics of each criterion into account. The proposed limit state criterion is universal and can be used for the evaluation of the rock mass state in the vicinity of any geotechnical structures. The main aim of the paper is to establish a criterion that will accurately separate quasi-continuum states of rock masses from discontinuum ones. This separation can be further used for numerical simulation of geomechanical behavior of rock masses in the vicinity of underground structures using continuum methods, such as the finite element method (FEM), and discrete methods, such as the discrete element method or distinct element method (DEM) in correspondent areas. The application of the proposed complex limit state criterion is demonstrated on the classic examples of rock mass strength/failure assessment in the vicinity of a single mining excavation. The results of the study can be used either for the determination of potential failure zones in the rock mass in the vicinity of underground structures or for the development of specialized CAE software, which are based on coupled FEM-DEM numerical methods.

摘要

在对岩体的应力-应变状态进行评估时, 应当采用考虑岩体物理特性的准则体系, 而非一个特定的破坏准则. 为此, 本文提出了一个用以预测岩体极限状态及其由连续向不连续状态潜在转变的复杂极限状态准则. 该准则具有通用的极限状态标准, 可用于评估任何岩体结构附近的极限状态. 本文主要是建立一个能够准确区分岩体准连续状态和非连续状态的准则, 并可进一步用于地下结构附近岩体地质力学数值模拟的连续介质方法(如有限元法)及离散介质方法(如离散元方法或相应的离散单元法). 以上的复杂极限状态准则在对单个采矿开挖区附近岩体强度/破坏评估的经典应用中得到证实. 本文研究工作不仅可用于确定地下结构附近岩体的潜在破坏区域, 还可用于开发基于FEM-DEM耦合数值方法的CAE专业软件