A method for calculating the parameters of anchorage on the basis of solutions of spatial problems of the theory of elasticity

Abstract

A three-dimensional model of the rock mass, secured by anchor support, was created. The analysis of changes in the volumetric stress-strain state of the rock mass due to the installation of anchoring was carried out. On the basis of the spatial model, a method for calculating the parameters of bolting has been developed. Volumetric stress-strain state components were found from solving spatial problems of the theory of elasticity. The results of the study of stress distribution in the rock mass allowed us to identify areas with different degrees of hardening, to establish the boundaries of the unstrengthened zone and the area of softening. The following parameters are sequentially determined in the calculation: the stress state around a single anchor and the area of its influence; the number of mutually affecting anchors; the stress state caused by the tension of a system of mutually affecting anchors; the initial stress state around an unanchored work; the resulting stress field; hardening ratios in the anchored area; distribution of the hardening ratio; the hardening degree and effectiveness of the anchor support. Optimization of the parameters of bolting may result in a significant economic effect due to the increase of the lifetime of the workings and reduction of the costs of installing anchors.