Understanding the Impact of Test Configuration on Welded-Wire Mesh Laboratory Test Results

Abstract

Underground mines use a combination of rock reinforcement and surface support elements to maintain the structural integrity of excavations in rock. The design of an effective ground support system requires an understanding of the mechanical behaviour of individual ground support components and how they interact under load. This paper reviews the mechanical behaviour of welded wire steel mesh routinely used in underground mines. It further reviews the advantages and limitations of using testing rigs used to quantify the performance of mesh. In particular, it illustrates the impact of rig configuration and testing parameters on mesh performance. The main focus of this work is the development and calibration of 3D discrete element method of numerical models capable of reproducing mesh behaviour under specific testing configurations. The developed models successfully reproduced the load redistribution on the mesh wires, the load–displacement response, and failure mechanisms observed in laboratory tests. The calibrated models were subsequently used to determine the impact of testing rig configurations, including loading plate dimensions and orientation, and mesh dimensions on the performance of mesh under load. This work has significant practical implications on how to interpret results obtained from different testing rigs. Furthermore, the results of this work can provide guidance towards designing new testing rig configurations as well as demonstrating the need for the development of testing methods and procedures. Finally, it illustrates the challenges that have to be overcome if the explicit modelling of mesh will be a reliable part of the ground support design process.