Support Design during Depillaring Operation in Bord and Pillar Panel Using Numerical Simulation Method

Abstract

In an underground coal mine, most successful and economical approach to support the underground structure is roof bolting technology. The most preferred method of working in Indian coal mine is Bord and Pillar. It has been observed from the past histories that, the maximum number of accidents happens during depillaring operation. In this paper, the primary focus is to understand and analyze the roof behavior with roof bolting system in underground coal mine using numerical simulation approach. A three-dimensional (3D) model of the depillaring panel with support design using roof bolt technology is complicated to simulate. Therefore, the simulation is done near the goaf edge, where maximum chances of roof failure have been observed. On another word, it can say that simulation is done before the main fall. An elasto-plastic model has been taken for study considering physico-mechanical properties, geo-mining condition, roof bolt and grout properties as an input parameter. A case of a depillaring panel of underground coal mine has been chosen for study. The result is observed regarding axial load exerted on the bolt during mine operation. Instrumented rock bolt data has been taken for validation of the model from field observation. It has been observed in the model that maximum axial load developed on the bolt is very close to the field observation.

Estimation of Hoek-Brown Strength Parameters from Time-Dependent Geotechnical Classification as Coal Roof Index (CRI) using Critical Plastic Strain Technique

“…Nowadays, the Numerical modelling technique is a widely acceptable and more appropriate technique for support design and stability assessment in underground structures such as tunnels, galleries, junctions, and working face in underground coal mines. Several authors such as [5], [6], [7], [8] has suggested that the numerical tool is far more advanced as compared to an empirical method and they considered FOS to be 1.5 to obtain rock load height for stable cases. The rock mass classification is a prime input parameter in the numerical method.…”