论文部分内容阅读
Knowing the loading on the roof bolt in a coal mine roadway is critical for the safe and cost effective operation of the mine in both room-and-pillar and longwall systems.For example, in a retreat longwall system, it is important to have a better understanding of the load distribution on the roadway sup ort as the coal panel is mined out in retreat.Much research on this subject involved theoretical and numerical modelling studies as well as field measurement with extensometers and hollow eylinder load cells.This paper describes a new technology of a roof bolt load cell known as the U-Cell that has the potential to serve as a robust, mine safety tool that can be deployed under routine operating conditions in underground coal mines.The U-cell is a coupler load cell device that can be screwed onto the threaded end of a roof bolt prior to installation.It measures the axial load at the head of the bolt.This load cell is interfaced with wireless data acquisition system.Guidelines are presented for the interpretation of results based on data obtained from field trials.Successful field installations demonstrate the viability and practicality of the U-Cell and, moreover, provide a reliable tool for mine design and safety.