Abstract：As the wide applications of the technique of bolt reinforcement, such questions as how to estimate the stability of the bolted surrounding rock of gate, and how to estimate the potential of bolt reinforcement are need to answer. But there is no efficient theory to calculate the safety of the bolt reinforcement for rock engineering hitherto，because of the complexity of rock mass. In this paper, the mechanism of enhancement of rock strength by the composite action of bolts and rock is discussed; a bolted roof stability potential mechanical model is put up , according to brittle damage theory. It provides a new way of the design or safety estimation of bolt reinforcement for roof quantificationally, breaks traditional way of the bolt reinforcement theory，in which bolt reinforcing rationale can not be used for design directly, and makes the bolt reinforcing rationale and bolt reinforcing design united
2003, Vol. 22 
