Abstract: With the traditional method, large-area supporting failure often arises in anchor cable which causes the result that the maintenance of roadway is very difficult and the cost is high in thick soft-weak roof of deep coal roadway. Through field investigation and theoretical analysis, the factors of anchor cable supporting failure have been studied. The study indicates that the main reasons of anchor cable supporting failure are deformation of cable holes during constructive process in thick soft immediate roof and anchor agent damage during installation. Accordingly, the new design method of anchor cable parameters applying to thick soft immediate roof is proposed. The results show that the length of anchor cable in accordance with the new method is shortened and the anchoring force is improved greatly, and therefore the maintenance of roadway is improved significantly.

Key words: thick soft roof, anchor cable supporting, failure