Abstract: The rock cables were usually failure in large area in compound roof and dynamic pressure roadway. And the roadway must be repaired for several times, this would result in high costs and affect safety. For this problem, the rock cable failure mechanism was analyzed in this paper. It was shown that the main reason for rock cable failure is inadequate cable preload applied. The key factors which caused rock cable failure were studied by numerical simulation and laboratory tests, and the reasonable length of rock cable was proposed, the length is 4-6m. The field tests shows that reasonable rock cable preload can shorten rock cable length, and the supporting effect of roadway would be significantly improved.

Key words: compound roof, rock cable supporting, failure mechanism, reasonable preload