Concrete-filled steel tubular stent which owns good mechanical properties and good economic benefit has been a new the roadway supporting materials. However, grouting hole cracked in some use, weakening the support performance seriously. Numerical simulation is applied to analyze the structure of the stent that has cracked, finding cracking is mainly due to stress concentration of the hole edge, and determining the preferred position of grouting hole, it can reduce the probability of cracking on grouting holes radically, ensuring the stability of concrete-filled steel tubular stent, and the analysis has general applicability, the application of Xinzhi further demonstrates the rationality of this method.

Large modern mechanical equipment has become an important factor in determining the productivity and security of a mine. Roadheaders have become the most common tools during digging a long tunnel. However, frequent fault that is imperceptible limit to maximize its performance. FTA based on triangular fuzzy number was applied to analyze the fault of the roadheader of Hongyang mine 3 of Shenyang Coal Trade Group, the probability distribution of the fault of a roadheader and coefficient of fuzzy probability important degree of basic events was got, then the more special precaution and repair could be applied. The above provided important reference for equipment supervisors of coal mine