Reliability Analysis of Underground Roadway Bolt Support Based on Central Point Method

In order to study the reliability of the bolt support design of underground roadway, the function equation of bolt support structure was established according to the central point method in bolt suspension theory and reliability theory. The reliability of the design method and the sensitivity of design parameters are analyzed. The results show that the reliability index β had a negative correlation with bolt interval a, rock density ρ and the thickness of loss layer H. There was a positive relationship between the index β and the bolt diameter d and the tensile strength of bolt σt. The two parameters of bolt diameter d and bolt interval a had the greatest significant influence on the reliability of the supporting structure. In the actual design, full consideration should be given to the influence of the actual construction team level on the row distance a between designed bolts, and attention should be paid to the reduction of bolt diameter d caused by various factors (such as corrosion) in the actual environment. Redundant design was recommended to ensure the reliability of the scheme.