Study On The Large Section Open-off Cut's Surrounding Rock Deformation & Support Parameter In 1121 Working Face Of Hongliu Coal Mine

1121 working face is the first coalface in Hongliu coal mine. The large mining height technology has been used, the requirements of the section of open-cut is 8.6×4.2m. The emergence of series of technical problems in the tunneling and supporting process is serious rib spalling and local tricking cause roof subsidence. In order to address these support challenges, studying on the surrounding rock deformation and selecting the reasonable support parameter in the large section open-off cut to achieve a high efficiency coal mine is particularly important.Through summarization of the existing roadway surrounding rock deformation mechanism and bolt support theory, analyzed the general deformation law of surrounding rock in the roadway. Combination with the surrounding rock deformation features and comparison of various design, We decided to use the dynamic method of bolting support design that base on the range of surrounding rock failure to redesign the support parameter of large section open-off cut.We carried out a study on surrounding rock deformation and the design of support parameter in open-off cut of 1121working face in Hongliu coal mine. Used convergence indicator, roof abscission layer monitor and dynamometer for anchor to observe the pressure. According to the dynamic information of ground pressure observation, we modified the existing support parameter to provide a guidance program for the similar projects.In the laboratory, we selected a physical material model that the constant of geometric similarity is 20 to simulate the that the support parameter had been modified. Through the constant rate of loading for the material model , we studied on the rock deformation features of the open-off cut and verified the reasonableness of support parameters by experimental equipments, such as total station, the resistance dynamometer and so on. Experimental results showed the revised support parameter can effective control the surrounding rock failure to sovle problems in the tunneling and supporting process.The results show that the dynamic method of bolting support design is reliable design method. Using this method achieved redesign for the existing support parameters and provides a useful design for the similar roadway.