Control Technology and Simulation Study of Floor Heave in High Stress Soft Rock Roadway

In order to solve the problems of large deformation and difficult control of the soft rock roadway floor under the influence of high stress and mining stress superposition in Zhaogu mining area, this paper analyzes the stress environment and failure mechanism of the surrounding rock by means of on-site investigation, numerical simulation and on-site industrial test. It is considered that the floor heave of the soft rock roadway is the result of the joint action of the surrounding rock fracture development, poor lithology, cementation, low strength of the original support and high ground stress. The distribution characteristics of stress, displacement and plastic zone of surrounding rock in soft rock roadway under different stress and support mode are analyzed by numerical simulation. Based on the above analysis, the combined control technology of “prestressed grouting anchor cable + grouting anchor bolt + grouting behind the wall + floor reconstruction” is proposed to effectively control the occurrence of roadway floor. The data of monitoring verifies that the grouting bolt changes the structure of broken coal and rock mass on the floor and restrains the occurrence of floor heave.