Coal Roadway Bolt-Mesh Support Optimization Study Of Jinyuan Colliery

Being an efficient and economical and safty reinforcing technique, bolt support with mesh has been widely used in different underground roadways. For complexity of interaction between bolt and surrounding rock, especially pre-stressed bolt, the reinforced principle is still in exploring stage and does not form perfectly theory system. The bolting design new mainly depends on engineering analogy and the design theory seriously falls behind the engineering practice especially in entry support of coal mine. According to the characteristics of entry surrounding rock in coal mine, the pre-stressed bolting for developing entry in coal mine has been contrast studied because the pre-stressed bolt possesses the characters of early load-bearing and quickly load-bearing and high surrounding rock load-bearing ability. The practice indicated that anchorage roof can form a combined beam structure, reduce roof tensile stress area and roof distortion, ameliorate surrounding rock stress distribution and enhance the stability of entry after a suitable pre-stress is applied to the bolt.According to the characteristic of developing entry, some numerical models have been established in this paper and the roadway distortion and surrounding rock stress distribution have been obtained by using ANSYS to simulate developing entry in different bolting parameters. According to safety factor, the destruction area of surrounding rock can be determined. At last, the pre-stressed bolting designs for Jinyuan colliery were used at the return way of face 1311, and the support effect is better than that of other general belts.