Abstract：8104 fully mechanized caving face return airway ( section 5. 2 m × 3. 5 m) in Shanxi Datong Tongxin mine was selected as engineering background, it is stated for the surrounding rock control problem, including the developing fracture of top coal, intensity deformation, large range of damage, prone to separation and roof fall in large-section thick top-coal. Combined with geological and production conditions at the scene, the truss cable is used for reinforced supports, and the superiority of a support system is analyzed. It is providing a prestressing force both in the horizontal and vertical directions, and a Synergy bearing control area as well as a stable anchoring point. Surrounding rock deformation law is simulated in the change process of a cable inclined angle from 10° to 40° by using FLAC3 D. The results are that with cable inclined angle increasing, roadway surrounding rock deformation decreases at first, then increases and reaches the minimum value at 20°of a cable inclined angle of 20°. After the return airway is influenced by mining, the relative maximal roof-tofloor convergence is 125 mm, and the relative maximal convergence both sides of is 94 mm.

Keyword：thick top-coal;truss cable;large-section;roadway;surrounding rock;