Abstract: In order to determine rational space between U-steel support and anchor cable in synergetic support system, the mechanical models of U-steel support and synergetic support for U-steel support and anchor cable have been established respectively. Anchor cable space in synergetic support has been determined by analyzing mechanical model based on principle of force method. It is studied that the anchor cable space in synergetic support for U-steel support and anchor cable relates to lateral pressure coefficient, the section size and burial depth of roadway. The analytical expression for lateral pressure coefficient of loose coal has been established. Furthermore, the synergetic support of U-steel support and anchor cable have been simulated. The result shows that deformation and plastic zone of surrounding rock in roadway and maximum bending moment of U-steel support are decreased notably due to reasonable spacing of anchor cable in synergetic support system of U-shaped shed and anchor cable, which achieves coupling support of U-shaped shed and surrounding rock as well as anchor cable and deep surrounding rock. The engineering practice shows that safety production in coal mine is guaranteed because of controlling the stability of surrounding rock of roadway effectively after reinforcing each key position of U-steel support by adopting anchor cable and joist steel.

Key words: soft roadway, U-shaped shed, synergetic support, anchor cable space, lateral pressure coefficient, numerical modeling