Abstract：Horizontal tunnel and surrounding rock of chamber within-800 m mining level of Zhaogu No. 2 coal mine are typical engineering and geophysical soft rock, They have such characteristics as complex engineering geologic condition, high geostress, high rheology rate, etc. Common supports such as anchorage and passive steel bracket might be easily destroyed one by one. So the chamber was rebuilt one or more times. Multiple supports were promoted based on New Austrian Tunneling Method. The primary support was including bolt, cable, beam strong support. The secondary support was adjacent rock grouting. The third support was double layer universal beam bracket. The fourth support was sprayed concrete. With above supports, passive and active supports could be harmonized. Creep numerical simulation showed that with the common supports the section convergence rate was 30% during 3 years, and the displacement of the chamber was large, the deformation rate was also higher. But deformation of the chamber could be controlled with passive and active support, and the deformation rate was less than 0. 05 mm per day. Field investigation showed that the largest surface deformation was only 28 mm after 2 year, and the deformation rate was less than 0. 20 mm per day. Therefore, rock mass integrality is fine in anchorage zone of cable, adjacent rock of the chamber was controlled in good condition.

Keyword：rock creep;high geostress;large section chamber;multiple supports;numerical simulation;