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Abstract In view of failure phenomena with nonlinear large deformation including roof subsidence，sidewall bulge and floor heave occurred in mesozoic compound soft rock of Shajihai coal mine in Xinjiang，according to the methods of geological survey，theoretical analysis，numerical calculation，physicochemical test，hydrological properties test of soft rock，in-situ test，the composite failure mechanism of molecular expansion，movement of structural plane and excavation disturbance for mesozoic compound soft rock roadway in this area is analyzed deeply. Then，an initiative supporting technology system which is based on constant resistance with large deformation coupling support is proposed. Firstly，through constant resistance device，the swelling and plastic energy of surrounding rock is released fully；and the support load，stress concentration are reduced. With the aid of high-resistance performance，the excessive harmful deformation is restrained；and the plastic zone of surrounding rock is controlled reasonably. Secondly，uncoordinated deformation between the surrounding rock and support，which is caused by large plastic deformation and the dislocation of weak structural plane，is eliminated through the secondary bolt-net-cable coupling support. Grouting bolt is used to control large deformation of floor heave. Ultimately，a collaborative bearing system of the surrounding rock-supporting structure is formed. The optimizations of construction process and parameter design are studied based on the design method of nonlinear large deformation mechanics and numerical analysis. Engineering practice shows that this technology has been successfully applied to ensure the stability of roadway.
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Received: 10 September 2012
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2013, Vol. 32 
