Abstract: Based on the analysis of the deformation and failure characteristics of the Tertiary soft rock roadway in China, the further research on the successful supporting practice of bolt-net-cable-double- layer truss in Liuhai coal mine has been carried out . The result of the field investigation shows that the tertiary soft rock roadway has been damaged in wide range with high repair rate, complex damage forms and nonlinear large deformation．The bolt-net-cable-double-layer truss support technology is put forward based on the comprehensive study of the compound deformation mechanism of high stress, jointing and intense swelling soft rock. Because of the characteristic of the coupling stress, the roadway deformation can be controlled effectively in time and space with the aid of bolt-net-cable, and it is also possible for the deformation and stress in the surrounding rock to become uniform. The anchor cable can take full advantage of the strength of deep hard surrounding rock, while the double layer truss can bear the rheological load of soft rock with high strength, wholeness, cooperativity and uniform contacted stress, making possible the effective transformation of high stress in the deep surrounding rock of roadway. Engineering practice shows that the new technology has been successfully applied to ensure the stability of roadway.

Key words: Tertiary soft rock roadway, deformation mechanism, double-layer truss, coupling support