Abstract: The determination of broken rock zone of roadway can improve the pertinence and effectiveness of roadway support design. However， for skarn deposit， due to the difference of metamorphism，it results in great spatial variety of skarn physical and mechanical properties. Low strength and swelling in water of skarn rock brings difficulty for the determination of broken rock zone of roadway. Aiming at the problem of underground roadway support in weak skarn deposit， using geological radar to detect the broken rock zone of surrounding rock of roadway was introduced in the skarn copper-iron deposit of Taiping Mine. The distribution characteristics of broken rock zone of surrounding rock mass were analyzed and the influence of rock mass quality on the detected results was discussed.The study results show that the properties of the surrounding rock mass of roadway in Taiping Mine are complicated and the differences of the broken rock zones in the roadway are large. The thickness of broken rock zone of crushed marble roadway is mainly within 1.75 m， while the thickness of broken rock zones of altered diorite roadways and skarn roadways are widely distributed in the range of 1.25~3.25 m and 1.75~3.50 m respectively.The bigger the size of roadway is， the thicker the broken rock zone of roadway. The detecting accuracy of the geological radar for the broken rock zones of surrounding rock mass of roadway depends on the difference in dielectric constant of surrounding rock mass between in the broken rock zone and in the outer plastic zone and the weaker the quality of the rock mass is， the less obvious the border of the broken rock zones of roadway on the radar image is. When detecting the broken rock zone in the roadway supported by bolt-mesh-shotcrete， the metal mesh has a shielding effect on the electromagnetic wave of the radar.When the mesh grid is small enough， it will affect the detection result of the geological radar. This work that using geological radar detects the broken rock zone of surrounding rock mass of roadway provides a reference experience for the mines with similar geological conditions.

Key words: geological radar, broken rock zone of roadway, skarn deposit, support design