Abstract：In order to solve the technical problem of restoring and reinforcing a deep soft rock tunnel, the supporting technology of a concrete-filled steel tube stand is put forward. By the bearing capacity test of a concrete-filled steel tube stand laid in a straight wall semi-circular arch and a U-shape steel stand with the same steel content, the ultimate load and distortion of those two types of stands under different loading conditions are observed. It turns out that the bearing capacity of a concrete filled steel tube stand is 2. 1 ~ 2. 4 times of that of a U-shape set with the same steel content, and it has good retractility. According to test results, an effective control over the large deformation and the long-term rheological state of a soft rock tunnel is developed, choosing concrete-filled steel-tube-stand parameters and applying them into the restoring and reinforcing engineering of the downhill tunnel of the second rail at the fifth coal seam, which has the typical property of soft rock at the Sixth Coal Mine of Ping Dingshan Tian An Coal Mining Co. Ltd. Meanwhile, the tunnel remains intact two years later after the restoration. It provides a reference for the restoration and reinforcement engineering of a deep soft rock tunnel.

Keyword：soft rock tunnel;concrete-filled steel tube stand;mechanical property;industrial test;