Abstract: The construction of the pile foundation of Beijing-Shanghai high-speed railway damaged the tunnel lining of a segment of Shanghai subway with large amounts of sludge silted into the tunnel. This paper introduces the repairing of the damaged tunnel and analyzes the site monitoring data to provide reference for alike projects. Firstly, stepped plugging wall was used to plug the solum in the tunnel, and the internal of the damaged tunnel was grouted. The upper solum in the tunnel was treated by ground filling and grouting to reinforce the turbulent solum. Moreover, the restoration segment was reinforced by vertical freezing on the ground and horizontal freezing as well as excavation construction inside the tunnel. Freezing soil curtain with high strength and good sealing property was produced by partial freezing in the upper damaged tunnel and in its surrounding 3 meters area. Subsequently, mining method was employed in the excavation and the damaged lining was repaired by in-situ restoration. The restoration finally achieved great success.

Key words: freezing method , freezing soil curtain , tunnel , plugging wall