Diseases in the liners of a twin-tunnel and their treatment

摘要

The characteristics and origin of diseases in the liners of a twin-tunnel in Yunnan Province of southwest China is studied and the treatment measure is proposed. The main diseases in the liners are cracks, peeling-off and groundwater-leakage. Cracks occur on the central wall and its basement, flank walls, arch crown as well as the inverted arch, and mostly in the central wall. Peeling-off mainly happens in the connecting part between central wall and arch crown. Groundwater-leakage takes place mostly in the connecting part between central wall and arch crown, and partly along the cracks. The cracks may be classified into vertical, horizontal and inclined ones according to their extending directions. The occurrence of these dis eases is related to geological condition, unreasonable design, and poor construction control. The engineering treatment measures for cracks, peeling-off and groundwater-leakage are proposed.