Abstract:

After the excavation of the tunnel between the FuJen University station and the Danfeng station of Taipei MRT Xinzhuang line, the construction company underestimated the real distance from the tunnel to the structure line of the base and a series mistakes happened on ChungCheng road when constructed. As a result of these factors, the upper segment loop of at the MRT tunnel beneath the ChungCheng road has been out of shape inwards due to the overpressure of grouting during the process of the urgent steps of salvage. Being careful examination of the damage of the tunnel at the site, the 439th to 471st loops have been unearthed under the projection of the newly constructed project. Besides the 462nd loop to the 470th are overdeformed exceeding the safety range of the steel bar and need to be repaired. In addition, the 459th loop needs to be repaired for the fissure in the direction of movement of vehicles. Under the calculation of the structural mechanics, the damaged loops for the 459th to the 470th are need to be repaired by the means of lining the copper loops. This article reports the process of repairing the deformed tunnels form beginning to end to be a reference of the relevant work projects afterwards.

Key words: shield tunnel  rapid transit systems  deformed tunnel deep excavation  nearby buildling