STUDY ON LOAD RESISTANCE CAPACITY OF REINFORCEMENT FOR SHIELD TUNNEL

Abstract

 This research was conducted by TEPCO Power Grid, Inc. to study the reinforcement of shield tunnels with reduced load resistance capacity. For reinforcement, it was decided to apply the buried formwork method considering the workability in the tunnel, and the characteristics of load resistance capacity for reinforcement and its calculation method were examined by the load test of the test pieces that reproduced the reinforcing member. As a result of the test, the bending strength was equal to or higher than the calculation result by considering the thickness of the buried formwork. Regarding shear strength, shearing crack did not progress due to the buried formwork, and it was difficult for shear fracture to occur. However there were cases in which shear fracture occurred, it was evaluated that the shear strength needs to consider the thickness of the buried form as well as the bending strength. Based on the examination results, the calculation method of load resistance capacity of the reinforcing member was shown.