2020 Volume 58 Issue 8 Pages 589-596
The soundness of box type tunnels is maintained by ongoing repair of water leakage, flaking as such issues occur. However, the methods defined as standard methods by Tokyo Metro Co., Ltd. had not been updated in many years, and new materials that had become available in intervening years were not introduced. Further, instances of re-degradation of some repaired locations occurred. Therefore, to enable the selection of repair methods suitable for box type tunnels such as water cutoff work and cross-section repair work, and a method for the evaluation of repair methods considering the degradation level of the concrete base material was developed after the required performance and evaluation items were defined. In addition, an operation flow for introducing the method into actual construction work was established. These innovations have made possible the rapid introduction of new technologies.
