Identification of external load acting on the tunnel lining: Algorithm and model test

초록

The number and the length of old tunnel is increasing, and cases of damage to the tunnel lining are continuously reported. Therefore, it is important to examine the load acting on the tunnel lining for repair and reinforcement of the tunnel during operation. This study proposed an algorithm which can find the location and load when an additional load is applied to the tunnel due to changes in the ground conditions in the tunnel during operation. The back analysis algorithm using a differential evolution algorithm and a beam spring model was proposed, and the proposed algorithm was verified through model test. The test results were used in the proposed back analysis algorithm to identify the location and additional load. As a result, the location was accurately found and the load showed an error of about 2.5%. However, there was a maximum difference of 50% between the measured displacement and the displacement calculated by back analysis. In order to select appropriate maintenance and reinforcement measures in the future, it is necessary to improve the algorithm so that the cause of the additional load can be identified, and research according to the change of the lining is also necessary.