基於振動之重力式擋土牆性能評估技術初探

In order to detect the degradation of retaining structures before failure is caused so that the follow-up slope disasters can be prevented, this study aims to assess the stabilization performance of the widely used gravity retaining wall based on its vibration response, which can reveal the dynamic characteristics of the wall-soil interaction system. In addition, vibration-based performance indices were suggested to quantify the performance variation of retaining walls. Laboratory scale-model tests were also conducted to examine the feasibility of the proposed methods. Results showed that the moistening of backfill due to simulated rainfalls as well as its active failure caused merely slight change of the natural frequency of the wall-soil system, yet its stability decrease can be reflected using a vulnerability index which incorporate the natural frequency and the amplification factor of vibration. On the other hand, excavation near the toe of the wall and weakening of the soil beneath the foundation significantly influenced the natural frequency, and the rotational stiffness of the foundation can be accordingly estimated to quantify the overturning resistance of the wall.