Performance of a Combined Retaining Wall Structure Supporting a High Embankment on a Steep Slope: Case Study

Abstract

A combined retaining structure (CRS) that consists of numerous piles, a concrete platform, and a gravity retaining wall was built to support a high embankment constructed on a steep slope. In this study, the behavior of an actual CRS was explored to understand bending moment in the pile and lateral earth pressure distribution on the wall with its small lateral displacement and narrow width of retained soil. The internal force and deformation behavior of the CRS were monitored during and after embankment construction. Numerical modeling by FLAC3D was also performed to gain a further understanding of the performance of the CRS. Monitoring and modeling results indicated that the bending moments along piles are reduced effectively by the platform and the retaining wall. The magnitude of earth pressure was larger than that of Coulomb theory. Both the distribution and magnitude of the earth pressure were closely related to the wall displacement and the filling space behind the CRS. Furthermore, seismic behavior of the CRS was investigated. The results showed that the pile segment inside the platform could be damaged under a seismic load with high peak ground acceleration.