Influence of Facing Configuration on the Response of GRS Abutments
摘要
Over the years numerous cases of GRS abutment failure have been reported due to loss of strength at the facing-reinforcement interface. Evidently, a wide bracket of facing configurations is available before designers opt for the type of facing. Broadly, these configurations may be classified into three categories namely modular, continuous, and full height rigid (FHR). The present study aims to experimentally study the behavior of these three facing classifications through 1 g physical model tests subjected to serviceable cyclic lateral displacements. A N scaled down 1 g physical model (N = 5) of a field instrumented GRS abutment prototype was prepared with adjustable facing arrangements to reproduce field behavior in the model. The peak earth pressure coefficient (K) on the facing and vertical settlement of the footing (s/B) have been recorded for 100 cycles of lateral displacement (d/H) of top of facing at loading rate of 1 mm/min. Three modes of cyclic displacements have been applied simulating active condition (CA), passive condition (CP) and active–passive condition (CAP) for a constant footing offset of x/H = 0.1. The results indicated that relatively large earth pressure develops over the facing when reinforcements are integrated within the wall, i.e., FHR configuration. Despite this, the continuous nature of the FHR facing supplements the membrane resistance of the reinforcements causing reduced settlement of the footing. On the other hand, relative displacement between the panels in modular facing releases the pressure over the wall negating the connection strength at the interface resulting in larger settlements below footing. Conservatively, FHR facing may be adopted as an effective solution in resisting lateral cyclic disturbances.