Performance of geosynthetic-reinforced soil bridge pier and abutment, Denver, Colorado, USA

A GRS bridge abutment and two GRS bridge piers were constructed inside a 3.5-m deep pit. The structures were constructed with a "road base" backfill reinforced with layers of a woven geotextile. Hollow-cored concrete blocks were used as facing. One of the piers (i.e. the outer pier) and the abutment, both 7.6 m in height, were load tested. The load was applied using concrete barriers stacked in seven layers over three steel bridge girders. A total load of 2,340 kN, corresponding to 232 kPa pressure, was applied. The pier and the abutment were instrumented with metal pipes and elastic springs to monitor the vertical and lateral movement of the facing, and strain gages to monitor deformation of the reinforcement. This paper is to report the short-term and long-term behavior of such the structures upon loading. Comparisons of the behavior of the outer pier and the GRS pier at the Turner-Fairbank Highway Research Center, FHWA were made whenever appropriate.