Geosynthetic reinforced soil bridge abutments under base motion dynamic loading

Geosynthetic reinforced soil (GRS) bridge abutments are of great interest in different highway projects due to their ease of construction, flexibility, cost-saving, aesthetic aspects and good performance comparing to traditional ones. However, their seismic performance is of question due to their complex structure and lack of proper investigations. Therefore, this paper investigates GRS abutment performance under earthquake loading through numerical modelling using FLAC software. The effect of lateral restraint due to the bridge deck existence was analyzed in this study. Comparing the models with and without the bridge deck indicated that the bridge deck simulation affected static and seismic performance of GRS abutment considerably. Accordingly, restriction of the upper part of GRS abutment with bridge deck modelling decreased facing displacement and reinforcement loads considerably under static loading. Furthermore, simulation of bridge deck caused a noticeable reduction in facing displacement after seismic loading, while it had no considerable effects in reinforcement loads. Additionally, it was found that seismic loading imposed a great increase in facing displacement and reinforcement loads compared to static state. Therefore, it is crucial to investigate the dynamic performance of GRS abutments constructed in seismic prone areas.