Evaluation of Lateral Movement of Piled Bridge Abutment Undergoing Lateral Soil Movement in Soft Ground

Abstract

This paper describes the lateral movement of piled bridge abutments caused by backfills behind the abutments. To analyze the lateral movement of piled bridge abutments, a precise investigation was performed on the field monitoring data obtained from forty-three abutments where lateral movement has occurred. The investigation focuses not only on the lateral movement of the abutments, but also on the slope stabilizing effect of the foundation piles that support the abutments. Analyses on slope stability have been carried out for the abutments. These analyses consider the lateral movement of the abutments and the slope stabilization effect of the foundation piles. The results of the slope stability analysis and field investigation show that the lateral movement of bridge abutments may occur when the safety factor of the slope is less than either 1.5 in the case that does not consider the pile effect, or 1.8 in the case that considers the pile effect. The evaluation on the lateral movement of bridge abutments using only empirical indexes is not sufficient because the measured lateral movements do not always relate to some of the empirical indexes. Therefore, the slope stability analysis that considers lateral movements of the bridge abutment must be executed in order to precisely evaluate the possibility of lateral movement of the bridge abutment.