Performance of the Embedded Mechanically Stabilized Earth Abutment: A Case Study

This paper evaluated the performance of embedded mechanically stabilized earth (MSE) abutments with geosynthetic reinforcement when subjected to seasonal temperature and rainfall cycles under working conditions based on an experimental project. The field monitoring data indicated that seasonal temperature and rainfall played an important role in the in-service performance of the abutment. Compared with conventional MSE abutments, the embedded bridge substructure (pile) led to significant temperature differences within the abutment, especially in seasons with continuous temperature changes, forming two distinct temperature distribution patterns. The vertical distribution of the lateral facing deformation underwent a transition from a uniform pattern to a midbulging pattern, which was accelerated during increasing temperature and rainy seasons. The interaction between the embedded pile and reinforced soil behaved as a localized constraint effect and led to a limitation on the bulging phenomenon. The piles also restricted the short-term variations in earth pressure induced by both temperature and rainfall, particularly on the cross-section intersecting the pile. The lateral earth pressure behind the facing was coordinated with its lateral deformation. With the development of lateral facing deformation, lateral earth pressure behind the facing redistributed and a load shift phenomenon occurred from the abutment facing to the pile, with significant stress release behind the facing and stress concentration behind the pile at the middle height of the abutment. Particular attention should be paid to the interaction mechanism between the embedded pile and reinforced soil, as well as the thermal-induced behaviors of embedded MSE abutments.