Performance of a Back-to-back Geogrid Reinforced Soil Retaining Walls for Passenger-dedicated Railway during Service: Case study

To investigate the performance of a reinforced soil retaining wall during service for a passenger-dedicated railway (PDR), long-term remote observation testing of the back-to-back geogrid-reinforced retaining wall of Qing-Rong passenger-dedicated railway in Shandong Province has been conducted for 60 months. The performance of a reinforced retaining wall was investigated after the construction and the lateral earth pressure of the reinforced soil wall was analyzed. The vertical stress along the basis of the wall and the tensile force on the geogrid were measured with pressure cells and flexible deformation gauges, resulting in the distribution of data and changes in the service period. The test results showed that the pressure and the deformation of the wall were almost stable. It was determined that the lateral earth pressure on the back of the wall panel was approximately 119.2 % of the completion time during the 60 months after constructions. The vertical stress of the reinforced soil retaining wall remained almost stable during the 60 months post-construction. Stage-type changes were observed for the strain of the geogrid in the wall. The maximum strain of the measured geogrids only accounted for less than 30 % of the peak strain. Moreover, the deformation of the wall was relatively small which indicated that both sides of the wall were in good condition. These research results can serve as a reference for the design optimization of reinforced soil retaining walls for high-speed railways.