Field tests on Fiber-Reinforced Plastic (FRP) stormwater storage tank under road pavements for “Sponge City” development

Urban flooding has become one of the major issues in many cities around the world, due to rising sea level, increasing precipitation intensity, and land development. This research aims at the development of underground storage tanks (USTs) using fiber-reinforced plastic (FRP) materials for stormwater detention, storage, and reuse. The USTs are proposed to be placed underneath road or highway pavements. FRP as one of the emerging structural materials possesses several advantages including high strength-to-weight ratio and excellent corrosion resistance, compared with steel and other conventional materials. The mechanical performance of FRP USTs has rarely been investigated in existing literature; the majority of the existing studies have generally focused on leakage issues and associated environmental problems. This paper presents the results of the first-ever field test on an FRP UST buried underneath a pavement subjected to traffic loads. Sophisticated instruments using optic fiber sensors were installed to measure the responses of the FRP UST. The influences of traffic location and the water storage on the behavior of the FRP UST were investigated. The test results demonstrated the reliability of the FRP UST in resisting the traffic loads. Finally, finite element modelling was conducted to simulate the test results. The insights gained from the field test and the finite element analysis are expected to provide a general guidance on the design of FRP USTs under road pavements for “Sponge City” development.