Influence of Shapes of Corrugated Steel Plate on Load-Carrying Capacity of Reinforced Concrete Slab Culvert and Arch Effect with Lateral Restraint

To explore the influence of the shape of corrugated steel plate (CSP) on the reinforced concrete (RC) slab culvert rehabilitated with grouted CSP, and the discrimination of arch effect of grout, this paper established 72 numerical models of the rehabilitated system with box, arc and transition shapes of CSPs by combining laboratory test with numerical analysis, based on the laboratory experimental results. The variation law of the load-carrying capacity of the rehabilitated system changed with the shape parameters of CSPs was ascertained. In addition, based on the concept of reasonable arch axis, the formation mechanism of arch effect of grout was also ascertained and verified by five numerical models. The results indicate that, when the radius of the haunch of CSP remained constant, the load-carrying capacity of the rehabilitated system increases upon decreasing of the radius of side walls and crown; when the side walls and crown of CSP remained constant, the load-carrying capacity of the rehabilitated system increases with the increase of the radius of the arch haunches; the most effective way to improve the load-carrying capacity of the rehabilitated system is to increase the radius of the haunches, followed by reducing the radius of the vault and side wall. The arch effect of grout was related to the load types. When the shape of CSP can keep the arch axis continuous and within the rigid angle of grout, the load-carrying capacity of the rehabilitated system is the highest. The structural design of the RC slab culvert rehabilitated with CSP should comprehensively consider the shapes of CSP and the arch effect of grout according to the actual needs of the project, and try to avoid the rehabilitation design close to the original RC slab culvert as far as possible.