Experimental and analytical study on compressive bearing capacity of steel shell-concrete composite bridge tower

Abstract

To improve the mechanical performance and construction convenience of the bridge towers, a steel shell-concrete composite tower (SSC structures) was proposed. The steel shell consists of outer and inner steel plates, diaphragms, and stud connectors inside the cells. Then the high fluidity concrete is poured into the steel shell to form the composite tower. Through the uniaxial compressive tests of the specimens with different concrete strength and the nonlinear finite element parametric analyses, the force transfer mechanism of the steel shell, the infilled concrete, and the stud connectors at the steel–concrete interface were revealed. The results show that the proposed steel shell-concrete composite tower has a higher bearing capacity than the conventional concrete-filled steel tube tower, in which the bearing capacity of concrete was increased by about 20% from the test results due to the composite effect between steel and concrete. Diagonal breakage bands were formed when the specimens finally failed, on which the concrete was crushed, and the steel plates had large out-of-plane deformation and weld cracking. Through finite element calculation, it was found that the increase of stud forces mainly occurred after the yield of the steel wall plates, and the maximum values of the shear forces and tension forces were 3.6 kN and 4.7 kN, respectively. The results also show that the multiple-cell section has better mechanical performance than the double steel section, which is suitable for the section form of the composite bridge tower.