Analysis of a Segmental Bridge Considering Lateral Forces Using Analysis Tool

Abstract

This study aimed at examining the feasibility of using carbon fiber-reinforced polymer (FRP) rebars instead of steel ones in prestressed segmental concrete beams (PCBs) with external FRP tendons. By applying an experimentally validated program, numerical tests were performed on simply supported PCBs, with investigated variables including rebars’ type and area. Two types of tendons were considered, i.e., FRPs and reinforcing steel. The ratio of tensile rebars ranged from 0.22% to 2.16%. The results indicated that the beams with CFRP rebars exhibited better crack mode and higher ultimate load than the beams with GFRP or steel rebars. GFRP rebars led to considerably higher ultimate deflection and tendon stress increment than steel rebars. In addition, several models for calculating the ultimate stress in unbonded tendons were assessed. An analytical model was also proposed to predict the tendon stress at ultimate and flexural strength in externally PCBs with steel and FRP rebars. The model predictions agreed well with the numerical results.
A finite element model is proposed for numerical analysis of mechanical properties of precast segmental concrete test beam with external tendons. The 3D finite element model of test beam is established by SAP 2000 software, while the dry joint between segments is simulated by contact element, and the attachment between concrete beam and external prestressed tendons is achieved by node coupling method. Numerical simulation analysis reveals structural behavior, stress variations and crack opening cases of joints of the test beam by considering the concrete material and geometric nonlinearity. Influencing factors of the bending mechanical properties of the test beam are researched with different tendon types, secondary effect of external tendons and external tendon slip at deviation. Results of the numerical analysis reveal that the segmental joints are in the compressive state below the 300kN.Crack opening is the key factor of the mechanical properties of the test beam above the 300kN.The results can be used for structural design of precast segmental bridge.