Application of Flexibility Method to a Chain Suspension Stiffening Beam Bridge

Abstract

This paper intended to determine the influence line for structural members in a Chain Suspension Stiffening Beam Bridge (CSSBB). In an engineering case, flexibility method determined the redundant bar force in CSSBB as the unit live load stayed at different positions on the main bridge beam. These calculated redundant bar forces composed the influence line. The foregoing flexibility method considers suspenders deformation. Results indicate that redundant bar force is maximal when the unit live load stays at the main beam midpoint in Figure 2. The redundant bar force in Figure 3 is the actual force in bar 3 in the actual structure in Figure 2. The redundant bar forces and internal load equilibrium equations can determine the influence lines for other structural members. Simple-supported Beam Bridge (SSBB) can be constructed easily while and wire (cable) suspension bridge are suitable when the bridge is to cross a wide river. CSSBB and arch bridge demonstrates less deflection and less moment at the beam midpoint than the SSBB.