Analysis of Strong Stress Concentrations of Key Joints for Super-Spanned Steel Truss Bridges

Abstract

In this paper, the strategy of three scales was proposed to analyse strong stress distributions of key joints during the incremental launching construction. Firstly, the internal forces and reaction forces were obtained by the finite element method (FEM). Secondly, some key joints were separated from the whole structure. The displacements and boundary conditions of the separated joint were taken from the results of the FEM. Then the stress distributions of the separated joint were successfully obtained by using the FEM. Thirdly, the local stress concentration areas were separated from the key joint structure. The high stress distributions of the local stress concentration region were successfully obtained by using the extended boundary element method (XBEM). On the other hand, the stress of some joints were measured through mechanical test on the construction site. And calculation results of the FEM and XBEM were in good agreement with test results. A multi-scale method is developed to obtain the strong stress concentration during the construction of the super-spanned steel truss bridge accurately, which enables the safety of the construction. In addition, the present method can be further used to guide the design of super-tall building, super-spanned bridge, etc.