Study On Analysis And Design Methods Of Long-span RC Arch Bridge With Energy Dissipation Systems

Long-span RC arch bridge is a kind of bridge that is widely used in South-west area in China. The aim of this paper is to explore a more logical, effective and economical method for arch bridge aseismic design and vibration control, and to offer the experiment data and theory base. The response of the long-span RC arch bridge with energy dissipation system under multi-support seismic excitations is studied, considering main structure in elastic condition and the energy dissipation system damping in non-linear condition. The eigenvalues of the differential equation need to be computed repeatedly in the modal analysis of the structure with energy dissipation systems because of the non-linear damping. This complicated work takes a lot of time. The matrix perturbation method is effective to solve this kind of problem. A complex matrix perturbation method for the structures with non-proportion damping is educed. The modal truncation in the complex perturbation and iterative perturbation based on the first-order perturbation method are educed about the complicacy of the long-span arch bridge and the condition of the great change of the damping respectively. A first-order perturbational modification based on the forcing decoupling method is offered for the condition of the large error by the normal forcing decoupling method. A series of numerical examples show that the approximation results by these perturbation methods can reach well precision. A 2D plane model is established for Nimu-bridge, and a time-history response analysis is done by mode-superposition. The results show that the responses are decreased with the addition of viscous energy dissipation brace systems, and traveling wave effect is disadvantage to the structure, and pseudo static displacement is decreasing with the increasing of wave velocity. The approximation results by the first-order perturbation modification based on forcing decoupling method are precise. The response spectrum method for long-span structure by multi-support seismic excitation is researched, which is educed by A. Der Kiureghian. The range of the cross-correlation coefficients is discussed and some sujestions are proposed to the response spectrum method for long-span structures with energy dissipation systems.