Dynamic characteristics and experimental verification of the new type of deck arch bridge

In order to solve the problems of small structural stiffness and low natural frequency of the long-span deck arch bridge, a new type of arch bridge structure was proposed in this paper. The specific method is presentedas follows: the pillar is changed into a triangular mesh with the auxiliary arch. Therefore, the doublelayer truss structure is formed, which will improve the stiffness and stability of the structure then improve the dynamic characteristics of the structure. For studying the dynamic characteristics of the new type of deck arch bridge, two test bridges with 10 m span were built and environmental vibration test was carried out, then the natural frequency of the first in-plane vibration of the structure was measured. Finite element software was used to calculate the stiffness and dynamic characteristics of the structure. The test and finite element results show that the natural frequency of the first in-plane vibration of the new type of deck arch bridge is significantly higher than that of the traditional deck arch bridge. Furthermore, the measured vibration mode is consistent with the finite element analysis; On the premise of not increasing the amount of steel used, the natural frequency of new type of deck arch bridge is higher than that of the traditional deck arch bridge when the out-of-plane, in-plane and torsional vibration modes appear for the first time; The stiffness of the new type of deck arch bridge is greatly improved. The sum of the maximum absolute values of verticaldeflection of the main beam is greatly reduced under the action of dynamic trainloading. © 2021, Central South University Press. All rights reserved.