Mechanics Performance Analysis And Experimental Investigation On Modern Timber Arch Bridge

Modern timber structures, the superiority of which is obvious to all, are being widely used in foreign countries. Nevertheless, in our country, it is a kind of new structure. In this thesis larch, the information of the domestic forest resources as well as the quantity demanded of the modern timber structures in the market is taken into consideration to analyze the application prospects of the modern timber structures. And it is indicated that the promotion of the modern timber structures is both necessary and viable. Taken the Zhang Jiajie modem timber arch bridge as the project background, the finite element model is established to analyze and research the mechanics performance and the stability of the bridge. Meanwhile, together with the static load test, the bearing capacity of the arch bridge is assessed. The parameters, boundary conditions, stiffness of the arch rib and so on, which influence the dynamic property of the bridge, are taken in to consideration. The main conclusions of this thesis are as follows:1. Due to the small wood density, the proportion of the self-weight, relatived to the live load, is smaller. And the live load affect on the bridge effect is more apparent. With a reasonable structure stress and deformation, both the strength and the stiffness of the modern arch bridge are specification compliance. What’s more, the stability of this bridge conforms to the requirements of the specification. Although the design is based on the AASHTO, it can be satisfied with the Technical Specifications of Urban Pedestrian Overcrossing and Underpass of China.2. Compared with the bridge, the hingless arch bridge can be with a more reasonable structure stress and deformation. However contraposed to the design, fabrication, installation and transportation, the three-hinged arch bridge has more advantages.3. The vibration mode of the arch bridge is complex. The degree of the complexity is depended on the orders of vibration mode, the higher the order is, the higher the degree of the complexity and coupling is. Simultaneously, the natural vibration characteristics were calculated. It shows that the stiffness of the vertical of the bridge is smaller than that of the lateral of the bridge. The first vibration mode, whit a natural frequency of1.27Hz, is the vertical antisymmetric bend. 4. The stiffness of the arch rib and the lateral brace has little influence on the dynamic property of the bridge. But the boundary conditions and the lateral brace arrangement influence the vertical and the lateral the dynamic property of the bridge, respectively.5. Under the testing load, the mechanical behavior of the bridge does conform to the requirements of the specification. Meanwhile, the bridge still possesses a high safety stock and good dynamic performance.