Seismic Conceptual Design Principles Research Of Small And Medium Size Span Beam Bridges In High Earthquake Intensity Area

As well known, bridge is the throat of road system, which is an important part of road traffic network. No matter how long the brige is, once damaged, there would be a paralysis in road traffic network, WENCHUAN earthquake is a clear example in which the damage of bridges had once affected the relief work seriously. For this sense, seismic design of medium and small span of beam bridge and long-span bridges are equally important in high earthquake intensity area. Therefore, this article provided the seismic conception design principle,which based on the research of the influence of the earthquake response with the change of bridge structure forms, terrain and span.1) Establish the model of the beam bridge seismic response charac-teristics analysis with the method of CAD for VBA automatic modeling procedures and girder case. On this basis, this article analyzed the bridge seismic response characteristics with the difference of structure form.2) Analyze the seismic response characteristics of seismic design of medium and small span of beam bridge with the same span, whose structure forms are different.3) Put forward the bridge suitability of structure form of small and medium-size span beam pumping bridge, which based on the discussion of seismic response characteristics. It is concluded that the terrain suitability and, deck continuous beam bridges are selected in priority in the type of wide shallow terrain; continuous beam bridges or rigid frame-combined continuous beam are selected in priority in V-shaped terrain.4) Discuss the earthquake the influence of small and medium-sized span seismic response with the effect of collision. The influence of the transverse internal force of bridge piers are complex, and collision reduce the longitudinal internal force of bridge piers.5) Analyze the influence degree of the bridge structure forms, the terrain, bridge spans and earthquake intensity by orthogonal analysis, which effect on the bridges. Based on the above analysis, combining the traditional bridge seismic design viewpoint, the seismic concept design principles of small and medium-sized span beam bridge with high earthquake intensity are put forward.