The Study Of Bridge And Ship Collision Venture And Bridge Anti-collision Measures After The Enhancement Of The Waterway Grade

In recent years, with the enchancement of the waterway grade and the increasement of the design ship navigationscale, the required navigation clearance is increasing and the navigable waters conditions in bridge area are significantly changing. The bridge existes ship collision risk, it is nessarry to implement anti-collision facilities engineering to protect the bridge. At home and abroad, serious damage and collapse accidents caused by the ship collision with the bridge are gradually increasing, and due to ship collision, there is a large bridge suffered serious damage or even collapse of the average annual.In this paper, based on the Beijiang(Wu Shi to Sanshui estuary) waterway regulation project, after the channel regulation, the river channel rank is promoted from grade IV to grade III, the bridge exists the ship collision risk, it needs to implement anti-collision facilities engineering to protect the bridge. According to the ship bridge collision probability model of yaw, the influences of the parameters on the ship bridge collision probability are analyed, the annual collision probability of the ship collision with each wading pier of the bridge is calculated, the bridges and the large wading piers withe ship collision risk are determined. After the establishment of the damage probability model of the ship hitting the bridge, the capacity of anticollision, the ship impact force and the year collision frequency of each part of the bridge have been analysed.The annual impact and collapse frequency of the piers of the navigable bridge opening has been obtained, and the anti-collision protection area of bridge has been determined.By use of the finite element model of the collision, the simulations of ship collision on the independent anti-collision pier structure with three piles and six piles have been done and the experimental results show that: after the ship impact on the independent anti-collision pier with three piles, the structural deformation is large, the anti-impact ability of the pier structure is insufficient, the structure does not have the capacity of anti-collision to the representative navigational fleet in the bridge area. The independent anti-collision piers with six piles have good control of structure deformation and good structure stability, and still have the carrying capacity. The increasement of the upper cap and pier structure is to provide more sufficient inertia force and binding force. However, the improvement on the anti-collision ability of the pile structure mainly relys on the lower part structure, and the structure still has the affluent carrying capacity.Aiming at the various collision characteristics,based on the schemes of anti-collision pier structure, four kinds of optimization scheme of anti-collision have been put forward: centralized anti-collision pile group, fence type anti-collision group pile, water floating anti-collision belt lifting and descending with water level, and the anti-collision floating casing box. And a representative structure has been put forwards for the four kinds of anti-collision optimization scheme. A three-dimensional finite element model has been established to do the simulations under the work control conditions, the experimental results show that the representative structure scheme proposed is feasible, which can meet the anti-collision requirements of the ship in the regulated river.And the bridge is divided into three categories of single span arch bridge, continuous arch bridge and pier bridge. All kinds of bridge anti-collision protection area have been put forward. Combined with the structure of each bridge and hydrological and topographical characteristics, the recommended schemes of the bridge anti-collision measures have been respectively proposed.