Refined Design For Pontoons Of Floating Cable-Stayed Bridge And Global Analysis Of The Bridge Subjected To Large Ship Collision

The “Costal high-way E39” project was proposed by Norwegian Highway Authority in 2014.It is designed to connect Trondheim and Kristiansand with bridges crossing the western fjords,which is able to increase the transportation efficiency and to promote economical development.The environment around the fjords are complex,which makes the traditional bridge design infeasible.An innovative floating bridge concept is suggested.It will be supported only by the pontoons and the cables.Due to the existence of the pontoons,the possibility of ship bridge collision is greatly increased.Therefore,it is important to investigated the ship bridge collision problem.This thesis summaries the extensive research results of ship bridge collision and compares the difference among different mechanics.Take the Norwegian floating bridge for example,based on the non-linear finite element analysis and aimed at the collision problem between the ship and the pontoon,the 3D finite element model of the pontoon and the bridge are set up in Patran software.Then the collision analysis is carried out in the non-linear finite element software LS-DYNA to propose a pontoon design that is highly resistant against ship collision.In the analysis of bridge global response to ship collision,the bridge is built in the software USFO and the ship is modeled as a spring which has the same property as the ship.Four scenarios of ship bridge collision have been simulated in USFO to evaluate the bridge response in terms of maximum impact force,the maximum displacement etc.and the results are evaluated by the theoretical analysis and relative regulations.In addition,the effect of the ship speed and the collision angel are investigated.Based on the collision equation and time-domain analysis,this thesis investigates the global response of the floating bridge after ship bridge collision.The pontoon design is refined to obtain enough strength.The results and the method in the thesis could be a reference for the Norwegian floating bridge design and could contribute to future development.