Design And Implementation Of Temporary Structure Of Pier Under Water In Xiangjiang Bridge On Huaihua-Hengyang Railway

With the fact of the huge area of oceans, rivers and lakes in China, the construction of bridges over the wide water area is in high development. The demand for the bridges of huge spans crossing the river or the ocean gradually increase. Along with the fact that the geological conditions get increasingly complex and the water level gets deeper, the requirement and dependence of the large bridge for the temporary structure of bridge piers are getting higher and higher. Meanwhile, with different trestles and cofferdams of divers types of bridges appearing, a variety of new construction methods have been introduced in the period of the bridge construction and some relevant technical problems have also emerged. It requires learning the advanced technologies from the existing temporary structures of bridge piers domestics and overseas. The research combined with the actual situation of the practical projects is also necessary. This thesis relies the conditions and scale of the construction of Huai Shao Heng Railway Bridge over the XiangJiang River to study the design and the key technology of the construction of the temporary structures, and the detailed contents are these:(1) Combined with the engineering practice, expounds the objective and contents of the subject, collecting the data about water pier construction of temporary pier structure constructed in water and summarizes the development status, combined with the engineering background, carry out the research plan.(2) Combined with the design data, the hydrological and geological conditons, bridge foundation construction scheme in water are conceived, design trestle, cofferdam design projects are compared and selected, and overall planning of construction is carried out, trestle is designed and finite element model is created, the overall structure, the foundation of the local structures and the strength, stiffness and stability under various conditions are checked.(3) Research on the design parameters of steel cofferdam, select the structure and detailed design, the three kinds of working conditions of double-wall steel cofferdam are calculated and analysis detailed; the working state of the lift stations are analyzed and checked.(4) According to the actual situation, studied the concrete implementation plan of construction, including blasting cleaning, steel trestle construction, steel cofferdam construction and assembled, and the steel casing construction, cofferdam bottom cleaning, cofferdam bottom sealing and drilling platform construction technology are studied.