The Construction Technology Of The Pier In Water Of The Bridges No.1,2 And 3 Over River Mingyue Of The Railway From Dazhou To Wanzhou

The Da-Wan Railway is the key engineering of the national 9th-Five-Year Project. The building-up of the railway will promote the reform and opening of Chongqing, Sichuan and South Shanxi, is of great advantage to the industry and agriculture of East Sichuan and the zone around the Sanxia Reservoir. It will accelerate the social economy of Southwest China and help the people at old revolution area get rich.The Mingyue River is located in mountainous area. There are eight bridges over the Mingyue River on the Da-Wan Railway. As far as the No. 1, No. 2, No. 3 bridges of all eight bridges, the piers are high and hollow, the sand layers of their foundations are thick, and the water is deep. The low water period and the time limit for the three projects are short. The constructions are difficult. Due to the above reasons, the three bridges are the control projects of overall the railway. If the construction method is not suitable, the excavation of foundation would easily induce the shifting sand. Before the construction of the three bridges, the construction technology is investigated by the construction units. The No. 1, No.2, No.3 bridges are regarded as the key of the engineering. The treatment of underwater sand layer and the construction technique of hollow high pier are regarded as the key of the QC Project.Facing to many difficulties, the construction units are active to overcome the disadvantage factors, such as bad geologic condition and rainy period. The open-way pioneer spirit is developed, which is fighting our way and conquering bravely the difficulties. Organizing with reason, arranging with care and strengthening the management on site ensure the construction successfully, and ensure that the projects are finished in time. The projects have been checked and accepted by the Ministry of Railways in 2002. The 100-year dream of people in Sichuan and Chongqing has been realized in new century.Some construction techniques are developed in the pier construction of the No. 1, No. 2, No.3 bridges over the Mingyue River, for example, mud-jacking for the shifting sand for the bridge in deep water and turning over stripping form with climbing formwork for the hollow high pier. Some suggestions are presented in this thesis. A good design proposal is not only to satisfy structure function, but also to be convenient for construction and economy. Before the construction, the construction method should be investigated in detail, the geologiccondition should be explored, the construction proposal should be determined with reason, the possible problems should be foreseen, found out, and solved in advance to avoid losses. This is the key to guarantee quality and benefit of the project in the limited time period.According to the author' s personal engineering practice, the construction program, construction technique, construction proposal, design change and some problems of the pier in water of the No. 1, No. 2, No. 3 bridges over the Mingyue River on the Da-Wan Railway are introduced in this thesis. The understanding and lesson from the projects are discussed. They can be as the reference to similar engineering design and construction in future and should be summarized and put in wide use.