Down-lying, bed-contacting and sinking control technologies of super large steel cofferdam

Abstract

The invention discloses a control technology of putting down, touching rocks and settlement of a super cofferdam. The invention belongs to the bridge engineering foundation construction field and is applicable to the cofferdam construction in the bridge high-low pile cap foundation. Namely the invention adopts the control technology of putting down, touching rocks and settlement to realize controllable initiative, adjustable ration, controllable position and adjustable deviation during the settlement of the cofferdam. The technology adopts a uniquely designed lifting system and a horizontal guide device to ensure that the cofferdam is safely and accurately settled to the designed position under the synchronous action of the lifting system and the horizontal guide device and through the wall cabin batch water filling mode as well as under the controllable state that the gravity is greater than the buoyancy. The invention effectively solves the problems of putting down and touching rocks of the super cofferdam as well as the settlement precision in the covering layer under the disadvantageous conditions such as tidal rivers with frequent hydrologic change, bigger riverbed height difference and so on, and improves the installation accuracy of the cofferdam.

Description

technical field [0001] The invention relates to a cofferdam construction method for bridge high and low pile cap foundations, belonging to the technical field of bridge foundation construction. Specifically, after the construction of the bridge pier foundation bored piles is completed, the completed pile steel casing is used as the guide pile, and under the joint action of the lifting system and the horizontal guide device, the super-large steel cofferdam can be used in tidal rivers with frequent changes and the height difference of the river bed is relatively small. Safely and accurately sink to the design position under severe unfavorable conditions. Background technique [0002] Nanjing Dashengguan Yangtze River Bridge is located in the Nanjing section of the lower reaches of the Yangtze River, where the water is deep and the current is fast. In order to build the Nanjing Dashengguan Yangtze River Bridge quickly, with high quality and with hig...

AI Technical Summary

Problems solved by technology

[0003] The conventional installation and construction of steel casing cofferdams on bridge caps is generally done when the height difference between the upstream and downstream riverbeds is not large. The process is not easy to control, especially for super-large steel cofferdams, the sinking accuracy is difficult to meet the requirements, and accidents of tilting and misalignment are prone to occur, resulting in delays in the construction period and increased construction costs

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