Cofferdam island type foundation pit structure and method for canal lining repairing under condition of uninterrupted water delivery

Abstract

The invention discloses a cofferdam island type foundation pit and method for canal lining repairing under the condition of uninterrupted water delivery. The cofferdam island type foundation pit and method are characterized in that a water canal (1) comprises a lining plate (2) arranged in the water delivery direction and inclined canal slopes (3) arranged symmetrically along with the lining plate (2); a cofferdam (4) is arranged on the water canal (1), the cofferdam (4) is located in the middle of the water canal (1), and the lower end of the cofferdam (4) and the canal slopes (3) are fixed together; the lower portion of the cofferdam (4) and the water canal (1) form a dry ground foundation pit (5); and the cofferdam (4) is of a module type buoyancy tank steel structure, and an air and water discharging structure (4.1) is arranged inside the cofferdam (4). The defect that a canal structure can be damaged by a cofferdam in the prior art is overcome. The cofferdam island type foundation pit and method have the advantages that the water head in the foundation pit is reduced greatly, and the uplift pressure borne by the lining in the foundation pit is reduced effectively.

Description

technical field [0001] The invention relates to the technical field of water conservancy and hydropower engineering construction diversion, and more specifically relates to a cofferdam island type foundation pit structure and method under the condition of channel lining repair without interrupting water delivery. Background technique [0002] In order to solve the imbalance of regional water resources, there are more and more water transfer projects in our country. With the completion and operation of the project, the water delivery channel is affected by various factors such as channel water level changes, drainage system operation conditions, freeze-thaw, construction quality, etc., and the concrete lining board may be damaged in the form of cracking, collapse, anti-floating instability, etc. , to a certain extent, it will lead to the increase of local head loss of the channel, the damage of the anti-seepage system, and in severe cases, the instability of the slope, which ...

AI Technical Summary

Problems solved by technology

Concrete and masonry cofferdams are difficult to construct underwater; earth-rock cofferdams have a large section, and it is relatively difficult to form a foundation pit layout in a limited channel section. Water and soil loss may lead to inverted siphons along the water delivery and channel siltation, affecting the water delivery capacity of the channel ; Steel sheet pile cofferdams are generally inserted into the weir foundation at a certain depth to maintain stability, or the foundation is poured with concrete, which will cause damage to the channel structure

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