The structure and construction method of cofferdam island type foundation pit under the condition of channel lining repair without interruption of water delivery

Abstract

The invention discloses a cofferdam island type foundation pit and a construction method under the condition of channel lining repair without interruption of water delivery, and is characterized in that: the water channel (1) includes a lining board (2) laid along the water delivery direction and a The lining board (2) is symmetrically arranged with an inclined slope (3); a cofferdam (4) is arranged on the water channel (1), and the cofferdam (4) is located in the water channel (1) The middle part and the lower end are fixed together with the canal slope (3); the bottom of the cofferdam (4) forms a dry foundation pit (5) with the water channel (1), and the cofferdam (4) is The steel structure of the modular buoyancy box is provided with an exhaust and drainage structure (4.1) inside the cofferdam (4), which overcomes the disadvantage that the cofferdam in the prior art will cause damage to the channel structure, and has the ability to greatly reduce the foundation The water head in the pit can effectively reduce the uplift pressure on the inner lining of the foundation pit.

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 a construction method under the condition of canal lining repair and uninterrupted 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 channel will be affected by various factors such as channel water level changes, drainage system operation status, freeze-thaw, construction quality, etc., and there may be damage in the form of concrete lining plate 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, whi...

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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