Combined cofferdam and construction method thereof

Abstract

The invention provides a combined cofferdam and a construction method thereof. The combined cofferdam includes a pile membrane cofferdam body, an earth rock cofferdam body and a water blocking curtain, wherein the pile membrane cofferdam body comprises steel pipe piles and first impermeable membrane cloths laid on the water contact surfaces of the steel pipe piles; the earth rock cofferdam body isarranged on the land side of the pile membrane cofferdam body, and a second impermeable membrane cloth is laid on the water contact surface of the earth rock cofferdam body. According to the water blocking curtain, two rows of high-pressure rotary spraying piles are inserted into the portion, corresponding to the center of the earth rock cofferdam body, of a river bottom, the high-pressure rotaryspraying piles are meshed with one another to form the curtain, and therefore an interlayer wall is formed in the earth rock cofferdam body. Three different cofferdam structures are provided for combination to achieve the purposes of blocking water, reinforcing the cofferdam and protecting the environment.

Description

technical field [0001] The invention relates to a cofferdam structure and a construction method thereof. Background technique [0002] There are various types of cofferdam structures, each with advantages and disadvantages. [0003] In the renovation construction in waters such as rivers and lakes, in order to ensure that the water will not stop during the construction period along the line, traditional grass cofferdams are generally arranged in the middle of the river, and the construction sequence is first on the right bank and then on the left bank to meet the maximum flow rate of 6m 3 / s request. The grass soil cofferdam crest elevation is 30cm above the water surface to design the cofferdam section, the water depth is 2.5m, and the weir height is 2.8m. Considering the weir crest width is 1.0m and the slope ratio is 1:0.75~1.0, the cofferdam section is 8.68m 2 ~10.64m 2 between. The cross-section of the grass cofferdam is relatively large, which cannot meet the water...

AI Technical Summary

Problems solved by technology

The disadvantages of this kind of steel frame anti-seepage membrane cofferdam are: the cross section is large, and the proportion of the cross section of the waterway is large, which is not suitable for the construction of the waterway; the steel frame is huge, only suitable for construction in anhydrous sites, not suitable for underwater construction , due to the huge steel frame, the construction is very inconvenient

[0005] In addition, there is a structural form combining pile-membrane cofferdam and grass-soil cofferdam. The disadvantage is that it cannot adapt to complex geological conditions and has poor stability.

[0006] In short, in the existing technology, facing the environment with complex geological conditions and large water depth, the existing technology has problems of insufficient stability, incapable of dry trench construction, and environmental protection

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