Small-size combined anti-seepage cofferdam structure

Abstract

A small-size combined anti-seepage cofferdam structure comprises an external structure above a ground line, an internal structure above the ground line and a lower structure below the ground line, the external structure above the ground line comprises outer layer cofferdams which are arranged on the two sides and formed by stacking bagged soil, the internal structure above the ground line comprises an anti-seepage soil layer filled between the bagged soil arranged on the two sides, the lower structure comprises a steel sheet pile layer inserted into the anti-seepage soil layer, and the steel sheet pile layer is downwards inserted into an impervious layer below the ground line. The scheme is small in occupied area, simple and convenient to construct, low in manufacturing cost, small in pollution, multiple in advantages and good in practicability.

Description

Technical Field

[0001] The utility model relates to a small-sized combined impervious cofferdam structure, belonging to the technical field of water conservancy and hydropower engineering. Background Art

[0002] In water conservancy projects, as an important water retaining structure, the cofferdam greatly reduces seepage and provides a dry working environment for the construction of permanent buildings. However, except for a very small number of cofferdams that are retained as part of the permanent building, most of the other cofferdams are demolished after the completion of the construction of the permanent building. At present, the cofferdam structures adopted in the water conservancy industry all have certain limitations more or less. For example, the earth-rock cofferdam occupies a large area, and there is a certain pollution to the river water during construction and demolition; the construction of the steel sheet pile cofferdam is relatively more complex than that of the earth-rock cofferdam; while the concrete cofferdam has a high cost and requires a high construction site. Therefore, for some water conservancy projects with small investment and low water retaining height, a cofferdam structure that takes into account the characteristics of small occupied area, low cost, easy demolition and small pollution is needed. Content of the Utility Model

[0003] The purpose of the utility model is to overcome the shortcomings of the existing technology and provide a small-sized combined impervious cofferdam structure with low cost, small occupied area, convenient demolition, and especially reduced pollution to the river water.

[0004] To achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A small-sized combined impervious cofferdam structure includes an external structure above the ground line, an internal structure above the ground line, and a lower structure below the ground line. The external structure above the ground line includes an outer cofferdam formed by stacking bagged soil on both sides. The internal structure above the ground line includes an impervious soil layer filled between the bagged soil arranged on both sides. The lower structure includes a steel sheet pile layer inserted into the impervious soil layer, and the steel sheet pile layer is inserted downward into the impervious layer below the ground line.

[0006] Further, the slope ratio on the water-receiving side of the outer cofferdam is arranged between 1:0.2 and 1:0.5, and the slope ratio on the water-facing side is arranged between 1:0.5 and 1:1.

[0007] Further, the impervious soil layer is a clay layer or a clayey soil layer.

[0008] Further, the height H of the outer cofferdam is less than 3m.

[0009] The beneficial effects of the utility model are:

[0010] Using bagged soil as the external structure of the cofferdam, compared with the commonly used earth-rock cofferdam, the slopes on both sides can be arranged within a steeper range, which not only reduces the overall engineering quantity of the cofferdam, but also can reduce the floor area of the cofferdam, which is beneficial to the overall layout of hydraulic engineering with narrow river beds and cramped sites. Moreover, it reduces the construction of earth and stone, which is beneficial to reducing river bed pollution. Combining impervious soil and steel sheet piles for imperviousness not only improves the impervious effect of the part above the ground of the cofferdam, but also has a good impervious effect on the pervious layer below the ground. The single-row steel sheet pile is used as the impervious body of the pervious layer below the ground, which not only reduces the construction difficulty, but also can be recycled after use, reducing the cost. This cofferdam structure has the advantages of small floor area, simple construction, low cost and little pollution, and has many advantages and good practicability, and is suitable for popularization and application in this field. Brief Description of the Drawings

[0011] Figure 1 is a schematic cross-sectional view of a small-sized combined impervious cofferdam structure of the present utility model;

[0012] Figure 2 is a schematic diagram of an embodiment in which a small-sized combined impervious cofferdam structure of the present utility model is arranged in a river bed. Detailed Description of the Invention

[0013] The present utility model will be further described in detail below in conjunction with the drawings of the specification and specific embodiments.

[0014] As Figure 1 , Figure 2 shown, a small-sized combined impervious cofferdam structure includes an external structure above the ground line, an internal structure above the ground line, and a lower structure below the ground line. The external structure above the ground line includes an outer cofferdam 01 arranged on both sides and formed by stacking bagged soil 1. The internal structure above the ground line includes an impervious soil layer 2 filled between the bagged soil 1 arranged on both sides. The lower structure includes a steel sheet pile layer 3 inserted into the impervious soil layer 2, and the steel sheet pile layer 3 is inserted downward into the impervious layer 5 below the ground line 4. The steel sheet pile layer 3 is formed by arranging a plurality of steel sheet piles. The steel sheet piles are inserted from the inside of the impervious soil layer 2 and extend into the impervious layer 5 below the ground line. The part above the ground is impervious by the impervious soil layer 2 and the steel sheet pile layer, and the part below the ground is impervious by the steel sheet pile layer.

[0015] For the small-sized combined impervious cofferdam of this solution, during construction, first conduct surveying and setting out according to the layout to determine the position of the cofferdam axis. Then, clean and level the ground at the axis position. Next, stack the bagged soil and fill the impervious soil layer by layer from low to high along both sides of the axis until the top of the cofferdam is reached. Finally, drive the steel sheet piles. The bagged soil can be prepared by a professional soil factory or on-site. Appropriate filling materials need to be selected. The bagged soil should be stacked vertically in layers. After each layer is stacked, the impervious soil is filled, and then mechanical or manual extrusion is used to ensure the compaction between the bagged soils. Repeat this process until the cofferdam is filled to the top. The driving of the steel sheet piles is carried out after the cofferdam is filled to the top. First, conduct surveying and positioning, and then drive the piles. It can be carried out by means such as driving on water or on land. After the steel sheet piles are driven, the construction is completed. This solution not only occupies a small area and is easy to construct, achieving the purpose of water retention, but also most of the materials can be recycled, reducing both water pollution and construction costs, and having good practicability.

[0016] Furthermore, the slope ratio on the water-receiving side of the outer cofferdam 01 is arranged between 1:0.2 and 1:0.5, and the slope ratio on the water-facing side is arranged between 1:0.5 and 1:1. According to the height and width of the cofferdam itself, the best stability can be achieved within this slope ratio range.

[0017] Furthermore, the impervious soil layer 2 can select soil materials with a permeability coefficient meeting the requirements, such as clay or clay loam, etc., to form a clay layer 2 or a clay loam layer, with good impervious effect.

[0018] Furthermore, the height H of the outer cofferdam 01 is generally less than 3m, and the top width of the cofferdam can be arranged according to actual needs.

[0019] The above specific implementation manners are used to explain the present utility model, which is only the preferred embodiment of the present utility model, rather than a limitation to the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and protection scope of the claims of the present utility model fall within the protection scope of the present utility model.

Claims

1. A small-sized combined anti-seepage cofferdam structure, characterized in that The invention comprises an external structure above the ground line, an internal structure above the ground line and a lower structure below the ground line, wherein the external structure above the ground line comprises an outer cofferdam (01) arranged on both sides and formed by stacking bagged soil (1), the internal structure above the ground line comprises an impermeable soil layer (2) filled between the bagged soil (1) arranged on both sides, and the lower structure comprises a steel sheet pile layer (3) inserted into the impermeable soil layer (2), and the steel sheet pile layer (3) is inserted downward into an impermeable layer (5) below the ground line (4).

2. A small-sized combined anti-seepage cofferdam structure as claimed in claim 1, characterized in that The slope ratio of the outer cofferdam (01) on the backwater side is arranged between 1:0.2 and 1:0.5, and the slope ratio on the frontwater side is arranged between 1:0.5 and 1:

1.

3. A small-sized combined anti-seepage cofferdam structure as claimed in claim 1, characterized in that The anti-seepage soil layer (2) is a clay layer or a clay soil layer.

4. A small-sized combined anti-seepage cofferdam structure as claimed in claim 1, characterized in that The height H of the outer cofferdam (01) is less than 3 m.

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