Cofferdam structure and construction method for storing useful materials

Abstract

The present invention relates to a cofferdam structure for taking into account the storage of useful materials and its construction method, which is applicable to the technical fields of design and construction of large and medium-sized water conservancy and hydropower projects. The technical solution adopted by the present invention is as follows: A construction method of a cofferdam structure for taking into account the storage of useful materials, characterized in that: the cofferdam structure is designed to determine the type of cofferdam and the anti-seepage body; based on the designed cofferdam structure, the seepage calculation of the cofferdam is carried out to determine the elevation of the phreatic line of the downstream cofferdam body of the anti-seepage body, and the range of the useful material filling area is determined according to the range of the anti-seepage body, the elevation of the phreatic line of the cofferdam body and the shape of the two banks' slopes; the cofferdam filling construction is carried out, and the useful material filling area is filled in layers. When carrying out the same-layer construction, the ordinary material filling areas at both ends of the useful material filling area are constructed first, and then the useful material filling area in the middle is constructed.

Description

Technical Field

[0001] The present invention relates to a cofferdam structure for taking into account the storage of useful materials and a construction method thereof. It is applicable to the technical fields of design and construction of large and medium-sized water conservancy and hydropower projects. Background Art

[0002] Large and medium-sized water conservancy and hydropower projects are usually built in high mountain and canyon areas far from cities. A large amount of rock waste will be generated during the excavation construction of slopes, foundations, underground projects, etc., while a large amount of stone materials are required for the backfill of cofferdams, sites, etc. and the concrete pouring of buildings. Therefore, carrying out reasonable rock balance planning and effectively using the excavated rock materials of the project as filling materials or concrete aggregates can not only greatly save project investment, but also reduce the damage to the environment caused by a large amount of waste slag, which is of extremely great significance.

[0003] The engineering excavation and filling processes are concentrated in the early stage of the project, while the concrete pouring is mainly carried out after the engineering excavation is completed. The usual practice is as follows: in the early stage, the excavated rock waste first meets the filling construction requirements. The poorer stone materials are used for the filling of sites, roadbeds, etc., and the better stone materials are used for the filling of important structures such as cofferdams; after meeting the filling material requirements, the remaining poorer stone materials are discarded to the waste slag yard, and the better stone materials are stored in the transfer yard. After the concrete pouring starts, they are mined and processed from the transfer yard and used as concrete aggregates; after the full-line pouring elevation of the dam exceeds the elevation of the upstream cofferdam, the dam is used to block water, the cofferdam is demolished, and the slag materials after the demolition of the cofferdam are discarded to the waste slag yard.

[0004] From the practical effect, the above measures currently have the following problems:

[0005] (1) The amount of rock for cofferdam filling is large, which will consume a large amount of high-quality excavated rock materials, resulting in a reduction in the available material sources for concrete aggregates. It is necessary to supplement them by means of quarrying materials or purchasing materials externally, causing a great increase in cost and waste of resources.

[0006] (2) A very large waste slag site needs to be arranged for the cofferdam demolition materials, which will occupy the scarce land resources in the high mountain and canyon areas.

[0007] (3) When the cofferdam demolition materials are discarded to the waste slag yard, it is necessary to carry out site surface cleaning, and set up water and soil conservation facilities such as toe-of-slope retaining walls, slope protection, and site intercepting and draining, which requires a large project investment. Summary of the Invention

[0008] The technical problem to be solved by the present invention is: in view of the above problems, to provide a cofferdam structure for taking into account the storage of useful materials and a construction method thereof.

[0009] The technical solution adopted by the present invention is as follows: A cofferdam structure that takes into account the storage of useful materials, having a cofferdam impervious body, and an upstream filling area and a downstream filling area located upstream and downstream of the cofferdam impervious body, is characterized in that: an area for filling useful materials is provided above the phreatic line of the cofferdam body in the downstream filling area, and useful materials to be mined after the demolition of the cofferdam structure are filled in this area for filling useful materials.

[0010] Ordinary material filling areas are provided between the two ends of the area for filling useful materials and the bank slopes on both sides.

[0011] The area for filling useful materials has multiple layers, and ordinary material filling areas are provided between each layer of the area for filling useful materials and the bank slopes on both sides.

[0012] A geomembrane is provided between the area for filling useful materials and the adjacent ordinary material filling areas.

[0013] The side surface of the ordinary material filling area in contact with the area for filling useful materials is a slope surface.

[0014] A construction method for the cofferdam structure that takes into account the storage of useful materials is characterized in that:

[0015] Design the cofferdam structure to determine the type of cofferdam and impervious body;

[0016] Based on the designed cofferdam structure, conduct cofferdam seepage calculation to determine the elevation of the phreatic line of the downstream cofferdam body, and determine the range of the area for filling useful materials according to the range of the impervious body, the elevation of the phreatic line of the cofferdam body, and the shape of the bank slopes on both sides;

[0017] Conduct cofferdam filling construction, and layer by layer fill the area for filling useful materials. When conducting construction of the same layer, first construct the ordinary material filling areas at both ends of the area for filling useful materials, and then construct the area for filling useful materials in the middle.

[0018] The beneficial effects of the present invention are as follows: The present invention provides an area for filling useful materials downstream of the cofferdam impervious body and above the phreatic line of the cofferdam body, and this area for filling useful materials also maintains a certain distance from the bank slopes on both sides, reducing the pollution of the fillers in the area for filling useful materials caused by the sediment carried by river water and groundwater, facilitating the mining of the fillers in the area for filling useful materials after the demolition of the cofferdam, and avoiding waste of resources. When the cofferdam of the present invention is demolished, the fillers in the area for filling useful materials are used as concrete aggregates, serving two purposes with one material, which can greatly save project investment. In the present invention, the side surface of the ordinary material filling area in contact with the area for filling useful materials is a slope surface, and a geomembrane is laid to prevent the mixing and pollution of the high-quality fillers in the area for filling useful materials and the ordinary fillers in the ordinary material filling area. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of the embodiment.

[0020] Figure 2 It is a schematic structural diagram of the downstream side of the embodiment.

[0021] 1, Useful filling material; 2, Cofferdam impervious body; 3, Seepage line of cofferdam body; 4, Ordinary filling material; 5, Slope surface; 6, Geomembrane; 7, Stratification line; 8, Bank slope. Specific implementation mode

[0022] As Figure 1 , 2 shown, this embodiment is a cofferdam structure that takes into account the storage of useful materials, with a cofferdam impervious body, and an upstream filling area and a downstream filling area arranged upstream and downstream of the cofferdam impervious body.

[0023] In this example, the downstream filling area is divided into an upper filling area and a lower filling area. The upper filling area is located above the seepage line of the cofferdam body in the downstream filling area. The upper filling area has a useful material filling area. There are ordinary material filling areas between the two ends of the useful material filling area and the two bank slopes, so that the useful material filling area is kept at a certain distance from the bank slope.

[0024] In this embodiment, the useful material filling area is filled with the filling material (useful filling material) that is prepared to be mined back after the cofferdam is demolished, and the ordinary material filling area is filled with the filling material (ordinary filling material) that is not prepared to be mined back later; the lower filling area and the upstream filling area are filled with ordinary filling material.

[0025] In this embodiment, the upper filling area is a multi-layer structure formed by layered construction. In the middle of each layer structure is the useful material filling area, and the two ends are the ordinary material filling areas. The side surface where the ordinary material filling area contacts the useful material filling area is a slope surface to ensure the structural stability of the previously constructed ordinary material filling area.

[0026] To prevent the mixing of ordinary filling material into the useful filling material, in this example, a geomembrane is laid on the contact surface between the useful filling material and the ordinary filling material (between the lower filling area and the adjacent useful material area, between the useful material areas and the adjacent ordinary material filling areas).

[0027] The specific construction method of this embodiment is as follows:

[0028] a. Conduct the design of the cofferdam structure to determine the types of the cofferdam and the cofferdam impervious body;

[0029] b. Based on the designed cofferdam structure, conduct the seepage calculation of the cofferdam to determine the elevation of the seepage line of the downstream cofferdam body, and determine the range of the useful filling material area according to the range of the impervious body, the elevation of the seepage line, and the shapes of the two bank slopes;

[0030] c. Classify the cofferdam filling materials. The ordinary filling materials are filled into the upstream filling area, the lower filling area, and the ordinary material filling area, and the high-quality useful filling materials are filled into the useful material filling area; strictly control the filling materials, and while meeting the indexes of the cofferdam filling materials, prevent the muddy materials, weathered materials, and materials with relatively low strength from entering the useful material filling area;

[0031] d. When conducting cofferdam filling construction in the useful material filling area, the transport vehicles and compaction equipment entering the filling area shall be washed to avoid polluting the useful materials.

[0032] e. When filling the cofferdam, the downstream filling area shall be constructed with layered compaction according to the above-mentioned layered line. First, construct the lower filling area below the useful material filling area, and then construct the upper filling area. When constructing the upper filling area at the same layer, first construct the ordinary material filling areas on both sides, and then construct the useful material filling area in the middle; a slope shall be set between the ordinary material filling area and the useful material filling area 1 to prevent ordinary fillers from mixing into the useful fillers; when part of the ordinary material filling area is above the useful material filling area, a geomembrane shall be used for separation to prevent ordinary materials from mixing into the useful materials. Figure 2 When demolishing the cofferdam and conducting construction at the same layer, first demolish the useful material filling area in the middle, and then demolish the ordinary material filling areas on both sides. After the useful material filling area is demolished, the useful fillers shall be recovered and processed as concrete aggregates.

[0033]

[0034] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the technical principle of the present invention, several improvements and modifications can be made. For example, in addition to using a geomembrane to isolate the ordinary material and the useful material, a geotextile or other methods can also be used for isolation. These improvements and modifications should also be regarded as the protection scope of the present invention.​

Claims

1. A cofferdam structure that takes into account the storage of useful materials, having a cofferdam impervious body, and an upstream filling area and a downstream filling area located upstream and downstream of the cofferdam impervious body, characterized in that: The upper part of the weir body seepage line in the downstream filling area has a useful material filling area where the filler is intended to be mined after the removal of the cofferdam structure; Ordinary material filling areas are provided between both ends of the useful material filling area and the bank slopes on both sides; The useful material filling area has multiple layers, and ordinary material filling areas are provided between each layer of the useful material filling area and the bank slopes on both sides; A geomembrane is provided between the useful material filling area and the adjacent ordinary material filling area; The side surface of the ordinary material filling area in contact with the useful material filling area is a slope surface.

2. A construction method for the cofferdam structure considering the storage of useful materials according to claim 1, characterized in that: Carry out the design of the cofferdam structure to determine the type of the cofferdam and the cofferdam impervious body; Based on the designed cofferdam structure, carry out the seepage calculation of the cofferdam to determine the elevation of the downstream weir body seepage line of the impervious body, and determine the range of the useful material filling area according to the range of the impervious body, the elevation of the weir body seepage line, and the shape of the bank slopes on both sides; Carry out the cofferdam filling construction, and layer by layer construct the useful material filling area. When carrying out the construction of the same layer, first construct the ordinary material filling areas at both ends of the useful material filling area, and then construct the useful material filling area in the middle.

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