Emergency riverbed water retaining weir suitable for underwater construction

Abstract

The utility model provides an emergency riverbed water retaining weir adapting to underwater construction, including residual weir body and residual cutoff wall in residual weir body, residual weir body top lays reinforced geotextile, reinforced geotextile is in close contact with residual cutoff wall top, sets up weir body main part on reinforced geotextile, and the weir body main part is formed by geotextile bag filling, fills sand material in geotextile bag, sets up composite geomembrane in the inside of the upstream side of weir body main part, one end of composite geomembrane is connected with reinforced geotextile, the other end of composite geomembrane extends to the top of weir body main part, and sets up slope foot counterpressure body on the downstream side of weir body main part. The utility model utilizes the pivot construction period left original downstream cofferdam plastic concrete cutoff wall and residual weir body as the foundation of new water retaining weir, avoids the large amount of earthwork excavation and backfill engineering needed for completely new foundation, significantly reduces the engineering quantity, shortens the construction period, maximizes the saving of engineering investment, realizes the effective utilization to the existing resources.

Description

Technical Field

[0001] This utility model relates to the field of reinforcement technology for flood-damaged dams, specifically to an emergency riverbed dam adapted for underwater construction. Background Technology

[0002] In some downstream areas of rivers, continuous riverbed erosion combined with drought has resulted in actual water levels significantly lower than the original design operating levels under medium and low flow conditions, posing a serious threat to the safety and normal operation of water conservancy projects. The fundamental solution lies in controlling further downstream riverbed erosion or effectively raising the water level downstream of the project. Constructing emergency backwater weirs downstream of the project in a timely manner is the preferred emergency measure for rapidly raising water levels and alleviating the current predicament.

[0003] When selecting the axis for the layout of a flood-retaining weir, the further downstream the axis is, the more drastic the riverbed evolution becomes, and the larger the required weir body. Therefore, from the perspective of economy and engineering rationality, the axis of the emergency flood-retaining weir should be located as close as possible to the key project. At the same time, it is necessary to ensure that the upstream and downstream river channels are straight to avoid adverse effects on navigation safety and flood discharge sections. However, how to quickly and reliably construct an emergency flood-retaining weir that integrates stability and seepage prevention under underwater construction conditions is an urgent problem to be solved. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by providing an emergency riverbed impoundment weir adapted for underwater construction. It utilizes the plastic concrete anti-seepage wall and residual weir body of the original downstream cofferdam left over from the construction phase of the project as the foundation for the new impoundment weir, avoiding the large amount of earthwork excavation and backfilling required for completely new foundations. This significantly reduces the amount of work, shortens the construction period, saves the maximum amount of project investment, and achieves effective utilization of existing resources.

[0005] To address the aforementioned technical problems, this utility model provides an emergency riverbed impoundment weir adapted for underwater construction, comprising a residual weir body and a residual anti-seepage wall within the residual weir body. A reinforced geotextile is laid on top of the residual weir body, and the reinforced geotextile is tightly attached to the top of the residual anti-seepage wall. The main body of the weir body is mounted on the reinforced geotextile and is formed by filling geotextile bags with sand. A composite geomembrane is installed inside the upstream side of the main body of the weir body, with one end connected to the reinforced geotextile and the other end extending to the top of the main body of the weir body. A counterweight body is installed at the downstream side of the main body of the weir body.

[0006] In some embodiments, one end of the composite geomembrane wraps around the geotextile bag of the main body of the dam, and the other end of the composite geomembrane extends to the top of the main body of the dam and then extends downward to 0.5m below the top of the main body of the dam and is laid horizontally to the downstream side of the main body of the dam.

[0007] In some embodiments, the reinforced geotextile includes a geotextile body and a plurality of reinforcing strips, the reinforcing strips being fixed to the geotextile body and having a plurality of tie strips disposed on the reinforcing strips.

[0008] In some embodiments, the reinforcing strip is a steel strand.

[0009] In some embodiments, the geotextile bags are staggered and filled.

[0010] In some embodiments, the geobags are filled with sand using a hydraulic filling method.

[0011] In some embodiments, the sand material is fine sand material, wherein the content of particles with a diameter greater than 0.075 mm in the fine sand material exceeds 50%, and the content of clay particles is less than 10%.

[0012] In some embodiments, the composite geomembrane has a two-layer fabric-one-layer membrane structure, comprising two layers of nonwoven fabric and a geomembrane between the two layers of nonwoven fabric.

[0013] In some embodiments, the slope of the downstream side of the slope toe counterweight is less than the slope of the downstream side of the main body of the weir.

[0014] In some embodiments, the slope toe counterweight is composed of multiple bags of sand laid down.

[0015] The beneficial effects of this utility model are as follows: 1. This utility model utilizes the plastic concrete anti-seepage wall and residual weir body of the original downstream cofferdam left over from the construction period of the hub as the foundation for the new impoundment weir, avoiding the large amount of earthwork excavation and backfilling required for completely new foundation construction, significantly reducing the amount of work, shortening the construction period, saving the maximum amount of project investment, and realizing the effective utilization of existing resources.

[0016] 2. The main body of the dam of this utility model is formed by filling and molding standardized and modular geotextile bags. Large-scale laying equipment can be used to quickly construct the main body of the dam underwater, which is particularly suitable for emergency situations such as flood control and disaster relief.

[0017] 3. This utility model, by laying reinforced geotextile and utilizing the residual weir as a foundation, has lower requirements for underwater foundation conditions and is suitable for adverse geological conditions.

[0018] 4. This utility model forms a complete and closed seepage prevention system through the tight connection of composite geomembrane, geotextile and residual seepage barrier wall, which can effectively raise the water level downstream of the hub.

[0019] 5. The main body of the dam of this utility model is constructed by staggered filling with geotextile bags, and a counterweight body is set on the downstream side of the main body of the dam toe, which increases the weight of the downstream toe, effectively resists the scouring and sliding force of the water flow, and ensures the overall stability and scouring resistance of the dam body under the action of water flow. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Attached reference numerals: 1-Reinforced geotextile; 2-Composite geomembrane; 3-Geotextile bag; 4-Slope toe counterweight; 5-Residual impermeable wall; 6-Residual weir; Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] This utility model provides an emergency riverbed impoundment weir adapted to underwater construction. It fully utilizes the original downstream cofferdam plastic concrete anti-seepage wall (i.e., residual anti-seepage wall 5) and residual weir body 6 left over from the project construction period as a foundation, upon which the impoundment weir is constructed. This method features a small workload, short construction period, and minimal investment. When determining the specific structural form of the impoundment weir, common sealing schemes include combinations of stone chips and boulders, combinations of bagged sand and membrane bag concrete, and geotextile bags 3. Through comprehensive analysis and comparison of multiple factors such as economic cost, project benefits, environmental impact, geological conditions, and construction feasibility, the geotextile bag 3 scheme was ultimately selected as the implementation plan due to its strong adaptability to foundation deformation, good impoundment effect, and the most economical option (it can directly utilize abundant fine sand resources near the project site for filling).

[0024] like Figure 1 As shown, the emergency riverbed impoundment weir includes a residual weir body 6 and a residual anti-seepage wall 5 in the residual weir body 6. The residual weir body 6 is provided with a reinforced geotextile 1, the main body of the weir body, and the slope toe counterweight body 4 from top to bottom.

[0025] The reinforced geotextile 1 is laid on top of the residual weir 6, and is tightly attached to the top of the residual anti-seepage wall 5 to ensure the anti-seepage effect of the emergency riverbed impoundment weir. The reinforced geotextile 1 includes a geotextile body and multiple reinforcing strips. The reinforcing strips are fixed to the geotextile body and have multiple tie strips. The reinforcing strips are made of steel strands. The unit area weight of the geotextile body is not less than 300g. The reinforcing strips are arranged at 4m intervals inside to enhance the overall integrity. A tie strip is set every 8m interval on the reinforcing strip to facilitate the connection between the reinforced geotextile 1 and the geotextile bag 3.

[0026] The main body of the dam is set on reinforced geotextile 1. The main body of the dam is formed by staggered filling of geotextile bags 3. The slope of its upstream and downstream side slopes is 1:3, the top width is 10m, and the planar dimensions of a single geotextile bag 3 are 8m×4m. The geotextile bags 3 are filled with sand using the hydraulic filling method. After filling and forming, the thickness of the geotextile bag 3 is about 0.5m. The sand is fine sand, and the content of particles with a diameter greater than 0.075mm in the fine sand exceeds 50%, while the content of clay particles is less than 10%.

[0027] A composite geomembrane 2 is installed inside the upstream side of the main dam body. The composite geomembrane 2 is positioned 2m vertically from the designed upstream slope. One end of the composite geomembrane 2 wraps around the geotextile bag 3 of the main dam body and connects to the reinforced geotextile 1. The end of the composite geomembrane 2 connected to the reinforced geotextile 1 is pressed against the clamping geotextile by the geotextile bag 3, ensuring a tight fit between the composite geomembrane 2 and the reinforced geotextile 1. The other end of the composite geomembrane 2 extends to the top of the main dam body and then downwards to 0.5m below the top of the main dam body, horizontally laid to the downstream side of the main dam body. This ensures seepage prevention on the upstream side and top of the emergency riverbed impoundment weir, and also ensures the composite geomembrane 2 is stably fixed within the main dam body. The composite geomembrane 2 has a two-layer fabric-one-membrane structure, consisting of two layers of non-woven fabric and a geomembrane between them. The non-woven fabric has a specification of 250g / m³. 2 The geomembrane is a 0.5mm thick PE geomembrane.

[0028] The slope counterweight 4 is located on the downstream side of the main weir body. The slope of the downstream side of the slope counterweight 4 is 1:2.5, which is less than the slope of the downstream side of the main weir body, ensuring the overall stability and scour resistance of the weir body under the action of water flow. The slope counterweight 4 is composed of multiple bags of sand. The bags are filled with medium-coarse sand, with a particle size greater than 0.25mm accounting for more than 50% and a clay content of less than 5%. The weight of a single bag of sand is more than 150kg.

[0029] The construction steps for this emergency riverbed impoundment weir include: First, barges equipped with grab dredgers were used to perform preliminary leveling of the surface of the remaining weir body 6, forming a relatively stable construction base.

[0030] Subsequently, using a positioning and laying vessel, combined with GPS tracking and positioning technology, and with the assistance of divers conducting underwater surveys and inspections when necessary, the pre-processed reinforced geotextile 1 was precisely laid within the designed dam foundation area.

[0031] On top of the laid reinforced geotextile 1, geotextile bags 3 are used to fill the dam body in layers from bottom to top with staggered joints to form the main body of the dam. The slope of the upstream and downstream sides of the main body of the dam body is 1:3 and the top width is 10m.

[0032] When the main body of the dam is filled to the predetermined elevation (2m vertical distance from the upstream slope of the design), the composite geomembrane 2 is laid. It is laid from 2m from the upstream slope toe, and then laid upstream to cover the top of the dam, and then extended downward to 0.5m below the top of the dam.

[0033] During the laying process, it is essential to ensure that the composite geomembrane 2, the reinforced geotextile 1, and the residual anti-seepage wall 5 are tightly connected or effectively overlapped, thereby forming a complete and closed anti-seepage system.

[0034] Finally, at the downstream toe of the main dam body, bagged sand is dumped to form a 15m wide counterweight body 4. This counterweight body 4 serves as a ballast and erosion protection slope, with a slope ratio controlled at 1:2.5. The dumping should be as compacted and level as possible to effectively resist water erosion.

[0035] By following the steps above, an emergency riverbed impoundment weir with reliable seepage prevention and structural stability can be quickly and efficiently constructed in the water.

[0036] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An emergency riverbed impoundment weir adapted for underwater construction, characterized in that: The structure includes a residual dam body (6) and a residual anti-seepage wall (5) within the residual dam body (6). A reinforced geotextile (1) is laid on the top of the residual dam body (6). The reinforced geotextile (1) is in close contact with the top of the residual anti-seepage wall (5). The main body of the dam body is set on the reinforced geotextile (1). The main body of the dam body is formed by filling geotextile bags (3). The geotextile bags (3) are filled with sand. A composite geomembrane (2) is set inside the upstream side of the main body of the dam body. One end of the composite geomembrane (2) is connected to the reinforced geotextile (1). The other end of the composite geomembrane (2) extends to the top of the main body of the dam body. A slope toe counterweight (4) is set on the downstream side of the main body of the dam body.

2. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: One end of the composite geomembrane (2) wraps around the geotextile bag (3) of the main body of the dam. The other end of the composite geomembrane (2) extends to the top of the main body of the dam and then extends downward to 0.5m below the top of the main body of the dam and is laid horizontally to the downstream side of the main body of the dam.

3. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The reinforced geotextile (1) includes a geotextile body and a plurality of reinforcing strips. The reinforcing strips are fixed on the geotextile body and a plurality of tie strips are provided on the reinforcing strips.

4. The emergency riverbed impoundment weir adapted for underwater construction according to claim 3, characterized in that: The reinforcing strip is a steel strand.

5. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The geotextile bags (3) are filled with staggered joints.

6. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The geotextile bag (3) is filled with sand using the hydraulic filling method.

7. The emergency riverbed impoundment weir adapted for underwater construction according to claim 6, characterized in that: The sand material is fine sand, in which the content of particles with a diameter greater than 0.075mm exceeds 50% and the content of clay particles is less than 10%.

8. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The composite geomembrane (2) has a two-layer fabric and one-layer membrane structure. The composite geomembrane (2) includes two layers of non-woven fabric and a geomembrane between the two layers of non-woven fabric.

9. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The slope of the downstream side of the slope toe counterweight (4) is less than the slope of the downstream side of the main body of the weir.

10. The emergency riverbed impoundment weir adapted for underwater construction according to claim 1, characterized in that: The slope toe counterweight (4) is made up of multiple bags of sand.

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