A cofferdam structure

Abstract

The utility model relates to the cofferdam construction technical field especially relates to a cofferdam structure. The cofferdam structure includes the cover plate, composite geomembrane and cofferdam body. The cover plate sets up on the alluvial-proluvial layer, and the composite geomembrane fixedly connects in the cover plate, and the cofferdam body sets up on the alluvial-proluvial layer, and the composite geomembrane is penetrated in the cofferdam body. Among them, the cover plate is provided with a curtain grouting layer and multiple consolidation grouting layers, and the multiple consolidation grouting layers are symmetrically arranged along the central axis L of the cofferdam structure, the curtain grouting layer is arranged at the central axis L of the cofferdam structure, the curtain grouting layer comprises multiple curtain grouting holes arranged at intervals, and the consolidation grouting layer comprises multiple consolidation grouting holes arranged at intervals. The cofferdam structure provided in the application can directly perform grouting reinforcement on the ground through the curtain grouting holes and the consolidation grouting holes on the cover plate, form a plate-shaped reinforcement area by using controllable consolidation grouting, and does not need to perform large-scale excavation on the alluvial-proluvial layer, thereby reducing the safety risk and saving the cost and time.

Description

Technical Field

[0001] This utility model relates to the field of cofferdam construction technology, and in particular to a cofferdam structure. Background Technology

[0002] Composite geomembrane core wall rockfill cofferdams have advantages such as reliable performance, strong deformation capacity, convenient construction, and low cost. They also avoid the encroachment on local land and environmental slope damage caused by the mining of impermeable soil, which is beneficial to environmental protection. For earth-rock cofferdams built on soft soil foundations of alluvial and diluvial deposits, reinforcement measures such as vibro-compaction, dynamic compaction, replacement, drainage consolidation, and reverse filtration are generally adopted.

[0003] In related technologies, due to the softness of alluvial deposits, composite geomembrane core wall cofferdams are often used in the treatment of deep alluvial deposit foundations. However, the treatment of alluvial deposit foundations often requires large-scale deep foundation pit excavation or complex grouting processes, which poses significant safety risks, high costs, and long construction periods. Utility Model Content

[0004] This application provides a cofferdam structure that improves, to some extent, the technical problems of high safety risks and low efficiency in alluvial and diluvial foundation treatment in related technologies.

[0005] This application provides a cofferdam structure constructed on the alluvial-diluvial layer of a riverbed, the cofferdam structure comprising:

[0006] A cover plate, the cover plate being disposed on the alluvial deposit;

[0007] A composite geomembrane, wherein the composite geomembrane is fixedly connected to the cover plate;

[0008] A weir body, which is set on the alluvial-diluvial deposit, and the composite geomembrane penetrates through the weir body;

[0009] The cover plate is provided with a row of curtain grouting layers and multiple rows of consolidation grouting layers. The multiple rows of consolidation grouting layers are symmetrically arranged along the central axis of the cofferdam structure. The curtain grouting layer is located on the central axis of the cofferdam structure. The curtain grouting layer includes multiple curtain grouting holes arranged at intervals. The consolidation grouting layer includes multiple consolidation grouting holes arranged at intervals.

[0010] In some embodiments, the consolidation grouting holes penetrate 2m into the strongly weathered layer, and the curtain grouting holes penetrate 2m into the weakly weathered layer.

[0011] In some embodiments, the spacing between two adjacent consolidation grouting holes in a row of consolidation grouting layers is 2m, and the spacing between two adjacent rows of consolidation grouting layers is 1.5m.

[0012] In some implementations, multiple consolidation grouting holes are staggered in two adjacent rows of consolidation grouting layers.

[0013] In some embodiments, the distance between two adjacent curtain grouting holes is 2m, and the distance between the curtain grouting layer and the adjacent consolidation grouting layer is 1.5m.

[0014] In some embodiments, the cover plate is provided with an anchoring groove and fasteners, the end of the composite geomembrane is attached to at least part of the inner wall of the anchoring groove, and the fasteners connect the composite geomembrane and the cover plate.

[0015] In some embodiments, the ends of the composite geomembrane are folded, and the folded portions of the composite geomembrane adhere to at least a portion of the inner wall of the anchoring groove.

[0016] In some embodiments, the inner wall of the anchoring groove has an inclined surface, and the end of the composite geomembrane is attached to the inclined surface.

[0017] In some embodiments, the anchoring groove is provided with a filling layer, which compacts the composite geomembrane.

[0018] In some embodiments, a transition layer is provided on both sides of the composite geomembrane, and the transition layer is in contact with the weir body.

[0019] The beneficial effects of this application are as follows:

[0020] In the cofferdam structure provided in this application, since the cover plate is provided with curtain grouting holes and consolidation grouting holes, grouting reinforcement can be carried out directly on the ground surface through the curtain grouting holes and consolidation grouting holes on the cover plate. The controllable consolidation grouting forms a plate-shaped reinforcement zone without the need for large-scale excavation in the alluvial deposits, thereby reducing safety risks and saving costs and time. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model.

[0022] Figure 1 A cross-sectional view of the cofferdam structure is shown.

[0023] Figure 2 This shows a cross-sectional view of the cofferdam structure from another perspective.

[0024] Figure 3 It shows Figure 1 A schematic diagram of the structure of the middle cover plate.

[0025] Figure 4 It shows Figure 1 A magnified view of a portion of point A in the middle.

[0026] Explanation of reference numerals in the attached figures:

[0027] 10-Cofferdam structure, 100-Cover plate, 110-Curtain grouting layer, 111-Curtain grouting hole, 120-Consolidation grouting layer, 121-Consolidation grouting hole, 130-Anchoring groove, 140-Fastener, 141-Stainless steel expansion bolt, 142-Pressure strip, 143-Inclined surface, 144-Filling layer, 150-Mortar anchor, 200-Composite geomembrane, 300-Dyke body, 310-Transition layer, L-Central axis. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] It should be noted that all directional indications in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0032] Please see Figures 1-3This application provides a cofferdam structure 10, constructed on the alluvial-diluvial deposits of a riverbed. These deposits are primarily composed of alluvial materials such as pebbles, sand, or clay, with varying particle sizes, poor roundness, indistinct stratification, high permeability, and a large overburden thickness. The cofferdam structure 10 provided in this application eliminates the need for large-scale excavation within the alluvial-diluvial deposits, thereby reducing safety risks and saving costs and time.

[0033] In this embodiment of the application, the cofferdam structure 10 includes a cover plate 100, a composite geomembrane 200, and a cofferdam body 300. The cover plate 100 is disposed on the alluvial-diluvial deposit, the composite geomembrane 200 is fixedly connected to the cover plate 100, the cofferdam body 300 is disposed on the alluvial-diluvial deposit, and the composite geomembrane 200 penetrates through the cofferdam body 300.

[0034] The cover plate 100 is provided with a row of curtain grouting layers 110 and multiple rows of consolidation grouting layers 120. The multiple rows of consolidation grouting layers 120 are symmetrically arranged along the central axis L of the cofferdam structure 10. The curtain grouting layer 110 is located at the central axis L of the cofferdam structure 10. The curtain grouting layer 110 includes multiple curtain grouting holes 111 arranged at intervals. The consolidation grouting layer 120 includes multiple consolidation grouting holes 121 arranged at intervals.

[0035] The cover plate 100 can be made of reinforced concrete, and its thickness can be designed according to soil conditions and grouting pressure. Surface reinforcement can be installed on the cover plate 100, and mortar anchors 150 can be installed on the bank slope section to enhance the overall structural integrity and stability. The curtain grouting layer 110 and the multi-row consolidation grouting layer 120 are both integrated into the cover plate 100. Cement grout can be applied to the ground through the curtain grouting layer 110 and the multi-row consolidation grouting layer 120 to cement the alluvial deposits into a hard, unified structure, improving the foundation bearing capacity and preventing cofferdam settlement or sliding. The cover plate 100 can distribute grouting pressure, preventing excessive local pressure from penetrating soft soil layers. When installing the cover plate 100, the foundation surface should be cleaned along the ground line first, and then the grouting of the cover plate 100 should be carried out. Mortar anchors 150 can be installed on the bank slope section.

[0036] Multiple rows of consolidation grouting layers 120 are symmetrically arranged along the central axis L of the cofferdam structure 10, meaning that an even number of rows of consolidation grouting layers 120 can be arranged symmetrically along the central axis L of the cofferdam structure 10. Specifically, four rows of consolidation grouting layers 120 can be arranged, with two rows of consolidation grouting layers 120 arranged on each side of the central axis L of the cofferdam structure 10, and a curtain grouting layer 110 arranged in the middle of the four rows of consolidation grouting layers 120. Consolidation grouting holes 121 and curtain grouting holes 111 are used for grouting. Through multi-row controllable consolidation grouting, a reinforced zone is quickly formed, improving the integrity and stability of the alluvial-flood deposit. The curtain grouting in the middle reinforces seepage prevention, forming a dual guarantee mechanism of "shallow rapid consolidation + deep precise seepage prevention". That is, consolidation grouting enhances the stability of the alluvial-flood deposit at the dam foundation, and forms a plate-shaped water-stopping curtain under the action of grout consolidation, reducing the seepage channels in the curtain grouting zone and improving the curtain seepage prevention effect. The composite geomembrane 200 is fixedly connected to the cover plate 100 to form a seepage prevention curtain, which improves the overall integrity and seepage prevention effect, and realizes the organic combination of the grouting curtain and the composite geomembrane 200 curtain.

[0037] Consolidation grouting can utilize a cement-accelerator two-component grout, with the setting time dynamically adjusted according to site conditions to ensure thorough consolidation and rapid solidification, thereby improving construction efficiency. Curtain grouting can employ ultrafine cement grout to form a seepage barrier. Central curtain grouting reinforces seepage prevention and reduces the risk of seepage damage in the consolidated area. Curtain grouting and consolidation grouting complement each other functionally and are spatially integrated. Consolidation grouting provides "shallow reinforcement" as a pretreatment for curtain grouting's "deep seepage prevention," providing the necessary conditions for subsequent curtain grouting. Curtain grouting forms a deep seepage barrier, blocking deep leakage paths and creating a three-dimensional protection system with the shallow consolidated area.

[0038] The dam body 300 can be constructed using riprap, with a riprap slope protection on the upstream water-facing side. The dam body 300 primarily uses stone for filling, which is simple to construct, readily available, and allows for full utilization of excavated material. The riprap slope protection on the upstream water-facing side reduces scouring and erosion, ensuring the stability and safety of the cofferdam structure 10.

[0039] In the cofferdam structure 10 provided in this application, since the cover plate 100 is provided with curtain grouting holes 111 and consolidation grouting holes 121, grouting reinforcement can be carried out directly on the ground surface through the curtain grouting holes 111 and consolidation grouting holes 121 on the cover plate 100. The plate-shaped reinforcement zone is formed by controllable consolidation grouting, without the need for large-scale excavation of deep pits in the alluvial deposits, thereby reducing safety risks and saving costs.

[0040] In some embodiments, the consolidation grouting hole 121 extends 2m into the strongly weathered layer, and the curtain grouting hole 111 extends 2m into the weakly weathered layer.

[0041] The strongly weathered layer and the weakly weathered layer are located in the bedrock under the alluvial-diluvial deposit. The consolidation grouting hole 121 extends 2m below the strongly weathered layer to ensure that the soft soil and the strongly weathered layer are reinforced together. The curtain grouting hole 111 extends 2m below the weakly weathered layer because there are still micro-cracks in the weakly weathered layer, which need to be plugged with ultrafine cement.

[0042] In some embodiments, in a row of consolidated grouting layers 120, the distance between two adjacent consolidated grouting holes 121 is 2m, and the distance between two adjacent rows of consolidated grouting layers 120 is 1.5m. In two adjacent rows of consolidated grouting layers 120, multiple consolidated grouting holes 121 are staggered.

[0043] The consolidation grouting is carried out in two sequences, first grouting the riverbed area and then grouting the bank slope area from left to right. With the cofferdam axis as the center, grouting is carried out from the outside to the inside. The downstream consolidation grouting hole 121 is grouted first, and then the upstream consolidation grouting hole 121 is grouted. The optimization of the construction sequence can make the grout fully grouted and compacted, thus improving the grouting quality.

[0044] In some embodiments, the distance between two adjacent curtain grouting holes 111 is 2m, and the distance between the curtain grouting layer 110 and the adjacent consolidation grouting layer 120 is 1.5m.

[0045] Consolidation grouting has a lower pressure, while curtain grouting has a higher pressure. Consolidation grouting can be carried out first, followed by curtain grouting. Through differentiated design of materials and pressures and optimization of construction sequence, precise control of shallow reinforcement and deep seepage prevention can be achieved, solving the problem of needing both foundation reinforcement and seepage prevention on deep alluvial layers.

[0046] Please see Figure 1 and Figure 4 In some embodiments, the cover plate 100 is provided with anchoring grooves 130 and fasteners 140. The end of the composite geomembrane 200 is attached to at least part of the inner wall of the anchoring groove 130. The fasteners 140 connect the composite geomembrane 200 and the cover plate 100, thereby mechanically connecting the composite geomembrane 200 and the cover plate 100. The composite geomembrane 200 and the grouting curtain are organically combined to form a seepage barrier. By connecting the anchoring groove 130 integrated on the grouting cover plate 100 with the upper seepage-proof composite geomembrane 200 as a whole, the organic combination of the grouting curtain and the composite geomembrane 200 curtain is achieved. The integrated design of the anchoring groove 130 and the grouting cover plate 100 reduces the construction difficulty and improves the anchoring reliability of the composite geomembrane 200.

[0047] Specifically, the dimensions of the anchoring groove 130 can be determined according to the seepage level of the cofferdam. The fasteners 140 may include stainless steel expansion bolts 141 and pressure strips 142. The thickness of the pressure strip 142 is greater than or equal to 3mm, and the width is 50mm to 80mm. The periphery of the pressure strip 142 is filled tightly with polysulfide sealant. The ends of the composite geomembrane 200 can be folded, and the folded portion of the composite geomembrane 200 is attached to at least part of the inner wall of the anchoring groove 130.

[0048] In some embodiments, the inner wall of the anchoring groove 130 has a slope 143, and the end of the composite geomembrane 200 is attached to the slope 143, thereby increasing the contact area between the end of the composite geomembrane 200 and the anchoring groove 130 to improve the connection strength. Specifically, the anchoring groove 130 may be a right trapezoidal shape.

[0049] In some embodiments, a filling layer 144 is provided inside the anchoring groove 130, and the filling layer 144 is compacted to form a composite geomembrane 200. The filling layer 144 can be fine aggregate concrete, that is, the anchoring groove 130 is filled with fine aggregate concrete and compacted to ensure that the ends of the composite geomembrane 200 are embedded in the anchoring groove 130 after welding to form a closed seepage-proof body.

[0050] In some embodiments, a transition layer 310 is provided on both sides of the composite geomembrane 200, and the transition layer 310 is in contact with the weir body 300.

[0051] The two sides of the composite geomembrane 200 are the upstream and downstream of the composite geomembrane 200. The transition layer 310 can be made of graded sand and gravel (particle size ≤ 80mm). Fine-particle materials are selected on the side close to the composite geomembrane 200, and the outer side gradually transitions to coarse-particle materials to form a filter layer between the rockfill and the composite geomembrane 200 to protect the composite geomembrane 200 from damage and prevent seepage.

[0052] In summary, the beneficial effects of this application are as follows:

[0053] 1) Simple structure and convenient construction: This utility model is based on alluvial and diluvial foundation, avoiding the need for large-scale deep foundation pit excavation or complex grouting process. The construction is simple and quick, reducing safety risks and construction costs, and shortening the construction period. It is suitable for cofferdam projects with deep soft foundation.

[0054] 2) Significant effects and good synergy: Curtain grouting and consolidation grouting complement each other functionally and are spatially integrated. Through differentiated design of materials and pressure, as well as optimization of construction sequence, they meet the needs of rapid consolidation and efficient seepage prevention in alluvial deposits, forming a triple guarantee mechanism of "shallow rapid consolidation + deep precise seepage prevention + organic combination of composite geomembrane". The grouting effect is highly efficient and the synergistic performance is excellent.

[0055] 3) Green and environmentally friendly, energy-saving and emission-reducing: It avoids large-scale foundation pit excavation and support and drainage. The composite geomembrane 200 anti-seepage wall avoids the encroachment of anti-seepage soil material mining on local land and environmental slope damage, which is conducive to environmental protection.

[0056] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0057] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A cofferdam structure constructed on the alluvial-diluvial layer of a riverbed, characterized in that, The cofferdam structure includes: A cover plate, the cover plate being disposed on the alluvial deposit; A composite geomembrane, wherein the composite geomembrane is fixedly connected to the cover plate; A weir body, which is set on the alluvial-diluvial deposit, and the composite geomembrane penetrates through the weir body; The cover plate is provided with a row of curtain grouting layers and multiple rows of consolidation grouting layers. The multiple rows of consolidation grouting layers are symmetrically arranged along the central axis of the cofferdam structure. The curtain grouting layer is located on the central axis of the cofferdam structure. The curtain grouting layer includes multiple curtain grouting holes arranged at intervals. The consolidation grouting layer includes multiple consolidation grouting holes arranged at intervals.

2. The cofferdam structure according to claim 1, characterized in that, The consolidation grouting holes penetrate 2m into the strongly weathered layer, and the curtain grouting holes penetrate 2m into the weakly weathered layer.

3. The cofferdam structure according to claim 1, characterized in that, In a row of the consolidated grouting layers, the distance between two adjacent consolidated grouting holes is 2m, and the distance between two adjacent rows of consolidated grouting layers is 1.5m.

4. The cofferdam structure according to claim 1, characterized in that, In two adjacent rows of consolidation grouting layers, multiple consolidation grouting holes are staggered.

5. The cofferdam structure according to claim 1, characterized in that, The distance between two adjacent curtain grouting holes is 2m, and the distance between the curtain grouting layer and the adjacent consolidation grouting layer is 1.5m.

6. The cofferdam structure according to any one of claims 1-5, characterized in that, The cover plate is provided with anchoring grooves and fasteners. The end of the composite geomembrane is attached to at least part of the inner wall of the anchoring groove. The fasteners connect the composite geomembrane and the cover plate.

7. The cofferdam structure according to claim 6, characterized in that, The ends of the composite geomembrane are folded, and the folded portion of the composite geomembrane adheres to at least a portion of the inner wall of the anchoring groove.

8. The cofferdam structure according to claim 6, characterized in that, The inner wall of the anchoring groove has an inclined surface, and the end of the composite geomembrane is attached to the inclined surface.

9. The cofferdam structure according to claim 6, characterized in that, The anchoring groove is provided with a filling layer, which compacts the composite geomembrane.

10. The cofferdam structure according to any one of claims 1-5, characterized in that, The composite geomembrane has transition layers on both sides, and the transition layers are in contact with the weir body.

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