Composite geomembrane joint structure at joint part of diaphragm wall
By introducing structures such as foam boards, waterstops, and connecting rods at the joints of geomembranes, the problem of easy damage to composite geomembrane joints is solved, the stability and seepage prevention effect of the joints are improved, and the seepage prevention performance of the building is ensured.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 中国水利水电第七工程局有限公司
- Filing Date
- 2025-05-13
- Publication Date
- 2026-05-19
AI Technical Summary
In hydraulic structures such as earth-rock dams or earth-rock cofferdams, the joints of composite geomembranes are easily affected by uneven deformation and temperature changes, leading to local stress concentration and cracking at the joints. Furthermore, existing connection methods are difficult to effectively prevent seepage damage.
Foam boards, waterstops, and connecting rods are added to the cast-in-place joint. The foam boards absorb and disperse stress, the waterstops support the geomembrane and act as a second layer of seepage prevention, and the connecting rods connect adjacent concrete caps to prevent displacement. Combined with sand and gravel filling and plastic concrete pouring, a stable joint structure is formed.
It effectively alleviates stress concentration and deformation at the joints of geomembranes, improves the stability and seepage prevention performance of the joints, prevents joint cracking and seepage damage, and enhances the seepage prevention effect of the building.
Smart Images
Figure CN224259280U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of engineering construction technology such as water conservancy, civil engineering and environment, and relates to a composite geomembrane joint structure at the joint of an anti-seepage wall. Background Technology
[0002] For hydraulic structures such as earth-rock dams or cofferdams, a combination of internal seepage control and foundation seepage control is often employed. Due to topographical and geological conditions, the foundations of these structures often suffer from unfavorable conditions such as overburden layers, faults, and weak interlayers. Therefore, high-strength, high-performing underground concrete cutoff walls are typically used for foundation seepage control. Composite geomembranes are often laid inside the structures, which saves on construction costs while effectively achieving seepage control. Ensuring an effective connection between the internal seepage control and foundation seepage control structures is a necessary prerequisite for preventing seepage damage such as contact erosion.
[0003] Taking earth-rock cofferdams as an example, the common connection methods between the top of the underground concrete cutoff wall and the composite geomembrane include casting, welding, and bonding. Casting refers to pouring concrete onto the top of the geomembrane and the cutoff wall to achieve the joint. Due to the limited width of the geomembrane, several sheets are needed in the project, making the joint of the composite geomembrane at the cutoff wall joint a key technical challenge. Therefore, this utility model provides a composite geomembrane joint structure at the cutoff wall joint based on a casting-type joint method between the top of the cutoff wall and the composite geomembrane. Summary of the Invention
[0004] This utility model discloses a composite geomembrane joint structure for the joint of an anti-seepage wall, addressing the shortcomings of existing technologies. By adding foam boards, waterstops, connecting rods, and aggregates to a cast-in-place joint, this utility model prevents damage at the composite geomembrane joint and solves the connection problem between adjacent concrete caps.
[0005] This utility model is achieved through the following technical solution:
[0006] A composite geomembrane joint structure for a seepage barrier wall joint is disclosed. The concrete seepage barrier wall is located at the bottom of a seepage trench formed between two concrete guide walls arranged along the upstream and downstream sides of a river. The structure is characterized by: a superimposed seepage barrier structure being poured and solidified above the concrete seepage barrier wall. The superimposed seepage barrier structure includes a concrete cap, plastic concrete, and a composite geomembrane. The plastic concrete is located in a trench excavated in the middle of the top surface of the concrete seepage barrier wall. The concrete cap is located above the plastic concrete and the concrete seepage barrier wall. The composite geomembrane penetrates and is solidified from the middle of the top surface of the concrete cap to the middle of the bottom surface of the plastic concrete. The superimposed seepage barrier structure has multiple composite geomembrane joint structures spaced at intervals along the longitudinal direction of the concrete seepage barrier wall.
[0007] The composite geomembrane joint structure includes: interface seams spaced longitudinally along the concrete cap and the concrete anti-seepage wall; the composite geomembrane is folded in the interface seams; foam boards are embedded at both ends of the interface seams along the upstream and downstream of the river; and waterstops are embedded longitudinally between the composite geomembrane and the concrete cap along the downstream side of the river.
[0008] Furthermore, each composite geomembrane joint structure is reinforced with pre-fixed connecting rods between adjacent concrete caps along the longitudinal direction of the concrete anti-seepage wall.
[0009] Furthermore, each composite geomembrane joint structure and the gap between the composite geomembrane and the joint are filled with sand and gravel.
[0010] Furthermore, a composite geomembrane joint structure is set at 10-meter intervals along the longitudinal direction of the concrete anti-seepage wall in the upper anti-seepage structure.
[0011] Furthermore, the bottom of the composite geomembrane is folded and fixed in the upstream direction on the plastic concrete bottom surface.
[0012] Furthermore, the width of the joints in the concrete caps, which are set longitudinally along the concrete anti-seepage wall, should be less than or equal to 1 cm.
[0013] This utility model has the following advantages:
[0014] (1) Placing foam boards in the overlapping parts of the geomembrane can act as a buffer. The earth-rock cofferdam is subjected to upstream water pressure, which may cause uneven deformation and easily lead to local stress concentration at the geomembrane joints. Foam boards can absorb and disperse stress, reduce the compression and friction on the overlapping parts of the geomembrane, and thus protect the geomembrane joints from damage.
[0015] (2) For composite geomembranes, temperature changes may cause changes in material properties. Foam boards can reduce the direct impact of external temperature changes on geomembranes and help maintain the stability of geomembranes.
[0016] (3) A waterstop is attached tightly to the downstream side of the composite geomembrane joint. This not only supports the geomembrane and prevents it from deforming, but also prevents the geomembrane joint from cracking, thus providing a second layer of seepage prevention.
[0017] (4) The concrete cap is segmented and a 1cm gap is reserved at the interface to prevent large-volume concrete structures from cracking due to topographical and geological conditions, upstream water pressure and other factors.
[0018] (5) Insert multiple connecting rods into adjacent concrete caps to connect adjacent concrete caps, prevent large relative displacement of adjacent concrete caps, and avoid further damage to the seepage prevention structure of the project.
[0019] (6) After the top of the underground concrete anti-seepage wall is excavated, the trench and the concrete guide walls on both sides are cleaned and smoothed in time, so that the plastic concrete poured in the trench is more firmly bonded to the concrete anti-seepage wall and the guide walls on both sides. Attached Figure Description
[0020] Figure 1 This is a top view of the geomembrane joint structure of this utility model;
[0021] Figure 2 This is a front view of the upstream and downstream direction of the composite geomembrane joint structure at the cap of this utility model;
[0022] Figure 3 This is a front view of the cofferdam along the axis of the composite geomembrane joint structure at the cap of this utility model.
[0023] The markings in the diagram are as follows: 1 is composite geomembrane, 2 is foam board, 3 is waterstop, 4 is concrete cap, 5 is filling sand and gravel, 6 is connecting rod, 7 is plastic concrete in the trench, 8 is underground concrete anti-seepage wall, and 9 is concrete guide wall on both sides. Detailed Implementation
[0024] The present invention will be further described below with reference to specific embodiments. These specific embodiments are further explanations of the principle of the present invention and are not intended to limit the present invention in any way. Any technology that is the same as or similar to the present invention does not exceed the protection scope of the present invention.
[0025] Refer to the attached diagram.
[0026] As shown in the figure, the composite geomembrane joint structure of the anti-seepage wall joint of this utility model includes: composite geomembrane 1, underground concrete anti-seepage wall 8, concrete cap 4, plastic concrete 7, foam board 2, waterstop 3, connecting rod 6, concrete guide wall 9, and filling sand and gravel 5.
[0027] The width of the composite geomembrane 1 used in general is limited, and multiple geomembranes 1 are required to completely cover the area from the left bank to the right bank. In order to accommodate the joints of the composite geomembrane 1, the concrete cap 4 at the top of the underground concrete cutoff wall 8 is segmented, with a unit length of 10m.
[0028] Foam board 2, 1cm thick, is placed between adjacent concrete caps 4 to protect the joint of the composite geomembrane 1 at the joint with the underground concrete anti-seepage wall 8.
[0029] The composite geomembrane 1 is pre-studded to a certain length and inserted into the plastic concrete 7.
[0030] In the concrete cap 4, a waterstop 3 is tightly attached to the downstream side of the joint of the composite geomembrane 1 to prevent water leakage at the joint and to support the joint.
[0031] The composite geomembrane 1 is joined in a specific shape within the foam board 2 and filled with sand and gravel 5 to stabilize the specific shape of the joint.
[0032] After the top of the underground concrete anti-seepage wall 8 is excavated, the groove is cleaned and smoothed in time to make the concrete anti-seepage wall 8 bond more firmly with the plastic concrete 7 poured in the groove.
[0033] Multiple connecting rods 6 are inserted between adjacent concrete caps 4 to prevent large relative displacement between two adjacent concrete caps 4.
[0034] The concrete cap 4 is compacted using a vibrator to ensure that the insertion tool for the composite geomembrane 1 has no edges or sharp corners, thus preventing damage to the geomembrane 1.
[0035] Before pouring the concrete cap 4, the surfaces of the guide walls 9 on both sides are cleaned to ensure that the concrete cap 4 is tightly bonded to the guide walls 9 on both sides.
[0036] This utility model relates to a composite geomembrane joint structure at the joint of a seepage-proof wall. Before constructing this structure, the concrete guide wall 9 and the concrete seepage-proof wall 8 must be completed. After completing the construction of the concrete guide wall 9 and the concrete seepage-proof wall 8, the construction of the composite geomembrane joint structure at the joint of the seepage-proof wall of this utility model is carried out according to the following steps:
[0037] I. Construction Preparation
[0038] 1. Materials and Equipment
[0039] Materials: 1. Composite geomembrane, 2. Plastic concrete, 3. Foam board, 4. Waterstop board, 5. Filling sand and gravel.
[0040] Core equipment: concrete mixing plant, concrete pump, grinding machine, hammer, chisel, plumb bob, and theodolite and other measuring and positioning tools.
[0041] 2. Site Environment
[0042] Confirm the site environment. Before construction begins, it is necessary to understand the working environment, including surrounding facilities, traffic conditions, weather conditions, etc., in order to accurately assess the risks and safety measures for construction.
[0043] 3. Construction schedule and personnel arrangement
[0044] Before construction begins, the construction time and personnel should be determined, and a corresponding plan should be developed to ensure the orderly progress of the construction.
[0045] II. Construction Steps
[0046] 1. Cleaning of the top of the seepage barrier wall and the surfaces of the guide walls on both sides.
[0047] Using a grinding machine and employing a dry grinding method, the sharp cutting edge of the grinding disc is aligned with the top surface of the concrete cut-off wall 8 and the surfaces of the two side concrete guide walls 9 by the power of the rotating grinding disc. The concrete surface is then ground by rotating and moving the grinding disc. The concrete surface is cleaned with a brush, water, and detergent to ensure effective contact between the top of the concrete cut-off wall 8, the two side concrete guide walls 9, and the subsequent concrete cap 7.
[0048] 2. Excavation of the top of the concrete anti-seepage wall
[0049] When selecting a removal method, the construction season and construction patterns must be considered. After determining the excavation range and depth at the top of the concrete cutoff wall, a trench is chiseled at the top of the concrete cutoff wall using a hammer and chisel, according to the design plan. The trench is in the shape of an inverted trapezoid, which facilitates the stability of the concrete poured into the trench later.
[0050] 3. Install geomembrane, foam board, waterstop, and connecting rods.
[0051] like Figure 1 As shown, two geomembranes 1 are placed inside a foam board. The geomembrane 1 at the joint is inverted U-shaped for stability. The foam board 2 is 1cm thick and filled with crushed stone 5 to maintain the shape of the geomembrane 1. The bottom of the foam board 2 is flush with the bottom of the concrete cap 4, and the top is more than 1cm higher than the concrete cap 4. The waterstop 3 is placed on the downstream side of the geomembrane 1 perpendicular to the foam board 2 and is tightly attached to the geomembrane 1, serving to support the geomembrane 1 and act as a second line of defense against seepage. The connecting rod 6 is embedded 1.2m into each of the two concrete caps 4, connecting the two concrete caps 4 and preventing large relative displacement. The ends of the composite geomembrane 1 need to be reserved with a length of 5 to 6cm and are curved to fit tightly against the bottom of the trench.
[0052] 4. Pouring plastic concrete in the trench
[0053] After installing the geomembrane 1, foam board 2, and waterstop 3, plastic concrete 7 is poured in the trench. The pouring location is determined according to the design plan, and a self-leveling pouring method is used to pour in sections, with each section not exceeding 10m in length.
[0054] 5. Concrete cap pouring
[0055] When the plastic concrete 7 in the trench has initially set, immediately begin pouring the concrete cap 4. During this process, ensure that any vibrations or insertion tools have no sharp edges or corners to prevent damage to the geomembrane 1. Monitor the concrete slump at all times and address any abnormalities promptly.
Claims
1. A composite geomembrane joint structure for a seepage barrier wall joint, wherein the concrete seepage barrier wall is set at the bottom of a seepage barrier trench formed between two concrete guide walls arranged upstream and downstream across both banks of a river; characterized in that: A superstructure is poured and solidified above the concrete cutoff wall. The superstructure includes a concrete cap, plastic concrete, and a composite geomembrane. The plastic concrete is located in a groove excavated in the middle of the top surface of the concrete cutoff wall. The concrete cap is located above the plastic concrete and the concrete cutoff wall. The composite geomembrane runs through and is solidified from the middle of the top surface of the concrete cap to the middle of the bottom surface of the plastic concrete. The superstructure has multiple composite geomembrane joints spaced at intervals along the longitudinal direction of the concrete cutoff wall. The composite geomembrane joint structure includes: interface seams spaced longitudinally along the concrete cap and the concrete anti-seepage wall; the composite geomembrane is folded in the interface seams; foam boards are embedded at both ends of the interface seams along the upstream and downstream of the river; and waterstops are embedded longitudinally between the composite geomembrane and the concrete cap along the downstream side of the river.
2. The composite geomembrane joint structure at the joint of the seepage-proof wall according to claim 1, characterized in that: Each composite geomembrane joint structure has pre-fixed reinforcing rods connecting adjacent concrete caps along the longitudinal direction of the concrete cutoff wall.
3. The composite geomembrane joint structure at the joint of the seepage-proof wall according to claim 1, characterized in that: In each composite geomembrane joint structure, the gap between the composite geomembrane and the joint is filled with sand and gravel.
4. The composite geomembrane joint structure at the joint of the seepage-proof wall according to claim 1, characterized in that: A composite geomembrane joint structure is set at 10-meter intervals along the longitudinal direction of the concrete anti-seepage wall in the upper anti-seepage structure.
5. The composite geomembrane joint structure at the joint of the seepage-proof wall according to claim 1, characterized in that: The bottom of the composite geomembrane is folded and fixed upstream from the bottom surface of the plastic concrete.
6. The composite geomembrane joint structure at the joint of the seepage-proof wall according to claim 1, characterized in that: The width of the joints in the concrete caps, spaced longitudinally along the concrete anti-seepage wall, shall be less than or equal to 1 cm.