Water blocking film structure attached outside soil facing surface of diaphragm wall and construction method of water blocking film structure

Abstract

The invention discloses an underground diaphragm wall soil facing surface external water blocking film structure and a construction method thereof.The underground diaphragm wall soil facing surface external water blocking film structure comprises a plurality of unit film blocks, the unit film blocks are attached to the underground diaphragm wall soil facing surface, the unit film blocks are arranged in a circle in the circumferential direction of the underground diaphragm wall, and each unit film block is provided with two opposite adjacent sides; the lower ends of the unit modules are connected to a reinforcement cage of the diaphragm wall through rope buckles, and the lower ends of the unit modules are buried in an impervious layer below a permeable layer; the splicer comprises two connecting plates, one sides of the two connecting plates are in lap joint with the adjacent sides of the two adjacent unit modules, hook plates are formed on the other sides of the connecting plates, the hook plates of the two connecting plates are connected together in a buckled mode, and a sealing piece is arranged between the two hook plates in a cushioned mode. The problem that water seepage exists when an existing subway station outer wall structure adopts a laminated wall system is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly relates to a water-blocking film structure externally attached to the soil-facing surface of a diaphragm wall and a construction method thereof. Background Art

[0002] Since subway stations usually adopt a structural self-waterproof design, that is, relying on the self-seepage resistance performance of structural concrete to resist the erosion of long-term groundwater. In recent years, although the construction level has been continuously improved and the management methods have been continuously improved, the leakage of the station structure still exists, which brings many difficulties to the operation and structural durability after completion, and also increases a lot of economic costs for leakage plugging and maintenance.

[0003] The reason lies in that the outer wall structure of the subway station adopts a composite wall system. The diaphragm wall on the outside of the composite wall system is used as a soil retaining and enclosing wall during the foundation pit excavation stage, and during the structural construction stage, an inner lining side wall is constructed on its inner side to form a composite side wall, which jointly bears the force as the basement exterior wall in the permanent use stage. This design can reduce the reinforcement of the basement exterior wall compared with the case of separating the two walls, saving construction costs, but the disadvantage is that it is impossible to construct a waterproof layer on the outside of the basement exterior wall. Since the diaphragm wall concrete adopts an underwater casting process, it is easy to be muddy, and structural cracks are also likely to occur during the construction process of the inner lining structure due to the influence of unstable strata. The inability to apply an external waterproof layer to the composite wall system is the main reason for the water seepage of the station. Summary of the Invention

[0004] In order to overcome the defects existing in the prior art, the present invention provides a water-blocking film structure externally attached to the soil-facing surface of a diaphragm wall and a construction method thereof, so as to solve the problem of water seepage in the existing composite wall system for the outer wall structure of subway stations.

[0005] To achieve the above object, a water-blocking film structure externally attached to the soil-facing surface of a diaphragm wall is provided, including:

[0006] A plurality of unit film blocks, the unit film blocks are attached to the soil-facing surface of the diaphragm wall, the plurality of unit modules are arranged in a circle along the circumferential direction of the diaphragm wall, the unit film block has two adjacent sides, the lower end of the unit film block is connected to the steel reinforcement cage of the diaphragm wall through a rope buckle, and the lower end of the unit module is buried in an impervious layer below the permeable layer;

[0007] A connector, including two connecting plates, one side of the two connecting plates overlaps on one adjacent side of two adjacent unit film blocks, a hook plate is formed on the other side of the connecting plate, the hook plates of the two connecting plates are buckled and connected together, and a sealing member is provided between the two hook plates.

[0008] Further, one side of the connecting plate is connected to the adjacent side of the unit film block through a rivet.

[0009] Further, the connecting plate is connected to the hook plate through an arc-shaped plate. The inner arc surface of the arc-shaped plate faces the hook opening of the hook plate, and the adjacent side of the unit membrane block is arranged opposite to the outer arc surface of the arc-shaped plate.

[0010] Further, the unit membrane block is an HDPE membrane.

[0011] Further, the seal is a water-swellable waterstop strip.

[0012] Further, the number of the seals is multiple, and the multiple seals are continuously arranged along the length direction of the gap between the two hook plates.

[0013] Further, the width of the unit membrane block is adapted to the width of the diaphragm wall.

[0014] The present invention provides a construction method for a water-blocking membrane structure externally attached to the soil-facing side of a diaphragm wall, including the following steps:

[0015] Lap one connecting plate of the joint device on each of the two adjacent sides of the unit membrane block;

[0016] During the construction of the diaphragm wall, hoist the steel reinforcement cage of the diaphragm wall, and connect the lower end of the unit membrane block to the steel reinforcement cage through a rope buckle, so that the unit membrane block fits on the outer side of the steel reinforcement cage;

[0017] Lower the steel reinforcement cage together with the unit membrane block into the trench, so that the lower end of the unit module extends into the impervious layer below the permeable layer;

[0018] Pour concrete in the trench, and the concrete coats the steel reinforcement cage to solidify and form a diaphragm wall, so that the unit membrane block fits on the outer side of the diaphragm wall;

[0019] During the construction of the next diaphragm wall, insert the hook plate of the connecting plate of the joint device on the unit membrane block on the next diaphragm wall into the hook opening of the hook plate of the connecting plate of the joint device on the already poured diaphragm wall. After the steel reinforcement cage of the next diaphragm wall is lowered, the two hook plates of the joint device are buckled together.

[0020] The beneficial effects of the present invention are as follows. For the water-blocking membrane structure externally attached to the soil-facing side of the diaphragm wall of the present invention, during the hoisting process of the steel reinforcement cage of the diaphragm wall, the soil-facing side is lowered synchronously. The placement depth of the water-blocking membrane structure externally attached to the soil-facing side of the diaphragm wall of the present invention is determined according to the formation conditions and the ultrasonic detection conditions of the diaphragm wall trench, so as to cut off the depth range of the permeable layer and the depth range of the collapse of the trench wall during grooving, achieving the effects of blocking the horizontal groundwater seepage path and reducing the over-excavation of the diaphragm wall concrete. The connection nodes of the water-blocking membrane structure externally attached to the soil-facing side of the diaphragm wall of the present invention are reliable, easy to construct in practice, and have good waterproof performance. Description of the Drawings

[0021] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings:

[0022] Figure 1 It is a schematic structural view of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall according to an embodiment of the present invention.

[0023] Figure 2 It is a schematic structural view of the connector according to an embodiment of the present invention.

[0024] Figure 3 It is a front view of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall according to an embodiment of the present invention.

[0025] Figure 4 It is a schematic view of the lowering state of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall according to an embodiment of the present invention.

[0026] Figure 5 It is a front schematic view of the lowering state of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall according to an embodiment of the present invention.

[0027] Figure 6 It is a schematic view of the lowering depth of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall according to an embodiment of the present invention. Detailed implementation manners

[0028] The present application will be further described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. Additionally, it should be noted that for the sake of description, only parts related to the invention are shown in the drawings.

[0029] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0030] Referring to Figures 1 to 6 As shown, the present invention provides a water-blocking film structure externally attached to the soil-facing side of the diaphragm wall, including a unit film block 1 and a connector 2.

[0031] In this embodiment, the number of unit film blocks 1 is multiple. Each unit film block 1 is attached to the soil-facing side of the diaphragm wall. The multiple unit modules are arranged in a circle along the circumferential direction of the diaphragm wall, forming a closed ring on the outer side of the diaphragm wall.

[0032] Specifically, the unit film block 1 has two adjacent sides opposite to each other in its width direction. The lower end of the unit film block 1 is connected to the steel reinforcement cage 4 of the diaphragm wall through a rope buckle 5. The lower end of the unit module is buried in the impervious layer below the permeable layer.

[0033] During installation, referring to Figure 3As shown, the upper end of the unit membrane block is connected to the balance beam through a rope buckle. The balance beam is hung on the sling of the hoisting machinery, so that the unit membrane block and the steel reinforcement cage of the diaphragm wall are lowered into the trench together.

[0034] The connector 2 includes two connecting plates 21. Among them, one side of the two connecting plates 21 overlaps on an adjacent side of two adjacent unit membrane blocks 1. The other side of the connecting plate 21 is formed with a hook plate 22. Refer to Figure 2 As shown, the hook plates 22 of the two connecting plates 21 are buckled and connected together. A sealing member 24 is provided between the two hook plates 22.

[0035] As a preferred embodiment, in combination with Figure 2 and Figure 3 As shown, one side of the connecting plate 21 is connected to the adjacent side of the unit membrane block 1 through a rivet 25.

[0036] Continue to refer to Figure 2 As shown, in this embodiment, the connecting plate 21 is connected to the hook plate 22 through an arc plate 23. The inner arc surface of the arc plate 23 faces the hook opening of the hook plate 22. The adjacent side of the unit membrane block 1 is arranged opposite to the outer arc surface of the arc plate 23. Through the setting of the arc plate, two adjacent unit membrane blocks are arranged coplanarly.

[0037] As a preferred embodiment, the connecting plate, the arc plate and the hook plate are integrally bent and formed from galvanized water-stop steel plates.

[0038] As a preferred embodiment, the unit membrane block 1 is an HDPE membrane. The unit membrane block serves as an external water-blocking membrane for the diaphragm wall and is made of high-density polyethylene material (HDPE), which has high tensile strength and high ductility. Even if the formation undergoes settlement and displacement, the external water-blocking membrane will not break. Since the high-density polyethylene material is transported to the construction site as a coil, its length and width do not match the width and length of the underground continuous wall, and it is necessary to carry out length extension construction at the construction site. The external water-blocking membrane adopts hot-melt lap joint construction.

[0039] The length of the unit membrane block is determined according to the depth of the permeable layer to be blocked. It is required that the unit membrane block completely blocks the permeable layer, and the lower part enters the impermeable layer by at least 3 meters (as Figure 3 shown).

[0040] In this embodiment, the width of the unit membrane block 1 is adapted to the width of the diaphragm wall. The width of the unit membrane block is determined according to the width of the underground continuous wall. At the same time, certain construction errors need to be considered, and it should be 3 cm wider than the width of the diaphragm wall.

[0041] Holes need to be drilled at the top and bottom of the unit membrane block for threading the rope buckle, connecting to the balance beam or tying to the steel reinforcement cage of the underground continuous wall, so as to be easily lifted into the trench together with the steel reinforcement cage of the underground continuous wall.

[0042] In this embodiment, the seal 24 is a water-swelling waterstop strip. A water-swelling waterstop strip is provided in the gap between the two hook plates of the connector, which can expand automatically under the action of groundwater to block the leakage path at the joint.

[0043] The number of seals 24 is multiple. The multiple seals 24 are arranged continuously along the length direction of the gap between the two hook plates 22.

[0044] In this embodiment, first, the diaphragm wall reinforcement cage is hoisted. When the reinforcement cage is lowered into the trench, the unit membrane module is hoisted synchronously. The unit membrane module is placed on the soil-facing side of the diaphragm wall and hoisted by a truck crane. Since holes are made at the top of the water-blocking membrane, it is connected to the hoisting spreader through a perforated rope buckle, and the externally attached water-blocking membrane is suspended to the corresponding height of the reinforcement cage. At the same time, holes are made at the bottom of the unit membrane module and it is connected to the reinforcement cage through a rope buckle, which can ensure that during the process of the diaphragm wall reinforcement cage and the unit membrane module being lowered into the trench synchronously, the unit membrane module can overcome the friction force in the hook opening of the hook plate under the self-weight of the reinforcement cage, ensuring that the two hook plates of the connector are successfully interlocked and lowered in place.

[0045] Unit membrane modules are provided on the outer sides of all diaphragm walls and are interconnected in place. Finally, multiple unit membrane modules enclose a closed system, blocking the horizontal groundwater leakage path of the basement exterior wall. Even if there are fine cracks in the structural concrete due to unstable strata, the basement exterior wall will not leak under the action of external water pressure.

[0046] At the same time, since the unit membrane module plays a role in controlling the flow of concrete similar to a formwork during the casting of the diaphragm wall concrete, it avoids the problem of excessive concrete casting (overbreak) caused by the concrete flowing around and the collapse of the trench wall during the construction of the diaphragm wall.

[0047] The present invention provides a construction method for an externally attached water-blocking membrane structure on the soil-facing side of a diaphragm wall, including the following steps:

[0048] S1. Lap one connecting plate 21 of the connector 2 on each of the two adjacent sides of the unit membrane module 1.

[0049] In this embodiment, since the high-density polyethylene material is transported to the construction site in the form of a coil, its length and width do not match the width and length of the diaphragm wall, and splicing construction needs to be carried out on the construction site. The externally attached water-blocking membrane uses hot-melt splicing construction.

[0050] The connector is made of galvanized waterstop steel plate, bent into a hook shape, and the cross-section is a chute that can be interlocked with each other. The hook opening of the hook plate of the connector is provided with a water-swelling waterstop material, which can expand automatically under the action of groundwater to block the leakage path at the joint.

[0051] Connectors need to be provided on both sides of the unit membrane module. The hook plates of the connectors on both sides of the unit membrane module face in opposite directions to ensure self-locking with subsequent joints.

[0052] S2. When constructing the diaphragm wall, hoist the steel reinforcement cage 4 of the diaphragm wall, and connect the lower end of the unit membrane block 1 to the steel reinforcement cage 4 through a rope buckle 5, so that the unit membrane block 1 fits on the outer side of the steel reinforcement cage 4;

[0053] S3. Lower the steel reinforcement cage 4 together with the unit membrane block 1 into the trench, so that the lower end of the unit module extends into the impervious layer below the pervious layer.

[0054] S4. Pour concrete in the trench, and the concrete covers the steel reinforcement cage 4 to solidify and form a diaphragm wall, so that the unit membrane block 1 fits on the outer side of the diaphragm wall.

[0055] S5. When constructing the next diaphragm wall, insert the hook plate 22 of the connecting plate 21 of the connector 2 on the unit membrane block 1 of the next diaphragm wall into the hook mouth of the hook plate 22 of the connecting plate 21 of the connector 2 of the already poured diaphragm wall. After the steel reinforcement cage 4 of the next diaphragm wall is lowered, the two hook plates 22 of the connector 2 are buckled together.

[0056] The water-blocking membrane structure attached to the soil-facing side of the diaphragm wall of the present invention is a full-section waterproof layer for the soil-facing side outside the diaphragm wall, which is significantly different from the waterproofing of the diaphragm wall joints.

[0057] The depth range of the unit membrane block of the water-blocking membrane structure attached to the soil-facing side of the diaphragm wall of the present invention should be adapted to the formation conditions and the ultrasonic detection conditions of the trench excavation, so as to completely cut off the pervious layer, and the depth of the attached membrane enters the impervious layer by at least 3 meters, and the collapse depth range of the trench wall needs to be cut off.

[0058] The adjacent unit membrane blocks of the water-blocking membrane structure attached to the soil-facing side of the diaphragm wall of the present invention are connected by a connector, which has an interlocking design, and an expansion water-stop strip is arranged in the holes between the locks. The connector is made of galvanized water-stop steel plate, bent into a hook shape, and the cross-section is a chute that can be buckled with each other. The inside of the chute is provided with a water-swelling water-stop material, and the connecting plate of the connector and the adjacent side of the unit membrane block are riveted.

[0059] The butt joint construction of the connector of the water-blocking membrane structure attached to the soil-facing side of the diaphragm wall of the present invention relies on the rope buckle of the unit membrane block and the diaphragm wall steel reinforcement cage, and overcomes the friction between the hook mouths of the hook plates of the connector under the pulling action of the self-weight of the diaphragm wall steel reinforcement cage, and then lowers the unit membrane block in place.

[0060] The water-blocking film structure externally attached to the soil-facing side of the diaphragm wall of the present invention synchronously lowers the soil-facing side during the hoisting process of the reinforcement cage of the diaphragm wall. The placement depth of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall of the present invention is determined according to the formation conditions and the ultrasonic detection of the diaphragm wall trench excavation, so as to cut off the depth range of the permeable layer and the depth range of the collapse of the trench wall, achieving the effects of blocking the horizontal groundwater seepage path and reducing the over-pouring of the diaphragm wall concrete. The connection nodes of the water-blocking film structure externally attached to the soil-facing side of the diaphragm wall of the present invention are reliable, easy to construct in practice and have good waterproof performance.

[0061] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principle. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solution formed by mutually replacing the above features with the technical features (but not limited to) disclosed in the present application that have similar functions.

Claims

1. A ground-connected wall with a water-blocking membrane structure on the soil surface, characterized in that: include: A plurality of unit membrane blocks, wherein the unit membrane blocks are attached to the soil facing surface of the ground-connected wall, the plurality of unit modules are arranged in a circle along the circumferential direction of the ground-connected wall, the unit membrane blocks have two opposite adjacent sides, the lower ends of the unit membrane blocks are connected to the steel cage of the ground-connected wall through rope buckles, and the lower ends of the unit modules are buried in the impermeable layer below the permeable layer; The connector comprises two connecting plates, one side of the two connecting plates is overlapped on an adjacent side of two adjacent unit membrane blocks, the other side of the connecting plates is formed with a hook plate, the hook plates of the two connecting plates are buckled and connected together, and a sealing member is provided between the two hook plates.

2. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 1 is characterized in that: One side of the connection plate is connected to the adjacent side of the unit membrane block by rivets.

3. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 1 is characterized in that: The connecting plate is connected to the hook plate through an arc plate, the inner arc surface of the arc plate is arranged toward the hook opening of the hook plate, and the adjacent side of the unit membrane block is arranged opposite to the outer arc surface of the arc plate.

4. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 1 is characterized in that: The unit membrane block is a HDPE membrane.

5. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 1 is characterized in that: The sealing element is a water-swelling water-stop strip.

6. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 5 is characterized in that: There are multiple sealing members, and the multiple sealing members are continuously arranged along the length direction of the gap between the two hook plates.

7. The water-blocking membrane structure attached to the soil surface of the ground-connected wall according to claim 1 is characterized in that: The width of the unit membrane block is adapted to the width of the ground-connected wall.

8. A construction method for a ground-connected wall with a water-blocking membrane structure attached to the soil surface as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: A connecting plate of the connector is overlapped on two adjacent sides of the unit membrane block; When constructing the ground-connected wall, the steel cage of the ground-connected wall is hoisted, and the lower end of the unit membrane block is connected to the steel cage through a rope buckle, so that the unit membrane block is attached to the outer side of the steel cage; Lowering the steel cage together with the unit membrane block into the groove, so that the lower end of the unit module extends into the impermeable layer below the permeable layer; Concrete is poured in the groove, and the concrete is coated on the steel cage to consolidate to form a ground-connected wall, so that the unit membrane block is attached to the outer side of the ground-connected wall; When constructing the next ground-connected wall, the hook plate of the connecting plate of the connector on the unit membrane block on the next ground-connected wall is inserted into the hook mouth of the hook plate of the connecting plate of the connector of the cast ground-connected wall. After the steel cage of the next ground-connected wall is lowered, the two hook plates of the connector are buckled together.

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