Construction method for reducing concrete consumption of special-shaped underground continuous wall

Abstract

The present application belongs to the technical field of underground continuous wall, and discloses a construction method for reducing the concrete consumption of special-shaped underground continuous wall, which is used for solving the problem of concrete waste caused by the setting of the external groove and providing a construction method for reducing the concrete consumption of special-shaped underground continuous wall.The present application comprises: (1) a construction groove and an external groove; (2) a wall steel reinforcement cage, wherein the wall steel reinforcement cage is provided with steel pads, the steel pads are provided with steel plates clamped in the clamping grooves, the steel plates are provided with baffle plates, and the baffle plates are used as the grout-stopping belts for contacting the wall of the external groove; (3) hoisting the wall steel reinforcement cage into the groove; (4) implanting a grouting flower pipe and placing sandbags into the external groove; (5) injecting grout into the external groove through the grouting flower pipe, and then taking out the steel plates from the steel pads; and (6) pouring concrete into the groove to form an underground continuous wall.The present application can effectively reduce the problem of concrete waste caused by the external groove and reduce the construction cost of the special-shaped underground continuous wall.

Description

Technical Field

[0001] This invention belongs to the field of diaphragm wall technology, specifically relating to a construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls. Background Technology

[0002] Diaphragm walls are a type of retaining and waterproofing structure used for ultra-deep foundation pits (depth > 10m). They offer advantages such as good structural continuity, excellent impermeability, and high overall rigidity. Especially in deep foundation pit projects in coastal areas, where high water levels make dewatering difficult, diaphragm walls are frequently used for support. Furthermore, diaphragm wall construction results in low vibration and noise, and high space utilization, making it ideal for urban construction. Diaphragm wall construction generally requires the pre-construction of guide walls as a benchmark for trench measurement; the guide walls also serve as retaining walls. The guide walls of diaphragm walls should be adaptable to different wall types, such as straight, L-shaped, and Z-shaped, with L-shaped and Z-shaped walls also known as irregular diaphragm walls. When constructing the guide walls of irregular diaphragm walls, to ensure that the mechanical trenching depth within the main trench area meets the requirements for lowering the reinforcing cage, an extension trench is usually constructed at a certain distance at the corners, such as... Figure 1 As shown in the diagram (the sloping filled area), the construction of the external trench means that the subsequent concrete pouring must be done together with the main trench. When constructing ultra-deep walls, this will significantly increase the volume of concrete poured.

[0003] However, since the external trench is indispensable for irregular diaphragm walls, the increased concrete pouring volume caused by the external trench was assumed during construction, and no further research was conducted on how to reduce the amount of concrete poured for the external trench.

[0004] However, for deep diaphragm walls, the design of the external trench results in a huge waste of concrete, leading to significant economic losses. Summary of the Invention

[0005] To address the problem of concrete waste caused by the installation of external trenches, this invention provides a construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls. This method effectively reduces concrete waste caused by external trenches and lowers the construction cost of irregularly shaped diaphragm walls.

[0006] To solve the technical problem, the technical solution adopted by this invention is as follows:

[0007] A construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls, characterized by comprising:

[0008] (1) The trench for constructing irregularly shaped underground continuous walls and the external trench connected to the trench.

[0009] (2) Fabricate a wall reinforcement cage, on which steel pads are installed, and clamping grooves are provided on the steel pads. A steel plate is clamped in the clamping grooves, and a baffle is provided on the steel plate. The steel plate is located between the baffle and the wall reinforcement cage. The two ends of the baffle extend out of the steel plate and are adapted to the width of the external groove. Furthermore, grout-stopping strips for contacting the wall of the external groove are provided on both sides and the lower end of the baffle.

[0010] (3) Hoist the wall reinforcement cage from step (2) into the trench;

[0011] (4) Insert the grouting pipe into the outer groove, and then put sandbags into the space between the outer groove and the baffle.

[0012] (5) Inject grout into the outer trench through the grouting pipe; after the grout reaches the design strength, remove the steel plate from the steel pad on the wall reinforcement cage;

[0013] (6) Pour concrete into the trench to form a continuous underground wall.

[0014] In some embodiments, a screw is installed on the steel pad, and a strip hole is provided on the baffle. The screw passes through the strip hole and is fitted with a fastening nut. The baffle is fixedly installed on the steel pad by the screw and the fastening nut.

[0015] In some embodiments, a plurality of support blocks or support strips are connected to the side of the steel plate facing the baffle. One side of each support block or support strip is fixedly connected to the steel plate, and the other side of each support block or support strip is used to contact and support the baffle. In specific implementations, the support blocks or support strips are chamfered or rounded around their perimeter to prevent damage to the baffle during sliding contact.

[0016] In some embodiments, a through hole is provided inside the support block or support bar, and a spring and a sealing ball are installed in the through hole. A circular hole is provided at one end of the support block or support bar near the baffle. One end of the spring is fixedly connected to the bottom of the through hole, and the other end of the spring is in contact with the sealing ball. At least a portion of the sealing ball can extend out of the circular hole, and grease is injected into the through hole through an oil filler.

[0017] In some embodiments, a guide post consisting of four "L"-shaped guide strips is installed inside the through hole, the sealing ball is sleeved inside the guide post, and there is a gap between adjacent guide strips; a guide plate that can slide inside the guide post is also installed inside the guide post, one end of the guide plate is fixedly connected to a spring, and the other end of the guide plate is in contact with the sealing ball.

[0018] In some embodiments, the guide plate has a spherical surface on the side facing the sealing sphere that is adapted to the sealing sphere.

[0019] In some embodiments, a pin hole or threaded hole is provided on the steel pad at the top of the wall reinforcement cage, and the pin hole or threaded hole is equipped with a pin or locking screw. A through hole is provided on the steel plate at the position corresponding to the pin hole or threaded hole.

[0020] In some embodiments, the upper end of the steel plate is provided with lifting lugs, or the upper end of the steel plate is provided with lifting holes.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The construction method for reducing concrete usage in irregularly shaped diaphragm walls according to this invention involves the following steps: After the outer trench is constructed, steel blocks are installed on the wall reinforcement cage according to the width of the outer trench, and steel plates are fitted onto them. Baffles are installed on the steel blocks and supported and reinforced by the steel plates. Then, the wall reinforcement cage with steel plates and baffles is lowered into the trench. A grouting pipe is then inserted into the outer trench. After the grouting pipe is inserted, sandbags are filled into the outer trench. After the sandbags are filled, grout is injected through the grouting pipe to form a unified whole with the sandbags. After the injected cement grout solidifies, the steel plates can be removed from the steel blocks, and then the diaphragm wall can be poured. This method utilizes the baffles, sandbags, and injected grout to fill and compact the outer trench, preventing concrete from entering the outer trench during the pouring of the diaphragm wall, thus saving concrete usage and ultimately reducing the construction cost of the diaphragm wall.

[0023] This invention is particularly useful for deep diaphragm walls, saving a considerable amount of concrete and greatly reducing the construction cost of irregularly shaped diaphragm walls.

[0024] This invention utilizes a structure of baffles and steel plates. The steel plates not only support the baffles, preventing them from being ruptured by the grout injected through the grouting pipes, but also allow for repeated recycling, further reducing costs. More importantly, when pouring concrete for the wall's reinforcing cage, the baffles effectively prevent surface water from flowing back into the trench. While existing technologies, including external drainage channels, can prevent surface water from entering the trench to some extent, the channels are cast integrally with the trench. If surface water enters the external drainage channel during pouring, it inevitably flows into the trench, leading to poor quality diaphragm wall construction. This invention, with its grout injection through grouting pipes, sandbags, and baffles, ensures that even if surface water enters the external drainage channel during pouring, the baffles prevent it from entering the trench, thus guaranteeing the quality of the diaphragm wall construction. Attached Figure Description

[0025] Figure 1 This is a structural schematic diagram of an irregularly shaped diaphragm wall, in which... Figure 1 The image on the left shows an L-shaped diaphragm wall. Figure 1 The image on the right side shows a Z-shaped diaphragm wall;

[0026] Figure 2 This is a schematic diagram of a structure according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram showing the connection between the baffle and the steel plate of the present invention;

[0028] Figure 4 for Figure 3 A magnified view of a portion of point A in the diagram;

[0029] Figure 5 This is a schematic diagram of the structure of the sealed sphere on the support block;

[0030] Figure 6 A schematic diagram of a sealing sphere fitted inside a guide post;

[0031] Figure 7 This is a schematic diagram of the structure of the steel plate and steel pad of the present invention in cooperation with each other;

[0032] The markings in the diagram are: 1. Grouting pipe, 2. Grouting hole, 3. External guide wall, 4. Steel pad, 41. Locking screw, 5. Steel plate, 6. Grout stop strip, 7. Reinforcing cage of wall, 8. Baffle, 81. Strip hole, 9. Support block, 91. Through hole, 92. Circular hole, 93. Sealing ball, 94. Guide plate, 95. Spring, 96. Guide column, 961. Guide strip, 97. Oil nozzle, 10. Screw, 11. Fastening nut. Detailed Implementation

[0033] The present invention will be further described below with reference to embodiments. These embodiments are merely some, not all, of the embodiments of the present invention. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description; they do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0035] Combined with appendix Figure 2 To be continued Figure 7 The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls of the present invention includes:

[0036] (1) The trench 02 for constructing the irregular diaphragm wall and the external trench 01 connected to the trench 02;

[0037] (2) Fabricate a wall reinforcement cage 7. A steel pad 4 is installed on the wall reinforcement cage 7. A clamping groove 42 is opened on the steel pad 4. A steel plate 5 is clamped in the clamping groove 42. A baffle 8 is provided on the steel plate 5. The steel plate 4 is located between the baffle 8 and the wall reinforcement cage 7. The two ends of the baffle 8 extend out of the steel plate 5 and are adapted to the width of the external groove 01. The baffle 8 is provided with grout-stopping strips 6 on both sides and the lower end for contact with the wall of the external groove (i.e., the external groove guide wall 3). That is to say, the grout-stopping strips 6 cover the lower end face and two sides of the baffle 8, thereby sealing the gap between the baffle 8 and the external groove wall (i.e., the external groove guide wall 3) to prevent the grout injected by the subsequent grouting pipe 1 from flowing out from the edge of the baffle 8. The grout-stopping strips 6 themselves have a certain deformation capacity, which is conducive to the lowering of the entire wall reinforcement cage 7. The area of ​​the baffle is larger than that of the steel plate, and the steel plate 5 extends from all four sides of the baffle 8. Due to the shielding and protection of the steel plate 5 by the baffle 8, the steel plate 5 will not come into contact with the grout poured by the sandbags and grouting pipes 1.

[0038] In practical implementation, the grout-stopping strip 6 is made of EPDM rubber, and the strip has a built-in snap-fit, which can be directly fixed to the baffle 8. The baffle 8 of this invention is preferably made of engineering plastic.

[0039] (3) Hoist the wall reinforcement cage 7 from step (2) into the trench 02; when hoisting the wall reinforcement cage 7, ensure that the baffle 8 and steel plate 5 are securely installed to avoid safety accidents caused by the detachment of the steel plate and baffle. During the hoisting process, there should be no other construction personnel below the running trajectory of the wall reinforcement cage 7.

[0040] When the lower end of the wall reinforcement cage is hoisted into the outer placement groove 01, it is necessary to observe at any time whether the grout-stopping strips on both sides of the baffle hit the wall or get stuck, and adjust the hoisting angle in time.

[0041] (4) Insert the grouting pipe 1 into the outer groove 01, and then put sandbags into the space between the outer groove 01 and the baffle 8; wherein the filling height of the sandbags reaches the set elevation. The grouting pipe 01 has several grouting holes 2 on its circumferential wall, which can be understood by those skilled in the art and will not be described in detail here.

[0042] In the specific implementation process, the grouting pipe 1 can also be installed by hoisting. During the sandbag filling process, once the grouting pipe 1 is stable, it can be completely removed from the hoisting equipment. The grouting pipe 1 is set close to the wall of the outer trench, meaning it is set close to the guide wall 3 of the outer trench. This utilizes the clamping effect of the guide wall 3 and the sandbags to secure the grouting pipe 1 within the outer trench 01.

[0043] (5) Inject grout into the external discharge trench 01 through the grouting pipe 1; after the grout reaches the design strength, remove the steel plate 5 from the steel pad 4 on the wall reinforcement cage 7. The grout used for grouting is existing technology, which can be understood by those skilled in the art, and will not be described in detail here. For example, the grout is mainly composed of water, cement, fly ash, quick-setting agent, etc., and the cement grade should preferably be P.O32.5.

[0044] (6) Pour concrete into the trench 02 to form a continuous underground wall.

[0045] In some embodiments, a screw 10 is installed on the steel pad 4, and a slotted hole 81 is provided on the baffle 8. The screw 10 passes through the slotted hole 81 and is fitted with a fastening nut 11. The baffle 8 is fixedly installed on the steel pad 4 by the screw 10 and the fastening nut 11. The steel pad 4 is fixedly installed on the wall reinforcement cage 7. In specific implementations, to improve the stability of the steel pad 4 installed on the wall reinforcement cage 7, multiple steel pads 4 are also connected together by connecting plates.

[0046] Combined with appendix Figure 7 Since the steel pads 4 serve to hold the steel plate 5 and install the baffle 8, they are arranged along the bottom and left and right sides of the steel plate. The clamping groove 42 of the steel pad 4 located at the bottom of the steel plate 5 faces upwards, while the clamping grooves 42 of the steel pads 4 on the left and right sides of the steel plate are opposite each other. This allows the steel plate 5 to be clamped using the clamping grooves 42 of each steel pad 4. Finally, the upper end of the steel plate 5 is locked to the steel pad 4 using locking screws 41, thus completing the secure installation of the steel plate 5.

[0047] In some embodiments, a plurality of support blocks 9 or support bars are connected to the side of the steel plate 5 facing the baffle 8. One side of the support block 9 or support bar is fixedly connected to the steel plate 5, and the other side of the support block 9 or support bar is used to contact the baffle 8 and support the baffle 8. In specific implementation, the support blocks 9 or support bars are chamfered or rounded around their perimeter to prevent damage to the baffle 8 during sliding contact with the baffle.

[0048] Combined with appendix Figure 5 and attached Figure 6In some embodiments, the support block 9 or support bar has a through hole 91 inside, and a spring 95 and a sealing ball 93 are installed in the through hole 91. A circular hole 92 is provided on the support block 9 or support bar near the baffle 8. One end of the spring 95 is fixedly connected to the bottom of the through hole 91, and the other end of the spring 95 is in contact with the sealing ball 93. At least a part of the sealing ball 93 can extend out of the circular hole 92, that is, the opening size of the circular hole 92 is smaller than the diameter of the sealing ball 93, so that a part of the sealing ball 93 can extend out of the circular hole 92 and will not fall out of the circular hole 92. Lubricating grease is injected into the through hole 91 through the grease nipple 97. When the sealing ball is not in contact with the baffle, it is in close contact with the circular hole under the action of the spring, forming a seal. When the sealing ball 93 is in contact with the baffle 8, the baffle 8 compresses the sealing ball 93, creating a gap between the sealing ball 93 and the circular hole 92. This allows grease to overflow from the circular hole 92, so that the overflowing grease can lubricate the baffle 8 and the support block 9 or support bar. This reduces the friction between the support block 9 or support bar, making it easier to remove the baffle. It also prevents damage to the baffle 8 during the removal of the steel plate 5.

[0049] Combined with appendix Figure 5 and attached Figure 6 In some embodiments, a guide post 96 consisting of four "L"-shaped guide strips 961 is installed inside the through hole 91. The sealing ball 93 is sleeved inside the guide post 96, and there is a gap between adjacent guide strips 961. A guide plate 94 that can slide inside the guide post 96 is also installed inside the guide post 96. One end of the guide plate 94 is fixedly connected to the spring 95, and the other end of the guide plate 94 contacts the sealing ball 93. Through the structural design of the guide post 96, it is easy to limit the movement trajectory position of the sealing ball 93, so that the sealing ball 93 can not only seal against the circular hole 92, but also ensure that the grease can always be in contact with the sealing ball. When the steel plate is removed, the rolling contact between the baffle 8 and the sealing ball 93 causes the sealing ball 93 to roll, so that the sealing ball 93 continuously contacts the grease during the rolling process, and is carried out of the circular hole 92 through the spherical surface of the sealing ball 93. Ultimately, when steel plate 5 is removed, lubricating grease can continuously overflow during the contact between baffle 8 and support block 9 or support bar.

[0050] In some embodiments, the guide plate 94 has a spherical surface on the side facing the sealing ball 93 that is adapted to the sealing ball, thereby further ensuring the rotation of the sealing ball.

[0051] In some embodiments, a pin hole or threaded hole is provided on the steel pad at the top of the wall reinforcement cage 7, and the pin hole or threaded hole is equipped with a pin shaft or locking screw 41. A through hole is provided on the steel plate 5 at the position corresponding to the pin hole or threaded hole.

[0052] In some embodiments, the upper end of the steel plate 5 is provided with a lifting lug, or the upper end of the steel plate 5 is provided with a lifting hole, so as to facilitate the installation of the steel plate on the wall reinforcement cage or the removal from the wall reinforcement cage, so as to facilitate the recycling of the steel plate 5. The construction method for reducing concrete usage in irregularly shaped diaphragm walls according to this invention involves the following steps: After the outer trench is constructed, steel blocks are installed on the wall reinforcement cage according to the width of the outer trench, and steel plates are fitted onto them. Baffles are installed on the steel blocks and supported and reinforced by the steel plates. Then, the wall reinforcement cage with steel plates and baffles is lowered into the trench. A grouting pipe is then inserted into the outer trench. After the grouting pipe is inserted, sandbags are filled into the outer trench. After the sandbags are filled, grout is injected through the grouting pipe to form a unified whole with the sandbags. After the injected cement grout solidifies, the steel plates can be removed from the steel blocks, and then the diaphragm wall can be poured. This method utilizes the baffles, sandbags, and injected grout to fill and compact the outer trench, preventing concrete from entering the outer trench during the pouring of the diaphragm wall, thus saving concrete usage and ultimately reducing the construction cost of the diaphragm wall.

[0053] This invention is particularly useful for deep diaphragm walls, saving a considerable amount of concrete and greatly reducing the construction cost of irregularly shaped diaphragm walls.

[0054] This invention utilizes a structure of baffles and steel plates. The steel plates not only support the baffles, preventing them from being ruptured by the grout injected through the grouting pipes, but also allow for repeated recycling, further reducing costs. More importantly, when pouring concrete for the wall's reinforcing cage, the baffles effectively prevent surface water from flowing back into the trench. While existing technologies, including external drainage channels, can prevent surface water from entering the trench to some extent, the channels are cast integrally with the trench. If surface water enters the external drainage channel during pouring, it inevitably flows into the trench, leading to poor quality diaphragm wall construction. This invention, with its grout injection through grouting pipes, sandbags, and baffles, ensures that even if surface water enters the external drainage channel during pouring, the baffles prevent it from entering the trench, thus guaranteeing the quality of the diaphragm wall construction.

Claims

1. A construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls, characterized in that, include: (1) The trench for constructing irregularly shaped underground continuous walls and the external trench connected to the trench. (2) Fabricate a wall reinforcement cage, on which steel pads are installed, and clamping grooves are provided on the steel pads. A steel plate is clamped in the clamping grooves, and a baffle is provided on the steel plate. The steel plate is located between the baffle and the wall reinforcement cage. The two ends of the baffle extend out of the steel plate and are adapted to the width of the external groove. Furthermore, grout-stopping strips for contacting the wall of the external groove are provided on both sides and the lower end of the baffle. (3) Hoist the wall reinforcement cage from step (2) into the trench; (4) Insert the grouting pipe into the outer groove, and then put sandbags into the space between the outer groove and the baffle. (5) Inject grout into the outer trench through the grouting pipe; after the grout reaches the design strength, remove the steel plate from the steel pad on the wall reinforcement cage; (6) Pour concrete into the trench to form a continuous underground wall.

2. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 1, characterized in that, A screw is installed on the steel pad, and a strip hole is opened on the baffle. The screw passes through the strip hole and is equipped with a fastening nut. The baffle is fixedly installed on the steel pad by the screw and the fastening nut.

3. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 2, characterized in that, Several support blocks or support bars are connected to the side of the steel plate facing the baffle. One side of the support block or support bar is fixedly connected to the steel plate, and the other side of the support block or support bar is used to contact the baffle and support the baffle. In the specific implementation process, the support blocks or support bars are chamfered or rounded around to avoid damaging the baffle during the sliding contact between the support blocks or support bars and the baffle.

4. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 3, characterized in that, The support block or support bar has a through hole inside, and a spring and a sealing ball are installed in the through hole. A circular hole is opened on one end of the support block or support bar near the baffle. One end of the spring is fixedly connected to the bottom of the through hole, and the other end of the spring is in contact with the sealing ball. At least a part of the sealing ball can extend out of the circular hole. Lubricating grease is injected into the through hole through an oil filler.

5. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 4, characterized in that, A guide post consisting of four "L"-shaped guide strips is installed inside the through hole. The sealing ball is sleeved inside the guide post, and there is a gap between adjacent guide strips. A guide plate that can slide inside the guide post is also installed inside the guide post. One end of the guide plate is fixedly connected to a spring, and the other end of the guide plate is in contact with the sealing ball.

6. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 5, characterized in that, The guide plate has a spherical surface on the side facing the sealing sphere that is compatible with the sealing sphere.

7. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to any one of claims 1-6, characterized in that, The steel pad at the top of the wall reinforcement cage is provided with a pin hole or a threaded hole, and the pin hole or threaded hole is equipped with a pin or a locking screw. A through hole is provided on the steel plate corresponding to the position of the pin hole or threaded hole.

8. The construction method for reducing the amount of concrete used in irregularly shaped diaphragm walls according to claim 7, characterized in that, The upper end of the steel plate is provided with lifting lugs, or the upper end of the steel plate is provided with lifting holes.

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