Steel sheet pile cofferdam structure

Abstract

The application provides a steel sheet pile cofferdam structure and belongs to the cofferdam building field.The steel sheet pile cofferdam structure comprises a plurality of steel sheet pile bodies which can be mutually inserted and assembled;the plurality of steel sheet pile bodies are driven into the deep bottom of a river channel by a pile driver, and two adjacent steel sheet pile bodies are mutually inserted;the plurality of steel sheet pile bodies cooperate with corner pieces to jointly form a rectangular cofferdam;the corner pieces are located at the four corner positions of the rectangular cofferdam;the inner wall of the rectangular cofferdam is provided with a plurality of surrounding purlin assemblies which are arranged from top to bottom and are rectangular;the surrounding purlin assemblies are uniformly provided with a plurality of support assemblies, and the support assemblies are in abutting cooperation with the inner wall of the rectangular cofferdam;the support assemblies in the surrounding purlin assemblies from top to bottom are jointly fixed and connected by bolt rods and nuts in one-to-one correspondence;the three-point support design, the adjustable assembly and the modular linkage structure are used to solve the problems of insufficient support strength, poor deformation adaptability and overall stability of the deep excavation cofferdam, and the construction safety and the structural reliability are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of cofferdam construction, and particularly relates to a steel sheet pile cofferdam structure. Background Technology

[0002] Sheet pile cofferdams typically consist of sheet piles, a support system, and other components. The sheet piles are interlocked and locked together to form a closed cofferdam, which serves to block water and soil.

[0003] In some water conservancy construction projects, such as building river dams or pouring bridge foundations, it is necessary to first use a cofferdam structure to create a barrier. After the barrier is in place, a support system is used to support the interior. Subsequently, the water inside the cofferdam is pumped out, and the foundation excavation is carried out gradually. As the excavation goes deeper, the exposed area of ​​the bottom of the driven steel sheet piles will increase. The original support system at the top can no longer meet the stability requirements of the cofferdam. At this point, it is necessary to add another support system to the excavated part to maintain the stability of the cofferdam, offset the pressure of the external water on the cofferdam, and thus prevent the cofferdam from collapsing.

[0004] In current sheet pile cofferdam structures, when the support system supports the curved sheet piles, the contact point between the support system and the sheet piles is usually tangential. As the excavation depth increases, the pressure around the cofferdam gradually increases, and the original tangential contact point can no longer guarantee the support strength, easily leading to deformation of the sheet piles. At the same time, the increased pressure around the cofferdam requires additional support components. After the existing support components are added, the pressure around the cofferdam causes the bottom of the sheet piles to indent inward, resulting in a decrease in the verticality of the sheet piles. Usually, the original support components cannot fit the inner wall of the lower side of the cofferdam, resulting in poor fit during the installation of the support components, further affecting the structural strength of the cofferdam.

[0005] To ensure the stability of the cofferdam structure, this invention provides a steel sheet pile cofferdam structure. Summary of the Invention

[0006] In view of the above problems, the steel sheet pile cofferdam structure provided in this application solves the problems of insufficient support strength, poor deformation adaptability and overall stability of deep excavation cofferdams through a three-point support design, adjustable components and modular linkage structure, which significantly improves construction safety and structural reliability.

[0007] To achieve the above objectives, this application provides the following technical solution: a steel sheet pile cofferdam structure, comprising several steel sheet pile bodies that can be interlocked and assembled, corner members, waler assemblies, and support assemblies; several steel sheet pile bodies are driven into the deep bottom of the river channel by a pile driver, and adjacent steel sheet pile bodies are interlocked; several steel sheet pile bodies, together with corner members, form a rectangular cofferdam; the corner members are located at the four corners of the rectangular cofferdam; the inner wall of the rectangular cofferdam is provided with several rectangular waler assemblies arranged from top to bottom, and several support assemblies are evenly arranged in the waler assemblies, and the support assemblies abut against the inner wall of the rectangular cofferdam; the support assemblies in the waler assemblies arranged from top to bottom are fixedly connected by bolts and nuts.

[0008] The sheet pile body consists of a semi-circular upright plate and U-shaped clamping plates located on both sides of the long side of the semi-circular upright plate, and the arc orientation of the semi-circular upright plates of two adjacent sheet pile bodies on the same side is opposite.

[0009] The support assembly includes a pusher, a side pusher, and a center pusher. The side pushers are symmetrically arranged at both ends of the pusher and can be adjusted simultaneously to press against the U-shaped plate. The center pusher is located in the middle of the pusher and adapts to fit the curved surface of the semi-circular vertical plate. The side pushers and the center pusher work together to form a three-point support structure.

[0010] Specifically, when supporting the cofferdam, the waler assembly and the support assembly form a multi-layered support for the cofferdam from top to bottom. Each layer of support is connected by bolts and nuts to form a longitudinal integral force-bearing system.

[0011] According to an advantageous embodiment, the waler assembly includes a rectangular side enclosure formed by a plurality of steel columns, the rectangular side enclosure being welded to the inner wall of the rectangular cofferdam by connecting strips; and each corner of the rectangular side enclosure is equipped with a reinforcing rib by bolts; the plurality of steel columns are connected to each other by steel sleeves, and the steel sleeves are connected to the steel columns by welding.

[0012] According to an advantageous embodiment, a rectangular hole is provided on the steel column corresponding to the support component for the support component to pass through.

[0013] According to an advantageous embodiment, the pushing member is composed of several strip-shaped horizontal steel bars and steel sleeves, with two vertically penetrating rectangular grooves symmetrically arranged on it, and mounting grooves are opened on both the front and rear sections of the pushing member; the side pushing member is snapped into the mounting groove, and the middle pushing member is arranged in the rectangular groove.

[0014] According to an advantageous embodiment, the side abutment includes a U-shaped mounting base, within which two shafts are symmetrically arranged via bearings. A gear is fixedly mounted in the middle of each shaft, and the gears in the two shafts mesh with each other. A push rod is fixedly mounted on each shaft, and two bolts are threaded onto the U-shaped mounting base for abutting the teeth of the gears.

[0015] According to an advantageous embodiment, a compensation block is slidably disposed inside the push rod, and the compensation block is moved by screwing on a bolt.

[0016] According to an advantageous embodiment, the middle abutment includes a detachable snap-fit ​​bracket, one end of which is disposed in a rectangular groove, and the other end is snap-fitted with an abutment block by a pin; the abutment block is crescent-shaped and adapted to the outer wall of the semi-circular vertical plate.

[0017] According to an advantageous embodiment, the crescent-shaped concave or convex surface of the abutment is selected for installation according to the arcuate orientation of the semi-circular upright plate.

[0018] According to an advantageous embodiment, the corner member is interlocked with the adjacent sheet pile body via a U-shaped clamp.

[0019] According to an advantageous embodiment, the length of the pushing member is adjusted according to the width of the rectangular cofferdam by increasing or decreasing the number of horizontal strips.

[0020] Compared with existing technologies, the sheet pile cofferdam structure provided in this invention has the following beneficial effects: 1. In this invention, the side abutments are symmetrically abutted against the U-shaped clamping plate, and the middle abutment is abutted against the semi-circular vertical plate, forming a three-point support structure with an isosceles triangle distribution. The isosceles triangle support system constitutes a stable statically determinate structure in terms of mechanics, optimizing the concentrated load transfer path of traditional support into a distributed force flow transfer. The side abutments act on the interlocking nodes of the U-shaped clamping plate (the point of strongest structural rigidity), forming two symmetrical base supports, which can effectively resist the relative displacement and opening between the sheet pile bodies; the middle abutment acts on the point of maximum curvature of the semi-circular vertical plate (the section with the maximum bending moment), forming a top support point, which can directly balance the bending stress on the plate surface. The support plane formed by the three points transforms the sheet pile body from a bending member into a member mainly bearing axial pressure, greatly reducing the risk of bending deformation of the sheet pile body. At the same time, the structure can maintain overall stability in deep water and high-pressure environments.

[0021] 2. The gear meshing design of the side abutment in this invention enables the mirror-symmetrical movement of the double-sided push rods, ensuring that the two support points always remain on the same axis, eliminating the torque problem caused by asymmetrical support. The compensation block is finely adjusted in length by bolts to ensure a tight fit with the U-shaped clamping plate. The crescent-shaped abutment of the middle abutment can be adapted to the concave and convex surfaces of the semi-arc vertical plate. The position can be adjusted by sliding the clamping frame to dynamically adapt to the deformation of the steel sheet pile and maintain verticality.

[0022] 3. The waler assembly in this invention adopts modular welding of steel columns and steel sleeves, and is reinforced with ribs to enhance corner stability. The overall structure is easy to install in layers. The upper and lower support assemblies are vertically fixed by bolts and nuts to form a longitudinal linkage force system, which disperses local pressure and improves the overall compressive strength of the cofferdam. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the cofferdam structure of the present invention, viewed from above.

[0024] Figure 2 This is a three-dimensional structural diagram of the cofferdam structure of the present invention viewed from below.

[0025] Figure 3 This is a top view of the cofferdam structure of the present invention.

[0026] Figure 4 This is a planar schematic diagram of the support component of the present invention.

[0027] Figure 5 For the present invention Figure 4 A magnified view of section A in the image.

[0028] The attached figures are labeled as follows: 1. Sheet pile body; 11. Semi-circular vertical plate; 12. U-shaped clamping plate; 2. Corner piece; 3. Waler assembly; 31. Steel column; 32. Connecting strip; 33. Reinforcing rib; 4. Support assembly; 41. Pushing member; 411. Rectangular groove; 412. Mounting groove; 42. Side abutment; 421. U-shaped mounting seat; 422. Shaft; 423. Gear; 424. Pushing rod; 425. Compensating block; 43. Central abutment; 431. Clip-on frame; 432. Abutment block; 5. Bolt rod; 6. Nut. Detailed Implementation

[0029] The following is in conjunction with the appendix Figure 1-5 This application will now be described in further detail.

[0030] Please see Figure 1 and Figure 2 A sheet pile cofferdam structure includes several sheet pile bodies 1 that can be interlocked and assembled, corner pieces 2, waler assemblies 3, and support assemblies 4. The sheet pile bodies 1 are driven into the deep bottom of the river channel by a pile driver, with adjacent sheet pile bodies 1 interlocking with each other. The sheet pile bodies 1, together with the corner pieces 2, form a rectangular cofferdam. The corner pieces 2 are located at the four corners of the rectangular cofferdam. The inner wall of the rectangular cofferdam is provided with several rectangular waler assemblies 3 arranged from top to bottom. Several support assemblies 4 are evenly arranged within the waler assemblies 3, and the support assemblies 4 abut against the inner wall of the rectangular cofferdam. The support assemblies 4 in the waler assemblies 3, arranged one-to-one, are fixedly connected by bolts 5 and nuts 6.

[0031] It should be noted that the sheet pile body 1 is an arc-shaped cold-formed sheet pile, model AU-400, made of Q345B material; the bolt rod 5 and nut 6 are both made of 10.9 grade high-strength bolts. The corner piece 2 is a specially welded irregular pile, with locking slots on both sides that are adapted to the U-shaped clamping plate 12 of the sheet pile body 1, and internal stiffening ribs to ensure corner rigidity.

[0032] During construction, the location of the cofferdam is first planned, and the four corner points of the cofferdam are measured using instruments. Then, using existing equipment (pile drivers), the corner pieces 2 are driven into the marked corner positions one by one, ensuring that the driving depth meets the requirements. Next, several sheet pile bodies 1 are driven into the spaces between adjacent corner pieces 2 using the pile drivers, ensuring that adjacent sheet pile bodies 1 are locked together to form a rectangular cofferdam. At the same time, the two sheet pile bodies 1 closest to the corner pieces 2 are also locked together with the corner pieces 2. After all the sheet pile bodies 1 are driven in, the waler assembly 3 is welded to the inner wall of the rectangular cofferdam. Then, several support assemblies 4 are evenly installed, ensuring that the support assemblies 4 are in close contact with the inner wall of the rectangular cofferdam. During subsequent construction, the water inside the rectangular cofferdam can be drained using a water pump, and the rectangular cofferdam can be inspected. Check if there are any seepage points on the inner wall of the rectangular cofferdam. If so, seal them with water-swellable sealing strips or polymer sealant. After the water is drained, excavation can proceed downwards using excavation equipment. After each excavation to a certain depth, waler components 3 need to be installed on the exposed inner wall of the rectangular cofferdam. At the same time, install several support components 4 that correspond one-to-one with the support components 4 above. (It should be noted that the installation of waler components 3 and support components 4 must be symmetrical and synchronous.) Then, use bolts 5 and nuts 6 to fix the upper and lower support components 4 together. Continue to excavate until the specified depth is reached. (During construction, the horizontal displacement and settlement of the top of the cofferdam should be monitored in real time. If the monitoring data is abnormal, work should be stopped immediately and reinforcement measures should be taken.)

[0033] It should be noted that the interlocking joints of the sheet pile body 1 are usually pre-designed with a water-stopping structure. In this embodiment, the water-stopping structure uses a U-shaped clamping plate 12.

[0034] Please see Figure 1 and Figure 3 The sheet pile body 1 is composed of a semi-arc vertical plate 11 and U-shaped clamping plates 12 located on both long sides of the semi-arc vertical plate 11; in the rectangular cofferdam formed, the arc orientation of the semi-arc vertical plates 11 of two adjacent sheet pile bodies 1 on the same side is opposite.

[0035] The semi-circular vertical plate 11 increases its contact area with the surrounding water. Simultaneously, the surrounding water pressure acting on the semi-circular vertical plate 11 is not on the same plane, effectively improving the bearing capacity of the sheet pile body 1. Adjacent sheet pile bodies 1 are interlocked by U-shaped clamps 12, ensuring the stability of the overall structure and guaranteeing tightness and sealing. This effectively prevents external water from flowing into the rectangular cofferdam, greatly reducing the probability of seepage at the interlocking joints. Typically, the surface of the sheet pile body 1 is coated with anti-rust paint, and the underwater portion is also coated with an epoxy asphalt anti-corrosion coating.

[0036] Please see Figure 1 and Figure 3 The waler assembly 3 includes a rectangular side enclosure formed by several steel columns 31, which is welded to the inner wall of the rectangular cofferdam by connecting strips 32; and each corner of the rectangular side enclosure is bolted with a reinforcing rib plate 33; the several steel columns 31 are connected by steel sleeves, and the steel sleeves and steel columns 31 are connected by welding; and the steel columns 31 corresponding to the support assembly 4 have rectangular holes for the support assembly 4 to pass through.

[0037] When installing the waler assembly 3, firstly, based on the length and width of the rectangular cofferdam, determine whether to weld steel sleeves onto the corresponding side walls. If welding steel sleeves is required, plan the installation position of the steel sleeves and weld them to the inner wall of the rectangular cofferdam using connecting strips 32. Then, insert one end of the steel column 31 into the inner wall of the steel sleeve and weld it using a welding machine. If welding steel sleeves is not required, the steel column 31 can be directly welded to the inner wall of the rectangle using connecting strips 32. After the rectangular side enclosure is installed, reinforce each corner with reinforcing ribs 33 to improve the overall stability of the rectangular side enclosure.

[0038] Please see Figure 3 , Figure 4 and Figure 5 The supporting component 4 includes a pusher 41 composed of several strip-shaped horizontal steel bars and steel sleeves; two vertically penetrating rectangular grooves 411 are symmetrically arranged on the pusher 41, and installation grooves 412 are opened on both the front and rear sections of the pusher 41; a side abutment 42 is snapped into the installation groove 412 and abuts against the U-shaped clamping plate 12 of the sheet pile body 1; a middle abutment 43 is arranged in the rectangular groove 411 and abuts against the semi-arc vertical plate 11 of the sheet pile body 1 in the middle of the side abutment 42; the number of strip-shaped horizontal steel bars in the pusher 41 is adapted to the width of the rectangular cofferdam.

[0039] When the inner wall of the rectangular cofferdam is supported by the support component 4, the pusher 41 is first assembled with steel sleeves and strip horizontal steel. Then, the side abutment 42 is snapped into the mounting groove 412 of the pusher 41. At the same time, the side abutment 42 is adjusted to keep it in contact with the interlocking U-shaped clamping plate 12 on the rectangular cofferdam to form a stable support. Finally, the middle abutment 43 is installed in the rectangular groove 411, keeping the middle abutment 43 in the middle of the side abutment 42 and in contact with the inner wall of the rectangular cofferdam. This forms a three-point support in the form of an isosceles triangle in multiple support areas, which fully improves the strength of the internal support structure and further prevents deformation and collapse caused by excessive external pressure on the rectangular cofferdam.

[0040] Please see Figure 5 The side abutment 42 includes a U-shaped mounting base 421 installed in the mounting groove 412; two shafts 422 are symmetrically arranged in the U-shaped mounting base 421 through bearings, and a gear 423 is fixedly arranged in the middle of the shaft 422. The gears 423 in the two shafts 422 mesh with each other. A push rod 424 is also fixedly arranged on the shaft 422. Two bolts for tightening the teeth of the gears 423 are also threaded on the U-shaped mounting base 421 (after the bolts are tightened, anti-loosening nuts or spring washers should be installed to prevent loosening due to vibration). A compensation block 425 is also slidably arranged in the push rod 424, and the compensation block 425 is moved by screwing the bolts.

[0041] When adjusting the side abutment 42, first adjust the opening angle between the two push rods 424. By pulling one of the push rods 424, the other push rod 424 can be adjusted synchronously through the gear 423. After completion, the bolts on both sides are screwed into the gear 423 to lock the angle. Then, the compensation block 425 is moved outward by rotating the bolt until it abuts against the U-shaped clamping plate 12. The symmetrical abutment of the compensation block 425 against the U-shaped clamping plate 12 can further maintain stability. The abutment position is a structure in which the two U-shaped clamping plates 12 interlock, which further prevents deformation of the fulcrum position.

[0042] Please see Figure 5 The aforementioned middle abutment 43 includes a detachable snap-fit ​​bracket 431. One end of the snap-fit ​​bracket 431 is slidably disposed in the rectangular groove 411, and the snap-fit ​​bracket 431 is disposed in the inner wall of the rectangular hole of the steel column 31 by means of sliding. The other end of the snap-fit ​​bracket 431 is snapped with an abutment block 432 by means of a pin. The abutment block 432 is crescent-shaped and adapted to the outer wall of the semi-circular vertical plate 11.

[0043] When using the middle abutment 43 for support, the installation method is first selected based on whether the semi-circular upright plate 11 at the abutment position is concave or convex relative to the abutment block 432. If it is concave, the crescent-shaped convex surface of the abutment block 432 is rotated to align with it during installation; if it is convex, the crescent-shaped concave surface of the abutment block 432 is rotated to align with it during installation. After completion, the snap-fit ​​bracket 431 is pushed to make the abutment block 432 and the surface of the semi-circular upright plate 11 align and abut tightly, and then the position is fixed inside the rectangular groove 411 of the abutment member 41 with bolts. At the same time, the snap-fit ​​bracket 431 is fixed to the steel column 31 with bolts. (Specific details are not provided in the original text.) Figure 3 , Figure 4 as well as Figure 5 As shown, Figure 3 When the crescent-shaped convex surface of the rotating abutment 432 is in contact with the semi-circular vertical plate 11, the bolt passes through the snap-fit ​​bracket 431 from bottom to top and then through the steel column 31, and is finally fixed by tightening the nut with the bolt; as Figure 3 When the crescent-shaped concave surface of the rotating abutment 432 is in contact with the semi-circular upright plate 11, the bolts are passed from top to bottom through the steel column 31 and then through the inside of the snap-fit ​​bracket 431 and screwed in to fix it.

[0044] After the cofferdam is used, it must be dismantled safely in reverse order. First, the support components 4 are dismantled layer by layer from bottom to top. Before dismantling a certain layer of support, the soil must be backfilled to the bottom elevation of that layer of support to balance the external water and soil pressure. After the support is dismantled, the waler components 3 are dismantled in sequence. Finally, a vibratory pile extractor is used in conjunction with a high-pressure water gun to loosen and flush the mud and sand in the steel sheet pile interlocks. The steel sheet pile body 1 and the corner piece 2 are pulled out in sequence for recycling and reuse.

[0045] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A steel sheet pile cofferdam structure, characterized in that, The system comprises several sheet pile bodies that can be interlocked and assembled, corner components, waler assemblies, and support assemblies. Several sheet pile bodies are driven into the deep bottom of the river channel by a pile driver, with adjacent sheet pile bodies interlocking. The sheet pile bodies, together with the corner components, form a rectangular cofferdam. The corner components are located at the four corners of the rectangular cofferdam. The inner wall of the rectangular cofferdam is provided with several rectangular waler assemblies arranged from top to bottom. Several support assemblies are evenly distributed within each waler assembly, and the support assemblies abut against the inner wall of the rectangular cofferdam. The support assemblies in the top-to-bottom waler assemblies are fixedly connected by bolts and nuts. The sheet pile body is composed of a semi-circular vertical plate and U-shaped clamping plates located on both sides of the long side of the semi-circular vertical plate, and the arc orientation of the semi-circular vertical plates of two adjacent sheet pile bodies on the same side is opposite. The support assembly includes a pusher, a side abutment, and a center abutment; The side abutments are symmetrically arranged at both ends of the pusher and can be adjusted simultaneously to abut against the U-shaped plate. The middle abutment is arranged in the middle of the pusher and adapts to fit the semi-circular vertical plate surface. The side abutments and the middle abutment work together to form a three-point support structure. Specifically, when supporting the cofferdam, the waler assembly and the support assembly form a multi-layer support for the cofferdam from top to bottom. Each layer of support is connected by bolts and nuts to form a longitudinal integral force-bearing system. The pushing member is composed of several strip-shaped horizontal steel bars and steel sleeves, with two vertically penetrating rectangular grooves symmetrically arranged on it, and mounting grooves are opened on both the front and rear sections of the pushing member; the side pushing member is snapped into the mounting groove, and the middle pushing member is set in the rectangular groove. The length of the pusher is adjusted according to the width of the rectangular cofferdam by increasing or decreasing the number of horizontal steel bars; The middle abutment includes a detachable snap-fit ​​bracket, one end of which is set in a rectangular groove, and the other end is snap-fitted with an abutment block by a pin; the abutment block is crescent-shaped and adapted to the outer wall of the semi-circular vertical plate.

2. The sheet pile cofferdam structure according to claim 1, characterized in that, The waler assembly includes a rectangular side enclosure formed by several steel columns, which is welded to the inner wall of the rectangular cofferdam by connecting strips; and each corner of the rectangular side enclosure is equipped with a reinforcing rib by bolts; the several steel columns are connected by steel sleeves, and the steel sleeves are connected to the steel columns by welding.

3. The steel sheet pile cofferdam structure according to claim 2, characterized in that, A rectangular hole is provided on the steel column corresponding to the support component for the support component to pass through.

4. The sheet pile cofferdam structure according to claim 1, characterized in that, The side abutment includes a U-shaped mounting base, within which two shafts are symmetrically arranged via bearings. A gear is fixedly mounted in the middle of each shaft, and the gears in the two shafts mesh with each other. A push rod is fixedly mounted on each shaft, and two bolts are threaded onto the U-shaped mounting base for tightening the teeth of the gears.

5. The sheet pile cofferdam structure according to claim 4, characterized in that, A compensation block is slidably disposed inside the push rod, and the compensation block is moved by screwing on a bolt.

6. The sheet pile cofferdam structure according to claim 1, characterized in that, The crescent-shaped concave or convex surface of the abutment block is selected for installation according to the arc orientation of the semi-circular upright plate.

7. The sheet pile cofferdam structure according to claim 1, characterized in that, The corner component is interlocked with the adjacent sheet pile body via a U-shaped clamp.

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