Locking steel pipe pile cofferdam structure and construction method thereof

Abstract

The present application relates to cofferdam structure technical field, especially relates to a kind of lock mouth steel pipe pile cofferdam structure and its construction method;Including pile body and I-beam, and the lower end of pile body is equipped with drill tooth;Two C-shaped tubes are provided in the inner cavity of pile body, the opening of C-shaped tube is opposite and penetrates the lateral wall of pile body, and the two wings of I-beam are inserted into adjacent two C-shaped tubes, and sealing mechanism is provided in C-shaped tube;The present application is connected by integrated C-shaped tube-I-beam rigid plug-in connection and built-in resettable sealing drive mechanism, systematically solves the series of problems in pile sinking interference, connection stiffness and component recovery of traditional process, and compatible static pressure pile planting construction, avoids vibration and soil squeezing effect;Its rigid interlocking connection provides bending stiffness much higher than prior art;Its reversible mechanical design provides fundamental guarantee for realizing nondestructive dismantling and reuse.

Description

Technical Field

[0001] This invention relates to the field of cofferdam structure technology, and in particular to a lock-joint steel pipe pile cofferdam structure and its construction method. Background Technology

[0002] Interlocking steel pipe piles are temporary or permanent retaining structures that connect to each other through specially designed interlocking structures on the sides of the piles to form a continuous wall. They are widely used in water conservancy, bridge, and deep foundation pit engineering. Their main types include U-shaped, Z-shaped, straight, and CT-shaped piles. The CT-shaped interlocking steel pipe pile consists of steel pipe piles with C-shaped interlocks on one side and T-shaped interlocks on the other. During construction, the piles are driven into the soil sequentially using vibration or pressing methods, and the C-shaped and T-shaped interlocks of adjacent piles interlock and tighten, thus connecting to form a continuous retaining or water barrier.

[0003] Steel pipe pile cofferdams are typically not dismantled and installed immediately within the same project. Their service life exhibits significant inter-project isolation: after a project ends, the components must undergo a complete cycle of on-site dismantling, return transportation, comprehensive inspection, maintenance and regeneration, and storage before they can be allocated to the next applicable project for use.

[0004] However, the following problems exist in the current engineering application of CT-type interlocking steel pipe piles: First, the pile driving process relies on vibration or impact, which generates strong vibration and soil squeezing effects, seriously interfering with the surrounding sensitive environment; Second, the C-type and T-type interlocks are flexibly hinged, resulting in low bending stiffness of the connection node and large lateral deformation of the cofferdam as a whole; Third, after construction, the pile body is tightly interlocked with the solidified filling material and soil layer, resulting in huge resistance to pile extraction during demolition, which easily causes damage to the interlocks and pile body, making it difficult to achieve non-destructive recycling and reuse of components.

[0005] Therefore, the problems of large vibrations during pile driving construction, low connection stiffness, and difficulty in dismantling and recycling are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the above problems, the present invention provides a lock-joint steel pipe pile cofferdam structure and its construction method to solve the aforementioned technical problems.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In the first aspect, a lock-joint steel pipe pile cofferdam structure is provided, including a pile body and an I-beam, with drill teeth provided at the lower end of the pile body; two C-shaped pipes are provided in the inner cavity of the pile body, the openings of the C-shaped pipes are opposite to each other and penetrate through the side wall of the pile body, the two wings of the I-beam are inserted into the two adjacent C-shaped pipes, and a sealing mechanism is provided inside the C-shaped pipes.

[0008] The sealing mechanism includes two cover plates that are fixedly installed at the upper and lower ends of the C-shaped tube respectively. Two arc-shaped plates are slidably installed between the two cover plates. Water-stop strips are installed on the arc-shaped plates. A sealing strip with a Z-shaped structure is provided inside the C-shaped tube. A driving part is provided between the two cover plates. A pushing part is also provided on the cover plates.

[0009] The drive unit includes a slide rod fixedly mounted on the cover plate, a bracket slidably mounted on the slide rod, and two rollers rotatably mounted on the bracket that fit against the two corners of the sealing strip.

[0010] Two pressure plates are fixedly installed on the top of the I-beam. When the I-beam is inserted into place, the pressure plates and the cover plate are fixedly connected by bolts. A pressure plate is fixedly installed at the lower end of the I-beam, and the side of the pressure plate is provided with an arc edge.

[0011] When the I-beam is inserted, the pressure plate at its lower end pushes the bracket downward, forcing the roller to roll and deform the sealing strip in a specific direction. This allows the C-shaped tube opening to open simultaneously as the I-beam flange enters. The downward movement of the bracket drives the two arc-shaped plates to slide through the pushing part, causing the water-stop strip on them to press tightly against the sealing gap.

[0012] As a preferred embodiment, the pushing part includes an arc-shaped groove, and the cover plate has arc-shaped grooves that correspond one-to-one with the arc-shaped plates. A slider is slidably installed in the arc-shaped groove. The upper slider is fixedly connected to the upper end of the corresponding arc-shaped plate. A support column is fixedly installed at the upper end of the slider. The upper end of the lower support column is fixedly connected to the lower end of the corresponding arc-shaped plate. An execution part is provided on the cover plate.

[0013] As a preferred embodiment, the actuator includes a push-pull plate. The upper end of the cover plate is slidably mounted with a push-pull plate corresponding to the sealing strip. A limit groove is opened on the push-pull plate, and the support slides through the corresponding limit groove. A wedge is fixedly installed on the upper end of the push-pull plate. The wedge has a right-angled triangular structure that is inclined from top to bottom towards the center of the C-shaped tube. The lower end of the bracket and the lower end of the pressure plate are both fixedly mounted with a push block that cooperates with the corresponding wedge. The push block has a right-angled trapezoidal structure.

[0014] As a preferred embodiment, a rope is fixedly installed on the upper end of the bracket, and the upper end of the rope slides through the cover plate above and is fixedly installed with a limit block. A bolt is threadedly connected to the pressure plate, and the lower end of the bolt passes through the pressure plate and is threadedly connected to the limit block.

[0015] As a preferred embodiment, the outer wall of the C-shaped tube has a fixing plate symmetrical about the opening. The fixing plate is welded to the C-shaped tube, and the end of the fixing plate away from the C-shaped tube passes through the pile body and is welded to the pile body.

[0016] As a preferred embodiment, a pair of reinforcing core materials are pre-embedded inside the sealing strip to constrain its deformation in a predetermined direction.

[0017] As a preferred embodiment, the waterstop strip is made of an elastic material that expands in volume when exposed to water.

[0018] As a preferred option, the connection between the fixing plate and the pile body is a full penetration weld.

[0019] As a preferred option, plow teeth are fixedly installed at the lower end of the cover plate.

[0020] The second aspect of the present invention provides a construction method for a cofferdam using interlocked steel pipe piles, which is completed by using an interlocked steel pipe pile cofferdam structure and includes the following steps: S1, fixing the C-shaped pipe and the sealing mechanism by full penetration welding to ensure accuracy and initial sealing.

[0021] S2. After measurement and layout, static pressure is applied to drive the pile, and the opening direction is strictly calibrated.

[0022] S3. The I-beam presses down on the drive bracket and sealing strip, simultaneously opening the opening and tightening the waterstop strip.

[0023] S4. After the I-beam is in place, tighten the pressure plate and cover plate with bolts.

[0024] The above-mentioned one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: First, the present invention systematically solves a series of problems in the traditional process in terms of pile driving interference, connection stiffness and component recycling through the integrated C-type pipe-I-beam rigid plug connection and the built-in resettable sealing drive mechanism, and is compatible with static pressure pile construction, avoiding vibration and soil squeezing effects; its rigid interlocking connection provides bending stiffness far higher than that of the prior art; its reversible mechanical design provides a fundamental guarantee for achieving non-destructive demolition and reuse.

[0025] Second, after the I-beam is inserted into place and locked, the mechanical constraints formed by multiple surface contacts between its flange and the inner wall of the C-shaped tube, and between the pressure plate and the cover plate, enable the connection node to reliably transmit bending moment and shear force, thereby significantly enhancing the overall lateral stiffness of the cofferdam structure and effectively controlling deformation.

[0026] Third, during dismantling, the upward movement of the I-beam causes the support and other components to reset in the opposite direction to the installation, causing the sealing strip to spring back and the waterstop strip to disengage. This releases the mechanical engagement and sealing pressure before pulling out the pile, reducing the resistance to pile extraction and greatly avoiding damage to the C-shaped pipe, lock, and pile body during forced extraction. This allows the core components to be recovered intact and reused.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0030] Figure 2 This is a schematic diagram of the structure of the I-beam of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure between the pile body and the C-shaped pipe of the present invention.

[0032] Figure 4 This is a partial structural cross-sectional view of the drive unit of the present invention.

[0033] Figure 5 This is a schematic diagram of the structure of the execution unit of the present invention.

[0034] Figure 6 This is a cross-sectional view of the sealing strip and roller shaft of the present invention.

[0035] Reference numerals: 10, pile body; 11, I-beam; 110, pressure plate; 12, C-shaped pipe; 2, sealing mechanism; 20, cover plate; 200, plow teeth; 21, arc plate; 22, waterstop strip; 23, sealing strip; 3, drive unit; 30, slide bar; 31, bracket; 32, roller; 33, rope; 34, bolt II; 4, pushing unit; 40, slider; 41, support column; 5, actuator; 50, push-pull plate; 51, wedge; 52, pushing block. Detailed Implementation

[0036] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] like Figure 1 and Figure 2 As shown, a type of interlocking steel pipe pile cofferdam structure includes a pile body 10 and an I-beam 11. The lower end of the pile body 10 is provided with drill teeth. The inner cavity of the pile body 10 is provided with two C-shaped tubes 12. The openings of the C-shaped tubes 12 are opposite to each other and penetrate through the side wall of the pile body 10. The two wings of the I-beam 11 are inserted into the two adjacent C-shaped tubes 12. A sealing mechanism 2 is provided inside the C-shaped tubes 12.

[0038] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, the sealing mechanism 2 includes two cover plates 20 that are fixedly installed at the upper and lower ends of the C-shaped tube 12 respectively. The upper cover plate 20 has a T-shaped groove. Two arc-shaped plates 21 symmetrical about the openings of the corresponding C-shaped tube 12 are slidably installed between the two cover plates 20. Water-stop strips 22 are installed on the arc-shaped plates 21. A sealing strip 23 is provided between the two arc-shaped plates 21. The sealing strip 23 has a Z-shaped structure. The two ends of the sealing strip 23 are fixedly connected to the two cover plates 20 respectively. A driving part 3 is provided between the two cover plates 20. A pushing part 4 is also provided on the cover plate 20.

[0039] like Figure 4 , Figure 5 and Figure 6 As shown, the drive unit 3 includes a pair of slide rods 30 fixedly installed between two cover plates 20. A bracket 31 is slidably installed on the slide rods 30. The bracket 31 has an inverted concave structure. Two rollers 32 are rotatably installed between the two vertical sections of the bracket 31, which respectively fit with the two corners of the sealing strip 23.

[0040] like Figure 1 , Figure 2 and Figure 6 As shown, two pressure plates 110 are fixedly installed on the top of the I-beam 11. When the I-beam 11 is inserted into place, the pressure plate 110 is fixedly connected to the corresponding cover plate 20 by bolts. A pressure plate is fixedly installed at the lower end of the I-beam 11, and the side of the pressure plate is provided with an arc edge that fits against the sealing strip 23.

[0041] like Figure 1 As shown, the outer wall of the C-shaped tube 12 has a fixing plate symmetrical about the opening. The fixing plate is welded to the C-shaped tube 12. The end of the fixing plate away from the C-shaped tube 12 passes through the pile body 10 and is welded to the pile body 10.

[0042] like Figure 1 As shown, the connection between the fixing plate and the pile body 10 is a full penetration weld. The full penetration welding process achieves complete fusion of the base material and the weld metal, forming a dense, homogeneous connection zone at the connection interface with mechanical properties similar to the base material. Firstly, this ensures the node can reliably transmit the design load, possessing excellent load-bearing capacity and fatigue resistance, providing a crucial strength foundation for the overall structure. Secondly, the dense weld formed by this process constitutes a continuous metallic sealing barrier, effectively isolating the penetration of external water and soil media, achieving the high water tightness required for the project, which is essential for the long-term durability of the structure. Therefore, full penetration welding is a key process choice that simultaneously ensures high connection strength and reliable water tightness of this connection node.

[0043] like Figure 4 As shown, a pair of reinforcing core materials are pre-embedded in the sealing strip 23 to constrain its deformation in a predetermined direction.

[0044] like Figure 3 and Figure 4 As shown, a plow tooth 200 is fixedly installed at the lower end of the cover plate 20 below.

[0045] like Figures 1 to 6 As shown, in specific operations, firstly, each component is manufactured and assembled in the factory or prefabrication site to ensure accuracy and sealing. The main body of the prefabricated steel pipe pile uses a large-diameter steel pipe as the pile body 10 and a small-diameter steel pipe as the C-shaped pipe 12. Multiple fixing plates are welded to the outer circumference of the C-shaped pipe 12. The pile body 10 of the steel pipe pile is precisely marked and CNC plasma cut to open through holes that perfectly match the cross-section of the fixing plates. After grinding the through holes, the C-shaped pipe 12 is placed into the pile body 10 and moved so that the fixing plates pass through the corresponding through holes. Then, the fixing plates are fixed to the pile body 10 by full penetration welding, so that the two C-shaped pipes 12 are fixed in the designated symmetrical positions on the inner wall of the pile body 10.

[0046] After the two C-shaped tubes 12 are welded, they are cut to create an opening for the I-beam 11 to move. The welded joints and openings are then ground. The lower end of the C-shaped tube 12 is then fully welded around its perimeter or sealed with a gasket and bolted to install the lower cover plate 20. The sealing strip 23, sliding rod 30, and other necessary components are pre-fixed on the lower cover plate 20 at corresponding positions. The plow teeth 200 are then welded to the lower end of the lower cover plate 20. The upper cover plate 20 is milled with a T-slot and then bolted to the upper end of the C-shaped tube 12. Positioning lines are then engraved on the pressure plate 110. The pressure plate is then fitted to the corresponding position of the I-beam 11, with the positioning lines aligned with the corresponding edge lines of the I-beam 11. Welding is then performed to complete the pre-assembly process.

[0047] Then, the on-site construction phase began. The construction team first determined the coordinates of the corner points of the cofferdam edge based on the overall design drawings, and set up a high-precision measurement control network on the construction site as the absolute benchmark for all subsequent operations. Next, an external total station was used to accurately transfer the central axis of the cofferdam wall from the control network, and the center point of each steel pipe pile was marked on this axis. At the same time, an external theodolite or laser collimator was used to mark out a horizontal orientation crosshair that was strictly perpendicular to the cofferdam axis at this point. This orientation line is the key basis for controlling the horizontal rotation angle of each pile 10, so as to ensure that the line connecting the openings of a pair of C-shaped pipes 12 inside the pile is perpendicular to the cofferdam wall surface, thereby ensuring that the openings of adjacent piles 10 can be perfectly aligned.

[0048] After the surveying and setting out are completed, the prefabricated piles 10 are driven into the soil using equipment such as a static pressure pile driver. At this time, the plow teeth 200 assist in breaking the soil, and the sealing strip 23 inside the C-shaped tube 12 maintains its initial shape to close the opening. After two adjacent piles 10 are driven into place, the connection operation is carried out. The I-beam 11, with the pressure plate 110 welded to the top and the pressure plate with the arc edge welded to the bottom, is hoisted between the two piles 10. The position is precisely adjusted so that the two wings of the I-beam 11 are aligned with the openings of the C-shaped tubes 12 on the two piles 10. Then, the I-beam 11 is pressed down vertically, and the C-shaped tube is released simultaneously as the I-beam 11 is pressed down. The initial sealing of the opening 12 and the establishment of a new seal: when the lower end of the I-beam 11 first contacts the upper end of the inverted concave bracket 31, the continuous pressing force directly pushes the entire bracket 31 to slide smoothly downward along the vertically fixed slide bar 30; the downward movement of the bracket 31 causes the roller 32 to move downward accordingly. Since the roller 32 is always in close contact with the two corners of the sealing strip 23, they generate a downward rolling force on the corners of the sealing strip 23; this directional rolling force forces the sealing strip 23 to undergo specific and controlled elastic bending deformation between the two fixed ends, thereby gradually loosening the seal on the opening of the C-shaped tube 12.

[0049] Meanwhile, the reinforcing core material pre-embedded in the sealing strip 23 plays a decisive role. It ensures that the sealing strip 23 strictly follows the Z-shaped deformation pattern when subjected to the asymmetrical rolling pressure of the roller 32 and the possible external soil pressure, producing only the directional bending required to open the opening, without unpredictable wrinkling or collapse. This reliably maintains the sliding seal with the opening edge during deformation, allowing the flange of the I-beam 11 to be inserted into the C-tube 12. During this process, the pressure plate at the lower end of the I-beam 11... The arc edge on its side first contacts and continuously pushes the sealing strip 23 inside the C-shaped tube 12, forcing the sealing strip 23 to undergo elastic deformation. The deformed sealing strip 23 drives the two rollers 32 that are tightly fitted with its corner to rotate. The rotation of the rollers 32 pushes the inverted concave bracket 31 to slide along the slide rod 30 fixed between the cover plates 20. Finally, when the sliding of the bracket 31 is about to be in place, the motion is transmitted to the two arc plates 21 through the pushing part 4, so that the water-stop strip 22 installed on the arc plate 21 gradually presses the flange surface of the I-beam 11.

[0050] As the I-beam 11 continues to be inserted, the seal is continuously strengthened until the I-beam 11 is fully inserted to the design depth. At this point, the pressure plate 110 at the top of the I-beam 11 fits tightly against the cover plate 20 above the C-shaped tube 12. Then, a bolt is used to pass through the pressure plate 110 and screw into the upper cover plate 20 to directly connect and fix the pressure plate 110 and the cover plate 20, thereby firmly locking the position of the I-beam 11. At the same time, the lower pressure plate maintains a tight state on the sealing strip 23, thus completing the sealing connection of one node.

[0051] When the cofferdam needs to be dismantled, the operation is carried out in reverse order: first, remove the bolt connecting the pressure plate 110 and the cover plate 20, then lift the I-beam 11. As the I-beam 11 is pulled out, the pressure of the lower pressure plate of the I-beam 11 on the sealing strip 23 is released, the sealing strip 23 returns to its shape, and drives the roller shaft 32 and the bracket 31 to move in the opposite direction. Then, through the pushing part 4, the two arc plates 21 slide back to their original positions, the waterstop strip 22 disengages from the flange of the I-beam 11, the sealing state is released, and the I-beam 11 can be completely removed. The pile body 10 can be pulled out of the soil using pile pulling equipment. After cleaning, inspection, and replacement of worn parts such as the waterstop strip 22, all core components such as the pile body 10, the C-shaped pipe 12 sealing mechanism 2, and the I-beam 11 can be put into the next project for recycling, realizing the disassembly and reuse of the structure.

[0052] like Figure 3 , Figure 4 and Figure 5 As shown, the pushing part 4 includes an arc-shaped groove. The cover plate 20 has an arc-shaped groove that corresponds one-to-one with the arc-shaped plate 21. A slider 40 is slidably installed in the arc-shaped groove. The upper slider 40 is fixedly connected to the upper end of the corresponding arc-shaped plate 21. A support column 41 is fixedly installed on the upper end of the slider 40. The upper end of the lower support column 41 is fixedly connected to the lower end of the corresponding arc-shaped plate 21.

[0053] like Figure 3 , Figure 5 and Figure 6 As shown, the execution unit 5 includes a push-pull plate 50. The upper end of the cover plate 20 is slidably installed with push-pull plates 50 corresponding to the sealing strips 23. The push-pull plates 50 have limit grooves. The support column 41 slides through the corresponding limit grooves. The upper end of the push-pull plate 50 is fixedly installed with a wedge block 51. The wedge block 51 has a right-angled triangular structure that is inclined from top to bottom towards the center of the C-shaped tube 12. The lower end of the bracket 31 and the lower end of the pressure plate 110 are both fixedly installed with a pushing block 52 that cooperates with the corresponding wedge block 51. The pushing block 52 has a right-angled trapezoidal structure.

[0054] like Figure 4 As shown, the waterstop strip 22 is made of an elastic material that expands in volume when exposed to water.

[0055] like Figure 4 , Figure 5 and Figure 6 As shown, a rope 33 is fixedly installed on the upper end of the bracket 31. The upper end of the rope 33 slides through the cover plate 20 above and is fixedly installed with a limit block. A bolt 34 is threadedly connected to the pressure plate 110. The lower end of the bolt 34 passes through the pressure plate 110 and is threadedly connected to the limit block.

[0056] like Figures 3 to 6As shown, during specific operation, when the I-beam 11 is hoisted and aligned, its two wings begin to be vertically pressed into the C-shaped tube 12 of the adjacent pile body 10. The lower end of the I-beam 11 contacts the upper end of the inverted concave bracket 31. As the pressing force continues, the pressure plate 110 and the lower pressure plate together push the bracket 31 to slide downward along the sliding rods 30 on both sides. The downward movement of the bracket 31 directly causes the rollers 32 mounted on its two vertical sections to move downward. These two rollers 32 are always tightly fitted at the two inner corners of the sealing strip 23, thereby applying a pair of downward and directional rolling forces pointing into the cavity to the sealing strip 23. This causes the sealing strip 23 to undergo a predetermined elastic bending deformation, and its upper part contracts towards the inside of the C-shaped tube 12 cavity, thereby gradually and smoothly releasing the seal on the upper edge of the opening and realizing the initial opening of the opening. During this process, the presence of the reinforcing core material ensures that the deformation is controllable and does not twist.

[0057] Simultaneously, the pushing block 52, fixedly mounted on the bracket 31, moves downwards, its inclined surface contacting the inclined surface of the wedge block 51 fixedly mounted on the upper end of the corresponding push-pull plate 50 and generating relative sliding. Since the push-pull plate 50 is slidably fitted onto the support column 41 through its limiting groove, and the support column 41 is fixedly connected to the corresponding arc-shaped plate 21, when the wedge block 51 is squeezed by the inclined surface of the pushing block 52, it will drive the entire push-pull plate 50 to slide horizontally along the cover plate 20. The horizontal movement of the push-pull plate 50 is transmitted to the support column 41 through its limiting groove, forcing the support column 41 to move along the trajectory of the arc-shaped groove, thereby driving the wedge block 51 fixedly connected to the support column 41. The arc-shaped plates 21 are guided by the arc-shaped groove between the cover plates 20, so that the corresponding two arc-shaped plates 21 slide stably closer together; as the I-beam 11 is continuously pressed in and the bracket 31 continues to move down, the pushing distance of the pushing block 52 on the wedge block 51 continues to increase, and the sliding displacement of the two arc-shaped plates 21 also increases accordingly, until the water-stop strip 22 made of water-swellable elastic material installed on it is tightly pressed against the flange surface of the inserted I-beam 11, forming a preliminary compression contact seal at the connection between the I-beam 11 and the opening of the C-shaped tube 12; this seal will be further strengthened by the self-expansion of the water-stop strip 22 after subsequent contact with water.

[0058] To ensure that the linkage system can automatically reset after the I-beam 11 is pulled out, the upper end of the bracket 31 is connected to a limit block via a rope 33. The rope 33 slides through the upper cover plate 20. When the I-beam 11 is inserted into place, the lower end of the bracket can be threaded to the limit block by rotating the bolt 34 on the pressure plate 110. When disassembling, the I-beam 11 is lifted, and the bracket 31 resets under the traction of the rope 33 and the limit block, causing the push block 52 to move upward, the sealing strip 23 to regain its elasticity, the arc plate 21 to slide backward under the action of the reset force, the water-stop strip 22 to disengage, and the opening to re-close, completing the reset of all components and preparing for reuse.

[0059] The entire process of pressing in and opening is achieved by using the bracket 31 as a power converter, which simultaneously converts the vertical pressing force of the I-beam 11 into the rolling force that drives the deformation of the sealing strip 23 and the horizontal extrusion force that drives the sliding of the arc plate 21, thus realizing the mechanical linkage between the dynamic sealing release of the opening and the establishment of the contact seal.

[0060] In addition, the present invention also provides a construction method for a lock-joint steel pipe pile cofferdam, which is completed by using a lock-joint steel pipe pile cofferdam structure, including the following steps: S1, in the factory, the C-shaped pipe 12 is fully welded to the steel pipe pile body 10 through the fixing plate on its outer wall to form a rigid whole. Then, upper and lower cover plates 20 are installed at both ends of the C-shaped pipe 12 to form a closed cavity, and a sealing mechanism 2 is assembled in the cavity: the sealing strip 23 with pre-embedded reinforcing core material is fixed at both ends, so that the roller 32 on the inverted concave bracket 31 fits the corner of the sealing strip 23, and the arc plate 21 with water-stop strip 22 is connected to the pushing part 4 in place.

[0061] S2. On-site, based on the survey network, the direction of the pile core and the opening of the C-shaped pipe 12 is determined. The pile body 10 is clamped by a static pressure pile driver. With the assistance of the lower drill teeth and plow teeth 200, it is rotated and pressed into the soil to the design elevation. The entire process is calibrated to ensure that the openings of the C-shaped pipe 12 of adjacent piles are accurately aligned.

[0062] S3. Hoist the I-beam 11 so that its two wings are aligned with the openings of the two adjacent piles. When pressing down, the lower end of the I-beam 11 pushes the bracket 31 down along the slide bar 30, which drives the roller 32 to roll the sealing strip 23, forcing it to bend in a direction and thus opening the opening simultaneously. At the same time, the bracket 31 moves down and pushes the wedge block 51 on the push-pull plate 50 through the inclined surface of the push block 52 at its lower end, which in turn drives the arc plate 21 to slide towards each other along the arc groove, so that the waterstop strip 22 presses tightly against the flange of the I-beam 11 to achieve a seal.

[0063] S4. When the I-beam 11 is inserted to the design depth, the pressure plate 110 at its top fits against the upper cover plate 20. Immediately tighten the two with bolt one. At this time, the bracket 31 is pulled by the rope 33 and the limit block, and can be locked with bolt two 34. The entire node enters a stable bearing and sealing state.

[0064] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0065] Furthermore, the terms "first," "second," "number one," and "number two" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," "number one," or "number two" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "connected" 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 mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A cofferdam structure using interlocking steel pipe piles, comprising piles and I-beams, wherein the lower end of the piles is provided with drill teeth; characterized in that: The pile body cavity is equipped with two C-shaped tubes with openings facing away from each other and penetrating the side wall of the pile body. The two wings of the I-beam are inserted into the two adjacent C-shaped tubes, and a sealing mechanism is installed inside the C-shaped tubes. The sealing mechanism includes two cover plates that are fixedly installed at the upper and lower ends of the C-shaped tube respectively. Two arc-shaped plates are slidably installed between the two cover plates. Water-stop strips are installed on the arc-shaped plates. A sealing strip with a Z-shaped structure is provided inside the C-shaped tube. A driving part is provided between the two cover plates. A pushing part is also provided on the cover plates. The drive unit includes a slide rod fixedly mounted on the cover plate, a bracket slidably mounted on the slide rod, and two rollers rotatably mounted on the bracket that fit against the two corners of the sealing strip; Two pressure plates are fixedly installed on the top of the I-beam. When the I-beam is inserted into place, the pressure plates and the cover plate are fixedly connected by bolts. A pressure plate is fixedly installed at the bottom of the I-beam, and the side of the pressure plate is provided with an arc edge. When the I-beam is inserted, the pressure plate at its lower end pushes the bracket downward, forcing the roller to roll and deform the sealing strip in a specific direction. This allows the C-shaped tube opening to open simultaneously as the I-beam flange enters. The downward movement of the bracket drives the two arc-shaped plates to slide through the pushing part, causing the water-stop strip on them to press tightly against the sealing gap.

2. The interlocking steel pipe pile cofferdam structure according to claim 1, characterized in that: The pushing part includes an arc-shaped groove. The cover plate has arc-shaped grooves that correspond one-to-one with the arc-shaped plates. A slider is slidably installed in the arc-shaped groove. The upper slider is fixedly connected to the upper end of the corresponding arc-shaped plate. A support column is fixedly installed on the upper end of the slider. The upper end of the lower support column is fixedly connected to the lower end of the corresponding arc-shaped plate. An execution part is provided on the cover plate.

3. The interlocking steel pipe pile cofferdam structure according to claim 2, characterized in that: The actuator includes a push-pull plate. Each of the upper ends of the cover plate is slidably mounted with a push-pull plate corresponding to a sealing strip. A limit groove is provided on the push-pull plate. The support column slides through the corresponding limit groove. A wedge is fixedly mounted on the upper end of the push-pull plate. The wedge has a right-angled triangular structure that is inclined from top to bottom towards the center of the C-shaped tube. A push block that cooperates with the corresponding wedge is fixedly mounted on the lower end of the bracket and the lower end of the pressure plate. The push block has a right-angled trapezoidal structure.

4. The interlocking steel pipe pile cofferdam structure according to claim 1, characterized in that: A rope is fixedly installed on the upper end of the bracket. The upper end of the rope slides through the cover plate above and is fixedly installed with a limit block. A bolt is threadedly connected to the pressure plate. The lower end of the bolt passes through the pressure plate and is threadedly connected to the limit block.

5. A cofferdam structure with interlocking steel pipe piles according to claim 1, characterized in that: The outer wall of the C-shaped tube has a symmetrical fixing plate about the opening. The fixing plate is welded to the C-shaped steel tube and fixed. The end of the fixing plate away from the C-shaped tube passes through the pile body and is welded to the pile body.

6. The interlocking steel pipe pile cofferdam structure according to claim 1, characterized in that: A pair of reinforcing core materials are pre-embedded inside the sealing strip to restrain its deformation in a predetermined direction.

7. The interlocking steel pipe pile cofferdam structure according to claim 1, characterized in that: The waterstop strip is made of an elastic material that expands in volume when exposed to water.

8. A cofferdam structure with interlocking steel pipe piles according to claim 1, characterized in that: The connection between the fixing plate and the pile body is a full penetration weld.

9. A cofferdam structure with interlocking steel pipe piles according to claim 1, characterized in that: The lower end of the cover plate is fixedly fitted with plow teeth.

10. A method for constructing a cofferdam using interlocking steel pipe piles, characterized in that: The cofferdam structure, constructed using the interlocking steel pipe piles as described in claim 1, is completed in accordance with the following steps: S1. Full penetration welding is used to fix the C-shaped tube and the sealing mechanism to ensure accuracy and initial sealing; S2. After measurement and layout, static pressure pile driving is performed, and the opening direction is strictly calibrated; S3. The I-beam presses down on the drive bracket and sealing strip, simultaneously opening the opening and tightening the waterstop strip; S4. After the I-beam is in place, use bolts to tighten the pressure plate and cover plate.

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