Construction method for steel sheet pile cofferdam in deepwater area

Abstract

The invention relates to the field of bridge construction, and particularly discloses a deepwater area steel sheet pile cofferdam construction method which comprises the following steps: steel casings are fixed, specifically, the steel casings are driven into a calibrated construction area, and the steel casings are fixed at four corners of a cofferdam area; a guide beam is erected, the guide beam is erected on the periphery of the steel casing, the guide beam is a cross beam, and a limiting groove is formed in the guide beam; the steel sheet piles are sunk, the steel sheet piles are inserted into the limiting grooves of the guide beams and driven to the designed depth, firstly, the steel sheet piles located at the four corners are driven, and then the steel sheet piles are driven on each side from the two sides to the middle in an extending mode till the steel sheet piles on each side are in butt joint and folded in the middle of the side. The technical scheme has the beneficial effects that the steel casing can determine the construction area and the position of the cofferdam, and the arranged guide beams can limit and guide the steel sheet piles. When the steel sheet piles sink, the deviation of the steel sheet piles can be reduced through the construction mode from the two ends to the middle, the steel sheet piles on the single side can be folded more smoothly, and the construction precision of the steel sheet piles is high.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and in particular to a method for constructing a steel sheet pile cofferdam in a deep water area. Background Art

[0002] A cofferdam is a temporary retaining structure used to build permanent water conservancy facilities during water conservancy project construction. Its function is to prevent water and soil from entering the construction site, allowing drainage to be drained within the cofferdam, foundation pits to be excavated, and buildings to be constructed.

[0003] Steel sheet pile cofferdam is the most commonly used sheet pile cofferdam, which can be constructed in deep water areas and can be reused many times. During the construction process, the steel sheet piles need to ensure verticality and sealing, so the steel sheet piles need to be limited during construction. In the prior art, in order to improve the construction quality of steel sheet piles, some innovations have been made, such as a deep-water super-long steel sheet pile cofferdam construction device with announcement number CN116065612A, which includes an inner guide beam of the cofferdam, an outer guide beam of the cofferdam and steel sheet piles, and also includes a first limiting mechanism for limiting the initial insertion of the super-long plate body of the steel sheet pile between the inner guide beam of the cofferdam and the outer guide beam of the cofferdam, and an auxiliary limiting mechanism for limiting the bottom position of the steel sheet piles between the inner guide beam of the cofferdam and the outer guide beam of the cofferdam into the deep water area. It can only limit the first steel sheet pile at a specific position and lacks flexibility. Summary of the Invention

[0004] In response to the defects in the existing technology, the present invention provides a method for constructing steel sheet pile cofferdams in deep water areas, which can limit the steel sheet piles at any position and ensure high-quality construction of the steel sheet piles.

[0005] A technical solution provided by the present invention is: a method for constructing a steel sheet pile cofferdam in a deep water area, comprising:

[0006] Fix the steel casing, drive it into the marked construction area, and fix the steel casing at the four corners of the cofferdam area;

[0007] Set up the guide beam, set up the guide beam on the periphery of the steel casing, the guide beam is a cross beam, and a limit slot is set on the guide beam.

[0008] Sink the steel sheet piles, insert them into the limit grooves of the guide beam and drive them to the designed depth. The steel sheet piles at the four corners are driven in first, and then the steel sheet piles on each side are driven in sequentially along the length of the guide beam until the steel sheet piles on each side are fully covered and the steel sheet piles on the four sides form a complete cofferdam.

[0009] The beneficial effects of this technical solution are as follows: the steel casing determines the construction area and the orientation of the cofferdam, and the guide beams limit and guide the steel sheet piles. When sinking the steel sheet piles, the construction method from both ends to the center reduces deviation of the steel sheet piles, allowing the steel sheet piles on one side to close more smoothly and achieving high construction precision.

[0010] Furthermore, the guide beam includes a main beam and a sliding arm, the sliding arm is movably assembled on the main beam, and the limiting groove is a spacing area between the main beam and the sliding arm.

[0011] Furthermore, a supporting platform is fixed on the steel casing, and both ends of the guide beam are respectively fixed on the two supporting platforms.

[0012] Furthermore, before driving the first steel sheet pile, baffles are arranged on the outside or inside of the guide beam according to the direction of water flow, and the baffles are arranged at intervals corresponding to the positions where the steel sheet piles are driven.

[0013] Furthermore, a guide ridge is provided on the side of the baffle facing the water flow, and two inclined guide surfaces are formed between the guide ridge and the two sides of the baffle.

[0014] Furthermore, a first slide rail is provided on the top of the guide beam, and the first slide rail is provided along the length direction of the guide beam. A moving block is slidably provided on the guide beam through the first slide rail. One end of the sliding arm is fixedly connected to the moving block through a cantilever, and the other end is an open end.

[0015] Furthermore, a second slide rail is provided on the side of the guide beam facing the sliding arm, and an auxiliary block is slidably provided on the second slide rail. The auxiliary block is connected to the sliding arm through a support rod, and the cantilever and the support rod form a triangular support for the movable arm.

[0016] Furthermore, a roller is provided at the end of the guide beam, a cable is provided on the roller, and the cable is connected to the sliding arm.

[0017] Furthermore, a bracket for limiting the baffle is welded on the guide beam in the direction of the water flow, and a retaining ring for plugging the baffle is provided on the bracket. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0019] Figure 1 This is a schematic diagram of the construction of the first steel sheet pile according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the construction of a single-segment steel sheet pile according to an embodiment of the present invention;

[0021] Figure 3 This is a construction diagram of driving all steel sheet piles according to an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of the connection between the sliding arm and the main beam in an embodiment of the present invention.

[0023] Reference numerals: steel casing 100 , support platform 110 , main beam 200 , steel sheet pile 300 , sliding arm 400 , cantilever 410 , moving block 420 , support rod 440 , roller 500 , cable 510 , retaining ring 600 . DETAILED DESCRIPTION

[0024] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0026] like Figure 1-4 As shown, this embodiment provides a method for constructing a steel sheet pile cofferdam in a deepwater area. The deepwater area is complex and may have undercurrents. When constructing the steel sheet piles 300, it is necessary to ensure the verticality of the steel sheet piles 300 to avoid excessive deviation from the designed size. The construction method of this embodiment includes: fixing the steel casing 100, driving the steel casing 100 into the marked construction area, and fixing the steel casing 100 at the four corners of the cofferdam area; erecting the guide beam, and erecting the guide beam on the periphery of the steel casing 100. The guide beam is a horizontal beam with a limit groove provided on the guide beam; sinking the steel sheet piles 300, inserting the steel sheet piles 300 into the limit groove of the guide beam and driving them to the designed depth. The steel sheet piles 300 located at the four corners are driven in first, and then the steel sheet piles on each side are driven in sequentially along the length direction of the guide beam until the steel sheet piles on each side are fully covered and the steel sheet piles on the four sides form a complete cofferdam. The steel casing 100, fixed at the four corners, accurately defines the size and shape of the cofferdam and limits the position of the steel sheet piles 300, ensuring the construction quality of the steel sheet piles 300. During construction, the guide beams can be placed inside or outside the steel casing 100. In other words, the steel casing 100 can be located inside or outside the cofferdam formed by the steel sheet piles 300.

[0027] In some embodiments, once the steel sheet piles are fully laid on the first side, the remaining three sides can be constructed from both sides toward the center, ultimately closing in the center of each side. The steel casing 100 can determine the construction area and the orientation of the cofferdam, and the guide beams can limit and guide the steel sheet piles 300. When sinking the steel sheet piles 300, the construction method from both ends to the center can reduce deviation of the steel sheet piles 300, allowing the steel sheet piles 300 on a single side to close more smoothly, thereby improving the construction accuracy of the steel sheet piles 300.

[0028] In some embodiments, the guide beam comprises a main beam 200 and a sliding arm 400. The sliding arm 400 is movably mounted on the main beam 200, with a retaining groove forming the space between the main beam 200 and the sliding arm 400. The sliding arm 400 and the guide beam are positioned on the inner and outer sides of the steel sheet piles 300, respectively, thereby constraining the steel sheet piles 300 in a substantially vertical position. This ensures that the steel sheet piles 300 maintain a designed angle during the sinking process, preventing them from shifting. The guide beam comprises four sections, distributed around the cofferdam construction area. Each section of the guide beam is equipped with a sliding arm 400, meaning that each sliding arm 400 is responsible for the construction of the steel sheet piles 300 in its respective section.

[0029] Furthermore, one end of the sliding arm 400 is connected to the main beam 200, and the other end is open, in an open state. The sliding arm 400 moves to a position where a steel sheet pile 300 can be driven in. After the current steel sheet pile 300 is driven in to the designed elevation, the sliding arm 400 is moved to the next position. The end of the movable arm connected to the main beam 200 overlaps with the steel sheet pile 300 in the direction of movement, which prevents the end of the sliding arm 400 connected to the main beam 200 from passing through the steel sheet pile 300. Correspondingly, the other end of the sliding arm 400 is in an open state and will not be blocked by the steel sheet pile 300, thus enabling unidirectional movement. During construction, the movable arm is moved to the farthest end facing the open end, which is the position where the first steel sheet pile 300 is driven in.

[0030] Furthermore, a first slide rail is provided at the top of the guide beam, extending along its length. A movable block 420 is slidably mounted on the guide beam via the first slide rail. The movable block 420 comprises a sliding structure that slidably engages with the first slide rail. The sliding arm 400 is fixedly connected to the movable block 420 via a cantilever 410. Changing the position of the movable block 420 allows the sliding arm 400 to be moved to different positions to guide the steel sheet piles 300 at different locations. To enhance support stability, a second slide rail is provided on the side of the guide beam opposite the sliding arm 400. An auxiliary block is slidably mounted on the second slide rail. The auxiliary block is connected to the sliding arm 400 via a support rod 440. The cantilever 410 and the support rod 440 form a triangular support for the movable arm, ensuring sufficient stability. Specifically, both the first and second slide rails can be chute slots, with a stopper edge disposed at the top edge of the chute to block the sliding structure. Correspondingly, the sliding structure can be a slider that slides within the chute slot. The second slider is an inclined slot that opens toward the guide beam. The auxiliary block is the bottom of the support rod 440. When the slider, along with the cantilever 410 and the sliding arm 400, moves synchronously, it also drives the support rod 440 within the inclined slot, supporting the sliding arm 400 as it moves to a new position. To facilitate adjustment of the sliding arm 400, a cable 510 is connected to the outside of the sliding arm 400, allowing it to be directly pulled. Furthermore, a reel 500 can be installed at the end of the guide beam, with the free end of the cable 510 secured to the reel. By rotating the reel 500, the cable 510 is reeled in, shortening and simultaneously pulling the sliding arm 400 toward the other side. During construction, if the work is proceeding smoothly, only the first few driven steel sheet piles 300 can be restrained and guided, while subsequent steel sheet piles 300 only need to be aligned with the previous one. The guide beam can also provide support on one side, which can effectively prevent the steel sheet piles 300 from running off course. In the case where only the first few steel sheet piles 300 need to be restricted, the movable arm can be directly pulled to the very end to free up construction space for the remaining steel sheet piles 300. Furthermore, the overall process of the steel sheet piles 300 during construction only needs to restrict and guide the first few, that is, of the four sections of the guide beam, the movable arm only needs to be installed on the section where the initial construction is carried out. The first slide rail and the second slide rail on the guide beam are both through-type settings, and the movable arm can be directly slid out after use to avoid affecting the construction of the steel sheet piles 300 in other sections.

[0031] like Figure 1-3As shown, in some embodiments, the movable arm is first used to drive the steel sheet piles located on the side of one segment. This steel sheet pile is also the first steel sheet pile. The steel sheet piles are then driven in sequentially until the entire side is covered. The steel sheet piles on this side are then used to drive the steel sheet piles of the remaining three segments into the riverbed. In other words, the movable arm only needs to be used on one segment and can be removed after use.

[0032] In some embodiments, a support platform 110 is fixed to the steel casing 100, and the two ends of the guide beam are respectively fixed to the two support platforms 110. The support platforms 110 can fix the guide beam to the steel casing 100, so that the guide beam has sufficient strength and will not deform during construction, thereby not affecting the accuracy of the steel sheet pile 300.

[0033] In some embodiments, complex hydrological conditions, high water flow velocities, or undercurrents in construction areas can impact the sinking steel sheet piles 300, causing them to deflect and shift from their intended placement. To mitigate the impact of the water flow on the steel sheet piles 300, some impact can be absorbed during construction, reducing the effect of the water flow on the steel sheet piles 300. Specifically, before driving the first steel sheet pile 300, baffles are positioned on either the outside or inside of the guide beam, depending on the direction of the water flow. These baffles are spaced at intervals corresponding to the locations where the steel sheet piles 300 will be driven. The width of the baffles is twice the width of the steel sheet piles 300. A bracket for retaining the baffles is welded to the guide beam facing the water flow. A retaining ring 600 is provided on the bracket to receive the baffles.

[0034] In some embodiments, the baffle is provided with a guide rib on the side facing the water flow, forming two inclined guide surfaces between the guide rib and the two sides of the baffle. Correspondingly, the area defined by the retaining ring 600 is triangular, matching the cross-sectional shape of the baffle. This triangular area prevents the baffle from twisting during the sinking process, thus ensuring the ultimate diversion effect. The guide rib protrudes from the baffle. When encountering water flow, the water flow corresponding to the baffle position is split into two parts by the guide rib. The two parts of water flow are diffused to the sides by the two guide surfaces, thereby forming a certain area of ​​stability on the back of the baffle. During construction, the steel sheet piles 300 enter the deep water area through this stable area and are driven into the riverbed.

[0035] In some instances, after the construction of the steel sheet piles 300 is completed, the steel sheet piles 300 driven into the riverbed will form a complete cofferdam. In order to increase the stability of the cofferdam, purlins are fixed on the steel sheet piles 300. Since the cofferdam is in water, the outside of the steel sheet piles 300 is river water, and the purlins cannot be installed on the outside of the steel sheet piles 300. Therefore, the purlins are fixed on the inside of the steel sheet piles 300. In order to increase stability, multiple purlins are set from top to bottom in the cofferdam. During construction, the pumping out of the accumulated water in the cofferdam and the construction of purlins can be carried out alternately. That is, after installing one layer of purlins, the water level is pumped to below the installation position of the next purlin, so that the next purlin can also be installed in the air, until the water in the cofferdam is pumped out and all the purlins in the cofferdam are completed. Pumping out water while installing purlins can maximize the balance of the pressure difference during the construction process and prevent the steel sheet piles 300 from being compressed and deformed. To ensure continued use of the guide beams, after all the steel sheet piles 300 are driven into the riverbed, the guide beams outside the cofferdam are welded to the outside of the steel sheet piles 300, securing them. The combined forces of the guide beams and the surrounding purlins secure the steel sheet piles 300, increasing their stability.

[0036] In the description of this application, it should be understood that the terms used in this application are for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0037] In this application, unless otherwise specified or limited, the terms "connected," "connect," "fixed," and the like should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0038] In the description of the present invention, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, systems, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A method for constructing a steel sheet pile cofferdam in a deep water area, characterized in that: include: Fixing the steel casing (100), driving the steel casing (100) into the marked construction area, and fixing the steel casing (100) at the four corners of the cofferdam area; The guide beam is erected on the periphery of the steel casing (100), the guide beam being a cross beam and having a limiting groove arranged on the guide beam. The steel sheet piles (300) are sunk and inserted into the limiting grooves of the guide beam and driven to the designed depth. The steel sheet piles (300) at the four corners are driven in first, and then the steel sheet piles (300) on each side are driven in sequentially along the length direction of the guide beam until the steel sheet piles (300) on each side are fully covered and the steel sheet piles (300) on the four sides form a complete cofferdam.

2. A deepwater steel sheet pile cofferdam construction method according to claim 1, characterized in that: The guide beam comprises a main beam (200) and a sliding arm (400), wherein the sliding arm (400) is movably assembled on the main beam (200), and the limiting groove is a spacing area between the main beam (200) and the sliding arm (400).

3. The method for constructing a steel sheet pile cofferdam in deep water according to claim 1, characterized in that: A support platform (110) is fixed on the steel casing (100), and both ends of the guide beam are respectively fixed on the two support platforms (110).

4. The method for constructing a steel sheet pile cofferdam in deep water according to claim 1, characterized in that: Before driving the first steel sheet pile (300), a baffle is arranged on the outside or inside of the guide beam according to the direction of water flow, and the baffles are arranged at intervals corresponding to the positions where the steel sheet piles (300) are driven.

5. A deepwater steel sheet pile cofferdam construction method according to claim 4, characterized in that: A guide ridge is provided on one side of the baffle facing the water flow, and two inclined guide surfaces are formed between the guide ridge and the two sides of the baffle.

6. The method for constructing a steel sheet pile cofferdam in deep water according to claim 2, characterized in that: A first slide rail is provided on the top of the guide beam, and the first slide rail is provided along the length direction of the guide beam. A moving block (420) is provided on the guide beam for sliding through the first slide rail. One end of the sliding arm (400) is fixedly connected to the moving block (420) through a cantilever (410), and the other end is an open end.

7. A method for constructing a steel sheet pile cofferdam in deep water according to claim 6, characterized in that: A second slide rail is further provided on the side of the guide beam facing the sliding arm (400), an auxiliary block is slidably provided on the second slide rail, and the auxiliary block is connected to the sliding arm (400) via a support rod (440), and the cantilever (410) and the support rod (440) form a triangular support for the movable arm.

8. The method for constructing a steel sheet pile cofferdam in deep water according to claim 7, characterized in that: A roller (500) is provided at the end of the guide beam, a cable (510) is provided on the roller (500), and the cable (510) is connected to the sliding arm (400).

9. The method for constructing a steel sheet pile cofferdam in deep water according to claim 5, characterized in that: A bracket for limiting a flow baffle is welded on the guide beam facing the direction of water flow, and a retaining ring (600) for inserting the flow baffle is provided on the bracket.

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