Steel cofferdam structure for auxiliary construction of deepwater foundation and its construction method

Abstract

The present application relates to a steel cofferdam structure and a construction method thereof for auxiliary construction of deepwater foundations. Applicable to the field of cofferdam technology. The technical solution includes a plurality of corner connection units, and a cofferdam wall body arranged between two adjacent corner connection units; the cofferdam wall body includes at least one cofferdam unit, which is spliced ​​by a number of hollow steel plates; a first limiting column is provided on the right side of the hollow steel plate, and a first limiting card slot that can cooperate with the first limiting column is provided on the left side of the hollow steel plate, and a sealing airbag that adapts to the gap between the first limiting card slot and the first limiting column is provided in the first limiting card slot; a top sealing structure is provided on the top of the hollow steel plate, and a bottom sealing structure that can cooperate with the top sealing structure to achieve sealing is provided on the bottom of the hollow steel plate; at least one connecting seat is fixed on the inner side of the hollow steel plate; a supporting and fixing mechanism is provided inside the steel cofferdam structure, and the supporting and fixing mechanism is fixedly connected to the connecting seats of each hollow steel plate on the steel cofferdam structure.

Description

Technical Field

[0001] The present invention relates to a steel cofferdam structure for auxiliary construction of deepwater foundations and a construction method thereof, and is applicable to the technical field of cofferdams. Background Art

[0002] A steel cofferdam is a temporary water-retaining structure commonly used in deepwater foundation construction. Its design and construction are crucial to ensuring safe and smooth construction. Steel cofferdams are typically available in single-wall and double-wall configurations. Single-wall steel cofferdams are relatively simple, consisting primarily of side panels and a concrete bottom. The side panels are typically welded from steel plates, with their thickness and strength determined according to project requirements. The concrete bottom forms a solid foundation at the bottom of the cofferdam, preventing water from seeping in. Double-wall steel cofferdams are more complex, consisting of inner and outer wall panels, horizontal ring plates, horizontal cross braces, vertical ribs, and bulkheads. Internal trusses, both horizontal and vertical, are installed between the inner and outer wall panels and serve as the primary load-bearing structure. Bulkheads, vertical steel plates, primarily connect the inner and outer wall panels, dividing the cofferdam into several compartments. This facilitates adjustment of the cofferdam's position and tilt, as well as balancing the difference in head between the inner and outer walls.

[0003] During the steel cofferdam construction process, a block-by-block approach is generally adopted. First, a stable construction platform is constructed. Then, the inner and outer wall panels, vertical ribs, horizontal trusses, and bulkhead panels are laid out and installed according to the design requirements. After all components are welded, a kerosene penetration test is performed to check the weld quality.

[0004] It is commonly used in deep-water foundation construction. Because the water conditions are relatively complex, in order to ensure that the construction can proceed smoothly, most of them adopt a double-walled steel cofferdam structure. The double-walled steel cofferdam structure is not only more complex in structure, but also time-consuming and labor-intensive to install and weld. In addition, after the construction of the bridge piers is completed, the steel cofferdam needs to be dismantled in a timely manner. The existing steel cofferdam is installed by welding, so it needs to be cut when dismantled, which not only delays the construction time, but also the steel cofferdam modules cannot be used again after being cut and dismantled. The recyclability is poor, which further increases the use of construction. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: in view of the above-mentioned problems, a steel cofferdam structure for auxiliary construction of deep-water foundations is provided.

[0006] The technical solution adopted by the present invention is: a steel cofferdam structure for auxiliary construction of deepwater foundation, characterized by comprising: a plurality of corner connection units located at the corners of the steel cofferdam structure, and a cofferdam wall body arranged between two adjacent corner connection units;

[0007] The cofferdam wall comprises at least one cofferdam unit, which is formed by splicing a number of hollow steel plates;

[0008] A first limiting post is provided on the right side of the hollow steel plate, and a first limiting slot that can cooperate with the first limiting post is provided on the left side of the hollow steel plate. A sealing airbag is provided in the first limiting slot that is adapted to the gap between the first limiting slot and the first limiting post;

[0009] The top of the hollow steel plate is provided with a top sealing structure, and the bottom of the hollow steel plate is provided with a bottom sealing structure that can cooperate with the top sealing structure to achieve sealing;

[0010] At least one connecting seat is fixed on the inner side surface of the hollow steel plate; a supporting and fixing mechanism is provided inside the steel cofferdam structure, and the supporting and fixing mechanism is fixedly connected to the connecting seats of each hollow steel plate on the steel cofferdam structure.

[0011] A first guide bar and a first guide groove are respectively provided on the hollow steel plates on the inner and outer sides of the first limiting column, and a first guide groove and a first guide bar are respectively provided on the hollow steel plates on the inner and outer sides of the first limiting groove, and the first guide groove is adapted to the first guide bar.

[0012] A plurality of guide wheels capable of cooperating with the first guide strip are installed in the first guide groove.

[0013] A counterweight settlement unit is provided at the lower end of the cofferdam unit, and a sealing ring is provided between two adjacent counterweight settlement units.

[0014] The counterweight settlement unit includes a box body with a right-angled trapezoidal cross section. A mounting slot that can cooperate with a hollow steel plate is fixed on the top of the box body. A cement pouring pipe that is connected to the inner cavity of the box body is fixed on one surface of the box body.

[0015] One end of the box body is provided with a groove, and the other end of the box body is fixed with a flange matched with the groove. The sealing ring is sleeved on the flange and its two ends are respectively pressed against the two adjacent side surfaces of the box body.

[0016] A cleaning port communicating with the inner cavity of the box is provided in the groove, and a sealing plate cooperating with the inner cavity of the cleaning port is fixed to the bottom of the groove by bolts.

[0017] The corner connection unit includes a steel column, a second limiting column capable of cooperating with the first limiting slot is provided on a first side surface of the steel column, and a second guide strip and a second guide slot are respectively provided on the inner and outer sides of the second limiting column;

[0018] A second limiting slot that can cooperate with the first limiting post is provided on the second side surface of the steel column, and a second guide slot and a second guide strip are provided on the inner and outer sides of the second limiting slot respectively;

[0019] The second guide strip can cooperate with the first guide groove, and the second guide groove can cooperate with the first guide strip.

[0020] The bottom end of the steel column is connected to a wedge-shaped solid steel corner, and the wedge-shaped solid steel corner is provided with a connecting slot and a connecting protrusion that can cooperate with the counterweight settlement unit at the lower end of the cofferdam unit.

[0021] The top sealing structure and the bottom sealing structure both have sealing grooves opened on the end surfaces of the hollow steel plates, and the sealing grooves are filled with sealing strips;

[0022] The sealing groove includes two linear sealing grooves and one circular arc sealing groove. The two linear sealing grooves are respectively located on the inner and outer sides of the end faces, and the linear sealing grooves extend from the left end to the right end of the hollow steel plate; the circular arc sealing groove corresponds to the first limit slot and connects the two linear sealing grooves.

[0023] The support and fixing mechanism includes a fixing structure and an internal support structure;

[0024] The fixing structure includes an adjusting rod, both ends of which are fixed with a cross connecting sleeve, a fixing seat is fixed on the cross connecting sleeve, an external threaded column that can pass through the connecting seat on the hollow steel plate is fixed on the fixing seat, and a locking nut is threadedly connected to the top of the external threaded column;

[0025] The inner support structure includes a support plate installed on the adjusting rod, a swivel seat rotatably connected to the adjusting rod is fixed on one surface of the support plate, a slide groove is provided on the other surface of the support plate, a slider is slidably connected in the slide groove, a locking bolt with one end pressed against the bottom of the slide groove is passed through the slider, and the end of the slider located outside the slide groove is hinged to the adjustable support rod.

[0026] The adjusting rod includes an adjusting sleeve, both ends of the sleeve are threadedly connected with connecting rods, one end of the connecting rod away from the sleeve is fixed with a connecting block that cooperates with the cross connecting sleeve, and the middle position of the outer circular surface of the sleeve is fixed with a limiting ring that cooperates with the swivel seat.

[0027] The adjustable support rod comprises an internal threaded sleeve, both ends of the internal threaded sleeve are threadedly connected to external threaded rods, and one end of the external threaded rod away from the internal threaded sleeve is fixed with a hinge seat hinged to the slider.

[0028] The top of the hollow steel plate is provided with a water inlet connected to the interior thereof, and the bottom of the hollow steel plate is connected with a drainage pipe connected to the interior thereof, and the drainage pipe can be plugged into and matched with the water inlet on the top of the hollow steel plate below.

[0029] A construction method for a steel cofferdam structure for auxiliary construction of a deepwater foundation, characterized by comprising the following steps:

[0030] S1: Install the cofferdam assembly platform according to the designed cofferdam size. Use a crawler crane to lift the box and wedge-shaped solid steel corner to the cofferdam assembly platform and assemble them in pairs. Assemble multiple boxes in sequence to form the counterweight settlement unit at the bottom. Multiple counterweight settlement units cooperate with the wedge-shaped solid steel corner at the corner to form the bottom blade of the cofferdam.

[0031] S2: Use a crawler crane to install the hollow steel plates symmetrically in the installation slots one after another. During the lowering process, the steel columns that match the hollow steel plates at the corners are lowered so that the first limiting columns extend into the first limiting slots on the adjacent hollow steel plates, and the first guide strips extend into the first guide slots on the adjacent hollow steel plates.

[0032] S3: After lowering a layer of hollow steel plates and steel columns, the hollow steel plates and steel columns are fixedly connected to the box body and the wedge-shaped solid steel corner in S1 by bolts. Then, a sealing airbag is filled into the gap between the first limiting column and the first limiting slot. The sealing airbag is then inflated to expand it, completing the sealing of the gap between the two adjacent hollow steel plates.

[0033] S4: Install the upper hollow steel plates and steel columns in sequence to the designed height of the cofferdam according to the construction steps in S2, and simultaneously connect and fix the hollow steel plates of different layers through the fixing structure to form the cofferdam wall;

[0034] S5: Install the corresponding internal support structure in the cofferdam wall according to the cofferdam height, and complete the installation of the cofferdam;

[0035] S6: Lower the cofferdam according to the construction procedures.

[0036] The beneficial effect of the present invention is as follows: the present invention changes the double-walled steel cofferdam used in the cofferdam construction into hollow steel plates that can be spliced ​​together. When making the steel cofferdam, it is only necessary to splice and connect the adjacent hollow steel plates through the cooperation of limit columns, slots, etc., and use a supporting and fixing mechanism to reinforce the connection between the hollow steel plates, so that the hollow steel plates can form a whole to form the cofferdam wall.

[0037] The present invention fixes each hollow steel plate into a whole by means of a fixed structure arranged inside the cofferdam, and cooperates with the internal support structure to support the steel cofferdam from the inside. During use, the fixed structure can be adjusted according to the needs of actual conditions to ensure the tightness of the connection between adjacent hollow steel plates, and the support position is adjusted according to the stress state of the cofferdam by means of an adjustable internal support structure to ensure the firmness and impact deformation resistance of the overall structure of the cofferdam.

[0038] The present invention can achieve sealing by filling sealing air bags and sealing strips in the gaps between adjacent hollow steel plates. There is no need to weld after the splicing is completed, which saves construction time and reduces construction costs. At the same time, since the steel cofferdam is spliced ​​by multiple modules, it can be easily dismantled and the dismantled steel cofferdam modules can be recycled, further reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The diagram is a structural diagram of a steel cofferdam structure used for auxiliary construction of deepwater foundations according to the present invention.

[0040] Figure 2 It is a structural schematic diagram of the cofferdam unit, counterweight settlement unit and fixed structure of the present invention.

[0041] Figure 3 It is a structural schematic diagram of the combination of fixed structures of the present invention.

[0042] Figure 4 It is a structural schematic diagram of the connection between the fixed structure and the internal support structure of the present invention.

[0043] Figure 5 Schematic diagram of the structure of the cofferdam unit.

[0044] Figure 6 This is a structural diagram of part of the cofferdam unit structure.

[0045] Figure 7 for Figure 6 Schematic diagram of the structure from another perspective.

[0046] Figure 8 Schematic diagram of the structure of the steel column in the corner connection unit.

[0047] Figure 9 Schematic diagram of the structure of a wedge-shaped solid steel corner.

[0048] Figure 10 Schematic diagram of the structure of the counterweight settlement unit.

[0049] Figure 11 This is a structural diagram of the counterweight settlement unit from another perspective.

[0050] Figure 12 Schematic diagram of the cross-sectional structure of the counterweight settlement unit.

[0051] Figure 13 It is a structural diagram of a fixed structure.

[0052] Figure 14 Schematic diagram of the structure of the sealed airbag.

[0053] Figure 15 Schematic diagram of the structure of the sealing strip.

[0054] Figure 16 Schematic diagram of the internal support structure.

[0055] In the accompanying drawings: 1, cofferdam unit; 101, hollow steel plate;

[0056] 102, fixed structure; 1021, adjusting rod; 1022, cross connecting sleeve; 1023, fixing seat; 1024, external threaded column;

[0057] 103, sealing airbag; 104, first limiting column; 105, first limiting slot; 106, sealing slot; 107, sealing strip; 108, first guide strip; 109, first guide slot; 110, guide wheel; 111, connecting seat; 112, water injection hole; 113, drain pipe;

[0058] 2. Corner connection unit; 201. Steel column; 202. Wedge-shaped solid steel corner; 203. Second limiting column; 204. Second limiting slot; 205. Second guide bar; 206. Second guide slot; 207. Connecting plate; 208. Connecting slot; 209. Connecting bump;

[0059] 3. Counterweight settlement unit; 301. Box; 302. Mounting slot; 303. Cement pouring pipe; 304. Groove; 305. Sealing plate; 306. Flange;

[0060] 4. Internal support structure; 401. Support plate; 402. Rotating seat; 403. Slide; 404. Slider; 405. Locking bolt; 406. Adjustable support rod;

[0061] 5. Sealing ring. DETAILED DESCRIPTION

[0062] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0063] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0064] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0065] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0066] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described based on the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should be understood that when it is mentioned that an element is connected to another element "on" or "under", it can not only be directly connected to the other element "on" or "under", but also be indirectly connected to the other element "on" or "under" through an intermediate element.

[0067] Example 1: This example is a steel cofferdam structure for auxiliary construction of deep-water foundations, including four corner connection units 2 located at the four corners of the steel cofferdam structure, and a cofferdam wall body arranged between two adjacent corner connection units 2.

[0068] In this example, the cofferdam wall includes two cofferdam units 1, which are composed of three rows and two columns of six hollow steel plates 101. The lower end of the cofferdam unit is connected to a counterweight settlement unit 3.

[0069] In this embodiment, a first limiting column 104 is fixed on one side of the hollow steel plate 101, and a first limiting slot 105 that cooperates with the first limiting column 104 is opened on the other side of the hollow steel plate 101. The sealing airbag 103 is arranged in the first limiting slot 105 and is sleeved on the first limiting column 104.

[0070] In this example, a top sealing structure and a bottom sealing structure that can cooperate with each other to achieve sealing are respectively provided at the top and bottom of the hollow steel plate 101. The top sealing structure and the bottom sealing structure are respectively opened in the top and bottom sealing grooves 106 of the hollow steel plate 101, and the sealing grooves 106 are filled with sealing strips 107.

[0071] In this embodiment, the sealing groove 106 includes two linear sealing grooves and one arc sealing groove. The two linear sealing grooves are respectively located on the inner and outer sides of the end faces, and the linear sealing groove extends from the left end to the right end of the hollow steel plate; the arc sealing groove corresponds to the first limit slot and connects the two linear sealing grooves.

[0072] In this example, the depth of the sealing groove 106 is half the height of the sealing strip 107. The sealing strip 107 extends beyond the sealing groove 106 and can connect the upper and lower hollow steel plates 101 to achieve a good sealing effect. The sealing strip 107 is composed of two parallel straight rubber strips and an arc rubber strip connecting the two rubber strips. The sealing strip 107 is integrally formed to ensure its sealing effect.

[0073] In this embodiment, the side of the hollow steel plate 101 on which the first limiting column 104 is fixed and the side on which the first limiting slot 105 is opened are both fixed with matching first guide bars 108 and first guide grooves 109. A number of guide wheels 110 that match the first guide bars 108 are installed in the first guide grooves 109. The surfaces of the guide wheels 110 are provided with arc grooves that match the first guide bars 108. When in use, they can fit with the first guide bars 108, thereby playing a role of limiting guidance, facilitating the installation between the two hollow steel plates 101 and between the hollow steel plates 101 and the steel column 201, so as to reduce the friction between the two adjacent hollow steel plates 101 during installation and improve the smoothness of installation.

[0074] In this embodiment, connecting seats 111 are fixed to the top and bottom of the inner side of the hollow steel plate 101, and the connecting seats 111 can be connected to the supporting and fixing mechanism provided inside the steel cofferdam structure.

[0075] In this example, the support fixing mechanism includes a fixed structure 102 and an internal supporting structure 4. The fixed structure 102 includes an adjusting rod 1021. Both ends of the adjusting rod 1021 are fixed with a cross connecting sleeve 1022. A fixing seat 1023 is fixed on the cross connecting sleeve 1022. An external threaded column 1024 that passes through the connecting seat 111 is fixed on the fixing seat 1023. A locking nut is threadedly connected to the top of the external threaded column 1024. The cross connecting sleeve 1022 extends in four directions. Not only can the upper and lower fixing seats 1023 be connected into an integral structure through the adjusting rod 1021, but the left and right fixing seats 1023 can also be connected into an integral structure, so that the fixed structure 102 inside the cofferdam maintains the characteristics of an integral structure, thereby improving its internal fixation stability.

[0076] In this embodiment, the inner support structure 4 is installed in the cofferdam wall body, and the inner support structure 4 includes a support plate 401 installed on the adjusting rod 1021. A swivel seat 402 rotatably connected to the adjusting rod 1201 is fixed on one surface of the support plate 401, and a slide groove 403 is provided on the other surface of the support plate 401. A slider 404 is slidably connected in the slide groove 403. A locking bolt 405 is passed through the slider 404, one end of which is pressed against the bottom of the slide groove 403. The slider 404 is hinged to an adjustable support rod 406 at one end located outside the slide groove 403.

[0077] In this embodiment, the corner connection unit 2 includes a steel column 201 and a wedge-shaped solid steel corner 202. A second limiting column 203 that cooperates with the first limiting slot 105 is fixed on the first side of the steel column 201, and a second limiting slot 204 that cooperates with the first limiting column 104 is opened on the second side. In this example, the first and second sides are perpendicular.

[0078] In this embodiment, the steel column 201 is provided with a second guide bar 205 and a second guide groove 206 that respectively cooperate with the first guide bar 108 and the first guide groove 109. The second guide groove 206 is also installed with a guide wheel 110. The top and bottom of the steel column 201 are fixed with connecting plates 207 with bolt holes. The steel column 201 is fixedly connected to the wedge-shaped solid steel corner 202 by bolts. The wedge-shaped solid steel corner 202 is provided with a connecting slot 208 and a connecting protrusion 209 that cooperate with the counterweight settlement unit 3.

[0079] In this example, a sealing ring 5 is provided between two adjacent counterweight settling units 3 to ensure tightness between two adjacent boxes 301. The counterweight settling unit 3 comprises a box 301 having a right-angled trapezoidal cross-section. A mounting slot 302 is fixed to the top of the box 301, which cooperates with the hollow steel plate 101, the first guide bar 108, and the first guide groove 109. A groove 304 is defined at one end of the box 301, which cooperates with the connecting protrusion 209. A flange 306 is fixed at the other end of the box 301, which cooperates with the groove 304. The sealing ring 5 is sleeved on the flange 306, with its ends respectively pressed against the sides of the two adjacent boxes 301.

[0080] In this embodiment, the sealing airbag 103 is composed of an arc segment and two straight-side segments connecting the arc segments. Outward-turned side edges are fixed on the two straight-side segments of the sealing airbag 103. The outward-turned side edges are away from the straight-side segments and contact the first guide strip 108 by passing through the first limiting slot 105. The sealing airbag 103 extends outward from the first limiting slot 105, which can fully fill the gap formed when the two adjacent hollow steel plates 101 are spliced, thereby improving the tightness and sealing of the connection between the two adjacent hollow steel plates 101.

[0081] The construction method of the steel cofferdam structure for auxiliary construction of deepwater foundation in this embodiment specifically includes the following steps:

[0082] S1: Install the cofferdam assembly platform according to the size of the designed cofferdam, use a crawler crane to lift the box 301 and the wedge-shaped solid steel corner 202 to the cofferdam assembly platform, and assemble them in pairs in sequence. Multiple boxes 301 are assembled in sequence to form the counterweight settlement unit 3 at the bottom. Multiple counterweight settlement units 3 cooperate with the wedge-shaped solid steel corner 202 at the corner to form the bottom blade of the cofferdam;

[0083] S2: Use a crawler crane to install the hollow steel plates 101 symmetrically downwards into the installation slots 302 one by one. During the lowering process, the steel column 201 cooperating with the hollow steel plate 101 at the corner makes the first limiting column 104 extend into the first limiting slot 105 on the adjacent hollow steel plate 101, and the first guide bar 108 extends into the first guide slot 109 on the adjacent hollow steel plate 101;

[0084] S3: After lowering a layer of hollow steel plates 101 and steel columns 201, the hollow steel plates 101 and steel columns 201 are fixedly connected to the box 301 and the wedge-shaped solid steel corner 202 in S1 by bolts. Then, the sealing airbag 103 is filled into the gap between the first limiting column 104 and the first limiting slot 105. The sealing airbag 103 is then inflated to expand, thereby completing the sealing of the gap between the two adjacent hollow steel plates 101.

[0085] S4: Install the upper hollow steel plate 101 and the steel column 201 in sequence according to the construction steps in S2 to the designed height of the cofferdam, and simultaneously connect and fix the hollow steel plates 101 of different layers through the fixing structure 102 to form the cofferdam wall;

[0086] S5: Install the corresponding internal support structure 4 in the cofferdam wall according to the cofferdam height, and complete the installation of the cofferdam;

[0087] S6: Lower the cofferdam according to the construction procedures.

[0088] Example 2: This example is basically the same as Example 1, with the only difference being that in this example the adjusting rod 1021 includes an adjusting sleeve, with connecting rods threadedly connected at both ends of the sleeve, a connecting block that cooperates with the cross connecting sleeve 1022 being fixed at the end of the connecting rod away from the sleeve, and a limiting ring that cooperates with the swivel seat 402 being fixed in the middle position of the outer circular surface of the sleeve. The adjusting rod 1021 can be adjusted to extend or shorten according to the connection length at both ends, and the movement of the connecting rods at both ends is controlled by rotating the adjusting sleeve, thereby improving the applicability of the fixed structure 102.

[0089] In this embodiment, the adjustable support rod 406 includes an internal threaded sleeve, both ends of which are threadedly connected to external threaded rods, and the end of the external threaded rod away from the internal threaded sleeve is fixed with a hinge seat hinged to the slider 404. By rotating the internal threaded sleeve, the external threaded rods at both ends are controlled to extend or shorten, which can support the steel cofferdam wall from the inside, and due to its adjustability, it can be adjusted according to the deformation of the steel cofferdam wall during use to ensure the stability of its support for the steel cofferdam wall.

[0090] Example 3: This example is basically the same as Example 1, with the only difference being that in this example, a water injection hole 112 is provided at the top of the hollow steel plate 101, and a drainage pipe 113 connected to the inner cavity of the hollow steel plate 101 is fixed at the bottom of the hollow steel plate 101. The drainage pipe 113 extends through the water injection hole 112 to the next layer of hollow steel plate 101. Water can be injected into the hollow steel plate 101 through the water injection hole 112 to control the settlement of the entire cofferdam and control the height of the cofferdam above the water surface.

[0091] A cement pouring pipe 303 connected to the inner cavity of the box 301 is fixed on one surface of the box 301. The cement pouring pipe 303 is used to pour concrete into the box 301 to form a concrete blade foot. A cleaning port connected to the inner cavity of the box 301 is opened in the groove 304. The cleaning port is used to clean the concrete inside the box 301 through the cleaning port after the cofferdam is removed, so that the box 301 can be continued to be used in the future and can be recycled after the cofferdam is removed to reduce construction costs. A sealing plate 305 that cooperates with the inner cavity of the cleaning port is fixed to the bottom of the groove 304 by bolts.

Claims

1. A steel cofferdam structure for auxiliary construction of deepwater foundations, characterized by: It includes a plurality of corner connection units located at the corners of the steel cofferdam structure, and a cofferdam wall body arranged between two adjacent corner connection units; The cofferdam wall comprises at least one cofferdam unit, which is formed by splicing a number of hollow steel plates; A first limiting post is provided on the right side of the hollow steel plate, and a first limiting slot that can cooperate with the first limiting post is provided on the left side of the hollow steel plate. A sealing airbag is provided in the first limiting slot that is adapted to the gap between the first limiting slot and the first limiting post; The top of the hollow steel plate is provided with a top sealing structure, and the bottom of the hollow steel plate is provided with a bottom sealing structure that can cooperate with the top sealing structure to achieve sealing; At least one connecting seat is fixed on the inner side of the hollow steel plate; a supporting and fixing mechanism is provided inside the steel cofferdam structure, and the supporting and fixing mechanism is fixedly connected to the connecting seats of each hollow steel plate on the steel cofferdam structure; The support and fixing mechanism includes a fixing structure and an internal support structure; The fixing structure includes an adjusting rod, both ends of which are fixed with a cross connecting sleeve, a fixing seat is fixed on the cross connecting sleeve, an external threaded column that can pass through the connecting seat on the hollow steel plate is fixed on the fixing seat, and a locking nut is threadedly connected to the top of the external threaded column; The inner support structure includes a support plate mounted on the adjustment rod, a swivel seat rotatably connected to the adjustment rod is fixed on one surface of the support plate, a slide groove is provided on the other surface of the support plate, a slider is slidably connected in the slide groove, a locking bolt with one end pressed against the bottom of the slide groove is passed through the slider, and an end of the slider located outside the slide groove is hingedly connected to the adjustable support rod; The adjusting rod includes an adjusting sleeve, both ends of the sleeve are threadedly connected to connecting rods, one end of the connecting rod away from the sleeve is fixed with a connecting block that cooperates with the cross connecting sleeve, and a limiting ring that cooperates with the swivel seat is fixed in the middle position of the outer circular surface of the sleeve; The adjustable support rod comprises an internal threaded sleeve, both ends of the internal threaded sleeve are threadedly connected to external threaded rods, and one end of the external threaded rod away from the internal threaded sleeve is fixed with a hinge seat hinged to the slider.

2. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 1 is characterized in that: A first guide bar and a first guide groove are respectively provided on the hollow steel plates on the inner and outer sides of the first limiting column, and a first guide groove and a first guide bar are respectively provided on the hollow steel plates on the inner and outer sides of the first limiting slot, and the first guide groove is adapted to the first guide bar.

3. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 2 is characterized in that: A plurality of guide wheels capable of cooperating with the first guide strip are installed in the first guide groove.

4. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 3 is characterized in that: A counterweight settlement unit is provided at the lower end of the cofferdam unit, and a sealing ring is provided between two adjacent counterweight settlement units.

5. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 4 is characterized in that: The counterweight settlement unit includes a box body with a right-angled trapezoidal cross section. A mounting slot that can cooperate with a hollow steel plate is fixed on the top of the box body. A cement pouring pipe that is connected to the inner cavity of the box body is fixed on one surface of the box body.

6. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 5, characterized in that: One end of the box body is provided with a groove, and the other end of the box body is fixed with a flange matched with the groove. The sealing ring is sleeved on the flange and its two ends are respectively pressed against the two adjacent side surfaces of the box body.

7. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 6, characterized in that: A cleaning port communicating with the inner cavity of the box is provided in the groove, and a sealing plate cooperating with the inner cavity of the cleaning port is fixed to the bottom of the groove by bolts.

8. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 7, characterized in that: The corner connection unit includes a steel column, a second limiting column capable of cooperating with the first limiting slot is provided on a first side surface of the steel column, and a second guide strip and a second guide slot are respectively provided on the inner and outer sides of the second limiting column; A second limiting slot that can cooperate with the first limiting column is provided on the second side surface of the steel column, and a second guide slot and a second guide strip are provided on the inner and outer sides of the second limiting slot respectively; The second guide strip can cooperate with the first guide groove, and the second guide groove can cooperate with the first guide strip.

9. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 8, characterized in that: The bottom end of the steel column is connected to a wedge-shaped solid steel corner, and the wedge-shaped solid steel corner is provided with a connecting slot and a connecting protrusion that can cooperate with the counterweight settlement unit at the lower end of the cofferdam unit.

10. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 9, characterized in that: The top sealing structure and the bottom sealing structure both have sealing grooves opened on the end surfaces of the hollow steel plates, and the sealing grooves are filled with sealing strips; The sealing groove includes two linear sealing grooves and one circular arc sealing groove. The two linear sealing grooves are respectively located on the inner and outer sides of the end faces, and the linear sealing grooves extend from the left end to the right end of the hollow steel plate; the circular arc sealing groove corresponds to the first limit slot and connects the two linear sealing grooves.

11. The steel cofferdam structure for auxiliary construction of deepwater foundation according to claim 10, characterized in that: The top of the hollow steel plate is provided with a water inlet connected to the interior thereof, and the bottom of the hollow steel plate is connected with a drainage pipe connected to the interior thereof, and the drainage pipe can be plugged into and matched with the water inlet on the top of the hollow steel plate below.

12. The construction method of a steel cofferdam structure for auxiliary construction of a deepwater foundation according to claim 11, characterized in that: The steps include: S1: Install the cofferdam assembly platform according to the designed cofferdam size. Use a crawler crane to lift the box and wedge-shaped solid steel corner to the cofferdam assembly platform and assemble them in pairs. Assemble multiple boxes in sequence to form the counterweight settlement unit at the bottom. Multiple counterweight settlement units cooperate with the wedge-shaped solid steel corner at the corner to form the bottom blade of the cofferdam. S2: Use a crawler crane to symmetrically lower the hollow steel plates in sequence and install them in the installation slots. Lower the steel columns that match the hollow steel plates at the corners, so that the first limiting columns extend into the first limiting slots on the adjacent hollow steel plates, and the first guide strips extend into the first guide slots on the adjacent hollow steel plates during the lowering process. S3: After lowering a layer of hollow steel plates and steel columns, the hollow steel plates and steel columns are fixedly connected to the box body and the wedge-shaped solid steel corner in S1 by bolts. Then, a sealing airbag is filled into the gap between the first limiting column and the first limiting slot. The sealing airbag is then inflated to expand it, completing the sealing of the gap between the two adjacent hollow steel plates. S4: Install the upper hollow steel plates and steel columns in sequence to the designed height of the cofferdam according to the construction steps in S2, and simultaneously connect and fix the hollow steel plates of different layers through the fixing structure to form the cofferdam wall; S5: Install the corresponding internal support structure in the cofferdam wall according to the cofferdam height to complete the installation of the cofferdam; S6: Lower the cofferdam according to the construction procedures.

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