Underwater bracing steel pipe pile cofferdam structure and construction method thereof

Abstract

The invention provides an underwater bracing steel pipe pile cofferdam structure and a construction method thereof, and relates to the technical field of cofferdam construction. The underwater supporting steel pipe pile cofferdam structure comprises a cofferdam formed by sequentially connecting a plurality of lock catch steel pipe piles, a supporting frame arranged in the cofferdam and a lowering system connected with the supporting frame. The cofferdam structure can have good stress performance and water stopping performance, and the consumption of cofferdam materials is reduced. Underwater supporting is adopted firstly, all enclosing purlins and inner supports are installed during cofferdam water pumping, all structures of the cofferdam participate in stress at the same time when cofferdam water pumping begins, the use amount of overall steel of the cofferdam is reduced, the construction cost is reduced, and meanwhile the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cofferdam construction, and in particular to an underwater braced steel pipe pile cofferdam structure and a construction method thereof. Background Art

[0002] As the load-bearing structure of long-span bridge pylons, the cap bears all the loads above the bridge cap, which are then transferred to the pile foundation. Therefore, the construction quality of the cap of long-span bridges has become a key control point in bridge construction.

[0003] Currently, the most common cofferdam structures used in deepwater capping construction include steel sheet pile cofferdams, interlocking steel pipe pile cofferdams, steel box cofferdams, and steel hanging box cofferdams. Steel box cofferdams and steel hanging box cofferdams offer high structural rigidity and are suitable for deeper water depths, but they also require complex, high-precision cofferdam fabrication and high material consumption. Steel sheet pile cofferdams and interlocking steel pipe pile cofferdams offer slightly less overall rigidity and are suitable for medium depths below the water level. However, they offer rapid construction and minimal material consumption, making them widely used in inland water capping cofferdam construction.

[0004] The most common construction method for steel sheet pile and interlocking steel pipe pile cofferdams is to first drive the steel sheet piles or steel pipe piles, then pump out the water and install internal supports layer by layer. This method often results in the most unfavorable working conditions for the structure occurring during the pumping and shoring stages. Furthermore, during the pumping and shoring stages, the cofferdam structure has already undergone significant deformation. As pumping continues, the cumulative deformation increases, making it impossible for the purlins and internal supports to provide timely support for the cofferdam deformation. This results in irrational structural stress and significant waste of cofferdam materials. Summary of the Invention

[0005] The purpose of the present invention is to provide an underwater supported steel pipe pile cofferdam structure and a construction method thereof, so as to alleviate the technical problems of waste of construction materials and low construction efficiency caused by unreasonable force on the cofferdam structure in the prior art.

[0006] In a first aspect, the present invention provides an underwater supported steel pipe pile cofferdam structure comprising: a cofferdam formed by sequentially connecting a plurality of locking steel pipe piles, a support frame disposed within the cofferdam, and a lowering system connected to the support frame.

[0007] In combination with the first aspect, each of the locking steel pipe piles is provided with a C-shaped locking buckle and a T-shaped locking buckle; The T-shaped lock of one of the two adjacent locking steel pipe piles is connected to the C-shaped lock of the other one.

[0008] In combination with the first aspect, a waterproof bag is filled between any two adjacent locking steel pipe piles, and grouting is injected into the waterproof bag to form a waterproof structure between the two locking steel pipe piles.

[0009] In combination with the first aspect, the support frame includes a support frame and a multi-layer frame structure, and the support frame is connected between any two adjacent layers of the frame structure; The frame structure includes a purlin and an inner support connected to the inner part of the purlin.

[0010] In combination with the first aspect, the lowering system includes a cantilever beam, a through-hole jack, a precision-rolled threaded steel bar and a load-bearing main beam; The through-hole jack is installed on the cantilever beam, and the through-hole jack cooperates to install the precision-rolled threaded steel bar. The load-bearing main beam is connected to the bottom end of the precision-rolled threaded steel bar, and the load-bearing main beam is connected to the bottom of the support frame.

[0011] In a second aspect, the present invention provides a method for constructing an underwater supported steel pipe pile cofferdam structure, comprising: Install the lowering system; Processing to form a support frame connected to the lowering system; Lowering the support frame; A plurality of locking steel pipe piles are sequentially connected on the outside of the support frame to form a cofferdam.

[0012] In conjunction with the second aspect, the present invention provides a first possible implementation of the second aspect, wherein the step of installing the lowering system includes: Holes are bored at a preset height of the steel casing, cantilever beams are installed, through-hole jacks are installed at the ends of the cantilever beams, and fine-rolled threaded steel bars are inserted into the through-hole jacks; Making a load-bearing main beam, and installing the load-bearing main beam at the lower end of the precision-rolled threaded steel bar; The load-bearing main beam is positioned below the processing platform of the support frame, and after the processing of the support frame is completed, the support frame is connected to the load-bearing main beam.

[0013] In conjunction with the first possible implementation manner of the second aspect, the step of processing and forming a support frame connected to the lowering system includes: Welding brackets on the steel casing to form a processing platform for the support frame; Installing a layer of purlins and inner supports on the processing platform, and connecting the inner supports to the inside of the purlins; Welding a support frame on the installed layer of purlins and inner supports, and installing the next layer of purlins and inner supports on the support frame, and repeating this process until the number of purlins and inner supports reaches a preset number; Guide frames are welded on the surrounding purlins and the inner supports of each layer.

[0014] In conjunction with the second aspect, the step of lowering the support frame includes: Lifting the load-bearing main beam so that the load-bearing main beam contacts and is welded to the lowest purlin; Debugging the lowering system and dismantling the processing platform; The through-hole jack is started to lower the support frame, and after the support frame is lowered into place, a wedge is used to wedge into the gap between the guide frame and the steel casing.

[0015] In combination with the second aspect, the step of sequentially connecting a plurality of locking steel pipe piles on the outside of the support frame to form a cofferdam includes: Weld a circle of I-beams outside the first layer of the perimeter purlin, and use the perimeter purlin as a guide for driving the locking steel pipe piles, and sequentially drive the locking steel pipe piles to a preset depth until the locking steel pipe piles form a closed cofferdam; A waterproof bag is filled between any two adjacent locking steel pipe piles, and grouting is injected into the waterproof bag; Under the condition that all the locking steel pipe piles are tightly matched with the cofferdam purlins, water is pumped out from inside the cofferdam.

[0016] The embodiments of the present invention bring the following beneficial effects: a cofferdam is formed by connecting a plurality of locking steel pipe piles in sequence, a support frame is provided inside the cofferdam, and a lowering system for connecting the support frame is provided. The cofferdam and the support frame form an integral structure, which improves the integrity of the cofferdam, makes the structural force more reasonable and safe, and utilizes the lowering system to realize the lowering operation of the support frame, thereby improving construction efficiency.

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in related technologies, the following briefly introduces the drawings required for use in the specific embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of an underwater supported steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 2 A schematic diagram of the locking steel pipe piles of the underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 3 A schematic plan view of the lowering of the support frame of the underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 4 A schematic elevation view of a lowered support frame of an underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 5 A schematic cross-sectional view of the lowering of the support frame of the underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 6 A schematic diagram of a lowering system for an underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention; Figure 7 A schematic diagram of the steel casing and lowering system in the underwater supported steel pipe pile cofferdam structure provided by an embodiment of the present invention.

[0020] Icons: 1-locking steel pipe pile; 11-C-type locking buckle; 12-T-type locking buckle; 2-support frame; 21-purlin; 22-inner support; 23-support frame; 3-lowering system; 31-cantilever beam; 32-through jack; 33-high-quality rolled threaded steel bar; 34-load-bearing main beam; 4-steel casing; 5-guide frame. DETAILED DESCRIPTION

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and "third" are only used to describe the difference in names and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, unless separately marked, should be understood as basic quantities of the International System of Units, or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0023] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0024] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, an underwater braced steel pipe pile cofferdam structure provided by an embodiment of the present invention comprises: a cofferdam formed by sequentially connecting a plurality of locking steel pipe piles 1, a support frame 2 disposed within the cofferdam, and a lowering system 3 connected to the support frame 2. This underwater braced steel pipe pile cofferdam structure ensures that the cofferdam and support frame 2 are integrally stressed, and the lowering system 3 allows the support frame 2 to be lowered, thereby improving construction efficiency.

[0025] In the embodiment of the present invention, each locking steel pipe pile 1 is provided with a C-shaped locking buckle 11 and a T-shaped locking buckle 12 ; the T-shaped locking buckle 12 of one of the two adjacent locking steel pipe piles 1 is cooperatively connected to the C-shaped locking buckle 11 of the other.

[0026] The C-shaped lock buckle 11 has a notch into which the end of the T-shaped lock buckle 12 can be inserted and snapped, thereby enabling a quick connection between the C-shaped lock buckle 11 and the T-shaped lock buckle 12. Each locking steel pipe pile 1 is mounted with a C-shaped lock buckle 11 and a T-shaped lock buckle 12 at opposite locations along its circumference. The C-shaped lock buckle 11 of any two adjacent locking steel pipe piles 1 can be connected to the T-shaped lock buckle 12 of the other locking steel pipe pile 1, thereby enabling multiple locking steel pipe piles 1 to be connected one by one and formed into a closed cofferdam.

[0027] Furthermore, a waterproof bag is filled between any two adjacent locking steel pipe piles 1, and grouting is injected into the waterproof bag to form a waterproof structure between the two locking steel pipe piles 1, thereby plugging leaks and forming a relatively fixed overall structure of multiple locking steel pipe piles 1.

[0028] See also Figure 4 、 Figure 5 and Figure 6 The support frame 2 includes a support frame 23 and a multi-layer frame structure, and the support frame 23 is connected between any two adjacent frame structures; the frame structure includes a purlin 21 and an inner support 22 connected to the inside of the purlin 21.

[0029] See also Figure 4 、 Figure 5 、 Figure 6 and Figure 7The lowering system 3 includes a cantilever beam 31, a through-hole jack 32, a precision-rolled threaded steel bar 33, and a load-bearing main beam 34; the through-hole jack 32 is installed on the cantilever beam 31, and the through-hole jack 32 cooperates with the installation of the precision-rolled threaded steel bar 33. The load-bearing main beam 34 is connected to the bottom end of the precision-rolled threaded steel bar 33, and the load-bearing main beam 34 is connected to the bottom of the support frame 2. Among them, four through-hole jacks 32 can be used to synchronously lower the support frame 2, thereby preventing the support frame 2 from deflecting during the lowering process. In addition, transverse and longitudinal guide frames 5 can be welded to each layer of purlins 21 and inner supports 22 to limit the support frame 2 and prevent it from deflecting.

[0030] like Figures 1 to 7 As shown, the underwater braced steel pipe pile cofferdam structure construction method provided by an embodiment of the present invention includes: installing a lowering system 3; forming a support frame 2 connected to the lowering system 3; lowering the support frame 2; and sequentially connecting multiple locking steel pipe piles 1 on the outside of the support frame 2 to form a cofferdam. When the cofferdam is pumped out, all purlins and internal support frames 2 have been installed. When the cofferdam is pumped out, all cofferdam structures are simultaneously subjected to stress, which significantly reduces the bending moment of the steel pipe piles and the overall steel consumption of the cofferdam, thereby reducing the project cost while also improving construction efficiency.

[0031] In an embodiment of the present invention, the steps of installing the lowering system 3 include: Holes are bored at a preset height in the steel casing 4, and a cantilever beam 31 is installed. A through-hole jack 32 is installed at the end of the cantilever beam 31, and a finished rolled threaded steel bar 33 is inserted into the through-hole jack 32; Make a load-bearing main beam 34 and install it on the lower end of the finished rolled threaded steel bar 33; Subsequently, the lowering system 3 can be debugged. After the debugging is completed, the load-bearing main beam 34 is located below the processing platform of the support frame 2. After the processing of the support frame 2 is completed, the support frame 2 is connected to the load-bearing main beam 34.

[0032] The load-bearing part of the lowering system 3 (the load-bearing main beam 34) is located below the supporting frame 2, and there is no need to raise the steel casing 4, which saves steel and reduces the structural height.

[0033] In an optional embodiment, four lifting points can be set for the support frame 2, and four through-hole jacks 32 are used to synchronously drive the corresponding precision-rolled threaded steel bars 33, and then drive the load-bearing main beam 34, so that all lifting points of the support frame 2 are lowered synchronously.

[0034] In the embodiment of the present invention, the steps of processing and forming the support frame 2 connected to the lowering system 3 include: Welding the brackets on the steel casing 4 to form a processing platform for the support frame 2, wherein the processing platform can be located 1m above the water surface; A layer of purlin 21 and inner support 22 is installed on the processing platform, and the inner support 22 is connected to the inside of the purlin 21 by welding to prevent the inner support 22 inside the purlin 21 from falling off.

[0035] Weld the support frame 23 onto the installed layer of purlins 21 and inner supports 22, and install the next layer of purlins 21 and inner supports 22 on the support frame 23, and repeat this process until the number of purlins 21 and inner supports 22 reaches the preset number. A guide frame 5 is welded on each layer of purlin 21 and inner support 22, wherein the guide frame 5 and the steel casing 4 should have a distance of 5 cm.

[0036] In an embodiment of the present invention, the step of lowering the support frame 2 includes: The load-bearing main beam 34 is lifted so as to contact and weld the load-bearing main beam 34 to the lowest purlin 21 .

[0037] Debug the lowering system 3 and dismantle the processing platform; The through-hole jack 32 is started to lower the support frame 2. After the support frame 2 is lowered into place, the support frame 2 can be positioned and adjusted, and then a steel wedge is used to wedge into the gap between the guide frame 5 and the steel casing 4 for fixing.

[0038] Furthermore, the steps of sequentially connecting a plurality of locking steel pipe piles 1 on the outside of the support frame 2 to form a cofferdam include: Weld a circle of I-beams outside the first layer of purlins 21, and use the purlins 21 as a guide for driving the locking steel pipe piles 1. Drive multiple locking steel pipe piles 1 to a preset depth in sequence until multiple locking steel pipe piles 1 form a closed cofferdam. A waterproof bag is filled between any two adjacent locking steel pipe piles 1, and grouting is injected into the waterproof bag; wherein the diameter of the waterproof bag is slightly larger than the diameter of the C-shaped locking buckle 11, and water stopping is achieved by grouting in the waterproof bag.

[0039] Divers can be sent to check the fit between the underwater purlin 21 and the locking steel pipe pile 1. If there is a gap, mark it and then fill the gap with steel plates at the marked position.

[0040] Under the condition that all the locking steel pipe piles 1 are tightly matched with the surrounding purlin 21, the water inside the cofferdam is pumped out. When pumping out water, the overall structure of the steel pipe pile cofferdam has been formed and the structure is well stressed.

[0041] In an optional embodiment, holes are bored in the steel casing 4 to install the cantilever beam 31 of the lowering system 3, thereby improving the structural stability.

[0042] In an optional embodiment, the load-bearing main beam 34 is located below the processing platform of the support frame 2, so that the lifting point of the lowering system 3 is at the bottom surface of the support frame 2, avoiding the steel casing 4 from being raised, and saving the material usage of the fine-rolled threaded steel bars 33 of the lowering system 3.

[0043] In an optional embodiment, a corbel is welded on the steel casing 4 to form a processing platform, which can fully utilize the existing steel casing 4 and save materials. The processing platform is located 1.0m above the water surface to minimize the structural height.

[0044] 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater supported steel pipe pile cofferdam structure, characterized in that: include: A cofferdam formed by sequentially connecting a plurality of locking steel pipe piles (1), a support frame (2) arranged in the cofferdam, and a lowering system (3) connected to the support frame (2).

2. The underwater supported steel pipe pile cofferdam structure according to claim 1 is characterized in that: Each of the locking steel pipe piles (1) is provided with a C-shaped locking buckle (11) and a T-shaped locking buckle (12); The T-shaped lock (12) of one of the two adjacent lock steel pipe piles (1) is cooperatively connected to the C-shaped lock (11) of the other one.

3. The underwater supported steel pipe pile cofferdam structure according to claim 1, characterized in that: A waterproof bag is filled between any two adjacent locking steel pipe piles (1), and grouting is performed in the waterproof bag to form a waterproof structure between the two locking steel pipe piles (1).

4. The underwater supported steel pipe pile cofferdam structure according to claim 1, characterized in that: The support frame (2) comprises a support frame (23) and a multi-layer frame structure, and the support frame (23) is connected between any two adjacent layers of the frame structure; The frame structure comprises a purlin (21) and an inner support (22) connected to the inside of the purlin (21).

5. The underwater supported steel pipe pile cofferdam structure according to claim 1 is characterized in that: The lowering system (3) includes a cantilever beam (31), a through-hole jack (32), a precision-rolled threaded steel bar (33) and a load-bearing main beam (34); The through-hole jack (32) is installed on the cantilever beam (31), and the through-hole jack (32) cooperates with the installation of the finished rolled threaded steel bar (33). The load-bearing main beam (34) is connected to the bottom end of the finished rolled threaded steel bar (33), and the load-bearing main beam (34) is connected to the bottom of the support frame (2).

6. A method for constructing an underwater supported steel pipe pile cofferdam structure, characterized in that: include: Install the lowering system (3); Processing and forming a support frame (2) connected to the lowering system (3); Lowering the support frame (2); A plurality of locking steel pipe piles (1) are sequentially connected on the outside of the support frame (2) to form a cofferdam.

7. The underwater support steel pipe pile cofferdam structure construction method according to claim 6 is characterized in that: The steps of installing the lowering system (3) include: A hole is bored at a preset height in the steel casing (4), a cantilever beam (31) is installed, a through-hole jack (32) is installed at the end of the cantilever beam (31), and a precision-rolled threaded steel bar (33) is inserted into the through-hole jack (32); Making a load-bearing main beam (34), and installing the load-bearing main beam (34) on the lower end of the finished rolled threaded steel bar (33); The load-bearing main beam (34) is positioned below the processing platform of the support frame (2), and after the processing of the support frame (2) is completed, the support frame (2) is connected to the load-bearing main beam (34).

8. The underwater braced steel pipe pile cofferdam structure construction method according to claim 7, characterized in that: The step of machining and forming the support frame (2) connected to the lowering system (3) comprises: Welding a bracket on the steel casing (4) to form a processing platform for the support frame (2); Installing a layer of purlins (21) and inner supports (22) on the processing platform, and connecting the inner supports (22) to the inside of the purlins (21); Welding a support frame (23) on the installed layer of purlins (21) and inner supports (22), and installing the next layer of purlins (21) and inner supports (22) on the support frame (23), and repeating this process until the number of layers of purlins (21) and inner supports (22) reaches a preset number; A guide frame (5) is welded to each layer of the surrounding purlin (21) and the inner support (22).

9. The underwater support steel pipe pile cofferdam structure construction method according to claim 8, characterized in that: The step of lowering the support frame (2) comprises: Lifting the load-bearing main beam (34) so ​​that the load-bearing main beam (34) contacts and welds the bottommost purlin (21) to fix the beam; Debugging the lowering system (3) and dismantling the processing platform; The through-hole jack (32) is activated to lower the support frame (2), and after the support frame (2) is lowered into place, a wedge is used to wedge into the gap between the guide frame (5) and the steel casing (4).

10. The underwater braced steel pipe pile cofferdam structure construction method according to claim 8, characterized in that: The steps of sequentially connecting a plurality of locking steel pipe piles (1) on the outside of the support frame (2) to form a cofferdam include: Welding a circle of I-steel outside the first layer of the purlin (21), and using the purlin (21) as a guide for driving the locking steel pipe piles (1), driving a plurality of the locking steel pipe piles (1) in sequence to a preset depth until the plurality of the locking steel pipe piles (1) are surrounded to form a closed cofferdam; A waterproof bag is filled between any two adjacent locking steel pipe piles (1), and grouting is injected into the waterproof bag; Under the condition that all the locking steel pipe piles (1) are tightly matched with the cofferdam purlin (21), water is pumped out from inside the cofferdam.

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