Steel pipe pile cofferdam

Abstract

The utility model provides a kind of steel pipe pile cofferdam.The steel pipe pile cofferdam includes multiple steel pipe piles enclosed in the outer periphery of bearing platform, and the inner side of the lower end of the steel pipe pile is provided with inner sealing bottom concrete and force transmission belt between bearing platform, the force transmission belt is located in the upper end of inner sealing bottom concrete, the outer side of the lower end of the steel pipe pile is provided with outer sealing bottom concrete and clay, and the clay is located in the upper end of outer sealing bottom concrete;Multiple steel pipe piles are arranged with n first enclosures and m second enclosures on the part outside the force transmission belt, and n>m≥1.The utility model sets inner sealing bottom concrete and force transmission belt which are attached to bearing platform inside steel pipe pile, sets outer sealing bottom concrete and clay outside steel pipe pile, ensures controllable water seepage amount of surrounding rock bottom, and improves the overall stability of cofferdam.

Description

Technical Field

[0001] This utility model relates to the field of cross-river bridge technology, and in particular to a steel pipe pile cofferdam. Background Technology

[0002] In the construction of large or extra-large bridges, there are numerous bridges spanning rivers and streams. From the commencement of construction to completion and opening to traffic, bridges often face numerous technical challenges. For example, the foundations of most river-crossing bridge piers are located within the river channel and are affected by the scouring of the river flow. Most bridge abutments are designed as low-pile rock-embedded foundations, and the water depth in most rivers exceeds 15-20 meters. Therefore, the excavation of the abutments becomes a major difficulty in bridge construction.

[0003] Current methods for solving the challenges of deep-water foundation construction typically include steel cofferdams, steel pipe pile cofferdams, double-walled steel cofferdams, and steel sheet pile + steel pipe pile cofferdams. Double-walled steel cofferdams are the most commonly used in engineering projects. They require a large amount of steel, have complex manufacturing processes, and demand high construction precision, resulting in a longer construction period. Furthermore, transporting, lowering, and installing double-walled steel cofferdams is quite difficult.

[0004] Steel pipe pile cofferdams can overcome the above-mentioned shortcomings, featuring convenient installation and dismantling, and high reusability. However, in shallow overburden layers with high water levels, often consisting of hard rock, controlling the verticality of ultra-long steel pipe piles during driving is difficult. Therefore, a cofferdam structure based on patent publication number CN217949094U, suitable for deep-buried structures in thin-overburden waters, connects steel pipes via interlocking connections. This eliminates the need for pre-drilling during construction, using the steel pipes as buoys for underwater cast-in-place pile construction, minimizing impact on the geological structure. However, this structure involves underwater cast-in-place piles extending into the underground rock layer at the lower end of the steel pipes, excavating to the bottom of the upper enclosed body to reach the underground rock layer, and then sealing the bottom with concrete. This structure carries the risk of water seepage at the bottom of the cofferdam and exhibits poor stability. Utility Model Content

[0005] The purpose of this utility model is to provide a steel pipe pile cofferdam to improve the overall stability of the cofferdam.

[0006] The technical solution of this utility model is: a steel pipe pile cofferdam, comprising a plurality of steel pipe piles surrounding the outer perimeter of a pier cap, wherein an inner bottom sealing concrete and a force transmission band are provided between the inner side of the lower end of the steel pipe piles and the pier cap, the force transmission band being located at the upper end of the inner bottom sealing concrete, and an outer bottom sealing concrete and clay are provided on the outer side of the lower end of the steel pipe piles, the clay being located at the upper end of the outer bottom sealing concrete; n first walers and m second walers are spaced apart on the portions of the plurality of steel pipe piles located outside the force transmission band, where n>m≥1.

[0007] In the above scheme, an inner sealing concrete and force transmission strip that fits into the pile cap are set inside the steel pipe pile, and an outer sealing concrete and clay are set outside the steel pipe pile to ensure that the seepage at the bottom of the surrounding rock is controllable and improve the overall stability of the cofferdam. Depending on the concrete pouring situation, different numbers of first and second walers are set to improve the overall stability of the steel pipe pile.

[0008] Preferably, the upper surface of the clay is flush with the upper surface of the force transmission strip; the boundary line between the clay and the outer sealing concrete is lower than the lower surface of the foundation.

[0009] Preferably, the second waler is positioned close to the foundation, and the first waler is positioned above the second waler.

[0010] Preferably, the steel pipe pile is provided with multiple support beams, and n first walers and m second walers are installed on the support beams in a one-to-one correspondence.

[0011] Preferably, a first diagonal brace is connected at the corner of the first waler; a first lateral support is connected between the two opposite sides of the first waler.

[0012] Preferably, a shear plate is provided at the root of the first diagonal brace connected to the first waler.

[0013] Preferably, a second diagonal brace is connected at the corner of the second waler; a second lateral support is connected between the two opposite sides of the second waler.

[0014] Preferably, a shear plate is provided at the root of the second diagonal brace connected to the second waler.

[0015] Preferably, reinforcement members are connected at the corners of both the first and second walers.

[0016] Preferably, multiple steel pipe piles are connected by interlocking fasteners.

[0017] Compared with related technologies, the beneficial effects of this utility model are as follows: I. This utility model sets an inner bottom sealing concrete and a force transmission strip that fits into the pile cap on the inside of the steel pipe pile, and sets an outer bottom sealing concrete and clay on the outside of the steel pipe pile, so as to ensure that the seepage at the bottom of the surrounding rock is controllable and improve the overall stability of the cofferdam. Second, after the construction of this utility model is completed, the first waler and the second waler can be removed, thereby improving the recycling rate; Third, compared with double-walled steel cofferdams, this utility model effectively avoids the safety risks of transporting, lowering, and installing on water, and has good construction period and economic benefits. Attached Figure Description

[0018] Figure 1A schematic diagram of the plan structure of the steel pipe pile cofferdam provided by this utility model at the first waler position; Figure 2 A schematic diagram of the plan structure of the steel pipe pile cofferdam provided by this utility model at the second waler position; Figure 3 For along Figure 1 AA section view diagram; Figure 4 For along Figure 1 A schematic diagram of the BB section rotated 90° counterclockwise.

[0019] In the attached diagram: 1. Steel pipe pile; 2. First waler; 3. First transverse brace; 4. First diagonal brace; 5. Reinforcing member; 6. Shear plate; 7. Pipe cap; 8. Locking device; 9. Second waler; 10. Second transverse brace; 11. Second diagonal brace; 13. Outer bottom sealing concrete; 14. Inner bottom sealing concrete; 15. Clay; 16. Force transmission belt; 17. Support beam. Detailed Implementation

[0020] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" appearing below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0021] like Figure 3 , Figure 4 As shown, this embodiment provides a steel pipe pile cofferdam comprising multiple steel pipe piles 1 surrounding the periphery of a pile cap 7. An inner sealing concrete 14 and a force transmission band 16 are provided between the inner lower end of each steel pipe pile 1 and the pile cap 7. The force transmission band 16 is located above the inner sealing concrete 14. An outer sealing concrete 13 and clay 15 are provided on the outer lower end of each steel pipe pile 1. The clay 15 is located above the outer sealing concrete 13. The upper surface of the clay 15 is flush with the upper surface of the force transmission band 16; the boundary line between the clay 15 and the outer sealing concrete 13 is lower than the lower surface of the pile cap 7.

[0022] On the outer side of the force transmission zone 1, multiple steel pipe piles 1 are provided with n first walers 2 and m second walers 9 at intervals, where n > m ≥ 1. In this embodiment, n = 4 and m = 2. The second walers 9 are located close to the pile cap 7, and the first walers 2 are located above the second walers 9. Multiple support beams 17 are provided on the multiple steel pipe piles 1, and four first walers 2 and two second walers 9 are installed on the support beams 17 in a one-to-one correspondence. Both the first walers 2 and the second walers 9 are rectangular frames.

[0023] like Figure 1As shown, a reinforcing member 5 and a first diagonal brace 4 are connected at the corner of the first waler 2. The reinforcing member 5 is connected to the two sides forming the corner. The first diagonal brace 4 is supported between the two sides forming the corner. A first transverse support 3 is connected between the two opposite sides of the first waler 2. A shear plate 6 is provided at the root of the first diagonal brace 4 connected to the first waler 2. Both the first diagonal brace 4 and the first transverse support 3 are segmented, assembleable, and detachable structures, which are convenient for disassembly, relocation, and reuse.

[0024] like Figure 2 As shown, a reinforcing member 5 and a second diagonal brace 11 are connected at the corner of the second waler 9. The installation structure of the reinforcing member 5 and the second diagonal brace 11 on the second waler 9 is the same as that in the first waler 2. A second transverse support 10 is connected between the two opposite sides of the second waler 9. A shear plate 6 is provided at the root of the second diagonal brace 11 connected to the second waler 9. Similarly, the second diagonal brace 11 and the second transverse support 10 are also segmented, assembleable, and detachable structures, which facilitate disassembly, relocation, and reuse.

[0025] The I-beam size of the second waler 9 is larger than that of the first waler 2, forming supports of different strengths.

[0026] like Figure 2 As shown, multiple steel pipe piles 1 are connected by locking buckles 8. The locking buckle 8 is a C9 locking lug.

[0027] The construction method for steel pipe cofferdams provided by this utility model includes the following steps: S1. After steel pipe pile 1 arrives on site, first hang a plumb line on steel pipe pile 1 and use a chalk line to mark the installation position of lock buckle 8. Place lock buckle 8 on the chalk line, first perform tack welding, and then perform full welding. Then perform non-destructive testing on the full weld position of the lock buckle. After passing the test, proceed to the next step.

[0028] S2. Determine the cofferdam dimensions based on the planar dimensions of the pier cap 7, and clear the riverbed within the cofferdam area. Use a rotary drilling rig to first drill small-diameter pilot holes, then drill larger-diameter pilot holes sequentially, and finally remove impurities from the holes. This method of drilling small holes first and then larger holes effectively prevents hole collapse during the pilot hole process and minimizes hole repair work.

[0029] S3, before driving steel pipe pile 1, apply grease and sawdust to the locking position 8. This effectively reduces the resistance during the driving process and provides good water-stopping effect. Then, use a ZD90 vibratory hammer to drive the steel pipe pile 1 to form a cofferdam.

[0030] S4, concrete is poured on the outer side of the lower end of the steel pipe pile 1 to form the outer bottom sealing concrete 13, and clay 15 is used to fill the gap between the outer bottom sealing concrete 13 and the riverbed to stop the water.

[0031] S5, within the area of ​​the inner sealing concrete 14, is divided into six zones using No. 56 I-beams. Three guide pipes are arranged in each zone, and concrete is poured through the guide pipes to form the inner sealing concrete 14, which is poured up to the top of the riverbed. This method can ensure the embedment depth of the guide pipes for the first pour of concrete, thereby ensuring the quality of the sealing concrete pouring.

[0032] S6, dewatering the cofferdam. Based on the water level within the cofferdam, promptly install the first waler 2, the first transverse support 3, and the first diagonal brace 4 of the four layers, and weld reinforcement 5 at the corners of the first waler 2. Weld shear plates 6 to reinforce the contact area between the first diagonal brace 4 and the first waler 2.

[0033] S7, then install two more layers of second walers 9, second transverse supports 10 and second diagonal braces 11, with reinforcement measures consistent with the first waler 2.

[0034] S8, excavate foundation 7 according to the 7 square meter dimensions of the foundation. Install reinforcing steel bars, then pour concrete. Finally, pour the force transmission strip 16.

[0035] S9 involves the construction of internal supports and force transmission strip 16 at different stages of the main bridge structure construction. After the concrete of force transmission strip 16 reaches the design strength, the internal supports and walers can be removed to convert the load-bearing system.

[0036] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A steel pipe pile cofferdam, comprising a plurality of steel pipe piles (1) surrounding the outer periphery of a pile cap (7), characterized in that, The lower inner side of the steel pipe pile (1) is provided with an inner sealing concrete (14) and a force transmission belt (16) between the pile cap (7). The force transmission belt (16) is located at the upper end of the inner sealing concrete (14). The lower outer side of the steel pipe pile (1) is provided with an outer sealing concrete (13) and clay (15). The clay (15) is located at the upper end of the outer sealing concrete (13). Multiple steel pipe piles (1) are provided with n first walers (2) and m second walers (9) at intervals on the part outside the force transmission belt (16), where n>m≥1.

2. The steel pipe pile cofferdam according to claim 1, characterized in that, The upper surface of the clay (15) is flush with the upper surface of the force transmission strip (16); the dividing line between the clay (15) and the outer sealing concrete (13) is lower than the lower surface of the foundation (7).

3. The steel pipe pile cofferdam according to claim 1, characterized in that, The second waler (9) is set close to the pier (7), and the first waler (2) is located above the second waler (9).

4. The steel pipe pile cofferdam according to claim 1, characterized in that, The steel pipe pile (1) is provided with multiple support beams (17), and n first walers (2) and m second walers (9) are installed on the support beams (17) in a one-to-one correspondence.

5. The steel pipe pile cofferdam according to claim 1, characterized in that, A first diagonal brace (4) is connected at the corner of the first waler (2); a first transverse support (3) is connected between the two opposite sides of the first waler (2).

6. The steel pipe pile cofferdam according to claim 5, characterized in that, The root of the first diagonal brace (4) connected to the first waler (2) is provided with a shear plate (6).

7. The steel pipe pile cofferdam according to claim 1, characterized in that, A second diagonal brace (11) is connected at the corner of the second waler (9); a second transverse support (10) is connected between the two opposite sides of the second waler (9).

8. The steel pipe pile cofferdam according to claim 7, characterized in that, The second diagonal brace (11) is connected to the root of the second waler (9) and is provided with a shear plate (6).

9. The steel pipe pile cofferdam according to any one of claims 1-8, characterized in that, Reinforcing members (5) are connected to the corners of the first waler (2) and the second waler (9).

10. The steel pipe pile cofferdam according to any one of claims 1-8, characterized in that, Multiple steel pipe piles (1) are connected by a locking mechanism (8).

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