An easily-mounted and dismounted pipe culvert foundation pit steel sheet pile supporting structure

Abstract

The utility model discloses an easily mounted and dismounted pipe culvert foundation pit steel sheet pile support structure belongs to geotechnical engineering support technical field, and the structure includes steel sheet pile, channel section steel encloses the purlin and counter support system, and the channel section steel encloses the purlin by channel section steel and is pasted in the inside of steel sheet pile, and the counter support system includes steel pipe and C type steel component, and the both ends of steel pipe are connected with C type steel component through bolt, and the C type steel component is pasted with the channel section steel encloses the purlin through the soil pressure occlusion mode, and does not need additional connecting piece, the utility model discloses still provided the unique length adjusting mechanism, and the accurate matching adjustment of steel pipe length is realized through bolt connection, the utility model discloses light, standardization component and the quick bolt connection mode of swift, replaced traditional heavy component and on -the -spot welding, has simple structure, installs and dismounts extremely fast, engineering cost reduces obviously, component can high frequency turnover use, construction process safety environmental protection and other outstanding advantages, especially suitable for municipal pipe ditch foundation pit engineering.

Description

Technical Field

[0001] This utility model relates to the field of geotechnical engineering support technology, and in particular to a steel sheet pile support structure for foundation pits in linear projects such as culverts and trenches in municipal engineering. Background Technology

[0002] In the construction of urban roads, pipelines, and other infrastructure, it is often necessary to excavate trenches on the ground to lay culverts or cables. To ensure construction safety and the stability of the surrounding environment, steel sheet piles are usually used as temporary retaining structures. When the excavation depth is large, the embedding effect of steel sheet piles alone is insufficient to resist lateral earth pressure and water pressure, and a transverse internal bracing system must be installed inside the excavation pit.

[0003] The existing conventional practice is to install two welded I-beams or H-beams as walers along the inner side of the sheet piles to collect and transfer the pressure on the sheet piles. In the width direction of the excavation pit, large-diameter, thick-walled steel pipes (e.g., 219mm or 325mm in diameter) are used as bracing members to transfer the pressure to the other side of the pit. The connection between these bracing pipes and the walers usually needs to be welded on-site, and sometimes stiffening ribs are also welded in to ensure the strength of the connection.

[0004] This traditional support method has the following serious drawbacks: High cost: The large amount of materials used for double-section I-beams and heavy steel pipes results in high unit prices and extremely heavy components, which in turn increases the cost of transportation and hoisting machinery, leading to high overall costs.

[0005] Low efficiency: The components are bulky, requiring precise coordination with large lifting equipment during installation, making the operation difficult. On-site welding procedures are complex, consuming a lot of manpower and time, and the welding quality is easily affected by weather, site conditions, and the skill level of the welders, becoming a bottleneck restricting the construction progress.

[0006] Installation and disassembly are difficult: When dismantling the rigid connection formed by welding, methods such as flame cutting must be used, which is cumbersome and slow. Moreover, the cutting process will cause irreversible damage to the component itself, which seriously affects the number of times the steel can be reused and its value.

[0007] Safety and environmental risks: Hot work operations such as welding and gas cutting at construction sites not only pose fire safety hazards, but also generate a large amount of smoke and arc light, which have adverse effects on the health of workers and the surrounding environment.

[0008] Therefore, developing a steel sheet pile foundation pit support structure that is simple in structure, low in cost, quick to construct, safe and environmentally friendly has become an urgent technical problem to be solved in this field. Utility Model Content

[0009] The purpose of this utility model is to overcome the above-mentioned defects of the prior art and provide an easy-to-install and disassemble steel sheet pile support structure for culvert foundation pits. This structure adopts lightweight and standardized components and achieves efficient installation and disassembly of the support system through innovative mechanical connection methods, thereby reducing costs, shortening the construction period, and improving safety.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: A steel sheet pile support structure for culvert foundation pit that is easy to install and disassemble includes: steel sheet piles 1, channel steel walers 2, and a bracing support system 3; The number of sheet piles 1 is at least two, which are vertically inserted into the bottom 12 of the foundation pit. The two sheet piles 1 are symmetrically distributed. The channel steel waler 2 is fixed inside the sheet piles 1 near the top 11 of the foundation pit. Multiple bracing systems 3 are distributed in parallel and are all vertically inserted into the channel steel waler 2.

[0011] Preferably, the supporting system 3 includes a supporting steel pipe 4 and a C-shaped steel component 5; the C-shaped steel component 5 includes a channel steel 6 and a steel pipe 7 welded to the channel steel 6. The steel pipe 7 is welded to the middle position on the convex side of the channel steel 6. The steel pipe 7 is a variable cross-section steel pipe, and the inner diameter of the cross-section on the open side is larger than the outer diameter of the supporting steel pipe 4. It is sleeved with the supporting steel pipe 4. Both the supporting steel pipe 4 and the steel pipe 7 have multiple bolt holes 9 at corresponding positions. The steel pipe 7 is fixed in the supporting steel pipe 4 by inserting bolts 10 into the bolt holes 9.

[0012] Multiple bolt holes 9 allow for a length adjustment range of ±200mm; bolts 10 are 8.8 grade high-strength bolts with specifications of M20×60, conforming to GB / T5782-2016 standard; the channel steel 6 and the channel steel waler 2 are bonded together by earth pressure interlocking, requiring no additional connecting parts.

[0013] Preferably, the supporting steel pipes 4 and 7 are arranged with matching bolt holes 9 at 90-degree intervals.

[0014] Preferably, the channel steel 6 and the steel pipe 7 are connected by welding, and stiffening ribs 8 are provided at the connection every 90 degrees, with a total of 4 stiffening ribs 8 provided at the connection between the channel steel 6 and the steel pipe 7.

[0015] Preferably, the contact surface between the channel steel 6 and the channel steel waler 2 is designed in a wedge shape, and the contact surface is sandblasted.

[0016] Preferably, the wedge-shaped design of the contact surface between the channel steel 6 and the channel steel waler 2 is 3°-5°, and the contact surface is sandblasted to a roughness of Ra12.5-25μm.

[0017] Preferably, the contact surface between the channel steel 6 and the channel steel waler 2 is coated with a friction-enhancing coating, which is composed of diamond powder and epoxy resin, so that the static friction coefficient reaches 0.45-0.55.

[0018] Preferably, the channel steel waler 2 is a channel steel of type [22a].

[0019] Preferably, the sheet pile 1 is a Larssen sheet pile, with a pile length 2-3 meters deeper than the foundation pit and a foundation pit width not exceeding 6 meters.

[0020] The construction method of the easily installable and disassembled steel sheet pile support structure for culvert foundation pits described in this utility model is as follows: 1) Survey and set out, drive 1 sheet pile; 2) Install the channel steel waler 2 and temporarily fix it; 3) Install the counter-bracing system 3 and adjust the support length to the design value; 4) Tighten bolt 10; 5) Monitoring of foundation pit excavation and support.

[0021] Compared with the prior art, the beneficial effects of this utility model are: 1. The use of lightweight material combination (steel pipe + channel steel) reduces the weight by more than 23.5% compared with traditional support structures, thereby reducing material costs and transportation difficulties; 2. The unique earth pressure interlocking design eliminates the need for additional connectors between the channel steel and the waler, simplifying the installation process and improving construction efficiency; 3. Modular length adjustment device, which can adapt to different pit widths and has strong versatility; 4. No welding is required; all connections are mechanical, making installation and dismantling convenient and highly reusable. 5. Fast construction speed: all components are standardized designs, enabling mass production in factories, stable quality, and strong interchangeability. Bolted connections are completely non-destructive and reversible, ensuring that all steel components can be dismantled and recycled intact after the project is completed, achieving nearly 100% reuse, greatly saving social resources, improving efficiency by more than 3 times compared to traditional methods, and reducing overall costs by more than 30%. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present utility model; Figure 2 This is a cross-sectional view of the foundation pit support according to an embodiment of the present invention; Figure 3 This is a detailed drawing showing the connection between the bracing system and the waler of this utility model; Figure 4 This is an enlarged cross-sectional view of the C-shaped steel component in this utility model; In the diagram: 1-Sheet pile, 2-Channel steel waler, 3-Bracket support system, 4-Bracket steel pipe, 5-C-shaped steel component, 6-Channel steel, 7-Steel pipe, 8-Stiffening rib, 9-Bolt hole, 10-Bolt, 11-Top of pit, 12-Bottom of pit. Detailed Implementation

[0023] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] Example: Please refer to the attached drawings. The easily installable and disassembled steel sheet pile support structure for pipe trench foundation pits of this utility model includes steel sheet piles 1, channel steel walers 2, and a bracing system 3. The steel sheet piles 1 are Larssen IV type, with a pile length of 6m, used for 4.0m deep pipe trench foundation pits. The channel steel walers 2 are made of [22a channel steel with specifications of 220×77×7mm and Q235B material, and are attached to the inner side of the steel sheet piles 1 at intervals of 2.5m.

[0025] like Figure 4 As shown, the bracing support system 3 includes bracing steel pipes 4 with a diameter of 48mm and C-shaped steel components 5. The channel steel 6 in the C-shaped steel components is made of [25a specification, 250×78×7mm, Q235B material]. The two ends of the bracing steel pipes 4 are connected to the steel pipes 7 by bolts 10. The channel steel 6 and the channel steel waler 2 are bonded together by earth pressure interlocking, requiring no additional connecting parts.

[0026] like Figure 4 As shown, the supporting steel pipe 4 and steel pipe 7 are sleeved together and locked by bolts 10 at different locations of screw holes 9, which can achieve a length adjustment range of ±200mm to meet the needs of 4-6m wide foundation pits.

[0027] like Figures 3-4 As shown, the contact surface between [25a channel steel 6 and [22a channel steel 2 adopts a 4° micro-wedge design and is sandblasted to a roughness of Ra 20μm. The contact surface is coated with a friction coefficient enhancement coating, which consists of diamond powder and epoxy resin, achieving a static friction coefficient of 0.50. Bolt 10 is an 8.8 grade high-strength bolt with a specification of M20×60, conforming to GB / T5782-2016 standard.

[0028] The construction method for this structure includes the following steps: 1) Measure and lay out the line to determine the location of the sheet piles; 2) Drive the sheet piles to ensure that the top elevation of the piles is consistent; 3) Install the [22a channel steel walers and use temporary fixing clamps for initial fixation; 4) Install the bracing system and adjust the support length to the design value; 5) Tighten the bolts with a torque wrench to a torque of 220 N·m; 6) Excavate and monitor the foundation pit; 7) After the foundation pit is backfilled, dismantle the support structure in reverse order.

[0029] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A steel sheet pile support structure for culvert foundation pits that is easy to install and disassemble, characterized in that, include: Steel sheet piles (1), channel steel walers (2), and bracing system (3); The number of sheet piles (1) is at least two, which are vertically inserted into the bottom (12) of the pit. The two sheet piles (1) are symmetrically distributed. The channel steel waler (2) is fixed inside the sheet piles (1) near the top (11) of the pit. Multiple bracing systems (3) are distributed in parallel and are vertically inserted into the channel steel waler (2). The supporting system (3) includes a supporting steel pipe (4) and a C-shaped steel component (5); the C-shaped steel component (5) includes a channel steel (6) and a steel pipe (7) welded on the channel steel (6). The steel pipe (7) is welded to the middle position on the convex side of the channel steel (6). The steel pipe (7) is a variable cross-section steel pipe. The inner diameter of the cross-section on the open side is larger than the outer diameter of the supporting steel pipe (4). It is sleeved with the supporting steel pipe (4). Both the supporting steel pipe (4) and the steel pipe (7) have multiple bolt holes (9) at corresponding positions. The steel pipe (7) is fixed in the supporting steel pipe (4) by inserting bolts (10) into the bolt holes (9). The channel steel (6) and the channel steel waler (2) are fitted together by earth pressure interlocking, without the need for additional connecting parts. The contact surface between the channel steel (6) and the channel steel waler (2) is designed in a wedge shape and is sandblasted.

2. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The supporting steel pipe (4) and the steel pipe (7) are both arranged with matching bolt holes (9) at 90-degree intervals.

3. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The channel steel (6) and the steel pipe (7) are connected by welding, and stiffening ribs (8) are provided at the connection every 90 degrees. A total of 4 stiffening ribs (8) are provided at the connection between the channel steel (6) and the steel pipe (7).

4. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The wedge-shaped design of the contact surface between the channel steel (6) and the channel steel waler (2) is 3°-5°, and the contact surface is sandblasted with a roughness of Ra12.5-25μm.

5. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The contact surface between the channel steel (6) and the channel steel waler (2) is coated with a coating that enhances the coefficient of friction.

6. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The channel steel waler (2) is a channel steel with model [22a].

7. The easily installable and disassembled sheet pile support structure for culvert foundation pits according to claim 1, characterized in that, The sheet pile (1) is a Larsen sheet pile, with a pile length 2-3 meters deeper than the foundation pit and a foundation pit width not exceeding 6 meters.

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