Section steel ribbing SMW construction method pile

Abstract

The utility model relates to the technical field of underground structure foundation pit engineering retaining structures, in particular to a section steel ribbing SMW construction method pile which comprises a mixing pile, H-shaped steel and a stiffening rib steel plate, the stiffening rib steel plate is arranged at the web position of the H-shaped steel to form a combined section steel structure, and the combined section steel structure is inserted into cement soil of the mixing pile. Compared with the prior art, the SMW construction method pile with the structural steel ribs has the advantages that an internally-inserted structural steel structure is improved on the basis of a conventional construction method pile, the web ribs are added, and the contact area between the structural steel and mixing pile cement soil is increased, so that the vertical bearing capacity of the construction method pile is improved, and meanwhile the lateral rigidity of the construction method pile serving as a building envelope is improved. The technical problem that the bearing capacity is small in a foundation pit project which serves as an enclosure structure and also serves as a vertical stress component at the same time can be solved, and the bottleneck that an existing construction method pile is only used for a foundation pit enclosure structure is planned to be broken through.

Description

Technical Field

[0001] The utility model relates to the technical field of underground structure foundation pit engineering retaining structure, in particular to a SMW method pile with steel ribs, which is suitable for projects in which the SMW method piles are used as retaining structures and also serve as vertical force-bearing components. Background Art

[0002] SMW piles have the characteristics of fast construction speed, good water-stopping performance, low cost, and green environmental protection. They have been gradually promoted and used in China since the end of the 20th century and are widely used in foundation pit retaining structures less than 13m deep. In recent years, in the design and construction of foundation pit projects, many design and construction problems such as pipelines across foundation pits and trestle boards are often encountered. However, due to the small vertical bearing capacity of the piles and the easy instability of the core material under the bending stress condition, in order to avoid affecting the water-stopping effect of the retaining structure, they are generally not used as vertical bearing components.

[0003] At present, the more conventional practice is to construct bored piles separately at the position across the foundation pit to provide vertical support force, and it is necessary to install mixing piles or rotary jet pile water-stop curtains on the outside of the bored piles. The number of engineering machinery involved increases, the construction is inconvenient, and it causes problems such as longer construction period, increased engineering risk, and higher engineering cost. Summary of the invention

[0004] The purpose of the utility model is to provide a SMW method pile with steel ribs in accordance with the above-mentioned deficiencies in the prior art. By ribbing the SMW method pile, both its lateral friction resistance and its bending stiffness as a compression-bending member are improved, thereby improving the vertical bearing capacity and lateral bearing capacity of the pile body, and improving the force-bearing performance of the method pile as a retaining structure and a vertical bearing member.

[0005] The purpose of this utility model is achieved by the following technical solutions:

[0006] A SMW pile with steel ribs, characterized in that it comprises a mixing pile, an H-shaped steel and a stiffening rib steel plate, wherein the stiffening rib steel plate is arranged at the web position of the H-shaped steel to form a combined steel structure, and the combined steel structure is inserted into the cement soil of the mixing pile.

[0007] Along the extending direction of the web of the H-shaped steel, a plurality of stiffening rib steel plates are arranged at intervals at the web position.

[0008] The plurality of stiffening rib steel plates are symmetrically arranged at the midline position of the web length direction of the H-shaped steel.

[0009] The stiffening rib steel plates are symmetrically arranged on both sides of the web of the H-shaped steel.

[0010] The stiffening rib steel plate extends along the height direction of the H-shaped steel and the bottom of the stiffening rib steel plate is higher than the bottom of the H-shaped steel.

[0011] The advantages of the utility model are:

[0012] 1) It solves the problem of insufficient vertical bearing capacity of traditional SMW piles, increases the contact area between steel and cement soil, and improves the vertical bearing capacity, thereby improving the applicability of structures such as pipeline bridges, trestle plates, and top plates in steel-cement-soil mixing wall enclosure structures;

[0013] 2) The steel-ribbed SMW piles not only bear horizontal water and soil pressure as the retaining structure, but also serve as vertical load-bearing components. Conventional core materials are prone to bending instability or large deformation, causing cement soil to crack and leak. Ribbed steel has high rigidity and relatively small deformation, which ensures the water-stopping performance of the retaining structure.

[0014] 3) It improves the disadvantage of the previous H-shaped steel wing plate spacing being too large, making the steel and the mixing pile cement soil more effectively combined, with better integrity and improved composite stress performance;

[0015] 4) According to the horizontal and vertical force characteristics of the construction piles in the specific project, the horizontal and vertical bearing capacity of the construction piles can be adjusted by adjusting the width and length of the stiffening rib steel plates, and the design can be refined to save more resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a plan view of the utility model;

[0017] Figure 2 This is a schematic diagram of the plan view of the utility model for the foundation pit trestle board;

[0018] Figure 3 The utility model is a cross-sectional schematic diagram of a foundation pit trestle board. DETAILED DESCRIPTION

[0019] The following is a further detailed description of the features of the present invention and other related features through embodiments in conjunction with the accompanying drawings to facilitate understanding by technicians in the same industry:

[0020] like Figure 1-3 As shown, the marks 1-10 in the figure respectively represent: mixing pile 1, H-shaped steel 2, stiffening rib steel plate 3, top ring beam 4, retaining wall 5, plain concrete backfill layer 6, trestle plate 7, reinforced concrete support 8, steel support 9, and main structure 10.

[0021] Example: Combination Figures 1 to 3As shown, in this embodiment, the SMW construction method piles with steel ribs are used as an example for explanation, and the foundation pit project mainly includes mixing piles 1, H-shaped steel 2, stiffening rib steel plates 3, top ring beams 4, retaining walls 5, plain concrete backfill layers 6, trestle slabs 7, reinforced concrete supports 8, steel supports 9, and main structures 10. Among them, the SMW construction method piles with steel ribs serve as both a retaining structure and a vertical force-bearing member of the trestle slab.

[0022] The implementation steps of this implementation are as follows:

[0023] (1) The core web of the H-shaped steel 2 is welded with the stiffening rib steel plate 3 to form Figure 1 The H-shaped steel 2 and the stiffening rib steel plate 3 are combined into a steel structure. The width and length of the stiffening rib steel plate 3 can be adjusted according to the horizontal and vertical design values ​​of the specific project. The vertical range is set to about 3m below the bottom of the pit. Finally, the surface of the H-shaped steel 2 is coated with a friction reducer.

[0024] (2) During the construction of the three-axis mixing pile 1, cement slurry and compressed air are sprayed out from the drill bit to mix the original soil evenly.

[0025] (3) Within 30 minutes after the construction of the mixing pile 1 is completed, the steel structure composed of the H-shaped steel 2 and the stiffening rib steel plate 3 is inserted into the cement soil of the mixing pile 1, leaving a height of about 500 mm above the top ring beam 4.

[0026] At this time, the contact area between the H-shaped steel 2 and the cement soil of the mixing pile 1 is increased by setting the stiffening rib steel plate 3. Under the condition that the lateral friction resistance per unit area remains unchanged, the lateral friction resistance between the H-shaped steel 2 and the mixing pile 1 is effectively increased, thereby improving the overall vertical bearing capacity of the construction pile. At the same time, the ribbed H-shaped steel 2 increases the bending stiffness of the H-shaped steel 2. In the foundation pit project, the SMW construction pile mainly relies on the internal steel to provide lateral stiffness. On the basis of not increasing the diameter of the mixing pile 1 and the size of the H-shaped steel 2, the stiffening rib steel plate 3 can effectively improve the overall lateral stiffness of the construction pile, and improve the horizontal bearing capacity and deformation resistance of the pile body.

[0027] (4) After the pile reaches the designed strength, the top ring beam 4 and the concrete retaining wall 5 are constructed. The top of the top ring beam 4 is backfilled with plain concrete 6 to the top of the H-beam 2. The contact surface between the H-beam 2 and the concrete is wrapped with a PVC plastic sheet so that the H-beam 2 can be pulled out and recycled later.

[0028] (5) Construction of the trestle slab 7. The top plain concrete structure of the H-shaped steel 2 and the top ring beam 4 on both sides of the foundation pit serves as the support of the trestle slab 7. The trestle slab 7 is smoothly connected to the road surrounding the foundation pit and is used for traffic relief of the foundation pit project or transportation construction within the site.

[0029] When SMW method piles are used in retaining structures and also serve as vertical load-bearing components, the stress state of the steel section changes from a bending component to a compression-bending component, which increases the risk of steel section instability. By adding ribs to the steel section web, the moment of inertia and gyration radius of the steel section are increased, and the stability coefficient is effectively improved, thereby improving the overall stability of the steel section. This allows the method piles to be used not only in foundation pit retaining structures, but also as vertical load-bearing components.

[0030] (6) The foundation pit is excavated in layers and sections. The first reinforced concrete support 8 and the second steel support 9 are constructed in sequence. After excavating to the bottom of the pit, the main structure 10 is rebuilt.

[0031] (7) After the main structure is completed, the top plate is backfilled with soil, the trestle plate 7 is removed, the plain concrete backfill layer 6 on the top of the top ring beam 4 is chiseled out, the H-shaped steel 2 is pulled out and recycled, and finally the road surface structure is restored.

[0032] Although the above embodiments have described the concepts and embodiments of the purpose of the utility model in detail with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and modifications can still be made to the utility model without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A SMW pile with steel ribs, characterized in that: It comprises a mixing pile, an H-shaped steel and a stiffening rib steel plate, wherein the stiffening rib steel plate is arranged at the web position of the H-shaped steel to form a combined steel structure, and the combined steel structure is inserted into the cement soil of the mixing pile.

2. The SMW pile with steel ribs according to claim 1, characterized in that: Along the extending direction of the web of the H-shaped steel, a plurality of stiffening rib steel plates are arranged at intervals at the web position.

3. The SMW pile with steel ribs according to claim 2, characterized in that: The plurality of stiffening rib steel plates are symmetrically arranged at the midline position of the web length direction of the H-shaped steel.

4. The SMW pile with steel ribs according to claim 1 or 2, characterized in that: The stiffening rib steel plates are symmetrically arranged on both sides of the web of the H-shaped steel.

5. The SMW pile with steel ribs according to claim 1, characterized in that: The stiffening rib steel plate extends along the height direction of the H-shaped steel and the bottom of the stiffening rib steel plate is higher than the bottom of the H-shaped steel.

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