Supporting structure for foundation pit excavation
By using a combination of sheet piles and I-beams in the foundation pit, the problem of deformation and displacement of temporary retaining walls during long-term support projects was solved, thus improving the stability and safety of the foundation pit.
Patent Information
- Application Number
- CN202422777590.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-11-14
AI Technical Summary
Existing temporary retaining walls, as foundation pit support structures, are prone to deformation and displacement during long-term support projects, affecting the safety of the foundation pit. They also have poor weather resistance and are difficult to withstand long-term wind and rain erosion and groundwater action.
Sheet piles are driven into the foundation pit using a static method and supported and fixed by horizontal and vertical I-beams. The horizontal I-beams abut against the inner surface of the sheet piles, and the vertical I-beams abut against the outer surface of the horizontal I-beams. The waist-to-height ratio is 1.3-1.5:1. No I-beams are set between the sheet piles. The bottom of the foundation pit is equipped with a base plate and plain concrete to enhance the bearing capacity.
This achieved long-term stable support for the foundation pit, reduced the self-weight of the I-beams, slowed down the natural settlement of the support structure, and improved the safety and stability of the foundation pit.
Smart Images
Figure CN223497178U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of foundation pit support technology, and in particular to a support structure for foundation pit excavation. Background Technology
[0002] In civil engineering construction, foundation pit excavation is an indispensable step. Traditional foundation pit support methods often employ temporary retaining walls, which are widely used due to their advantages such as fast construction speed and low material cost.
[0003] However, with the increase in the depth of the foundation pit excavation and the increasing complexity of geological conditions, the stability and durability of temporary retaining walls have gradually revealed serious problems, especially in projects that require long-term support, where their limitations are particularly prominent. Specifically, they are prone to deformation and displacement, affecting the safety of the foundation pit; they have poor weather resistance and cannot withstand long-term wind and rain erosion and groundwater action, resulting in a significant reduction in the support effect. Utility Model Content
[0004] The problem this application aims to solve is that while existing temporary retaining walls are widely used as foundation pit support structures due to their fast construction speed and low material cost, they are prone to deformation and displacement, which can affect the safety of foundation pits when facing long-term support projects.
[0005] To solve the above-mentioned technical problems, this application provides a support structure for foundation pit excavation, including steel sheet piles that are statically driven into the foundation pit to be excavated. The steel sheet piles are supported and fixed by horizontally placed I-beams. The I-beams are divided into horizontally arranged and vertically arranged horizontal and longitudinal steels. There are two horizontal steels, which are used to abut against the inner wall of the steel sheet piles, and the longitudinal steels abut against the horizontal steels.
[0006] Furthermore, the horizontal steel is arranged horizontally so that the outer surface of the horizontal steel abuts against the inner surface of the sheet pile.
[0007] Furthermore, the longitudinal steel is arranged vertically, with its two ends along its length abutting against the outer surfaces of the two transverse steel.
[0008] Furthermore, the ratio of the web height between the transverse and longitudinal steel bars is 1.3-1.5:1.
[0009] Furthermore, there are two sets of sheet piles, symmetrically arranged inside the excavation pit.
[0010] Furthermore, no I-beams are installed between the sheet piles.
[0011] Furthermore, a steel waler is arranged on the upper part of the inner wall of the top of the sheet pile, and a corbel that is adapted to and connected to the steel waler is arranged on the upper part of the inner wall of the bottom of the sheet pile.
[0012] Furthermore, inclined steel pipes are welded to the horizontally adjacent steel walers.
[0013] Furthermore, there are four sets of sheet piles, arranged in a ring around the inside of the excavation pit, with adjacent sheet piles abutting against each other.
[0014] Furthermore, a horizontal base plate is provided at the bottom of the foundation pit to provide horizontal support, and plain concrete is poured below the base plate to enhance the bearing capacity.
[0015] Because the support structure of this application is designed with I-beams composed of transverse and longitudinal steel to support the sheet piles, it can achieve long-term support of the foundation pit through the I-beams and sheet piles, and reduce the self-weight of the I-beams by using the transverse and longitudinal steel to slow down the natural settlement of the support structure. This solves the problem that although the temporary retaining walls of the prior art are widely used as foundation pit support structures due to their fast construction speed and low material cost, they are prone to deformation and displacement when facing long-term support projects, which can affect the safety of the foundation pit. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of a single pipeline in Example 1.
[0017] Figure 2 This is a top view of the structure of Example 1.
[0018] Figure 3 This is a schematic diagram of the cross-sectional structure of the dual pipeline in Example 1.
[0019] Figure 4 This is a cross-sectional structural diagram of Example 2.
[0020] Figure 5 This is a top view of the structure of Example 2.
[0021] In the diagram: 1. Steel sheet pile; 2. Horizontal steel; 3. Longitudinal steel; 4. Pipeline; 5. Steel waler; 6. Corbel; 7. Pump station; 8. Base plate; 9. Plain concrete; 10. Diagonal tie pipe. Detailed Implementation
[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0023] This application relates to a support structure for foundation pit excavation. Example 1
[0024] When the foundation pit is a long, narrow pipeline foundation pit, such as Figure 1-3 As shown, the support structure includes two sets of sheet piles 1 driven into the excavated pit using a static method. These sheet piles are symmetrically arranged inside the pit. As excavation progresses, to prevent deformation or overturning of the sheet piles 1 due to the significant pressure from the soil, they are supported and fixed by horizontally placed I-beams. To meet the support requirements of the sheet piles 1 while minimizing the weight of the I-beams and preventing settlement of the support structure, the I-beams are divided into horizontally arranged horizontal steel beams 2 and vertically arranged longitudinal steel beams 3. The web height ratio between the horizontal steel beams 2 and the longitudinal steel beams 3 is 1.3-1.5:1. There are two horizontal steel bars 2, which are used to abut against the inner wall of the sheet pile 1. In order to improve the connection strength between the horizontal steel bars 2 and the sheet pile 1, the horizontal steel bars 2 are arranged horizontally so that the outer surface of the horizontal steel bars 2 abuts against the inner surface of the sheet pile 1. The longitudinal steel bars 3 are arranged vertically so that their two ends in the length direction abut against the outer surfaces of the two horizontal steel bars 2 respectively. This maximizes the contact area between the horizontal steel bars 2 and the sheet pile 1, and also maximizes the contact area between the longitudinal steel bars 3 and the horizontal steel bars 2. This allows the horizontal steel bars 2 and the longitudinal steel bars 3 to effectively withstand the force from the horizontal earthwork.
[0025] When there is only one pipeline 4, the excavation depth of the foundation pit is 2.5-6.0m, the length of the sheet pile 1 is 6-12m, the support width between the sheet piles 1 is 1.3-1.5m, the arrangement depth of the I-beams is 1.5m, the arrangement spacing of the I-beams is 3m, the transverse steel 2 is I-36, and the longitudinal steel 3 is I-25.
[0026] When there are two pipelines 4, the excavation depth of the foundation pit is 2.5-6.0m, the length of the sheet pile 1 is 6-12m, the support width between the sheet piles 1 is 3.35-7.0m, the spacing between the pipelines 4 is 2.0-4.2m, the arrangement depth of the I-beams is 1.0-1.5m, the arrangement spacing of the I-beams is 3m, the transverse steel 2 is I-36, and the longitudinal steel 3 is I-25.
[0027] In use, firstly, select sheet piles of appropriate size 1 according to the pre-excavation depth of the foundation pit, and then select I-beams of appropriate size according to the pre-support width. Then, use static pressing to pre-press the sheet piles 1 into the position of the foundation pit to be excavated. Then, earthwork can be excavated and transported between the sheet piles 1 to avoid the excavated earth being abandoned next to the foundation pit and causing collapse or landslide. After excavating to a depth suitable for the arrangement of I-beams, start the arrangement of I-beam support to stabilize the foundation pit supported by the sheet piles 1 with the help of transverse steel 2 and longitudinal steel 3. During construction, effective drainage measures should be taken to deal with the accumulation of rainwater or groundwater. After the foundation pit is excavated, the horizontal displacement, vertical displacement of the top of the sheet piles 1 and the vertical displacement of the ground surface next to the foundation pit should be monitored every day. When the rate of change of the monitored samples reaches the specified value or exceeds 70% of the specified value for three consecutive days, it should be reported and the monitoring frequency should be increased to twice a day to ensure the stability of the foundation pit after excavation. Example 2
[0028] When the foundation pit is a square pump station foundation pit, such as Figure 4-5 As shown, the support structure includes four sets of sheet piles 1 driven into the excavated pit using a static method. These sheets are arranged around the inside of the pit. As the excavation progresses, to prevent deformation or overturning of the sheet piles 1 due to the large pressure from the soil, adjacent sheet piles 1 are abutted against each other. As the excavation depth increases, more sheet piles 1 need to be added to expand the support depth. To ensure a stable connection between the sheet piles 1 driven in sequentially, a steel waler 5 is arranged on the upper part of the inner wall of each sheet pile 1. Correspondingly, a corbel 6 is arranged on the upper part of the inner wall of the bottom of each sheet pile 1, thus forming a stable connection between the upper and lower sheet piles 1. This allows the sheet piles 1 to be driven in stably group by group. At the same time, the horizontally adjacent steel walers 5 can be further fixed by adding inclined steel pipes 10 welded to them.
[0029] To prevent the pump station 7 from settling due to its excessive weight, a horizontal base plate 8 was added to the bottom of the pit to provide horizontal support. Plain concrete 9 was also poured below the base plate 8 to enhance the bearing capacity.
[0030] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.
[0031] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).
[0032] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.
[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A support structure for foundation pit excavation, characterized in that: This includes sheet piles that are statically driven into the excavated pit. The sheet piles are supported and fixed by horizontally placed I-beams. The I-beams are divided into horizontally arranged and vertically arranged horizontal and longitudinal steels. There are two horizontal steels, which are used to abut against the inner wall of the sheet piles, and the longitudinal steels abut against the horizontal steels.
2. The support structure for foundation pit excavation according to claim 1, characterized in that: The horizontal steel is arranged horizontally so that the outer surface of the horizontal steel abuts against the inner surface of the steel sheet pile.
3. The support structure for foundation pit excavation according to claim 1, characterized in that: The longitudinal steel is arranged vertically, with its two ends along its length abutting against the outer surfaces of the two transverse steel.
4. The support structure for foundation pit excavation according to claim 1, characterized in that: The web height ratio between the transverse and longitudinal steel bars is 1.3-1.5:
1.
5. The support structure for foundation pit excavation according to any one of claims 1-4, characterized in that: There are two sets of sheet piles, symmetrically arranged inside the excavation pit.
6. The support structure for foundation pit excavation according to claim 1, characterized in that: No I-beams are installed between the sheet piles.
7. The support structure for foundation pit excavation according to claim 6, characterized in that: The upper part of the inner wall of the top of the sheet pile is provided with a steel waler, and the upper part of the inner wall of the bottom of the sheet pile is provided with a corbel that is adapted to and connected to the steel waler.
8. The support structure for foundation pit excavation according to claim 7, characterized in that: Diagonal steel pipes welded to the horizontally adjacent steel walers are installed between them.
9. The support structure for foundation pit excavation according to any one of claims 6-8, characterized in that: There are four sets of sheet piles, arranged in a ring around the inside of the excavation pit, with adjacent sheet piles abutting against each other.
10. The support structure for foundation pit excavation according to claim 9, characterized in that: The bottom of the foundation pit is equipped with a horizontal base plate to provide horizontal support, and plain concrete is poured below the base plate to enhance the load-bearing capacity.