Opposite supporting structure of strip-shaped foundation pit

Abstract

The utility model relates to the field of foundation pit supporting, in particular to a diagonal bracing supporting structure of a strip-shaped foundation pit, which comprises supporting piles respectively arranged on two sides of the foundation pit, the supporting piles are longitudinally distributed along the foundation pit, top beams are arranged on the top surfaces of the supporting piles on the same side of the foundation pit, and a plurality of buttresses are arranged on the top surfaces of the top beams. A prestressed steel support is arranged between the two opposite buttresses on the two sides of the foundation pit. According to the structure, the arrangement of the prestressed steel supports is more flexible, good supporting force can be provided, the relatively strict foundation pit deformation control requirement is met, cable-stayed anchor cables do not need to be arranged, the problem that no implementation face exists on the supporting piles can be effectively solved, the structure can be suitable for the situation that an underground structure top plate in the strip-shaped foundation pit is higher than the field level elevation, and the construction efficiency is improved. The engineering amount of supporting piles is reduced, the economic benefit is prominent, the construction period is greatly shortened, the situation that the foundation pit construction site is seriously insufficient is effectively and reasonably solved, and the method is particularly suitable for long and narrow deep foundation pit supporting engineering such as pipe gallery foundation pits.

Description

Technical Field

[0001] The utility model relates to the technical field of foundation pit engineering, in particular to a supporting structure for a strip foundation pit. Background Art

[0002] At present, my country's urban construction continues to develop, and a large number of cities have begun to study and build underground comprehensive pipe corridors, changing the rough and unreasonable development mode of cities in the past. The emergence of new methods has affected the construction technology related to pipe corridor construction to a certain extent. In order to ensure the smooth and safe production of pipe corridor construction, a more scientific, reasonable and safe support method should be adopted.

[0003] The excavation depth of the foundation pit of the underground comprehensive pipeline corridor is generally large, and it is more likely to face complex engineering geological conditions, such as changes in groundwater levels and uneven soil mechanical properties, which will significantly affect the stability of the foundation pit. At present, for the deep foundation pit projects of urban underground comprehensive pipeline corridors in the shape of narrow strips, inclined anchor cables are usually used for support. However, if the geological conditions of the site are poor and the surrounding conditions are limited, inclined anchor cables cannot be used to control the displacement of the pit top. The use of traditional support systems will take longer and cost more. Utility Model Content

[0004] The purpose of the utility model is to solve the problem in the prior art that the tunnel foundation pit lacks a suitable support method when the site geological conditions are poor and the surrounding conditions are limited, and to provide a bracing support structure for a strip foundation pit.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A supporting structure for a strip foundation pit comprises supporting piles respectively arranged on both sides of the foundation pit, wherein the supporting piles are distributed longitudinally along the foundation pit, the top surfaces of the supporting piles located on the same side of the foundation pit are provided with a crown beam, the top surface of the crown beam is provided with a plurality of piers, and a prestressed steel support is provided between two opposite piers on both sides of the foundation pit.

[0007] By adopting the support structure of a strip foundation pit described in the utility model, pile rows are arranged on both sides of the foundation pit, and prestressed supports are arranged by arranging piers on the crown beams on the piles, which plays a role of conversion, making the arrangement position and spacing of the prestressed steel supports more flexible, which can not only provide better supporting force and meet the relatively strict requirements for foundation pit deformation control without the need to set inclined anchor cables, so that it is suitable for situations where the site geological conditions are poor and the surrounding conditions are restricted, but also can effectively solve the problem of no implementation surface on the supporting piles, and can also be suitable for situations where the top plate of the underground structure in the strip foundation pit is higher than the site level elevation, reducing the engineering volume of the supporting piles, with outstanding economic benefits, and greatly saving the construction period, effectively and reasonably solving the serious shortage of foundation pit construction sites, and is particularly suitable for narrow and deep foundation pit support projects such as pipeline corridor foundation pits.

[0008] Preferably, the distance L between two adjacent piers located on the same side of the foundation pit is ≥3B, where B is the distance between two adjacent supporting piles located on the same side of the foundation pit.

[0009] Further preferably, the supporting piles are provided below the piers.

[0010] Further preferably, the pier is a reinforced concrete structure, and the top of the supporting pile below the pier has dense steel bars, and the dense steel bars extend into the corresponding pier.

[0011] Further preferably, the cross section of the pier is rectangular, and the length and width of the pier are the same as the pile diameter of the supporting pile.

[0012] Improving the stability of the piers will help improve the ability to control foundation pit deformation.

[0013] Preferably, both ends of the prestressed steel support are connected to the piers via connecting pieces, one of which comprises an iron plug.

[0014] It is convenient to install the prestressed steel support after prestressing.

[0015] Preferably, the slope surface outside the supporting piles has a mesh sprayed concrete layer.

[0016] Preferably, the prestressed steel support is a steel pipe.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0018] 1. The utility model adopts a strip foundation pit support structure, and the arrangement position and spacing of the prestressed steel supports are more flexible, which can provide better supporting force and meet the relatively strict foundation pit deformation control requirements without the need to set up inclined anchor cables, so that it is suitable for situations where the site geological conditions are poor and the surrounding conditions are restricted, and can effectively solve the problem of no implementation surface on the support piles. It can also be used for situations where the top plate of the underground structure in the strip foundation pit is higher than the site level elevation, reducing the engineering volume of the support piles, with outstanding economic benefits, greatly saving the construction period, and effectively and reasonably solving the serious shortage of foundation pit construction sites. It is especially suitable for narrow and deep foundation pit support projects such as pipeline corridor foundation pits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional schematic diagram of a supporting structure for a strip foundation pit in Example 1;

[0020] Figure 2 It is a schematic elevation view of a supporting structure for a strip foundation pit in Example 1;

[0021] Figure 3 is a schematic diagram of reinforcement of the support piles in Example 1;

[0022] Figure 4 It is a schematic diagram of reinforcement of the pier in Example 1.

[0023] Icon: 1-support piles; 11-reinforced steel bars; 2-prestressed steel support; 3-crown beam; 4-pier; 5-connector. DETAILED DESCRIPTION

[0024] The utility model is described in detail below in conjunction with the accompanying drawings.

[0025] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in combination with test examples and specific implementation methods. However, this should not be understood as the scope of the above-mentioned subject matter of the utility model is limited to the following embodiments, and all technologies realized based on the content of the utility model belong to the scope of the utility model.

[0026] In the description of the specific embodiments of the present invention, unless otherwise specified, the terms indicating the orientation or position relationship such as "upper", "lower", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or the orientation or position relationship of the product / equipment / device of the utility model when it is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the utility model or simplifying the description in the specific embodiments, so that technicians can quickly understand the scheme, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0027] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding devices / components / elements are within the error / deviation range, they can still achieve their functions in the solution of the utility model.

[0028] In addition, the expressions “first”, “second”, “third”, etc. that appear in the terms are merely descriptions used to distinguish the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0029] In addition, in the description of the embodiments of the present invention, "several", "multiple" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0030] In addition, in the description of the technical solution of the utility model, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal communication of two components.

[0031] Example 1

[0032] The present embodiment adopts a supporting structure for a strip foundation pit, which comprises supporting piles 1 respectively arranged on both sides of the foundation pit, wherein the supporting piles 1 are distributed longitudinally along the foundation pit, and a prestressed steel support 2 is provided between two supporting piles 1 opposite to each other on both sides of the foundation pit.

[0033] The prestressed steel support 2 can be arranged on the waist beam of the support pile 1, or a crown beam 3 can be provided on the top surface of the support pile 1 on the same side of the foundation pit, and the prestressed steel support 2 can be replaced and arranged between the crown beams 3 on both sides. The prestressed steel support 2 can be made of steel pipes, steel parts, etc. The slope surface outside the support pile 1 has a mesh sprayed concrete layer.

[0034] Specifically, in this embodiment, Figure 1-Figure 4 As shown, the top surface of the crown beam 3 is provided with a plurality of piers 4 at intervals, and the prestressed steel support 2 can be replaced and arranged between two piers 4 on both sides. By setting the piers 4, a conversion effect is played, which effectively solves the problem of no implementation surface on the support pile 1, and can also be applied to the situation where the top plate of the underground structure is higher than the site level elevation, such as Figure 1 As shown, the amount of supporting piles is effectively reduced, the economic benefits are outstanding, and the construction period is greatly saved.

[0035] The distance L between two adjacent piers 4 located on the same side of the foundation pit is set according to the actual deformation control requirements, such as L≥3B, B is the pile distance between two adjacent supporting piles 1 located on the same side of the foundation pit, which can effectively control deformation and save economic costs. The piers 4 and supporting piles 1 can be arranged correspondingly or staggered.

[0036] In order to effectively support the prestressed steel support 2, the bottom of the pier 4 can be correspondingly arranged above the supporting pile 1. The pier 4 is a reinforced concrete structure. The top of the supporting pile 1 below the pier 4 has a dense steel bar 11, and the dense steel bar 11 extends into the corresponding pier 4. Figure 3-4 As shown, the cross section of the pier 4 is rectangular, and the length and width of the pier 4 are the same as the pile diameter of the supporting pile.

[0037] The two ends of the prestressed steel support 2 are connected to the pier 4 through the connector 5. To facilitate the application of prestress, one end of the prestressed steel support 2 is fixedly connected and the other end is set as a flexible end. After the steel support is placed in place, the jack is placed in the top pressure position of the flexible end, and the pump is turned on after the oil pipe is connected to apply prestress step by step according to the design requirements. After the prestress is applied in place, the plug iron is put in and welded firmly to fix the flexible end, and the force transmission steel plate set inside the connector 5 of the flexible end is strongly welded to the inner wall of the steel pipe.

[0038] This application can effectively balance the soil pressure difference between the inside and outside of the foundation pit during the excavation process, suppress the deformation of the pit wall, thereby ensuring the stability of the foundation pit slope and reducing the risk of collapse. Especially in the construction of narrow and deep foundation pits, it can greatly improve the safety factor of the construction process, with flexible layout and strong adaptability. This support structure takes into account multiple aspects such as engineering safety, economic cost, construction efficiency and environmental protection, demonstrates superior technical performance and engineering practicality, and provides strong technical support and safety guarantees for the development of urban underground space.

[0039] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A support structure for a strip foundation pit, characterized in that: The invention comprises support piles (1) respectively arranged on both sides of a foundation pit, wherein the support piles (1) are distributed longitudinally along the foundation pit, the top surfaces of the support piles (1) located on the same side of the foundation pit are provided with a crown beam (3), the top surfaces of the crown beam (3) are provided with a plurality of piers (4), and a prestressed steel support (2) is provided between two opposite piers (4) on both sides of the foundation pit.

2. The support structure for a strip foundation pit according to claim 1, characterized in that: The distance L between two adjacent piers (4) located on the same side of the foundation pit is ≥ 3B, where B is the distance between two adjacent support piles (1) located on the same side of the foundation pit.

3. The support structure for a strip foundation pit according to claim 2, characterized in that: The supporting pile (1) is correspondingly provided below the buttress (4).

4. The support structure for a strip foundation pit according to claim 3 is characterized in that: The buttress (4) is a reinforced concrete structure, and the top of the support pile (1) below the buttress (4) has a dense steel bar (11), and the dense steel bar (11) extends into the corresponding buttress (4).

5. The support structure for a strip foundation pit according to claim 3, characterized in that: The cross section of the buttress (4) is rectangular, and the length and width of the buttress (4) are the same as the pile diameter of the supporting pile (1).

6. The support structure for a strip foundation pit according to claim 1, characterized in that: The two ends of the prestressed steel support (2) are connected to the pier (4) via connecting pieces (5), respectively, and one of the connecting pieces (5) comprises a plug iron.

7. A strip foundation pit support structure according to any one of claims 1 to 6, characterized in that: The slope surface outside the support pile (1) is provided with a mesh sprayed concrete layer.

8. A strip foundation pit support structure according to any one of claims 1 to 6, characterized in that: The prestressed steel support (2) is a prestressed steel pipe.

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