Concrete enclosing purlin and permanent structure side wall structure for deep foundation pit engineering

Abstract

The utility model relates to the technical field of design and construction of deep foundation pit engineering and permanent structure engineering, in particular to a concrete enclosing purlin and permanent structure side wall structure for deep foundation pit engineering. Steel bar connectors of a permanent structure side wall are reserved in the upper position and the lower position of the concrete enclosing purlin, steel bars of the permanent structure side wall are connected with the steel bar connectors, the permanent structure side wall and the concrete enclosing purlin form an integral structure after being poured, and after the concrete enclosing purlin is chiseled away, the concrete enclosing purlin is embedded in the concrete enclosing purlin. The inner side faces of the side walls of the permanent structure are flush with the inner side faces of the side walls of the permanent structure. The utility model has the advantages that the problems of controlling the deformation of the deep and wide foundation pit and meeting the requirement on the backbuilding of a permanent structure can be solved, the construction efficiency can be improved, the construction cost is saved, the construction quality is improved, and the purpose of realizing refined engineering is further achieved.

Description

Technical Field

[0001] This utility model relates to the design and construction technology of deep foundation pit engineering and permanent structure engineering, specifically to a concrete waler that also serves as a permanent structural side wall structure for deep foundation pit engineering. Background Technology

[0002] With the rapid development of cities, the development of underground space and the construction of underground rail transit stations are increasing. The depth and scale of the foundation pits for underground structures are also increasing, and the requirements for the layout and replacement of supports within the foundation pits are becoming more and more stringent.

[0003] Currently, in the internal support design of deep foundation pit projects, vertical support typically employs a combination of one concrete support and multiple steel supports, or multiple concrete supports, or a combination of multiple concrete supports and multiple steel supports. The conventional approach is to first remove the concrete walers or use inclined bracing as a replacement before constructing the permanent structural sidewalls. However, with the progress of urban development, the surrounding environment of deep foundation pits is becoming increasingly complex. Using methods such as first removing the concrete walers or using inclined bracing as a replacement can easily lead to increased foundation pit deformation, which is detrimental to the surrounding environmental protection. Starting from the perspective of controlling foundation pit deformation and simultaneously meeting the requirements for internal structural reconstruction, the concrete walers are combined with permanent structural sidewalls. This ultimately satisfies the needs of deep foundation pit support and permanent structural sidewall reconstruction, improving construction efficiency, saving construction time, and reducing project costs.

[0004] With the acceleration of urbanization and the continuous development of engineering technology in China, deep foundation pit projects are becoming increasingly deeper. As available land in urban centers becomes increasingly scarce, buildings are extending deeper underground to meet the spatial demands of urban development, leading to a continuous increase in foundation pit depth. This places higher demands on foundation pit support technology and structural backfilling for deep foundation pits.

[0005] Based on experience in deep foundation pit engineering, ultra-deep and ultra-wide foundation pits, especially those exceeding 25m in depth and 40m in width, generally employ a multi-layered concrete support system. The coordinated operation of multiple concrete supports allows for more precise control of foundation pit deformation, protecting surrounding buildings, roads, and underground pipelines. The concrete supports can be flexibly arranged according to the shape and size of the foundation pit, adapting to various irregular shapes, and can integrate well with other support structures (such as diaphragm walls and cast-in-place piles) to form a stable support system. In summary, the multi-layered concrete support system offers significant advantages in ensuring foundation pit safety and stability, controlling deformation, adapting to complex conditions, and reducing costs, making it a widely used support method in deep foundation pit engineering.

[0006] Therefore, there is an urgent need to solve the problem of concrete walers serving as permanent structural side walls, which will have a guiding role for similar projects in the future. Summary of the Invention

[0007] The purpose of this utility model is to address the shortcomings of the existing technology by providing a concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering. By constructing part of the permanent structural sidewall during the construction of the concrete waler and reserving related structures for the permanent structural sidewall, and by incorporating the concrete waler as part of the permanent structural sidewall, the support safety of the deep foundation pit during the excavation stage is ensured. At the same time, it also serves as a permanent structural sidewall, thereby improving construction efficiency, saving construction costs, enhancing construction quality, and further achieving the goal of creating a high-quality project.

[0008] The objective of this utility model is achieved through the following technical solution:

[0009] A concrete waler serving as a permanent structural sidewall for deep foundation pit engineering includes a diaphragm wall and a concrete waler. The concrete waler is located inside the diaphragm wall and the two are fixedly connected. The key feature is that reinforcement for the permanent structural sidewall is provided during the construction of the concrete waler, and steel bar connectors for the permanent structural sidewall are pre-installed at the upper and lower positions of the concrete waler. The steel bars of the permanent structural sidewall are connected to the steel bar connectors. After the permanent structural sidewall is poured, it forms an integral structure with the concrete waler. After the concrete waler is removed, its inner surface is flush with the inner surface of the permanent structural sidewall.

[0010] The permanent structural sidewall includes an initial portion poured concurrently with the construction of the concrete waler and a later portion poured during the deep foundation pit backfilling stage, with the steel reinforcement connector installed on the initial portion.

[0011] A pouring hole is provided between the initial portion of the permanent structural sidewall and the concrete waler.

[0012] A galvanized waterstop steel plate is installed in the initial part of the permanent structural sidewall, and the galvanized waterstop steel plate extends into the later part.

[0013] A water-swellable sealing strip is provided between the initial and later portions of the permanent structural sidewall.

[0014] A full-section grouting pipe is installed in the initial part of the permanent structural sidewall.

[0015] The underground continuous wall is pre-embedded with U-shaped stirrups, and the ends of the U-shaped stirrups are equipped with steel bar connectors. The concrete waler is connected to the steel bar connectors.

[0016] The advantages of this utility model are:

[0017] 1) It can compensate for the shortcomings of deep and wide foundation pits where steel supports cannot be used or concrete supports must be replaced.

[0018] 2) It can reduce the amount of concrete walers that need to be removed, make full use of the combination of the completed concrete waler structure and the permanent structure, and effectively save resources.

[0019] 3) Compared with steel support, which leaves many round holes for post-casting and cuts off the inner lining wall reinforcement, this technology can effectively ensure the effective connection of the inner lining wall reinforcement and the integrity of one-time casting.

[0020] 4) It can effectively ensure the overall stability of the foundation pit and reduce the risk of replacing supports during the foundation pit backfilling stage.

[0021] In summary, this approach can solve the problems of controlling the deformation of deep and wide foundation pits and meeting the requirements for the re-construction of permanent structures. It can also improve construction efficiency, save construction costs, and enhance construction quality, thereby achieving the goal of creating a high-quality project. Attached Figure Description

[0022] Figure 1 This is a schematic diagram showing the relationship between the underground continuous wall and the concrete waler in this utility model;

[0023] Figure 2 This is a schematic diagram of the reinforcement of the underground continuous wall and concrete waler in this utility model;

[0024] Figure 3 This is a schematic diagram showing the relationship between the underground continuous wall, concrete waler, and inner lining wall in this utility model;

[0025] Figure 4 This is a schematic diagram showing the relationship between the concrete waler, which also serves as a permanent structural side wall, and the removal of excess material after the process.

[0026] Figure 5 This is a schematic diagram of the final structure after the connection of the underground continuous wall, concrete waler, and inner lining wall in this utility model. Detailed Implementation

[0027] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0028] like Figure 1-5 As shown in the figure, numbers 1-14 represent: 1. Diaphragm wall; 2. Concrete waler; 3. Lining wall; 4. Pouring hole; 5. Galvanized waterstop steel plate; 6. Diaphragm wall reinforcement; 7. Concrete waler U-shaped reinforcement; 8. Concrete waler reinforcement; 9. Lining wall reinforcement connector; 10. Lining wall; 11. Water-swellable waterstop strip; 12. Full-section grouting pipe; 13. Partial concrete waler; 14.

[0029] Example: Combining Figures 1 to 5 As shown, the concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering in this embodiment includes the following construction methods:

[0030] 1) Based on the scale, depth, and internal structural form of the foundation pit project, determine the retaining structure system, including diaphragm wall 1, concrete waler 2, and support system. The concrete waler 2 is located inside the diaphragm wall 1, and the support system is located inside the concrete waler 2. The diaphragm wall 1 is used to support the soil outside the pit.

[0031] 2) Based on the calculation of the depth and width of the foundation pit, determine the location where the concrete waler of this project needs to also serve as a permanent structural side wall.

[0032] 3) Determine the thickness and reinforcement of the sidewall where the concrete waler also serves as a permanent structural sidewall based on the calculations of the internal structure re-construction stage of the deep and wide foundation pit.

[0033] 4) such as Figure 1 As shown, during the deep foundation pit excavation stage, the preliminary portion of the permanent structural sidewalls is completed simultaneously with the construction of the concrete waler 2. This preliminary portion includes the inner lining walls 3 located on the upper and lower sides of the concrete waler 2. At the same time, tamping holes 4 are provided between the concrete waler 2 and the inner lining walls 3. A galvanized waterstop steel plate (t=4mm) is installed above the inner lining walls 3.

[0034] In this embodiment, as Figure 2 As shown, during the construction of the concrete waler 2, concrete waler reinforcement bars 8 are installed inside it. U-shaped reinforcement bars 7 are pre-installed inside the diaphragm wall 1. Reinforcement connectors are pre-installed at the ends of the U-shaped reinforcement bars 7, connecting the U-shaped reinforcement bars 7 and the concrete waler reinforcement bars 8 to form a whole. This improves the connection performance between the concrete waler 2 and the diaphragm wall 1, especially ensuring the stress resistance and fall prevention of the concrete waler 2. Simultaneously, inner lining wall reinforcement bars 9 are constructed inside the inner lining wall 3. These inner lining wall reinforcement bars 9 are also connected to the concrete waler reinforcement bars 8 to form a whole, further improving the connection performance between the inner lining wall 3 and the concrete waler 2. Inner lining wall reinforcement connectors 10 are installed at the ends of the inner lining wall reinforcement bars 9.

[0035] Step 5: As Figure 3 As shown, during the deep foundation pit backfilling stage, the concrete surfaces on both sides of the concrete waler 2 are roughened and treated according to the construction joint requirements. Simultaneously, the water-swellable sealing strips 12 and full-section grouting pipes 13 are installed. After acceptance, the later-stage inner lining wall 11 is poured; this inner lining wall 11 is the later part of the permanent structural sidewall. At this time, the gap between the inner lining wall 11 and the inner lining wall 3 is sealed by grouting through the full-section grouting pipes 13. Simultaneously, the full-section grouting pipes 13 also pour grout into the pouring holes 4 to connect the inner lining wall 3, the inner lining wall 11, and the concrete waler 2 into a unified structure, ensuring the concrete at the interface between the front and rear concrete sections is compacted. Water sealing between the inner lining wall 3 and the inner lining wall 11 is achieved through the water-swellable sealing strips 12.

[0036] Step Six: As Figure 4 As shown, once the internal structure meets the design requirements, the excess concrete waler portion, i.e., part of the concrete waler 14, is removed. During the removal of this part of the concrete waler 14, it is ensured that the inner surface of the remaining concrete waler 2 is flush with the inner surfaces of the inner wall 3 and the inner wall 11.

[0037] Step 7: Finally, the concrete waler is used as a permanent structural side wall. Structurally, the permanent structural side wall consists of three parts: the remaining concrete waler 2, the inner lining wall 3 which is constructed at the same time as the concrete waler 2, and the inner lining wall 11 which is constructed later.

[0038] In this embodiment, during construction, the concrete waler 2 is designed according to the grade, durability, and impermeability of permanent structural concrete.

[0039] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A concrete waler serving as a permanent structural sidewall for deep foundation pit engineering, comprising a diaphragm wall and a concrete waler, wherein the concrete waler is disposed on the inner side of the diaphragm wall and the two are fixedly connected, characterized in that: During the construction of the concrete waler, reinforcement of the permanent structural sidewall is provided, and steel bar connectors for the permanent structural sidewall are reserved at the upper and lower positions of the concrete waler. The steel bars of the permanent structural sidewall are connected to the steel bar connectors. After the permanent structural sidewall is poured, it forms an integral structure with the concrete waler. After the concrete waler is removed, its inner surface is flush with the inner surface of the permanent structural sidewall.

2. A concrete waler serving as a permanent structural sidewall for deep foundation pit engineering according to claim 1, characterized in that: The permanent structural sidewall includes an initial portion poured concurrently with the construction of the concrete waler and a later portion poured during the deep foundation pit backfilling stage, with the steel reinforcement connector installed on the initial portion.

3. A concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering, as described in claim 2, is characterized in that: A pouring hole is provided between the initial portion of the permanent structural sidewall and the concrete waler.

4. A concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering, as described in claim 2, is characterized in that: A galvanized waterstop steel plate is installed in the initial part of the permanent structural sidewall, and the galvanized waterstop steel plate extends into the later part.

5. A concrete waler serving as a permanent structural sidewall for deep foundation pit engineering according to claim 2, characterized in that: A water-swellable sealing strip is provided between the initial and later portions of the permanent structural sidewall.

6. A concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering, as described in claim 2, is characterized in that: A full-section grouting pipe is installed in the initial part of the permanent structural sidewall.

7. A concrete waler that also serves as a permanent structural sidewall for deep foundation pit engineering, as described in claim 1, is characterized in that: The underground continuous wall is pre-embedded with U-shaped stirrups, and the ends of the U-shaped stirrups are equipped with steel bar connectors. The concrete waler is connected to the steel bar connectors.

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