A kind of based on original foundation pit support system's heightening enclosure structure

Abstract

The utility model relates to the technical field of foundation pit support, concretely to a kind of heightening enclosure structure based on original foundation pit support system, comprising: existing enclosure pile, the enclosure pile is distributed along the periphery of foundation pit;New steel pipe pile, the new steel pipe pile is set between adjacent existing enclosure pile;Hole guide structure, the soil body between existing enclosure pile is penetrated, for implanting steel pipe pile;Lap joint component, the lap joint component makes steel pipe pile and existing enclosure pile lateral lap joint;Grouting reinforcement unit, including two grouting steel flower pipe, the soil body of steel pipe pile area is penetrated. Through the inter-pile new structure and original support lap joint, eliminate the unsupported section formed due to the difference in elevation, such as 3.3m height difference, realize new and old system collaborative stress.This avoids the waste of completely discarding the original structure, reduces the construction difficulty and cost of pile reconstruction, while improving the overall stability of foundation pit excavation.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit support technology, specifically a heightened support structure based on the original foundation pit support system. Background Technology

[0002] In the rapid development of urban construction, underground space development often faces the complex challenge of connecting new and old projects. The core issue stems from changes in ground elevation caused by dynamic adjustments in urban planning. For example, if the original construction site elevation of 3.60m needs to be raised to 6.90m, the existing foundation pit support structure, such as the top elevation of the retaining piles, remains at 3.60m. Although its strength meets the usage requirements, the elevation difference creates unsupported sections (typically with a height difference of 3.3m), making it unsuitable for the new construction conditions.

[0003] Traditional solutions have serious limitations. If the original structure is completely abandoned, it is necessary to rebuild it by adding piles in the adjacent area, which not only increases the project cost and extends the construction period, but also disturbs the stability of the surrounding strata during secondary construction. If conventional reinforcement technology (such as adding cast-in-place piles on the inside) is used, it is only suitable for scenarios where the foundation pit is deepened downwards, and cannot solve the rigid requirement of increasing the elevation upwards. This contradiction stems from the fundamental conflict between the static design of the existing support system and the dynamic changes in urban planning, which is particularly prominent in the phased development of land plots. Due to the difference in the construction sequence of adjacent plots, the site elevations are different, and the old and new retaining structures cannot directly cooperate to bear the load, ultimately resulting in an engineering dilemma of both resource waste and safety risks. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides an enhanced retaining structure based on the original foundation pit support system. By inserting steel pipe piles through pre-drilled holes between existing retaining piles and overlapping the original structure, the unsupported sections caused by the planned elevation increase are eliminated. The new structure forms a synergistic force-bearing whole with the original support system, ensuring support continuity and avoiding resource waste caused by direct abandonment, thus solving the aforementioned technical problems.

[0005] One embodiment of this utility model provides a heightened retaining structure based on the original foundation pit support system, comprising: There are existing retaining piles, which are distributed around the perimeter of the foundation pit; New steel pipe piles are added, and the new steel pipe piles are set between adjacent existing retaining piles; A pilot hole structure, which penetrates the soil between the existing retaining piles, is used to implant the steel pipe piles. An overlapping assembly that allows the steel pipe pile to laterally overlap with the existing retaining pile; The grouting reinforcement unit includes two grouting steel pipes that penetrate the soil in the area of ​​the steel pipe piles; New retaining piles, wherein the new retaining piles are located on one side of the existing retaining piles; Several concrete support structures are provided on the existing retaining piles, wherein some of the concrete support structures are provided on the existing retaining piles at one end and on new retaining piles at the other end. Backfill space, which is located above the existing retaining piles.

[0006] This invention relates to a heightened retaining structure based on the original foundation pit support system. By adding a new structure between the piles and overlapping it with the original support, it eliminates unsupported sections caused by elevation differences, such as a 3.3m height difference, achieving synergistic stress distribution between the old and new systems. This avoids the waste of completely abandoning the original structure, reduces the construction difficulty and cost of pile reconstruction, and simultaneously improves the overall stability of the foundation pit excavation.

[0007] In one embodiment, the axis of the pilot hole structure 3 is parallel to the existing retaining pile, and its depth extends below the effective embedment depth of the original support structure.

[0008] In one embodiment, the grouting pressure of the grouting reinforcement unit is not less than 1.5 MPa, and the water-cement ratio of the grout is 0.5:1.

[0009] In one embodiment, the wall thickness of the steel pipe pile is greater than 10mm, and the material is Q355B grade seamless steel pipe.

[0010] In one embodiment, the lap assembly includes steel plate ribs welded to the outside of the steel pipe pile, the width of which matches the cross-section of the existing retaining pile.

[0011] In one embodiment, the structure transfers loads through overlapping components, enabling the existing retaining piles and the newly added steel pipe piles to form a collaborative force-bearing system.

[0012] The above technical solution provides a heightened retaining structure based on the original foundation pit support system, which has the following beneficial effects: 1. By drilling holes between existing retaining piles to insert steel pipe piles and overlapping the original structure, the unsupported sections caused by the planned elevation increase are eliminated. The new structure and the original support system form a coordinated whole to ensure the continuity of support and avoid the waste of resources caused by direct abandonment.

[0013] 2. Make full use of the existing structural strength to reduce material consumption and construction costs of pile reconstruction. By optimizing the pile reinforcement process (pre-drilling + grouting steel pipe), shorten the construction cycle and reduce interference with the surrounding environment.

[0014] 3. The combined design of steel pipe piles and grouting steel pipes strengthens the integrity of the soil between piles, and the overlap between the old and new structures transfers loads, improving the overturning resistance. Engineering verification has shown that the deformation of the foundation pit is effectively controlled, meeting the requirements for safe construction. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a cross-sectional view of the existing enclosure structure after utilization. Figure 2 This is a cross-sectional view of the existing enclosure structure before its utilization.

[0017] The markings in the diagram are explained as follows: 1. Existing retaining piles; 2. New steel pipe piles; 3. Hole structure; 4. Overlapping components; 5. Grouting reinforcement unit; 6. New retaining piles; 7. Concrete support structure; 8. Backfill space. Detailed Implementation

[0018] The above detailed description is a specific description of a feasible embodiment of the present utility model. This embodiment is not intended to limit the patent scope of the present utility model. All equivalent implementations or modifications that do not depart from the so-called equivalent implementations or modifications of the present utility model should be included in the patent scope of this case.

[0019] Combination Figures 1 to 2 As shown, one embodiment of this utility model provides a heightened retaining structure based on the original foundation pit support system, comprising: There are existing retaining piles 1, which are distributed around the perimeter of the foundation pit; 2 new steel pipe piles are added, which are set between adjacent existing retaining piles 1. The diameter of the steel pipe piles is 325mm and the pile spacing is 600mm. The pilot hole structure 3 has a hole diameter of 350mm and penetrates the soil between the existing retaining piles 1 for implanting steel pipe piles. Overlapping component 4, which enables the steel pipe pile to laterally overlap with the existing retaining pile 1, with an overlap length greater than 4.4m; Grouting reinforcement unit 5 includes two 6m long grouting steel pipes that penetrate the soil in the area of ​​the steel pipe pile; New retaining pile 6, the new retaining pile 6 being located on one side of the existing retaining pile 1; A plurality of concrete support structures 7 are provided on the existing retaining piles 1, wherein some of the concrete support structures 7 are provided on the existing retaining piles 1 at one end and on the new retaining piles 6 at the other end. Backfill space 8 is located above the existing retaining piles 1.

[0020] In this embodiment of the invention, by adding a new structure between the piles and overlapping it with the original support, the unsupported section formed due to elevation differences, such as a 3.3m height difference, is eliminated, achieving synergistic force sharing between the old and new systems. This avoids the waste of completely abandoning the original structure, reduces the construction difficulty and cost of pile reconstruction, and improves the overall stability of the foundation pit excavation. Several concrete support structures 7 are used to maintain the overall stability of the foundation pit, the backfill space 8 is used for backfilling, and the new retaining piles 6 are set on the basis of the existing retaining piles 1.

[0021] In one embodiment, the axis of the pre-hole structure 33 is parallel to the existing retaining pile 1, and its depth extends below the effective embedment depth of the original support structure.

[0022] In this embodiment of the invention, the depth of the pilot hole is ensured to cover the stress range of the original support, enhancing the integrity of the soil and the stability of the pile foundation. This prevents pile displacement or settlement caused by shallow pilot holes, improving the reliability of the reinforcement measures.

[0023] In one embodiment, the grouting pressure of the grouting reinforcement unit 5 is not less than 1.5 MPa, and the water-cement ratio of the grout is 0.5:1.

[0024] In this embodiment of the invention, the grouting process is optimized to improve the reinforcement effect of the steel pipe, thereby enhancing the impermeability and overall strength of the soil between the piles. This reduces the risk of soil erosion and ensures the long-term safety of the foundation pit during excavation.

[0025] In one embodiment, the wall thickness of the steel pipe pile is greater than 10mm, and the material is Q355B grade seamless steel pipe.

[0026] In this embodiment of the invention, the bearing capacity and durability of the newly added piles are enhanced through the design of high-strength materials, thus resisting lateral water and soil pressure. This avoids structural failure due to insufficient material strength and extends the service life of the support system.

[0027] In one embodiment, the overlapping component 4 includes steel plate ribs welded to the outside of the steel pipe pile, the width of which matches the cross-section of the existing retaining pile 1.

[0028] In this embodiment of the invention, the connection method between the new and old structures is optimized to ensure efficient load transfer and avoid displacement or overturning caused by weak connections. This simplifies the construction process and reduces the difficulty of on-site coordination.

[0029] In one embodiment, the structure transfers loads through the overlapping component 4, so that the existing retaining piles 1 and the newly added steel pipe piles 2 form a cooperative force-bearing system.

[0030] In this embodiment of the utility model, the new and old structures are seamlessly integrated, the residual strength of the existing support is fully utilized, and the input of new materials and construction interference are reduced.

[0031] It should also be noted that the underground structure needs to be connected to the main structure in the next phase of construction, which will make the two retaining structures fit together closely. The original structure was 3.60m above ground level during construction. According to the planning requirements, the backfill elevation after construction is 6.9m. However, the original retaining structure capping beam elevation is only 3.60m during construction. If the original retaining structure is to be used, a 3.3m unsupported section will be created, which cannot be excavated directly. Under the above circumstances, the retaining structure scheme was adjusted to construct steel pipe piles with a diameter of 350mm along the edge of the foundation pit between the existing retaining piles, and add two 6m grouting steel pipes. The steel pipe piles overlapped with the original retaining structure by 4.4m. Conventional pile-supported excavation was then carried out. If the original retaining structure were completely abandoned, additional piles would need to be added next to the insufficiently long piles, which would not only increase the construction period and cause economic waste, but also affect the layout of the internal structure. This utility model ensures the safety and reliability of the foundation pit, achieving significant time, economic, and space benefits.

[0032] Furthermore, two new steel pipe piles were added. Figure 1 In the middle of the figure, there is a vertical black columnar structure that covers the top of the original support to the new elevation (6.90m) with a spacing of 600mm. The pilot hole structure 3 is located in the blank gap between the newly added steel pipe piles 2, with a width corresponding to a hole diameter of 350mm. The overlapping component 4 is located at the junction of the existing retaining piles and the newly added steel pipe piles 2, which is represented by the shadow area where the two overlap laterally.

[0033] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made using the paper parts and drawings of the present utility model under the inventive concept of the present utility model, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A heightened retaining structure based on the original foundation pit support system, characterized in that, include: There are existing retaining piles (1), which are distributed around the perimeter of the foundation pit; New steel pipe piles (2) are added, and the new steel pipe piles (2) are set between adjacent existing retaining piles (1); The pre-hole structure (3) penetrates the soil between the existing retaining piles (1) and is used to implant the steel pipe pile (2). Overlap assembly (4), which enables the steel pipe pile (2) to laterally overlap with the existing retaining pile (1); The grouting reinforcement unit (5) includes two grouting steel pipes that penetrate the soil in the area of ​​the steel pipe pile (2); New retaining pile (6), the new retaining pile (6) is located on one side of the existing retaining pile (1); Several concrete support structures (7) are provided on the existing retaining piles (1), wherein one end of some of the concrete support structures (7) is provided on the existing retaining piles (1) and the other end is provided on the new retaining piles (6); Backfill space (8) is located above the existing retaining piles (1).

2. The heightened retaining structure based on the original foundation pit support system according to claim 1, characterized in that, The axis of the borehole structure (3) is parallel to the existing retaining pile (1), and its depth extends below the effective embedment depth of the original support structure.

3. The heightened retaining structure based on the original foundation pit support system according to claim 1, characterized in that, The grouting pressure of the grouting reinforcement unit (5) is not less than 1.5 MPa, and the water-cement ratio of the grout is 0.5:

1.

4. The heightened retaining structure based on the original foundation pit support system according to claim 1, characterized in that, The wall thickness of the steel pipe pile (2) is greater than 10mm, and the material is Q355B grade seamless steel pipe.

5. A heightened retaining structure based on the original foundation pit support system according to claim 1, characterized in that, The overlapping component (4) includes steel plate ribs welded to the outside of the steel pipe pile (2), the width of which matches the cross section of the existing retaining pile (1).

6. The heightened retaining structure based on the original foundation pit support system according to claim 1, characterized in that, The structure transmits loads through the overlapping components (4), so that the existing retaining piles (1) and the newly added steel pipe piles (2) form a cooperative force-bearing system.

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