High-low double-layer supporting structure utilizing original supporting piles of adjacent foundation pits
By adopting high and low double-layer support structures in adjacent foundation pits, using the original support piles and new lower support piles, combined with large inclination anchors, a support system is formed, which solves the safety guarantee problems of small distances and large depths between foundation pits in adjacent buildings, and ensures foundation pit safety and reduces costs.
Patent Information
- Application Number
- CN202421789121.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-26
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-07-26
AI Technical Summary
In urbanization construction, the distance between the foundation pits of adjacent buildings is small and the depth is large, which makes it impossible to set up multiple anchors as usual. The small space of the foundation pit is not conducive to internal support, and more targeted safety measures are needed.
A high and low double-layer support structure is adopted, and the original support piles of adjacent foundation pits are used to provide partial support, and a lower new support pile is set up on one side. It is connected through anchors to form an inclined support system to reduce the impact on adjacent buildings.
While ensuring the safety of the foundation pit, it is achieved to avoid the impact of multiple anchor rods on adjacent buildings in the traditional method, make full use of the original support piles, and reduce the new construction structure and costs.
Smart Images
Figure CN222862293U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of building construction, in particular to a high and low double-layer supporting structure utilizing original supporting piles of adjacent foundation pits. Background Art
[0002] After decades of urbanization, the density of buildings in cities has increased, the distance between adjacent foundation pits of different buildings has become smaller and smaller, and the foundation pits have become deeper and deeper. In order to avoid the basement structure of adjacent buildings, it is impossible to set multiple anchor rods according to the conventional support design; at the same time, the narrow space of the foundation pit is not conducive to the setting of internal support. In the engineering earth excavation, support construction, and underground structure construction stages, safety issues require more targeted solutions. Utility Model Content
[0003] The utility model aims to address the deficiencies in the prior art and provides a high and low double-layer support structure utilizing original support piles of adjacent foundation pits, comprising original support piles arranged in the adjacent foundation pits, newly added support piles arranged on the side of the original support piles away from the adjacent buildings, the height of the newly added support piles being less than the height of the original support piles, the original support piles and the newly added support piles being connected together through the soil between the foundation pits, anchor rods being arranged in the soil between the foundation pits, the anchor rods being inclined in a gradually decreasing height from the newly added support piles toward the original support piles, one end of the anchor rod being fixedly arranged outside the newly added support piles and fixed by a steel waist beam, and the other end of the anchor rod extending below the adjacent building.
[0004] Preferably, the newly added supporting piles are made of a steel cage and concrete. The steel cage includes main bars, reinforcing bars, main bar joints, stirrups and a cage frame. The concrete adopts C25 strength grade concrete with a slump of 180 to 220 mm.
[0005] Preferably, a cap beam is provided at the pile head position of the newly added supporting pile, and the size of the cap beam matches the newly added supporting pile, with a specification of 1m×0.6m.
[0006] Preferably, the anchor hole diameter of the anchor rod is 150 mm, the inclination angle is 22°, the anchor bar of the anchor rod adopts 1860 steel strand, the free section is wrapped with soft plastic and then tied to the bracket and then lowered, and a bracket is set every 2.0 m to ensure that the anchor rod is centered.
[0007] Preferably, the steel waist beam is made by placing two 28b I-beams in parallel.
[0008] Compared with the prior art, the utility model has the following beneficial effects: the utility model provides partial support by retaining the original single-row supporting piles of the adjacent foundation pit, retaining part of the soil on the side close to the foundation pit of this project to ensure the anchoring length of the original supporting piles, supporting this part of the soil with a new row of lower supporting piles, cap beam construction, foundation pit excavation, and anchoring the new lower supporting piles in the middle with an anchor rod, etc., so that the original adjacent foundation pit's higher single-row supporting piles, retained anchoring soil, new lower single-row supporting piles and new single-row large-angle anchor rods together form a high-low double-layer support system; the design is concise, which can avoid the influence of multiple anchor rods in traditional methods on the basement structure of adjacent buildings, and can make full use of the original supporting piles of the adjacent foundation pits, use fewer new construction structures, and thus achieve foundation pit safety at a lower cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:
[0010] Figure 1 It is a schematic diagram of the structure of the utility model;
[0011] Figure 2 It is a side view of the utility model.
[0012] In the figure: 1. Original supporting piles; 2. Newly added supporting piles; 3. Cap beam; 4. Anchor rod; 5. Adjacent buildings; 6. Soil between foundation pits; 7. Foundation pit of this building; 8. Steel waist beam. DETAILED DESCRIPTION
[0013] The technical solution of the utility model is described in detail below with reference to the accompanying drawings, but the protection scope of the utility model is not limited to the embodiments.
[0014] Reference Figure 1 and Figure 2 The utility model discloses a high and low double-layer supporting structure utilizing the original supporting piles of adjacent foundation pits, including an original supporting pile 1 arranged in the adjacent foundation pit, a newly added supporting pile 2 is arranged on the side of the original supporting pile 1 away from the adjacent building 5, the height of the newly added supporting pile 2 is less than the height of the original supporting pile 1, the original supporting pile 1 and the newly added supporting pile 2 are connected together by a soil body 6 between the foundation pits, an anchor rod 4 is arranged in the soil body 6 between the foundation pits, the anchor rod 4 is inclined in a shape in which the height gradually decreases from the newly added supporting pile 2 to the original supporting pile 1, and one end of the anchor rod 4 is fixedly arranged outside the newly added supporting pile and fixed by a steel waist beam 8, and the other end of the anchor rod 4 extends below the adjacent building.
[0015] In the present invention, combined with the specific conditions of the construction site, the original support piles 1 of the adjacent foundation pit are used to provide partial support; at the same time, part of the soil 6 between the foundation pits is retained on the side close to the foundation pit of this project to increase the anchoring length of the original support piles 1, so that the cantilever length of the higher single row of original support piles 1 does not exceed 8m; a row of lower newly added support piles 2 is used to support this part of the soil 6, and the steps are as follows:
[0016] Drilling: The drilling of the newly added 2 support piles can be done by using a rotary drilling rig, and the hole diameter can be selected to be 1m.
[0017] Steel cage production: After drilling, the steel cage is hoisted. The main reinforcement of the steel cage can be 24 C22 steel bars, which are arranged throughout the length. The reinforcement is wound in a ring shape with a special winch and welded into shape. The main reinforcement joints are connected by straight threads. The stirrups are A8 steel bars, which are spirally wound on the cage frame at a spacing of 200mm and tied firmly. The lap length of the binding is not less than 300mm. Steel bar earrings are welded every 2m outside the steel cage to ensure that the thickness of the main reinforcement protective layer is not less than 50mm.
[0018] Concrete pouring: After installing the steel cage, pour concrete. C25 strength grade concrete can be used, and the slump is 180-220mm. Concrete pouring uses a 250mm diameter conduit to ensure continuous pouring of concrete. When pouring concrete, the distance from the bottom of the conduit to the bottom of the hole is 500mm. The actual concrete pouring height should be 500mm higher than the designed pile top elevation to ensure that the concrete below the design elevation meets the design requirements.
[0019] After the newly added supporting pile 2 is completed, the cap beam 3 is constructed at the pile head of the newly added supporting pile 2. The size of the cap beam 3 matches the supporting pile 2 and can be selected as 1m×0.6m. The upper and lower main bars of the cap beam each use 10 C22 steel bars, which are configured throughout the length. The stirrups use A12 steel bars with 4 hoops arranged at a spacing of 200mm. The concrete uses C25 strength grade concrete. After the cap beam construction is completed and the concrete strength reaches the requirement, the foundation pit 7 of this building can be excavated. When the excavation of the foundation pit 7 of this building makes the cantilever length of the newly added supporting pile 2 reach 8m, an anchor rod 4 is set on the newly added lower supporting pile 2 for anchoring:
[0020] Drilling: Casing drilling rig is recommended. The anchor hole diameter can be 150mm. Considering that the anchor rod needs to avoid the basement structure of the adjacent building, the anchor cable inclination angle should be designed to be larger, preferably 22°.
[0021] Anchor rod lowering: After the hole is formed, anchor rod 4 is lowered. The anchor bar of anchor rod 4 can be made of 1860 steel strands. The free section can be wrapped with soft plastic and tied to a bracket before lowering into the hole. A bracket is set every 2.0m to ensure that anchor rod 4 is centered. The grouting pipe is made of plastic pipe, the thickness of which is just enough to be inserted into the center hole of the centering device. The inner end is 0.5 to 1.0m away from the bottom of the hole. The grouting outlet and the end are firmly tied with woven bags to facilitate lowering into the anchor hole.
[0022] Grouting: The grouting material can be cement paste prepared with P.0 4 2.5 cement, and the water-cement ratio can be selected as 0.5.
[0023] Steel waist beam: The steel waist beam 8 can be made of two 28b I-beams placed in parallel.
[0024] Tensioning: Tensioning and locking are carried out after the concrete strength reaches 15 MPa. Anchor rod 4 is first tensioned to the standard value, and then restored to the locking value for locking after stabilization.
[0025] The utility model comprises a higher single-row original supporting pile 1 of an original adjacent foundation pit, a retained soil 6 between foundation pits, newly added lower original supporting piles 2 and newly added single-row large-angle anchor rods 4, which together form a high-low double-layer supporting system, which can avoid affecting the basement structure of an adjacent building and fully utilize the original supporting piles of the adjacent building foundation pit to support the foundation pit of the present building, which is of great significance to the safety and economy of foundation pit construction.
[0026] As above, although the utility model has been shown and described with reference to specific preferred embodiments, it should not be interpreted as limiting the utility model itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the utility model defined in the attached claims.
Claims
1. A high-low double-layer support structure using the original support piles of adjacent foundation pits, characterized by: It includes original supporting piles arranged in adjacent foundation pits, and newly added supporting piles are arranged on the side of the original supporting piles away from the adjacent building, the height of the newly added supporting piles is less than the height of the original supporting piles, the original supporting piles and the newly added supporting piles are connected together through the soil between the foundation pits, and anchor rods are arranged in the soil between the foundation pits, and the anchor rods are inclined in a gradually decreasing height from the newly added supporting piles toward the original supporting piles, and one end of the anchor rod is fixed outside the newly added supporting pile and fixed by a steel waist beam, and the other end of the anchor rod extends under the adjacent building.
2. The high-low double-layer support structure using the original support piles of adjacent foundation pits according to claim 1, characterized in that: The newly added supporting piles are made of a steel cage and concrete. The steel cage includes main bars, reinforcing bars, main bar joints, stirrups and a cage frame. The concrete adopts C25 strength grade concrete with a slump of 180 to 220 mm.
3. The high-low double-layer support structure using the original support piles of adjacent foundation pits according to claim 2, characterized in that: A cap beam is provided at the pile head position of the newly added supporting pile, and the size of the cap beam matches the newly added supporting pile, with a specification of 1m×0.6m.
4. The high-low double-layer support structure using the original support piles of adjacent foundation pits according to claim 3, characterized in that: The anchor hole diameter of the anchor rod is 150mm, the inclination angle is 22°, the anchor reinforcement of the anchor rod is made of 1860 steel strand, the free section is wrapped with soft plastic and then tied to the bracket and then lowered, a bracket is set every 2.0m to ensure that the anchor rod is centered.
5. The high-low double-layer support structure using the original support piles of adjacent foundation pits according to claim 4, characterized in that: The steel waist beam is made by placing two 28b I-beams in parallel.