Concrete-filled steel tube foundation pit inner supporting structure with built-in cross-shaped core plate
By adopting a built-in cross-core steel pipe concrete structure in the support structure of the foundation pit, the problems of volatile steel pipes, long concrete construction period and unreusable concrete are solved, and the efficient stability and compressive resistance of the structure are achieved, reducing costs and construction periods.
Patent Information
- Application Number
- CN202422453694.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2034-10-11
AI Technical Summary
During the construction of existing foundation pits, steel pipe support is prone to instability, concrete support has a long construction period and cannot be reused, reinforced concrete support is complex and has high cost, resulting in high risk of project accidents, long construction period, large space occupation and high cost.
The built-in cross core plate steel pipe concrete structure is adopted. By installing cross core plates in the steel pipe and filling them with concrete, lightweight concrete support is formed to enhance the structural compression and bending stiffness, and the stress-bearing contact surface is increased through the variable cross core plate end section to reduce the diameter and number of support.
It improves the overall stability and compressive resistance of the support structure in the foundation pit, reduces the diameter and number of steel pipes, simplifies installation and transportation, shortens construction period, reduces costs, solves the problem of non-reusing of the support structure, and improves the self-weight and bearing capacity limitations.
Smart Images
Figure CN223135153U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of foundation pit construction support, in particular to a concrete-filled steel tubular foundation pit internal support structure with a built-in cross core plate. Background Technique
[0002] With the development of China's economy, the infrastructure construction in China has developed rapidly, and the urban rail transit construction has become an essential part of urban construction. Since the rail transit lines need to achieve transfer between different lines, the stations are built deeper and larger, and it is not difficult to encounter soft soil layers, underground pipelines, existing structures, etc. During construction, deformation needs to be strictly controlled. At present, the construction methods for building subways mainly include the open-cut method, the cut-and-cover method or the shield method. The open-cut subway station foundation pit often adopts an internal support type retaining structure. The lateral internal support applied during the foundation pit excavation is crucial for ensuring the stability of the foundation pit and preventing accidents such as collapses. The main disadvantages or deficiencies of the currently commonly used internal support structures are as follows:
[0003] 1. When using steel pipe supports, the slenderness ratio of the steel pipes is relatively large and the bending moment of inertia is relatively small. Under the action of a large lateral earth pressure, the steel pipes are prone to instability phenomena such as distortion. In severe cases, it will cause huge engineering accidents. If the diameter of the steel pipes is increased and the wall thickness of the steel pipes is increased, the space occupied by the steel pipe supports will be relatively large, the cost will be high, and it will affect the mechanical operation space, resulting in an extended construction period. On the other hand, the actual cross-sectional area of the steel pipes is small, the stiffness is small, and the compressive strength is insufficient. If the foundation pit area is large, the one-way support length will be relatively long, and there are many splicing joints, which are prone to accumulate and form relatively large construction deviations, and the reliability of force transmission is difficult to guarantee.
[0004] 2. When using concrete supports, if cast-in-place concrete is used, it must be cured to a certain strength before the earthwork can be excavated after construction is completed. The construction period is long, the demolition is difficult, and a large amount of construction waste is generated, which cannot be reused. If precast concrete is used, it will be found that the concrete support structure is not easy to connect and it is not easy to protect the ends during storage and transportation, and it is easy to occur phenomena such as corner chipping and cracking. Moreover, whether it is cast-in-place or precast, the self-weight of the concrete is relatively large.
[0005] 3. When using reinforced concrete supports, the construction requires processes such as on-site steel bar binding, formwork support and formwork removal. The production and construction are complex and the construction period is long. If it is used as a temporary structure, after the construction is completed, it needs to be demolished by blasting or manually, and it cannot be reused, and the cost is high.
[0006] 4. When using concrete-filled steel tubular supports, the weight of the concrete filled in the steel pipes is large, which causes the support moment to increase, and actually has a greater impact on the compressive bearing capacity of the support. Content of the Utility Model
[0007] The purpose of the present utility model is to solve the deficiencies existing in the prior art, and to propose a built-in cross-core plate concrete-filled steel tube foundation pit internal support structure.
[0008] To achieve the above purpose, the present utility model adopts the following technical solutions:
[0009] A built-in cross-core plate concrete-filled steel tube foundation pit internal support structure, including a steel tube, a cross-core plate is arranged inside the steel tube, and the gap between the cross-core plate steel and the steel tube is filled with concrete.
[0010] Preferably, the cross-core plate includes an intermediate cross-section segment, and the two ends of the intermediate cross-section segment are integrally connected to the edge cross-section segments. The plate body width of the edge cross-section segments is greater than the plate body width of the intermediate cross-section segment.
[0011] Preferably, the plate body width of the edge cross-section segments matches the inner diameter of the steel tube.
[0012] Preferably, a reinforcement ring is arranged outside the intermediate cross-section segment.
[0013] Preferably, a plurality of through holes are arranged on the cross-core plate.
[0014] Preferably, a plurality of bumps are arranged on the cross-core plate.
[0015] Preferably, the concrete adopts lightweight concrete.
[0016] The beneficial effects of the present utility model: A built-in cross-core plate concrete-filled steel tube foundation pit internal support structure provided by the utility model greatly improves the overall compressive and flexural stiffness of the structure through the built-in cross-core plate, and the variable cross-section at the end of the cross-core plate increases the force-bearing contact surface at the end, far exceeding the bearing capacity of the original concrete-filled steel tube. It can effectively reduce the diameter of the steel tube and the number of internal supports, facilitate on-site installation, transportation and mechanical working space, speed up the project progress, improve the compressive capacity of the support structure, increase the overall stability of the structure, avoid the instability problem existing in the steel tube support, solve the problems of long construction period, difficult demolition and non-reusability existing in the concrete support, solve the problems of complex construction, long construction period and high cost existing in the reinforced concrete support, and also improve the problems of excessive self-weight and limited compressive bearing capacity existing in the concrete-filled steel tube support. Description of the Drawings
[0017] Figure 1 is the basic structure diagram of a built-in cross-core plate concrete-filled steel tube foundation pit internal support structure provided by the present utility model;
[0018] Figure 2 is Figure 1 the A-A cross-sectional view of
[0019] Figure 3 is the basic structure diagram of the cross-core plate. Detailed implementation mode
[0020] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0021] As Figures 1 - 3 shown, an internal cross-core plate concrete-filled steel tube foundation pit internal support structure in this embodiment includes a steel tube 1, flange plates 2 are arranged at both ends of the steel tube 1, and a cross-core plate 3 is arranged inside the steel tube 1.
[0022] The cross-core plate 3 is made of steel plate, and Q235 carbon structural steel or Q345 low-alloy high-strength structural steel is used in this embodiment. The gap between the cross-core plate steel 3 and the steel tube 1 is filled with concrete 9. The concrete 9 is lightweight concrete, which is used to reduce the weight of the concrete-filled steel tube support structure. The concrete 9 is micro-expansive concrete, and the strength grade is C30 - C40. This concrete expands in volume after solidification to realize the restraint on the steel tube and the cross-core plate, thereby forming an integral concrete-filled steel tube support structure. The internal cross-core plate greatly improves the overall compressive and flexural stiffness of the structure, and the variable cross-section at the end of the cross-core plate increases the force-bearing contact surface at the end, far exceeding the bearing capacity of the original concrete-filled steel tube. It can effectively reduce the diameter of the steel tube and the number of internal supports, facilitate on-site installation, transportation and mechanical working space, speed up the project progress, improve the compressive capacity of the support structure, increase the overall stability of the structure, avoid the instability problem existing in the steel tube support, solve the problems of long construction period, difficult demolition and non-reusability existing in the concrete support, solve the problems of complex construction, long construction period and high cost existing in the reinforced concrete support, and also improve the problems of excessive self-weight and limited compressive bearing capacity existing in the concrete-filled steel tube support.
[0023] The cross-core plate 3 includes an intermediate cross section 4, and edge cross sections 5 are integrally connected to both ends of the intermediate cross section 4. The plate width of the edge cross section 5 is greater than the plate width of the intermediate cross section 4. The plate width of the edge cross section 5 matches the inner diameter of the steel tube 1. By setting like this, the force-bearing contact surface at the end of the steel tube can be changed.
[0024] A reinforcing ring 6 is provided outside the middle cross section 4. The reinforcing ring 6 is in the form of a circular ring or a rectangular ring and is connected to the middle cross section 4 by welding. The middle cross section 4 can be reinforced by the reinforcing ring 6, further improving the compressive capacity and overall stability of the support structure. At the same time, the reinforcing ring 6 can also enable the steel pipe, the cross plate and the concrete to better form a whole, indirectly improving the compressive capacity and overall stability of the support structure. A plurality of through holes 41 are provided on the cross core plate 3. During the process of pouring concrete, the concrete can pass through the through holes 41, so that the concrete can fill the entire steel pipe, indirectly improving the compressive capacity and overall stability of the support structure. A plurality of bumps 7 are provided on the cross core plate 3. The contact area between the concrete and the cross core plate 3 can be increased through the bumps 7, enhancing the tensile force between the concrete and the cross core plate 3.
Claims
1. A concrete-filled steel tubular foundation pit internal support structure with a built-in cross core plate, characterized in that: It includes a steel pipe (1), and a cross-shaped core plate (3) is arranged inside the steel pipe (1). The gap between the cross-shaped core plate (3) and the steel pipe (1) is filled with concrete (9).
2. The concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 1, characterized in that: The cross-shaped core plate (3) includes an intermediate cross section (4), and edge cross sections (5) are integrally connected to both ends of the intermediate cross section (4). The plate width of the edge cross section (5) is greater than the plate width of the intermediate cross section (4).
3. The concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 2, characterized in that: The plate width of the edge cross section (5) is matched with the inner diameter of the steel pipe (1).
4. The concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 2, characterized in that: A reinforcing ring (6) is arranged outside the intermediate cross section (4).
5. A concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 2, characterized in that: A plurality of through holes (41) are arranged on the cross-shaped core plate (3).
6. The concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 2, wherein: A plurality of bumps (7) are arranged on the cross-shaped core plate (3).
7. The concrete-filled steel tubular foundation pit internal support structure with an internal cross core plate according to claim 1, characterized in that: The concrete (9) is lightweight concrete.