Rigidity-variable pile and construction method
By introducing a variable stiffness device into reinforced concrete piles and connecting it with the longitudinal reinforcement of the pile through cavity and cavity wall structures, the problems of cumbersome construction steps and uneven pile settlement are solved, thus simplifying construction and improving the safety of the pile foundation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-08
- Publication Date
- 2026-04-03
AI Technical Summary
The existing construction steps for variable stiffness piles are complicated and difficult, and the pile foundation is prone to differential settlement when there is uneven settlement, which affects the safety and cost of the foundation and superstructure.
A variable stiffness device is used, which includes reinforced concrete piles with cavities and cavity walls. The piles are connected to the longitudinal reinforcement through through-holes, simplifying the construction process and adjusting the stiffness. The connection between the longitudinal reinforcement of the piles and the foundation provides tensile bearing capacity.
Reduce construction steps and difficulty, improve the adaptability and safety of pile foundations, reduce seismic effects, simplify construction procedures, and reduce costs.
Smart Images
Figure CN121781583A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of geotechnical engineering technology, and specifically relates to a variable stiffness pile and its construction method. Background Technology
[0002] Due to industrial development and population growth, the number of high-rise buildings, long-span buildings, and long-span bridges is constantly increasing. However, many of these projects have poor foundation conditions and cannot directly withstand the pressure transmitted from the superstructure, necessitating the use of pile foundations. Under the action of the superstructure and foundation, uneven settlement may occur in the pile foundations, causing the pile tops to be at different horizontal levels, resulting in differential settlement and generating secondary stresses on the foundation and superstructure. This has a particularly significant impact on the internal forces of the foundation and may lead to structural insecurity or increased costs. In 2010, Yao Panfeng proposed an "active variable stiffness leveling pile and its construction method" and obtained an invention patent. However, this method requires secondary grouting after the foundation construction is completed, which increases the construction steps and difficulty. Summary of the Invention
[0003] This invention provides a variable stiffness pile and a construction method, achieving the goal of reducing construction steps and construction difficulty.
[0004] To achieve the above objectives, the present invention adopts the following technical solution.
[0005] A variable stiffness pile includes a reinforced concrete pile and a variable stiffness device; the variable stiffness device is located at the top of the reinforced concrete pile and is integrally connected to the reinforced concrete pile; the reinforced concrete pile includes pile concrete and pile reinforcement; the pile reinforcement includes pile transverse reinforcement and pile longitudinal reinforcement; the variable stiffness device has through holes; the pile longitudinal reinforcement extends into or passes through the through holes.
[0006] Preferably, the variable stiffness device includes a cavity, a cavity wall, and a cavity plate; the cavity is surrounded by the cavity wall and the cavity plate; the cavity does not intersect with the reinforcement holes; the transverse reinforcement of the pile and the longitudinal reinforcement of the pile form a reinforcement cage.
[0007] Preferably, the cavity wall is made of rubber or plastic; the cavity plate is made of rubber, plastic, or metal; the cavity wall and cavity plate are integral or fixedly connected.
[0008] Preferably, the cavity is multi-layered, with corresponding upper and lower sections arranged.
[0009] Preferably, there are multiple cavities; the cavities are arranged at intervals; the cavities are located inside the reinforcement holes; the diameter of the reinforcement holes is not less than the diameter of the longitudinal reinforcement of the pile.
[0010] Preferably, there is a leveling layer between the variable stiffness device and the reinforced concrete pile; the longitudinal reinforcement of the pile includes prestressed steel bars and / or non-prestressed steel bars.
[0011] Preferably, the variable stiffness device has a foundation at the top, and the longitudinal reinforcement of the pile is inserted into the foundation.
[0012] Preferably, the longitudinal reinforcement of the pile extends beyond the top of the pile concrete; the longitudinal reinforcement of the pile has anti-corrosion material within the range of the variable stiffness device.
[0013] Preferably, there is a sealing material between the longitudinal reinforcement of the pile and the through hole.
[0014] A construction method for variable stiffness piles, comprising the following steps:
[0015] Step 1: Forming the pile hole;
[0016] Step 2: Place the pile reinforcement cage into the pile hole;
[0017] Step 3: Pour the pile concrete;
[0018] Step 4: Excavate the soil around the pile;
[0019] Step 5: Remove the concrete at the top of the pile corresponding to the excavated soil, and excavate to the predetermined position.
[0020] Step 6: Install the variable stiffness device by passing the vertical reinforcing bars of the pile through the reinforcement holes;
[0021] Step 7: Fill with backfill material;
[0022] Step 8: Construction of the foundation.
[0023] Compared with the prior art, the present invention has the following features and beneficial effects.
[0024] 1. The variable stiffness device of the pile does not require secondary concrete pouring, which reduces construction steps and lowers construction difficulty.
[0025] 2. The pile's variable stiffness device uses a support with a cavity, and the stiffness is adjustable, making it suitable for different foundation conditions.
[0026] 3. The pile's variable stiffness device is equipped with through holes for reinforcing bars, allowing the reinforcing bars to be connected to the foundation and providing tensile bearing capacity.
[0027] 4. The variable stiffness device of the pile is made of rubber and plastic, which can reduce the horizontal seismic force at the bottom of the foundation. Attached Figure Description
[0028] The present invention will now be described in further detail with reference to the accompanying drawings.
[0029] Figure 1 Front view of a variable stiffness pile Figure 1 .
[0030] Figure 2 Front view of a variable stiffness pile Figure 2 .
[0031] Figure 3Schematic cross-section of the variable stiffness device area Figure 1 .
[0032] Figure 4 Schematic cross-section of the variable stiffness device area Figure 2 .
[0033] Figure 5 Schematic cross-section of the variable stiffness device area Figure 3 .
[0034] Attached reference numerals: A - reinforced concrete pile, B - variable stiffness device, 1 - pile concrete, 2 - pile reinforcement, 2.1 - pile transverse reinforcement, 2.2 - pile longitudinal reinforcement, 3 - through-hole, 4 - cavity, 5 - cavity wall, 6 - cavity plate, 7 - sealing material, 8 - leveling layer.
[0035] To better understand the purpose, technical solution, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings. Here, illustrative embodiments and their descriptions are used to explain the invention, but are not intended to limit the invention.
[0036] In the description of this invention, it should be understood that the terms "comprising / including," "consisting of," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a product, apparatus, process, or method that comprises a list of elements includes not only those elements but may also include, where necessary, other elements not expressly listed, or elements inherent to such a product, apparatus, process, or method. Without further limitation, an element defined by the phrase "comprising / including…" or "consisting of…" does not exclude the presence of additional identical elements in the product, apparatus, process, or method that includes said element.
[0037] In this invention, unless otherwise explicitly specified and limited, the term "fixed connection" should be interpreted broadly, for example, it can refer to a sleeve connection, an lap joint, a weld, a bolted connection, or a combination of the above connections; the terms "installation," "connection," and "linking" should also be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components; the term "continuous reinforcing bar" refers to a reinforcing bar that is continuous without breakage, or a reinforcing bar that is broken but with a fixed connection between the broken reinforcing bars. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0038] It should also be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device, component or structure referred to must have a specific orientation, be constructed or operated in a specific orientation, and should not be construed as a limitation of the present invention.
[0039] The implementation of the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments.
[0040] like Figure 1 and Figure 3 As shown, a variable stiffness pile includes a reinforced concrete pile A and a variable stiffness device B. The variable stiffness device B is located at the top of the reinforced concrete pile A and is connected to the reinforced concrete pile A as a whole. The reinforced concrete pile A includes pile concrete 1 and pile steel bars 2. The pile steel bars 2 include pile transverse steel bars 2.1 and pile longitudinal steel bars 2.2. The variable stiffness device B has a through-hole 3; the pile longitudinal steel bars 2.1 pass through the through-hole 3.
[0041] This invention incorporates a variable stiffness device at the top of the pile, effectively regulating pile settlement and eliminating the need for a secondary grouting cavity, thus simplifying construction procedures and reducing construction difficulty. The longitudinal reinforcing bars of the pile pass through reinforcement holes and connect to the foundation, providing tensile bearing capacity.
[0042] In practice, the longitudinal reinforcement 2.1 of the pile can also be inserted only into the through hole, providing only compressive bearing capacity and not tensile bearing capacity.
[0043] In specific implementation, such as Figure 1 , Figure 4 As shown, the variable stiffness device B in this invention includes a cavity 4, a cavity wall 5, and a cavity plate 6. The cavity 4 is surrounded by the cavity wall 5 and the cavity plate 6, and the transverse reinforcing bars 2.1 and the longitudinal reinforcing bars 2.2 of the pile form a reinforcing cage.
[0044] The inclusion of cavities allows for effective adjustment of the stiffness and deformation of the variable stiffness device, making it suitable for various foundation conditions. With a porosity ranging from 10% to 90%, it facilitates both the fabrication of the variable stiffness device and the achievement of greater load-bearing capacity and stiffness variations.
[0045] In practice, the cavity wall 5 is made of rubber or plastic, and the cavity plate 6 is made of rubber, plastic, or metal. The cavity wall 5 and the cavity plate 6 are either integrally formed or fixedly connected as one unit. Rubber and plastic have good durability and elasticity, making them easy to recover when the upper load is small.
[0046] In practice, the cavity 4 consists of 1 to 5 layers, arranged vertically in a corresponding manner, which helps to increase the allowable deformation value.
[0047] In practice, there are multiple cavities 4, which are arranged at intervals and are located inside the tendon-piercing hole 3.
[0048] In practice, the diameter of the through hole should not be less than 2.2 times the diameter of the longitudinal reinforcement of the pile, so that the reinforcement can pass through the through hole during construction.
[0049] In this invention, such as Figure 2 , Figure 4 and Figure 5 As shown, a leveling layer 8 is set between the variable stiffness device B and the reinforced concrete pile A. This facilitates the construction of the variable stiffness device B and allows the force of the variable stiffness device to be transmitted to the pile through the leveling layer.
[0050] In practice, the longitudinal reinforcement 2.2 of the pile is prestressed steel and / or non-prestressed steel. Increasing the amount of prestressed steel can reduce pile cracking and save steel reinforcement.
[0051] In practical implementation, the variable stiffness device B has a foundation 9 at the top, and the longitudinal reinforcement 2.2 of the pile extends beyond the top of the pile concrete 1. The longitudinal reinforcement 2.2 of the pile is inserted into the foundation 9, and the insertion depth is not less than the anchorage length. This provides pull-out resistance.
[0052] In practical implementation, the longitudinal reinforcement 2.2 of the pile is protected with anti-corrosion material within the range of the variable stiffness device B. This prevents or reduces corrosion of the reinforcement within the variable stiffness device section.
[0053] In practice, a sealing material 7 is placed between the reinforcing bar 2.2 and the through hole 3. The sealing material is cement mortar, concrete, cement grout, UHPC, etc., to further enhance the corrosion resistance and increase durability.
[0054] A construction method for variable stiffness piles, comprising the following steps:
[0055] Step 1: Forming the pile hole;
[0056] Step 2: Place the pile reinforcement cage 2 into the pile hole;
[0057] Step 3, pour the pile concrete 1;
[0058] Step 4: Excavate the soil around the pile;
[0059] Step 5: Remove the concrete at the top of the pile corresponding to the excavated soil, and excavate to the predetermined position.
[0060] Step 6: Install the variable stiffness device B and pass the vertical reinforcing bar 2.1 of the pile through the reinforcing bar hole 3;
[0061] Step 7: Fill with backfill material;
[0062] Step 8: Construction of the foundation.
[0063] In practice, a leveling layer can be added between steps five and six as needed.
[0064] The above embodiments only illustrate several implementation methods of this patent, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept, and these all fall within the protection scope of this invention. Therefore, the protection scope of this patent should be determined by the appended claims.
Claims
1. A variable stiffness pile, characterized in that: It includes a reinforced concrete pile (A) and a variable stiffness device (B); the variable stiffness device (B) is located at the top of the reinforced concrete pile (A) and is connected to the reinforced concrete pile (A) as a whole; the reinforced concrete pile (A) includes pile concrete (1) and pile reinforcement (2); the pile reinforcement (2) includes pile transverse reinforcement (2.1) and pile longitudinal reinforcement (2.2); the variable stiffness device (B) has a through hole (3); the pile longitudinal reinforcement (2.1) extends into the through hole (3) or passes through the through hole (3).
2. The variable stiffness pile according to claim 1, characterized in that: The variable stiffness device (B) includes a cavity (4), a cavity wall (5), and a cavity plate (6); the cavity (4) is surrounded by the cavity wall (5) and the cavity plate (6); the cavity (6) does not intersect with the reinforcing bar hole (3); the transverse reinforcing bars (2.1) and the longitudinal reinforcing bars (2.2) of the pile form a reinforcing cage.
3. The variable stiffness pile according to claim 2, characterized in that: The cavity wall (5) is made of rubber or plastic; the cavity plate (6) is made of rubber, plastic or metal; the cavity wall (5) and the cavity plate (6) are integral or fixedly connected.
4. The variable stiffness pile according to claim 2, characterized in that: The cavity (4) is multi-layered and arranged vertically.
5. The variable stiffness pile according to claim 2, characterized in that: There are multiple cavities (4); the cavities (4) are arranged at intervals; the cavities (4) are located inside the reinforcing bar holes (3); the diameter of the reinforcing bar holes (3) is not less than the diameter of the longitudinal reinforcing bars (2.2) of the pile.
6. The variable stiffness pile according to claim 1, characterized in that: There is a leveling layer (8) between the variable stiffness device (B) and the reinforced concrete pile (A); the longitudinal reinforcement (2.2) of the pile includes prestressed reinforcement and / or non-prestressed reinforcement.
7. The variable stiffness pile according to claim 1, characterized in that: The variable stiffness device (B) has a foundation (9) on top, and the longitudinal reinforcement (2.2) of the pile is inserted into the foundation (9).
8. The variable stiffness pile according to claim 1, characterized in that: The longitudinal reinforcement (2.2) of the pile extends out of the top of the pile concrete (1); the longitudinal reinforcement (2.2) of the pile has anti-corrosion material within the range of the variable stiffness device (B).
9. The variable stiffness pile according to claim 1, characterized in that: There is a sealing material (7) between the longitudinal reinforcement (2.2) of the pile and the through hole (3).
10. A construction method for variable stiffness piles, characterized in that: The steps are as follows: Step 1: Forming the pile hole; Step 2: Place the pile reinforcement cage (2) into the pile hole; Step 3, pour the pile concrete (1); Step 4: Excavate the soil around the pile; Step 5: Remove the concrete at the top of the pile corresponding to the excavated soil, and excavate to the predetermined position. Step 6: Install the variable stiffness device (B) and pass the vertical reinforcing bars (2.1) of the pile through the reinforcing bar hole (3); Step 7: Fill with backfill material; Step 8: Construction of the foundation.