Cloth bag type cast-in-situ bored pile
By setting up cloth bags and applying solid lubricant on the outside of the drilled cast pile, the filling coefficient exceeds the standard and negative friction resistance of the drilled cast pile when forming piles in the soil in the filling are solved, and the effect of reducing the project cost and improving the bearing capacity of the pile foundation is achieved.
Patent Information
- Application Number
- CN202421262865.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-06-04
AI Technical Summary
When drilling and cast-injected piles are piled in the filling soil, problems such as hole formation collapse and slurry loss are prone to problems such as hole formation collapse and the concrete filling coefficient exceeds the standard. The negative friction resistance caused by the self-weight settlement of the fill will increase the axial force and settlement of the pile body, reducing the vertical bearing capacity of the pile foundation.
The cloth bag is integrated on the outside of the cast pile. The cloth bag material is smoother than the concrete surface, which can effectively control the diffusion of concrete slurry and reduce the concrete filling coefficient. By applying a solid lubricant layer to the fill section, the friction between the concrete pile body and the fill is reduced, thereby reducing the negative friction resistance.
By reducing the concrete filling coefficient and negative friction resistance, the project cost is reduced, the vertical bearing capacity of the pile foundation is improved, and resource waste is avoided.
Smart Images
Figure CN222557623U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bored cast-in-place piles, in particular to a bag-type bored cast-in-place pile. Background Art
[0002] Cast-in-place piles are a common type of foundation piles. They are made by drilling holes in place and pouring concrete or reinforced concrete. Common cast-in-place piles include: (1) Bored cast-in-place piles: Use drilling equipment such as auger drills and rotary drilling rigs to drill holes in situ, and then pour concrete to form piles. There is no vibration or soil squeezing during construction, so it is suitable for use in densely built areas, but the pile settlement is slightly larger. (2) Pipe-sinking cast-in-place piles: Steel pipes with reinforced concrete pile shoes (pile tips) or flap-type pile shoes are sunk into the soil by hammering or vibration, and then the pipes are pulled out while concrete is poured to form piles. Compared with ordinary bored cast-in-place piles, pipe-sinking cast-in-place piles can avoid the problems of pile body sinking and insufficient holding force caused by floating soil at the pile tip of ordinary bored cast-in-place piles. However, the construction quality of pipe-sinking cast-in-place piles is difficult to control. If the pipes are pulled out too quickly, the pile body may shrink. In addition, since pipe-sinking cast-in-place piles are soil-extrusion piles, the piles cast in advance are easily tilted, fractured or even dislocated due to the soil-extrusion effect. In addition, the construction process will generate a lot of noise, which is not suitable for use in urban areas.
[0003] For the convenience of construction, bored cast-in-place piles are often used in fill. The general construction process of bored cast-in-place piles is: hole formation - hanging steel cage - pouring concrete. In the actual construction process of bored cast-in-place piles, due to the overhead and uneven fill, bored cast-in-place piles in fill will face problems such as hole collapse and slurry loss after hole formation, resulting in excessive concrete filling coefficient; in order to solve the problem of high filling coefficient, mud wall protection or steel casing is used to stabilize the hole wall during the hole formation process.
[0004] After bored cast-in-place piles are formed, if the settlement of the soil around the piles exceeds the settlement of the pile foundation, for example, when the fill is underconsolidated soil, there will be self-weight consolidation settlement after the pile foundation construction is completed, which will cause a downward pull load on the side surface of the pile, which is called negative friction. The negative friction on the pile side not only cannot constitute the bearing capacity of the foundation pile, but instead becomes an additional downward pull force acting on the pile body, resulting in an increase in the axial force and settlement of the pile body and a decrease in the vertical bearing capacity of the pile foundation. The problem of negative friction is widely present in pile foundation projects. If it is not handled properly, it will lead to serious failure of the pile foundation function and cause safety hazards to the engineering structure. Negative friction will be considered in the design of the pile foundation. In order to increase the bearing capacity of the pile foundation itself, the project cost will be increased accordingly. Nowadays, the negative friction of bored cast-in-place piles is reduced by solving the self-weight settlement of the fill, mainly to improve the mechanical properties of the fill itself, including strong tamping, grouting or the use of compaction piles, and the project cost is high. Utility Model Content
[0005] The utility model aims to provide a bag-type bored pile, which can reduce the negative friction of the bored pile, improve the vertical bearing capacity of the pile foundation, and reduce the construction cost.
[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0007] A bag-type bored pile comprises a bored pile, wherein the bored pile is a reinforced concrete structure, and a bag is integrally provided on the outer side of the bored pile, wherein the bag is used to wrap the poured concrete in the drill hole.
[0008] The utility model arranges a cloth bag integrally on the outer side of the bored pile. On the one hand, the cloth bag can effectively control the diffusion of concrete slurry during bored pile construction, thereby reducing the concrete filling coefficient; on the other hand, the cloth bag material is smoother than the concrete surface, which is conducive to reducing the friction between the concrete pile body and the backfill, thereby reducing the negative friction caused by the self-weight settlement of the backfill.
[0009] As a preferred solution of the utility model, a solid lubricant layer is applied to the bag in the fill section, which can effectively reduce the friction between the concrete pile body and the fill, thereby reducing the negative friction caused by the self-weight settlement of the fill. The solid lubricant is easy to store and has stable chemical properties, and has the function of protecting the bag from corrosion by acids, alkalis, organic solvents, etc.
[0010] As a preferred solution of the utility model, the solid lubricant layer is butter, which has good water resistance and long-lasting use.
[0011] As a preferred solution of the utility model, a steel cage is provided in the cast-in-place pile, and a puncture-proof protective cover is provided at the bottom of the steel cage. The puncture-proof protective cover is used to prevent damage to the bag when the steel cage is inserted during construction; the puncture-proof protective cover should have sufficient strength and toughness.
[0012] As a preferred solution of the utility model, the anti-puncture protection cover is a plastic component with low cost.
[0013] As a preferred solution of the utility model, the anti-puncture protection cover is sleeve-connected with each steel bar on the steel cage.
[0014] As a preferred solution of the utility model, the number of the anti-puncture protection covers is set to be several, the bottom of the anti-puncture protection cover is in the shape of a bullet head, and the cross-section of the anti-puncture protection cover is circular.
[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:
[0016] The bored cast-in-place pile structure proposed by the utility model is advantageous for reducing the filling coefficient of concrete and also advantageous for reducing the negative friction resistance caused by the self-weight settlement of fill, thereby reducing the construction cost and avoiding the waste of resources. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is a schematic structural diagram of a bag-type bored pile in this embodiment 1;
[0018] Figure 2 yes Figure 1 A partial enlarged view of .
[0019] Icons: 1-cloth bag; 2-steel cage; 3-anti-puncture protection cover; 4-drilling hole. DETAILED DESCRIPTION
[0020] The utility model is described in detail below in conjunction with the accompanying drawings.
[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.
[0022] Example 1
[0023] This embodiment provides a bag-type bored pile, such as Figure 1 , Figure 2 As shown, it includes a bored pile, which is a reinforced concrete structure. A cloth bag 1 is integrally provided on the outer side of the bored pile, that is, the concrete of the bored pile and the cloth bag 1 are bonded together. The cloth bag 1 is used to wrap the poured concrete in the drilled hole 4 to prevent the concrete slurry from seeping into the fill pores and causing the concrete filling coefficient to exceed the standard.
[0024] Furthermore, a solid lubricant layer is applied to the bag 1 at the fill section, which can effectively reduce the friction between the concrete pile body and the fill, thereby reducing the negative friction caused by the self-weight settlement of the fill. The solid lubricant is easy to store and has stable chemical properties, which can protect the bag 1 from corrosion by acids, alkalis, organic solvents, etc. In this embodiment, the solid lubricant layer is butter, which has good waterproof properties and is durable.
[0025] A steel cage 2 is provided in the cast-in-place pile, and a plurality of anti-puncture protective covers 3 are provided at the bottom end of the steel cage 2. The number of anti-puncture protective covers 3 is consistent with the number of vertical steel bars on the steel cage 2. The anti-puncture protective cover 3 is used to prevent damage to the cloth bag 1 when the steel cage 2 is inserted during construction; the anti-puncture protective cover 3 should have sufficient strength and toughness. Furthermore, the anti-puncture protective cover 3 in this embodiment is a plastic component with low cost; each anti-puncture protective cover 3 is connected to each steel bar on the steel cage 2; the bottom of the anti-puncture protective cover 3 is in the shape of a bullet head, and the cross-section of the anti-puncture protective cover 3 is round, without edges and corners, and is not easy to scratch the cloth bag 1.
[0026] During construction, after the hole is formed, the steel cage 2 is first wrapped with a cloth bag 1, including the bottom and side of the steel cage 2, and then a lubricant such as butter is applied only on the outer side of the cloth bag 1 in the fill section, and the bag is placed in the borehole 4. The cloth bag 1 is open at the top of the steel cage 2, and then concrete is poured in the cloth bag 1 to form a cast-in-place pile. The bottom of the cast-in-place pile is located in the embedded section, and the top is located in the fill section, wherein the fill section will generate negative friction resistance to the cast-in-place pile, and the embedded section provides positive friction resistance for the cast-in-place pile, such as a bearing layer.
[0027] In order to reduce the negative friction of bored piles and improve the vertical bearing capacity of pile foundations, this embodiment sets a cloth bag 1 on the outside of the bored pile. The cloth bag 1 is smoother than the concrete surface, and a lubricant is applied to the outside of the cloth bag 1 in the fill section, which can effectively reduce the friction between the concrete pile body and the fill, thereby reducing the negative friction caused by the self-weight settlement of the fill; this is more beneficial for end-bearing piles with upper fill and lower bedrock. In addition, to deal with the problem of high filling coefficient in the fill, compared with the existing technology using wall protection or steel casing, the cloth bag 1 in this embodiment can also prevent the problem of excessive concrete filling coefficient, and the price of the cloth bag 1 is more economical than measures such as steel casing.
[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A bag-type bored pile, characterized in that: The invention comprises a cast-in-place pile, wherein the cast-in-place pile is a reinforced concrete structure, and a cloth bag (1) is integrally provided on the outer side of the cast-in-place pile, and the cloth bag (1) is used to wrap the cast concrete in the drill hole (4).
2. A bag-type bored pile according to claim 1, characterized in that: A solid lubricant layer is applied to the cloth bag (1) at the filling section.
3. A bag-type bored pile according to claim 2, characterized in that: The solid lubricant layer is butter.
4. A bag-type bored pile according to any one of claims 1 to 3, characterized in that: A steel cage (2) is provided in the cast-in-place pile, and an anti-puncture protection cover (3) is provided at the bottom end of the steel cage (2).
5. The bag-type bored pile according to claim 4, characterized in that: The anti-puncture protective cover (3) is a plastic component.
6. The bag-type bored pile according to claim 4, characterized in that: The anti-puncture protective cover (3) is sleeve-connected to each steel bar on the steel cage (2).
7. The bag-type bored pile according to claim 4, characterized in that: The number of the puncture-proof protective covers (3) is set to be several, the bottom of the puncture-proof protective cover (3) is in the shape of a bullet head, and the cross-section of the puncture-proof protective cover (3) is circular.