Pipe pile core filling concrete pouring construction method
By draining water at the bottom of the pipe pile core, backfilling plain soil, and pouring bottom concrete, the problem of concrete loss at the bottom of the core-filled steel cage was solved, and high-quality pile core filling and bearing capacity improvement were achieved.
Patent Information
- Application Number
- CN202411301278.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2025-01-21
AI Technical Summary
In the construction of pipe piles, the concrete at the bottom of the core-filled steel cage is easily lost through the gap, resulting in loose quality defects in the lower concrete and is difficult to detect and solve by the naked eye.
By draining water at the bottom of the pile core, backfilling the plain soil and pouring the foundation concrete, a closed space is formed, the floating soil on the side walls is cleaned, the distance from the steel cage and the core-filled concrete to the bottom is shortened, grout leakage is reduced, and the outflowed concrete is filled with the foundation concrete in the space between the top and the bottom of the steel cage.
Effectively avoid the loss of the core concrete, improve the quality of construction, and ensure the carrying capacity and stability of the pile core.
Smart Images
Figure CN119332676A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of pipe pile construction, and in particular relates to a pipe pile core-filling concrete pouring construction method. Background Art
[0002] Pipe piles are widely used in the foundation piles of medium and high-rise buildings. Steel bars are placed in the pile core to connect with the structural pedestal beam (slab). Since the pile core is not poured with core-filled concrete throughout the entire length, in general, the core-filled steel cage does not have to reach the bottom of the hole. It only needs to be placed in the center of the drilled hole. This is because the main purpose of the core filling of the pipe pile is to enhance the bearing capacity and stability of the pipe pile, and it does not have to be filled to the bottom. The longitudinal position of the core filling needs to be determined according to the different characteristics of the stratum and the design requirements. Usually, when considering meeting the length of the pipe pile, the steel cage will be moved down a certain distance to increase the force-bearing area of the pipe pile and improve the bearing capacity.
[0003] The usual practice for core-filled steel cages is to place circular steel plates in the pipe piles to bear the poured core-fill concrete. Since the pile core is not a standard circular cross-section, in order to lower the circular steel plates smoothly, the circular steel plates are often 2-3cm smaller than the pile core. Concrete slurry is lost along the gaps, which not only causes a waste of concrete slurry, but also causes quality defects such as loose concrete in the lower part. This quality defect cannot be seen by the naked eye and is therefore difficult to be discovered and resolved during the construction process.
[0004] In order to avoid the problem that the concrete at the bottom of the core-filled steel cage is lost from the gaps when the core of the pipe pile is filled with concrete, resulting in the loosening of the lower concrete, the present invention proposes a construction method for pouring concrete for core-filled pipe piles. Summary of the invention
[0005] In order to solve the above problems existing in the prior art, the present invention provides a method for pouring concrete for pipe pile core filling.
[0006] The purpose of the present invention can be achieved through the following technical solutions:
[0007] A method for pouring concrete for core filling of pipe piles, comprising the following steps:
[0008] S1: Pump out the water at the bottom of the pile core;
[0009] S2: After the water at the bottom of the pile core is completely drained, the bottom of the pile core of the pipe pile is backfilled with plain soil;
[0010] S3: pour C15 base concrete on top of the backfilled soil of the pile core;
[0011] S4: After the bottom concrete solidifies, the side wall of the pile core is cleaned;
[0012] S5: placing a steel cage in the pile core;
[0013] S6: Pour core-fill concrete on the steel cage of the pile core.
[0014] Furthermore, in S1, the accumulated water is drained through a drainage pipe extending into the bottom of the pile core, and the outlet of the drainage pipe is suspended in the water and gradually lowered as the water level drops until the accumulated water is completely drained.
[0015] Furthermore, in S2, the particle size of the soil backfilled in the pile core is less than 1 / 2 of the diameter of the pile core, and the particle size of the soil decreases from bottom to top in the pile core.
[0016] Furthermore, in S3, after the plain soil is backfilled to the elevation, a 50 cm high C15 foundation concrete is poured in the pile core.
[0017] Furthermore, in S4, water is injected into the pile core and stirred to clean the floating soil and slurry on the side wall of the pile, and then the sewage is pumped out through the drainage pipe, and the process is repeated until the water becomes clear, and finally the water is pumped out.
[0018] Furthermore, in S5, a steel cage is manufactured according to the design requirements, lowered to the design elevation and firmly fixed.
[0019] Furthermore, in S6, a pouring funnel is provided at the hole of the pipe pile, and the core-filling concrete is poured through the pouring funnel.
[0020] Furthermore, the top elevation of the pile core backfill soil is 60 cm lower than the bottom elevation of the core filling concrete, and 10 cm is reserved to avoid over-pouring of the bottom concrete.
[0021] The beneficial effects of the present invention are as follows: by first draining the water at the bottom of the pile core, backfilling with soil after the drainage of the accumulated water is completed, and pouring bottom concrete on the top of the soil after the backfilling of soil is completed, pouring the bottom concrete is to prevent the backfilled soil from being loose and causing settlement when pouring the core-filling concrete. The bottom concrete forms a frictional resistance with the pipe pile wall and the backfilled soil to jointly carry the core-filling concrete. On the other hand, the bottom concrete and the pipe pile wall form a closed space, and the floating soil and slurry of the pipe pile wall are washed in the pile core, increasing the frictional resistance between the core-filling concrete and the pipe pile wall. After the steps of bottom concrete and flushing the side wall of the pile core are completed, the steel cage is placed in the pile core, and then the core-filling concrete is poured on the pile core. By filling the bottom of the pile core with plain soil and then pouring base concrete on top of the plain soil, the distance between the steel cage and the core-filling concrete to the bottom can be shortened. When the core-filling concrete leaks out from the bottom of the steel cage, the leakage can be reduced and the outflowing core-filling concrete can be filled in the space between the top of the base concrete and the bottom of the steel cage and solidified, thus avoiding the loss of the core-filling concrete. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.
[0023] Figure 1 It is a schematic cross-sectional view of the core filling of the pipe pile of the present invention.
[0024] Figure 2 It is a schematic plan view of the core filling of the pipe pile of the present invention.
[0025] Figure 3 It is a schematic diagram of drainage before the pile core is filled with soil according to the present invention.
[0026] Figure 4 It is a schematic diagram of pile core backfill soil of the present invention.
[0027] Figure 5 It is a schematic diagram of pile core bottom concrete of the present invention.
[0028] Figure 6 It is a schematic diagram of pumping out water before pouring and filling concrete in the pile core of the present invention.
[0029] Figure 7 It is a schematic diagram of placing a steel cage in the pile core of the present invention.
[0030] Figure 8 It is a schematic diagram of pouring core-filling concrete for the pile core of the present invention.
[0031] In the figure: 1. Steel cage; 2. Core-fill concrete; 3. Pipe pile; 4. Bottom elevation of core-fill concrete; 5. Pile core; 6. Drain pipe; 7. Bare soil; 8. Bottom concrete; 9. Side wall of pipe pile. DETAILED DESCRIPTION
[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.
[0033] like Figure 1-8 As shown, a method for pouring concrete for core filling of pipe piles of the present invention comprises the following steps:
[0034] S1: Pumping out the water at the bottom of the pile core 5 of the pipe pile 3;
[0035] S2: After the water at the bottom of the pile core 5 is completely drained, the bottom of the pile core 5 of the pipe pile 3 is backfilled with plain soil 7;
[0036] S3: pouring C15 bottom concrete 8 on top of the plain soil 7 backfilled in the pile core 5;
[0037] S4: After the bottom concrete 8 solidifies, the side wall of the pile core 5 is cleaned;
[0038] S5: placing the steel cage 1 in the pile core 5;
[0039] S6: pouring core-filling concrete 2 on the steel cage 1 of the pile core 5;
[0040] During the construction of the pipe pile 3, according to the geological conditions and construction costs of the construction, the construction of the pipe pile 3 generally does not fill the concrete to the bottom of the pipe pile 3. On the one hand, the nature and distribution of the underground soil layer may vary depending on the geological conditions, and the soil at the bottom of the pipe pile 3 may have different bearing capacities and compressibility. If the bottom soil is soft or there are adverse geological phenomena (such as caves, underground rivers, etc.), directly filling concrete may not achieve the expected effect, and may even aggravate the foundation settlement; in areas with abundant groundwater, the bottom of the pipe pile 3 may be affected by groundwater, causing the concrete to be difficult to solidify or quality problems. If there is a lot of accumulated water at the bottom, it is easy to cause the concrete to be diluted, causing the concrete to be difficult to solidify or a long solidification time. On the other hand, if the bottom of the pipe pile 3 does not need to bear too much load or does not need special reinforcement, then filling concrete to the bottom may cause material waste and increase engineering costs. Filling concrete to the bottom of the pipe pile 3 requires longer construction time and higher technical requirements, which may affect the construction progress and efficiency of the entire project.
[0041] In order not to fill directly to the bottom of the pipe pile 3, the poured core-fill concrete 2 needs to be supported by the steel cage 1 and the circular steel plate at the bottom of the steel cage 1. Since the pile core 5 is not a standard circular cross-section, in order to smoothly lower the circular steel plate, the circular steel plate is often 2-3 cm smaller than the pile core 5. The concrete slurry is lost along the gap, which not only causes a waste of concrete slurry, but also causes a quality defect of loose concrete in the lower part. This quality defect cannot be seen by the naked eye and is therefore difficult to be discovered and resolved during the construction process.
[0042] When the circular steel plate of the steel cage 1 is used to bear the core-filled concrete 2, the leakage of the core-filled concrete 2 is inevitable. Therefore, it is necessary to avoid excessive leakage of the core-filled concrete 2. The bottom of the pile core 5 of the pipe pile 3 is filled with plain soil 7 for plugging. However, due to the accumulation of water or groundwater at the bottom of the pile core 5, if the plain soil 7 is directly filled into the bottom of the pile core 5, water-soil mixing is likely to occur. The bearing capacity of the pipe pile 3 mainly depends on the friction between the pile body and the surrounding soil and the bearing capacity of the soil at the pile end. When water-soil mixing occurs at the bottom of the pipe pile 3, the physical and mechanical properties of the soil will change, such as the decrease in cohesion between particles and the increase in porosity. These changes will cause the soil to weaken its support force on the pile body, thereby reducing the bearing capacity of the pipe pile 3. Especially under geological conditions such as deep muddy soft soil, water-soil mixing may make the soil looser, further exacerbating the reduction in bearing capacity.
[0043] Therefore, it is necessary to first pump out the water at the bottom of the pile core 5, and then backfill the soil 7 after the accumulated water is pumped out. After the backfilling of the soil 7 is completed, the bottom concrete 8 is poured on the top of the soil 7. The pouring of the bottom concrete 8 is to prevent the backfilled soil 7 from being loose and causing settlement when pouring the core-filling concrete 2. The bottom concrete 8 forms a frictional resistance with the side wall 9 of the pipe pile and the backfilled soil 7 to jointly carry the core-filling concrete 2. On the other hand, the bottom concrete 8 and the side wall 9 of the pipe pile form a closed space, and the pile core 5 is flushed with water to clean the floating soil and slurry on the side wall 9 of the pipe pile, increasing the frictional resistance between the core-filling concrete 2 and the side wall 9 of the pipe pile. After the steps of building the bottom concrete 8 and flushing the side wall of the pile core 5 are completed, the steel cage 1 is placed in the pile core 5, and then the core-filling concrete 2 is poured on the pile core 5. By filling the bottom of the pile core 5 with soil 7 and then pouring the bottom concrete 8 on the soil 7, the distance between the steel cage 1 and the bottom of the core-filling concrete 2 can be shortened. When the core-filling concrete 2 leaks out from the bottom of the steel cage 1, the leakage can be reduced and the flowing core-filling concrete 2 can be filled in the space between the top of the bottom concrete 8 and the bottom of the steel cage 1 and solidified, thereby avoiding the loss of the core-filling concrete 2. The backfilled soil 7 can be reused according to actual conditions using the soil 7 dug out of the pile hole, or it can be mixed with other materials to form the soil 7 that can be used to fill the pile core 5, thereby reducing the construction cost.
[0044] Specifically, in S1, the accumulated water is pumped out through the drain pipe 6 extending into the bottom of the pile core 5, and the mouth of the drain pipe 6 is suspended in the water and is gradually lowered as the water level drops until the accumulated water is completely discharged; when the accumulated water at the bottom of the pile core 5 is pumped out, since the bottom of the pile core 5 is a soil layer, if the drain pipe 6 is placed in the pile core 5 in one step, the suction force of pumping out the accumulated water will easily pump out the soil at the bottom of the pile core 5, resulting in the loss of soil at the bottom of the pile core 5, which may easily cause the bearing capacity of the pipe pile 3 to decrease. Therefore, by suspending the drain pipe 6 in the water and gradually lowering it as the water level drops, not only can the loss of soil be avoided, but also the debris floating or suspended in the accumulated water can be pumped out.
[0045] Further, in S2, the particle size of the backfilled soil 7 of the pile core 5 is less than 1 / 2 of the diameter of the pile core 5, and the particle size of the soil 7 in the pile core 5 decreases from bottom to top; since most of the soil 7 has a certain viscosity, it is easy to form a mass after absorbing water, and the diameter of the pile core 5 of the pipe pile 3 is limited. In order to avoid the pile core 5 being blocked when backfilling the soil 7, it is necessary to break up the soil 7 to prevent its particle size from being too large. At the same time, since the soil 7 will form a mass after absorbing water, it is easy to scrape the side wall of the pile core 5 during the backfilling process, so that the soil 7 is adhered to the side wall of the pile core 5, making it difficult to clean in the subsequent steps. After reducing the particle size of the soil 7 to less than 1 / 2 of the diameter of the pile core 5, not only the probability of the soil 7 colliding with the side wall of the pile core 5 is reduced, but also the weight of a single piece of soil 7 is reduced, and the amount of soil 7 adhering to the side wall of the pile core 5 after colliding with the side wall of the pile core 5 is reduced. On the other hand, in order to prevent the different-sized soil 7 from directly piling up at the bottom of the pile core 5 and causing gaps, it is necessary to reduce the particle size of the soil 7 from bottom to top at the bottom of the pile core 5. First, fill in larger pieces of soil 7, and then fill in smaller pieces of soil 7 on the larger pieces of soil 7, so that the smaller pieces of soil 7 fill the gaps between the larger pieces of soil 7. At the same time, in order to further improve the compactness of the soil 7 at the bottom of the pile core 5, the soil 7 needs to be vibrated after backfilling.
[0046] In S3, after the plain soil 7 is backfilled to the elevation, a 50 cm high C15 bottom concrete 8 is poured in the pile core 5. Since the plain soil 7 is backfilled in the pile core 5 to prevent a large amount of core-filling concrete 2 from being lost, and at the same time, when the side wall of the pile core 5 is subsequently cleaned, the water used for cleaning can be prevented from seeping into the plain soil 7, it is necessary to pour concrete on the top of the plain soil 7. In order to reduce the cost while ensuring the strength of the pipe pile 3, it is necessary to make most of the pile core 5 filled with plain soil 7, and only pour concrete on the top to prevent water penetration. C15 concrete has the characteristics of moderate strength, convenient construction, economy and practicality, and a wide range of applications. By pouring C15 concrete above the plain soil 7, water can be prevented from infiltrating into the plain soil 7 in a short time. If the water at the bottom of the pile core 5 is groundwater, in order to prevent the groundwater from rising back in a short time after filling the plain soil 7 and diluting the subsequently poured core-filling concrete 2, the bottom concrete 8 can also isolate the water in the pile core 5 from rising back.
[0047] After the backfilling of the plain soil 7 and the pouring of the bottom concrete 8 are completed, the next step is to place the steel cage 1 and pour the core-filling concrete 2. Since the side wall 9 of the pipe pile will adhere to the soil or mud during the filling of the plain soil 7, the friction between the core-filling concrete 2 and the side wall 9 of the pipe pile will be reduced during the subsequent pouring of the core-filling concrete 2, resulting in a problem of reduced bearing capacity of the pipe pile 3. Therefore, in order to avoid this problem, in S4, water is injected into the pile core 5 and stirred to clean the floating soil and slurry on the side wall 9 of the pipe pile, and then the sewage is pumped out through the drainage pipe 6. The process is repeated until the water becomes clear, and the water is finally pumped out. This is different from the method in S1 where the outlet of the drainage pipe 6 is suspended in the water and gradually lowered as the water level drops. Since the sewage after flushing will accumulate on the bottom concrete 8, and the core-filling concrete 2 needs to be poured on the top of the bottom concrete 8, in order to prevent the mud and sand after flushing from being sandwiched between the two, the outlet of the drainage pipe 6 needs to be placed directly at the bottom, and the sewage is pumped out repeatedly until it becomes clear water, thereby ensuring that the inside of the pipe pile 3 is cleaned.
[0048] Furthermore, in S5, the steel cage 1 is manufactured according to the design requirements, lowered to the design elevation and firmly fixed. Meanwhile, in S6, a pouring funnel is arranged at the hole of the pipe pile 3, and the core-filling concrete 2 is poured through the pouring funnel. The top steel bars of the steel cage 1 are bent outwards and form a funnel shape at the top. On the one hand, the pouring funnel can be placed. On the other hand, since the bottom of the steel cage 1 is suspended in the air, it is necessary to provide a fulcrum for the steel cage 1, and a funnel shape is formed outwards through the top of the steel cage 1. The top diameter of the funnel is larger than the inner diameter of the pipe pile 3, and the top of the pipe pile 3 can be supported by the funnel-shaped structure at the top of the steel cage 1.
[0049] Furthermore, the top elevation of the backfilled soil 7 of the pile core 5 is 60 cm lower than the bottom elevation 4 of the core filling concrete, and 10 cm is reserved to avoid over-pouring of the bottom concrete 8; before backfilling the soil 7, the theoretical backfill volume should be calculated first, and the soil 7 should be placed in a plastic bucket that can represent the volume. When 80% of the theoretical amount is backfilled, the backfill elevation should be measured with a measuring rope, and measurements should be made frequently during subsequent backfilling to avoid overfilling.
[0050] In general, the core-filled steel cage 1 does not have to reach the bottom of the hole, and it only needs to be placed in the center of the drilled hole. This is because the main purpose of the core filling of the pipe pile 3 is to enhance the bearing capacity and stability of the pipe pile 3, and it does not have to be filled to the bottom. The longitudinal position of the core filling needs to be determined according to the different characteristics of the stratum and the design requirements. Usually, when considering the length of the pipe pile 3, the steel cage 1 is moved down a certain distance to increase the force-bearing area of the pipe pile 3 and improve the bearing capacity.
[0051] The top elevation of the backfilled soil 7 of the pile core 5 is 60cm lower than the bottom elevation 4 of the core-filled concrete, and the bottom concrete 8 is poured 50cm. Since the pile core 5 is not a standard circular section and the pouring volume is small, it is not appropriate to use a measuring rope to measure the pouring surface height, but pouring is performed after the pouring volume is calculated. Therefore, 10cm is reserved to avoid over-pouring of the bottom concrete 8 and unable to handle it. After pouring, the theoretical pouring volume and the actual pouring volume should be checked. If the actual pouring volume is small, the reason should be analyzed quickly and the treatment should be completed before the initial setting of the concrete.
[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.
Claims
1. A method for pouring concrete for core filling of pipe piles, characterized in that: The following steps are involved: S1: Pumping out the water accumulated at the bottom of the pile core (5) of the pipe pile (3); S2: After the water accumulated at the bottom of the pile core (5) is completely drained, the bottom of the pile core (5) of the pipe pile (3) is backfilled with plain soil (7); S3: pouring C15 foundation concrete (8) on top of the plain soil (7) backfilled in the pile core (5); S4: After the bottom concrete (8) solidifies, the side wall of the pile core (9) is cleaned; S5: placing a steel cage (1) in the pile core (9); S6: pouring core-filling concrete (2) on the steel cage (1) of the pile core (9).
2. A method for pouring concrete for core filling of pipe piles according to claim 1, characterized in that: In S1, the accumulated water is drained through a drainage pipe (6) extending into the bottom of the pile core (9), and the outlet of the drainage pipe (6) is suspended in the water and gradually lowered as the water level drops until the accumulated water is completely drained.
3. A method for pouring concrete for core filling of pipe piles according to claim 1, characterized in that: In S2, the particle size of the backfilled soil (7) of the pile core (5) is less than 1 / 2 of the diameter of the pile core (5), and the particle size of the backfilled soil (7) decreases from bottom to top in the pile core (5).
4. A method for pouring concrete for core filling of pipe piles according to claim 3, characterized in that: In the step S3, after the plain soil (7) is backfilled to the elevation, a 50 cm high C15 foundation concrete (8) is poured into the pile core (5).
5. A method for pouring concrete for core filling of pipe piles according to claim 1, characterized in that: In S4, water is injected into the pile core (5) and stirred to clean the floating soil and slurry on the side wall of the pipe pile (3), and then the sewage is pumped out through the drainage pipe (6). This process is repeated until the water becomes clear, and finally the water is pumped out.
6. A method for pouring concrete for core filling of pipe piles according to claim 1, characterized in that: In S5, the steel cage (1) is manufactured according to the design requirements, lowered to the design elevation and firmly fixed.
7. A method for pouring concrete for core filling of pipe piles according to claim 1, characterized in that: In S6, a pouring funnel is provided at the hole of the pipe pile (3), and the core-filling concrete (2) is poured through the pouring funnel.
8. A method for pouring concrete for core filling of pipe piles according to claim 4, characterized in that: The top elevation of the backfilled plain soil (7) of the pile core (5) is 60 cm lower than the bottom elevation (4) of the core-filled concrete, and 10 cm is reserved to avoid over-pouring of the bottom concrete (8).