A construction method for optimizing the pile head and improving the anti-seepage performance of cast-in-place piles

Abstract

The present invention discloses a construction method for optimizing the pile head and improving the anti-seepage performance of a bored pile, comprising the following steps: leveling the working surface; hoisting tooling; installing the workpiece: placing a fixed pipe on the working platform, using the fixed pipe to limit the steel cage to ensure that the steel cage does not fall or float; pouring concrete: placing a guide tube on a guide tube pad, the guide tube passing through the guide tube pad and extending into the pile hole, and using the guide tube to pour concrete into the pile hole. Since the top elevation of the working platform is the same as the pile top elevation, excess slurry directly overflows during the pouring process; pouring is completed; and a cushion layer and waterproofing are constructed. Compared with traditional methods, the present invention can significantly reduce the labor, material, machinery, and slag removal costs incurred by chiseling the pile head, extending or cutting steel bars, shortening the construction period, and effectively improving the anti-seepage performance of the pile head, thereby facilitating project cost control, quality management, schedule management, and energy conservation and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering rotary bored cast-in-place pile construction, and specifically relates to a construction method for optimizing the pile head and improving the anti-seepage performance of the bored cast-in-place pile. The method can realize the rotary bored cast-in-place pile without removing the pile head slurry, effectively control the steel cage elevation, and improve the anti-seepage performance of the pile head. Background Art

[0002] Currently, the most common method for deep excavation support piles and pile foundations is to use rotary bored cast-in-place piles. However, when pouring the grout up to the pile head, a depth of approximately 800mm must be reserved. The subsequent removal / chisel away of the pile head incurs high labor, material, and machinery costs, as well as the cost of handling solid construction waste, and requires significant construction time. Furthermore, with traditional methods, the junction between the pile head and the surrounding cushion layer constitutes a construction joint, a weak point in anti-seepage and prone to leakage. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction method for optimizing the pile head of a bored pile and improving its anti-seepage performance, thereby solving the problems of multiple steps, long construction period and poor quality in traditional pile foundation construction treatment methods.

[0004] The object of the present invention is achieved through the following technical solutions:

[0005] A construction method for optimizing the pile head and improving the anti-seepage performance of a cast-in-place pile comprises the following steps:

[0006] Step 1: Level the working surface: Level the working surface at the pile hole to h below the pile top elevation, where h is the height of the working platform;

[0007] Step 2: Hoisting the tooling: Hoist the work platform to the working surface at the pile hole. A space for pouring the pile body is reserved inside the work platform. The upper hole of the space for pouring the pile body corresponds to the pile hole, and the lower hole of the space for pouring the pile body is larger than the pile hole. Hoist the steel cage into the pile hole.

[0008] Step 3, installing the workpiece: Place a fixed pipe on the working platform, use the fixed pipe to limit the steel cage to ensure that the steel cage does not fall or float, and place the guide tube pad on the working platform;

[0009] Step 4, pouring concrete: Place a conduit on the conduit pad, pass the conduit through the conduit pad and extend into the pile hole. Use the conduit to pour concrete into the pile hole. Since the top elevation of the working platform is the same as the pile top elevation, excess slurry will overflow during the pouring process.

[0010] Step 5, pouring completed: concrete and steel bars form the pile body. Since the working platform acts as a template, an integrated water-stop enlarged head is formed in the pouring space of the pile body.

[0011] Step 6: Construct cushion layer and waterproof.

[0012] Furthermore, in step 2, the working platform is a truncated cone structure, the pile casting space reserved inside the working platform is also a truncated cone structure, and the pile hole is a cylindrical structure.

[0013] Furthermore, the working platform includes a top ring plate, a bottom ring plate, an inner plate and an outer plate. The top ring plate and the bottom ring plate are welded between the top and bottom of the inner plate and the outer plate respectively. Axillary plates are connected between the top ring plate and the inner plate and between the bottom ring plate and the outer plate. A lifting lug for the fixed pipe to pass through is welded on the top ring plate.

[0014] Furthermore, in step 3, the fixing pipe is fixed to the reinforcing ribs adjacent to the top of the steel cage below the fixing pipe to fix the fixing pipe to the reinforcing ribs.

[0015] Furthermore, in the step 3, when placing the conduit pad, the steel cage is passed through the steel bar holes on the conduit pad.

[0016] Furthermore, in step 4, the gravity of the working platform, the conduit pad, the conduit and the concrete acts on the fixed pipe, which prevents the steel cage from floating up.

[0017] Furthermore, in step 4, the operator visually monitors the quality of the pile head concrete pouring through the overflow concrete.

[0018] Furthermore, in step 6, the inclined surface formed on the outside of the water-stop enlarged head facilitates waterproofing construction, reducing the cost and process waiting of constructing the internal corner R angle with mortar in the traditional process.

[0019] Beneficial effects of the present invention:

[0020] 1. The top elevation of the platform structure designed in the present invention is the designed elevation of the pile top (which may be slightly higher). The floating slurry during the pouring process overflows directly, which is easier to handle than the traditional method of breaking and removing solid waste residue at a later stage.

[0021] 2. Management personnel can visually monitor the quality of pile head concrete pouring, which also facilitates forming and finishing work, making quality more controllable. If, due to geological conditions, the laitance is less than the generally required 800mm height, concrete can be effectively saved. If the overflowing laitance is greater than usual, this invention is more conducive to controlling the quality of the pile head concrete, significantly saving the costs of later chiseling the pile head and re-pouring concrete.

[0022] 3. Compared with the traditional construction method, the present invention can save a lot of labor, machinery and material costs generated by the pile head chiseling operation, effectively save construction time, and is beneficial to environmental protection.

[0023] 4. The present invention can effectively control the elevation of the pile body reinforcement, prevent the reinforcement cage from falling or floating, reduce the labor, material and machinery costs of later extension or cutting of reinforcement, and effectively save construction time.

[0024] 5. The construction quality of the present invention is reliable, and it can effectively improve the anti-seepage performance of the pile head structure, and it is also convenient to quickly carry out subsequent operations.

[0025] 6. The platform structure of the present invention is manufactured once, can be recycled, and is green and environmentally friendly.

[0026] The aforementioned main solution of the present invention and its further options can be freely combined to form multiple solutions, all of which are solutions that can be adopted and protected by the present invention; and the (non-conflicting options) of the present invention can also be freely combined with each other and with other options. After understanding the solutions of the present invention, those skilled in the art will understand that there are many combinations based on existing technology and common knowledge, all of which are technical solutions to be protected by the present invention, and these are not exhaustive here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural stereogram of the working platform of the present invention.

[0028] Figure 2 It is a structural sectional view of the working platform of the present invention.

[0029] Figure 3 It is a construction schematic diagram of step 2 of the present invention.

[0030] Figure 4 It is a construction schematic diagram of step 3 of the present invention.

[0031] Figure 5 It is a construction schematic diagram of step 4 of the present invention.

[0032] Figure 6 It is a construction schematic diagram of step 5 of the present invention.

[0033] Figure 7 It is a construction schematic diagram of step 6 of the present invention.

[0034] In the figure: 1-working platform, 2-pile hole, 3-rebar cage, 4-fixing pipe, 5-conduit pad, 6-conduit, 7-pile body, 8-waterstop expansion head; 11-top ring plate, 12-bottom ring plate, 13-inner plate, 14-outer plate, 15-axillary plate, 16-lifting ear, 31-reinforcement rib. DETAILED DESCRIPTION

[0035] The following non-limiting examples illustrate the present invention.

[0036] Example 1:

[0037] refer to Figure 1 and Figure 2As shown, the working platform 1 is a truncated cone structure, welded with steel plates with a thickness of not less than 12 mm, and has a height h of 200 mm. The pile casting space reserved inside the working platform 1 is also a truncated cone structure, and the upper hole of the pile casting space has the same diameter as the pile hole 2. The working platform 1 is expanded 300 mm on both sides with the pile casting space as the center, which is the width of the platform working surface. The pile casting space is expanded from the upper hole to the lower hole and has an inclination of 60 degrees. The internal diagonals of the working platform 1 are reinforced with 12 mm axil plates with a spacing of 200 mm. Four round steel lifting ears with a diameter of 20 mm are welded on the top plane of the working platform 1.

[0038] Specifically, the working platform 1 includes a welded top ring plate 11, a bottom ring plate 12, an inner plate 13 and an outer plate 14. The top ring plate 11 and the bottom ring plate 12 are welded between the top and bottom of the inner plate 13 and the outer plate 14 respectively. Axillary plates 15 are connected between the top ring plate 11 and the inner plate 13 and between the bottom ring plate 12 and the outer plate 14. A lifting ear 16 for the fixing pipe 4 to pass through is welded on the top ring plate 11.

[0039] A construction method for optimizing the pile head and improving the anti-seepage performance of a cast-in-place pile comprises the following steps:

[0040] Step 1, leveling the working surface: level the working surface at the pile hole 2 (the pile hole 2 is a cylindrical structure) to h=200 mm below the pile top elevation, where h=200 mm is also the height of the working platform 1 .

[0041] refer to Figure 3 As shown, step 2, hoisting tooling: hoist the prepared work platform 1 to the work surface at the pile hole 2 and place it in place. A space for pouring the pile body is reserved inside the work platform 1. The upper hole of the pile body pouring space corresponds to the pile hole 2 (i.e., the size and position correspond up and down), and the lower hole of the pile body pouring space is larger than the pile hole 2. Hoist the prepared steel cage 3 into the pile hole 2 and place it in place.

[0042] refer to Figure 4 As shown, step 3 is to install the workpiece: two fixed pipes 4 are placed on the work platform 1, and the two ends of the fixed pipes 4 pass through the lifting ears 16 on the top of the platform. The lower part of the fixed pipes 4 is adjacent to the reinforcing ribs 31 on the top of the steel cage 3. The fixed pipes 4 are fixed to the reinforcing ribs 31, and the fixed pipes 4 are used to limit the steel cage 3 to ensure that the steel cage 3 does not fall or float.

[0043] A conduit pad 5 is placed on the working platform 1. The conduit pad 5 is provided with a hollow structure. When placing the conduit pad 5, the steel cage 3 is passed through the hollow steel bar holes on the conduit pad 5 to avoid interference between the conduit pad and the steel bars.

[0044] refer to Figure 5As shown, step 4 is pouring concrete: a conduit 6 is placed on the conduit pad 5, the conduit 6 passes through the conduit pad 5 and extends into the pile hole 2, and concrete is poured into the pile hole 2 using the conduit 6. During the pouring process, the gravity of the working platform 1, the conduit pad 5, the conduit 6 and the concrete acts on the fixed pipe 4, and the fixed pipe 4 prevents the steel cage 3 from floating up.

[0045] Because the top elevation of working platform 1 is the same as the pile top elevation, excess slurry overflows during pouring, allowing operators to visually monitor the quality of the pile head concrete pouring through this overflowing concrete. Depending on the geological conditions, if the overflowing slurry is minimal, concrete can be effectively saved. If the overflowing slurry is greater than normal, it can be more conducive to controlling the quality of the pile head concrete, significantly reducing the costs of later chiseling and re-pouring concrete.

[0046] refer to Figure 6 As shown, step 5, pouring is completed: concrete and steel bars form the pile body 7. Since the working platform 1 acts as a template and the lower hole of the pile body pouring space on the working platform 1 is larger than the pile hole 2, an integrally formed water-stop enlarged head 8 is formed in the pile body pouring space.

[0047] refer to Figure 7 As shown, step 6, construction of cushion layer and waterproofing: the working platform structure is 200mm high. After the pile body is poured, it just meets the requirements of the designed cushion layer thickness of 100mm and the exposed anchoring of the pile head concrete into the foundation 100mm.

[0048] The inclined surface formed on the outside of the water-stop enlarged head 8 facilitates waterproof construction, reduces the cost and process waiting of using mortar to construct the internal angle R angle in the traditional process, and is more beneficial to quality control and shortening the construction period.

[0049] This invention optimizes the pile heads of bored cast-in-place piles based on actual on-site conditions. It employs a construction method that eliminates the need for removing pile head slurry, effectively improves the pile head's impermeability, and effectively controls the height of the reinforcement cage. Compared to traditional methods, this method significantly reduces labor, material, machinery, and slag removal costs associated with removing pile heads and extending or cutting rebar, shortens construction time, and effectively improves the pile head's impermeability, facilitating project cost control, quality management, schedule management, and energy conservation and environmental protection.

[0050] The aforementioned basic examples and their further alternatives can be freely combined to form multiple embodiments, all of which are applicable and claimed embodiments of the present invention. In the scheme of the present invention, each alternative can be arbitrarily combined with any other basic examples and alternatives.

[0051] 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 scope of protection of the present invention.

Claims

1. A construction method for optimizing the pile head and improving the anti-seepage performance of a bored pile, characterized in that: The steps include: Step 1, leveling the working surface: leveling the working surface at the pile hole (2) to a height h below the pile top elevation, where h is the height of the working platform (1); Step 2, hoisting the tooling: hoisting the work platform (1) to the working surface at the pile hole (2), wherein a space for pouring the pile body is reserved inside the work platform (1), wherein the upper hole of the space for pouring the pile body corresponds to and coincides with the pile hole (2), and the lower hole of the space for pouring the pile body is larger than the pile hole (2); hoisting the steel cage (3) into the pile hole (2); Step 3, installing the workpiece: placing a fixing pipe (4) on the working platform (1), using the fixing pipe (4) to limit the steel cage (3) to ensure that the steel cage (3) does not fall or float, and placing a guide tube pad (5) on the working platform (1); Step 4, pouring concrete: placing a conduit (6) on the conduit pad (5), the conduit (6) passing through the conduit pad (5) and extending into the pile hole (2), and using the conduit (6) to pour concrete into the pile hole (2). Since the top elevation of the working platform (1) is the same as the pile top elevation, excess slurry directly overflows during the pouring process; Step 5, pouring is completed: concrete and steel bars form the pile body (7), and since the working platform (1) acts as a template, an integrally formed water-stop enlarged head (8) is formed in the pile body pouring space; Step 6: Construct cushion layer and waterproofing.

2. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 is characterized in that: In the step 2, the working platform (1) is a truncated cone structure, the pile body casting space reserved inside the working platform (1) is also a truncated cone structure, and the pile hole (2) is a cylindrical structure.

3. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 2 is characterized in that: The working platform (1) comprises a top ring plate (11), a bottom ring plate (12), an inner plate (13) and an outer plate (14); the top ring plate (11) and the bottom ring plate (12) are welded between the top and bottom of the inner plate (13) and the outer plate (14), respectively; axilla plates (15) are connected between the top ring plate (11) and the inner plate (13) and between the bottom ring plate (12) and the outer plate (14); and a lifting lug (16) for passing a fixed pipe (4) is welded to the top ring plate (11).

4. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 is characterized in that: In the step 3, the fixing pipe (4) is fixed to the reinforcing rib (31) on the top of the steel cage (3) below the fixing pipe (4), and the fixing pipe (4) and the reinforcing rib (31) are fixed.

5. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 or 4, characterized in that: In the step 3, when placing the conduit pad (5), the steel cage (3) is passed through the steel bar holes on the conduit pad (5).

6. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 is characterized in that: In step 4, the gravity of the working platform (1), the conduit pad (5), the conduit (6) and the concrete acts on the fixed pipe (4), and the fixed pipe (4) prevents the steel cage (3) from floating up.

7. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 or 6, characterized in that: In step 4, the operator visually monitors the quality of the pile head concrete pouring through the overflow concrete.

8. The construction method for optimizing the cast-in-place pile head and improving the anti-seepage performance according to claim 1 is characterized in that: In the step 6, the inclined surface formed on the outer side of the water-stop enlarged head (8) facilitates waterproof construction, reducing the cost and process waiting of constructing the inner corner R angle with mortar in the traditional process.

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