Method for constructing cast-in-place concrete pile at high altitude
By digging holes on the trestle in the deep foundation pit and laying roadbed boxes, and setting up pile machines and mud circulation systems, the problem of inaccessibility of pile driving machinery is solved, and convenient construction of adding concrete cast-in-place piles is achieved, reducing costs and foundation disturbances. The problem of mud circulation in a small site at the bottom of the pit has been solved.
Patent Information
- Application Number
- CN202411557827.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2024-12-24
AI Technical Summary
During the construction of deep foundation pits, concrete cast-in piles need to be added due to design changes, and the on-site trestle and support components are restricted, resulting in the pile driving machinery being unable to enter the construction work inside the foundation pit, and the earth in the pit has bottomed out, and the entry of the machinery will cause unstable foundation.
The holes are chiseled on the trestle in the foundation pit, lay the roadbed box and set up pile machines, and the drill rod is placed down the hole to form pile holes. The mud recycling system is used to construct concrete cast-in piles, and finally the holes are sealed.
It has achieved the safe and convenient addition of concrete cast-injected piles without removing the original support, which has solved the problem of mud recycling in the narrow site at the pit, and reduced construction costs and disturbed the foundation.
Smart Images
Figure CN119177658A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of building construction, and in particular to a method for high-altitude construction of concrete cast-in-place piles. Background Art
[0002] During the construction of deep foundation pits, concrete cast-in-place piles and foundation pit retaining structures are constructed first, followed by layered excavation of earthwork, and support erection, and the use of supports to build trestles. If the pile foundation, retaining structure, and earthwork are all completed, and additional concrete cast-in-place piles are required due to design changes, the limitations of on-site trestles, supports, and other components will prevent the piling machinery from entering the foundation pit for construction. In addition, since the earthwork in the pit has already bottomed out, the entry of machinery into the foundation pit for construction will inevitably cause disturbance of the soil in the pit, which is not conducive to the stability of the foundation. Summary of the invention
[0003] In order to overcome the defects of the prior art, a method for high-altitude construction of concrete bored piles is provided to solve the problem that when adding concrete bored piles in a foundation pit, the pile driver cannot enter the foundation pit for construction due to restrictions of components such as trestles and supports.
[0004] To achieve the above purpose, a method for high-altitude construction of concrete cast-in-place piles is provided, comprising:
[0005] A hole is chiseled on the trestle in the foundation pit so that the position of the hole corresponds to the position of the concrete cast-in-place pile;
[0006] Laying two roadbed boxes on the trestle, the two roadbed boxes are arranged on opposite sides of the opening;
[0007] Setting up a pile driver on the two roadbed boxes;
[0008] The drill rod of the pile driver is lowered through the hole to the bottom of the foundation pit to drill and form a pile hole. During the drilling construction of the pile driver, a mud box is installed at the bottom of the foundation pit and a small mud pool is arranged, and a large mud pool is arranged on the top of the foundation pit. The mud in the pile hole flows into the small mud pool, and the mud in the small mud pool is pumped into the mud box by a mud pump, and then the mud in the mud box is pumped into the large mud pool by a mud pump, and finally the mud in the large mud pool is pumped to the pile driver for recycling;
[0009] Casting concrete piles in the pile holes;
[0010] The hole on the trestle is blocked.
[0011] Furthermore, during the step of drilling a hole on the trestle in the foundation pit, the steel bars in the trestle are cut off from the middle of the hole and bent upward.
[0012] Furthermore, the step of blocking the hole on the trestle includes:
[0013] A hanging formwork is provided at the bottom of the opening;
[0014] Straightening the steel bars;
[0015] Providing a connecting steel bar, and connecting the connecting steel bar to the two cut steel bars;
[0016] Post-cast concrete is poured into the opening, and the post-cast concrete covers the two steel bars and the connecting steel bars.
[0017] The beneficial effect of the present invention is that the high-altitude construction concrete cast-in-place pile method of the present invention utilizes a roadbed box to lay a concrete trestle to reduce concentrated loads, and provides convenience for piling by opening holes in the trestle. At the same time, a construction method for opening holes in the trestle and sealing the hole openings is proposed.
[0018] The high-altitude construction concrete cast-in-place pile method of the present invention uses a mud recycling process in the process of setting up a pile driver on a trestle to construct a pile foundation, which effectively solves the problem of mud circulation in a narrow area at the bottom of a pit.
[0019] The high-altitude construction concrete bored pile method of the present invention utilizes the existing trestles as a construction platform to complete the construction of concrete bored piles without removing the original supports to facilitate the pile driver to operate at the bottom of the pit. It is adapted to local conditions, convenient to construct and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:
[0021] Figure 1 It is a schematic diagram of a method for high-altitude construction of concrete cast-in-place piles according to an embodiment of the present invention.
[0022] Figures 2 to 5 The figure is a schematic diagram of the steps of sealing a hole on a trestle according to an embodiment of the present invention. DETAILED DESCRIPTION
[0023] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.
[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0025] Reference Figures 1 to 5As shown, the present invention provides a method for high-altitude construction of concrete cast-in-place piles, comprising the following steps:
[0026] S1. A hole is chiseled on the trestle bridge 1 in the foundation pit so that the position of the hole corresponds to the position of the concrete cast-in-place pile.
[0027] In this embodiment, the diameter of the cast-in-place concrete pile is 700 mm. To facilitate the construction of the pile foundation, an air compressor is used to drill a 900 mm × 900 mm square hole on the trestle just above the pile hole (to facilitate the hanging of the pile foundation reinforcement cage and the conduit).
[0028] Positioning and laying out the opening: Draw a cross line with the pile center as the center, and draw a 900×900mm square grid on the trestle based on the cross line;
[0029] The hole opening is chiseled using an air compressor in the trestle layout area. Be careful not to cut the steel bars when chiseling.
[0030] Treatment of steel bars at the opening: Cut the steel bars along the center line and bend them out of the opening for use in later sealing of the opening.
[0031] S2. Two roadbed boxes are laid on the trestle 1, and the two roadbed boxes are arranged on opposite sides of the opening.
[0032] S3, setting up the pile driver 2 on the two roadbed boxes 11.
[0033] The roadbed box is laid and the pile driver is parked on the top of the roadbed box. A 50T crawler crane is used to lift the casing, drill bit, etc. to the bottom of the foundation pit. After the drilling rig and drill rod are installed, the drill bit is assembled at the bottom of the foundation pit, and the casing is buried, and finally the concrete cast-in-place pile construction is carried out.
[0034] After the square holes on the trestle are chiseled out, two 1.5×6m roadbed boxes are laid on the upper part of the trestle, and a pile driver is set up on the roadbed boxes. The roadbed boxes can be flexibly placed according to the construction conditions of the pile foundation. However, no matter how they are placed, it must be ensured that all the pile foundations are placed on the roadbed boxes.
[0035] The casing materials were transported to the bottom of the foundation pit using a 50T crawler crane, and then a PC120 excavator was used in conjunction with manual labor to transport them inside the foundation pit.
[0036] According to the measurement technical requirements, a foundation pit 200mm larger than the pile diameter is dug manually using a PC120 excavator with the center point of the pile as the center of the circle. The casing (casing diameter is 1000mm) is vertically fixed at the pile position using the cross center hanging hammer method for correction. It can only be buried after meeting the requirements.
[0037] (1) The deviation between the center of the casing and the center line of the pile position shall not exceed 20 mm, and it shall remain vertical and preferably 10 cm above the ground.
[0038] (2) To ensure the convenience of casing burial construction and the quality of pile formation, a 2m casing can be used for burial. At the same time, any obstacles must be cleared before burial.
[0039] (3) After correction, use clay to bury the casing to ensure that the casing does not leak mud or move during drilling.
[0040] (4) Keep records and conduct retests.
[0041] S4, the drill rod of the pile driver 2 is lowered through the hole to the bottom of the foundation pit to drill into a pile hole. During the drilling construction of the pile driver 2, a mud box 4 is installed at the bottom of the foundation pit and a small mud pool 3 is arranged, and a large mud pool 5 is arranged on the top of the foundation pit. The mud in the pile hole flows into the small mud pool 3, and the mud in the small mud pool 3 is pumped into the mud box 4 by a mud pump, and then the mud in the mud box 4 is pumped into the large mud pool 5 by a mud pump, and finally the mud in the large mud pool 5 is pumped to the pile driver 2 for recycling.
[0042] When drilling, inject mud to protect the wall while drilling. Before drilling, start the mud pump first. After the mud circulates normally, start the drilling rig to slowly rotate and lower the drill bit to the bottom of the hole. Before drilling, gently press and drill slowly. After drilling to 2-3m, gradually increase the speed and drilling pressure to drill normally. During drilling, frequently check the verticality of the drill rod, the level of the rotary platform and the mud condition of the drilling, and adjust them at any time, and keep detailed records. During the drilling construction, the parameters should also be adjusted in time according to different formations.
[0043] When adding a drill rod during drilling, stop drilling first, raise the drill bit 200mm above the bottom of the hole, and maintain mud circulation for 1 to 3 minutes to clean the bottom of the hole and remove the drilling debris in the pipeline before adding a drill rod. When installing the rod, tighten it firmly to prevent tools and drilling tools from falling into the hole.
[0044] When drilling, pay close attention to the stability of the pile frame, whether the casing and soil are sinking, be careful when connecting and removing the drill rod, and carefully check the tight connection of the drill rod joint each time.
[0045] During the construction of the pile foundation on the pier, the drill rod speed was reduced from 139 (r / min) on the ground to 44 (r / min) to avoid the risk of drill rod shaking and pile driver overturning due to excessive drill rod torque during suspended operations.
[0046] Due to the additional construction of pile foundation under pure support in this working condition, in terms of mud configuration, a mud box is considered for sedimentation, and a mud pool is set up on the ground. The mud flows out from the pile hole and enters the small mud pool set at the bottom of the pit. It is pumped into the mud box by a mud pump. The mud in the mud box is then pumped to the large mud pool set at the top of the pit by a mud pump and pumped to the pile driver by a mud circulation pump to realize mud circulation.
[0047] S5. Pour the cast-in-place concrete piles into the pile holes.
[0048] After the hole is drilled, the steel cage and lower guide tube are hoisted, the hole is cleaned and concrete is poured as required.
[0049] S6. Seal the hole on the pier 1.
[0050] In the step of drilling a hole on the trestle bridge 1 in the foundation pit, the steel bars 6 in the trestle bridge 1 are cut off from the middle position of the hole and the steel bars 6 are bent upward.
[0051] Specifically, step S6 includes:
[0052] S61. A hanging formwork 7 is arranged at the bottom of the opening.
[0053] See also Figure 2 When sealing the hole, first process a square hanging mold with a length and width of 1m respectively, open eight small holes on its upper part (for the wire to pass through), and stick foam double-sided tape around it to prevent leakage.
[0054] See also Figures 3 to 5 , thread the hanging formwork wire and tie a knot, transport it to the bottom of the foundation pit, and use two hemp ropes from the middle and lower part of the hole to lift the hanging formwork to the bottom of the hole.
[0055] The hanging formwork is fixed with two steel pipes and iron wire.
[0056] S62. Straighten the steel bar 6.
[0057] S63, providing a connecting steel bar 6, and connecting the connecting steel bar 6 to the two cut steel bars 6.
[0058] Straighten the bent steel bars at the opening and use steel bars of the same specifications for single-sided welding.
[0059] S64, pouring post-cast concrete into the opening, the post-cast concrete covering the two steel bars 6 and the connecting steel bars 7.
[0060] The high-altitude construction method of concrete bored piles of the present invention proposes a construction method in which a pile driving machine is set up above a trestle bridge and then concrete bored piles are constructed to solve the problem that newly added concrete bored pile construction machinery cannot enter the pit bottom for construction when the foundation pit is excavated to the bottom.
[0061] The high-altitude construction concrete cast-in-place pile method of the invention utilizes a roadbed box to lay a concrete trestle to reduce concentrated loads, provides convenience for piling by opening holes in the trestle, and also proposes a trestle hole opening and hole blocking construction method.
[0062] The high-altitude construction concrete cast-in-place pile method of the present invention uses a mud recycling process in the process of setting up a pile driver on a trestle to construct a pile foundation, which effectively solves the problem of mud circulation in a narrow area at the bottom of a pit.
[0063] The high-altitude construction concrete bored pile method of the present invention utilizes the existing trestles as a construction platform to complete the construction of concrete bored piles without removing the original supports to facilitate the pile driver to operate at the bottom of the pit. It is adapted to local conditions, convenient to construct and low in cost.
[0064] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.
Claims
1. A method for high-altitude construction of concrete cast-in-place piles, characterized in that: The following steps are involved: A hole is chiseled on the trestle in the foundation pit so that the position of the hole corresponds to the position of the concrete cast-in-place pile; Laying two roadbed boxes on the trestle, the two roadbed boxes are arranged on opposite sides of the opening; Setting up a pile driver on the two roadbed boxes; The drill rod of the pile driver is lowered through the hole to the bottom of the foundation pit to drill and form a pile hole. During the drilling construction of the pile driver, a mud box is installed at the bottom of the foundation pit and a small mud pool is arranged, and a large mud pool is arranged on the top of the foundation pit. The mud in the pile hole flows into the small mud pool, and the mud in the small mud pool is pumped into the mud box by a mud pump, and then the mud in the mud box is pumped into the large mud pool by a mud pump, and finally the mud in the large mud pool is pumped to the pile driver for recycling; Casting concrete piles in the pile holes; The hole on the trestle is blocked.
2. The method for high-altitude construction of concrete cast-in-place piles according to claim 1, characterized in that: During the step of drilling a hole on the trestle in the foundation pit, the steel bars in the trestle are cut off from the middle of the hole and bent upward.
3. The method for high-altitude construction of concrete cast-in-place piles according to claim 2, characterized in that: The step of blocking the hole on the trestle comprises: A hanging formwork is provided at the bottom of the opening; Straightening the steel bars; Providing a connecting steel bar, and connecting the connecting steel bar to the two cut steel bars; Post-cast concrete is poured into the opening, and the post-cast concrete covers the two steel bars and the connecting steel bars.