Controllable quick breaking construction method for pile head of row pile

Abstract

The invention discloses a row pile head controlled rapid breaking construction method. The row pile head controlled rapid breaking construction method comprises the following steps that soil covering around a pile is cleaned; elevation guiding measurement and double control line identification are broken, specifically, a pile top design elevation control line and an annular cutting joint control line are arranged at intervals from bottom to top; performing annular cutting joint cutting: performing joint cutting based on an annular cutting joint control line to obtain an annular cutting joint which is arranged in the circumferential direction of the pile body and is continuously closed; carrying out layered breaking construction by a pile breaking machine: carrying out layered breaking to a circular cutting joint; manual finishing and forming control of the pile head: finishing the section of the pile head to a designed elevation control line of the pile top; and quality acceptance and finished product protection. The controllable pile head breaking height and the controllable breaking range serve as the core, the problems that in the prior art, efficiency is low, construction quality stability is poor and construction cost is high are solved in the mode that annular cutting joint positioning, mechanical layered breaking and manual fine trimming are combined, and efficient, safe and controllable breaking of pile head concrete is achieved.

Description

Technical Field

[0001] This invention relates to the field of pile driving technology, specifically to a method for controlled and rapid demolition of pile heads in pile driving. Background Technology

[0002] With the continuous expansion of highway construction, pile retaining structures are widely used in road projects in mountainous areas and complex geological conditions to meet engineering requirements such as high slopes, anti-skid measures, and roadbed stability. Pile retaining structures typically consist of multiple piles arranged in rows at certain intervals, forming an integrated load-bearing system through capping beams or retaining structures. The construction quality of these structures directly affects their overall safety and durability.

[0003] During the construction of a pile retaining structure, after the pile foundation is completed and reaches its design strength, the concrete above the design elevation of the pile head needs to be removed to expose the reinforcing steel and reliably connect it to the upper retaining structure. Pile head removal is a critical step in the construction of a pile retaining structure, and its accuracy, quality, and efficiency have a significant impact on subsequent structural construction and the overall project schedule.

[0004] Currently, most highway engineering pile retaining structures utilize bored cast-in-place piles with small diameters and close spacing. The pile heads often need to be integrally cast with the capping beam, retaining wall, or other retaining components, placing high demands on the pile head breaking elevation, cross-sectional flatness, and exposed reinforcement. However, in actual construction, factors such as limited working space, a large number of piles, and complex construction organization often lead to low efficiency and significant quality fluctuations in pile head breaking, becoming a major factor restricting the construction quality and progress of pile retaining structures.

[0005] Therefore, developing a pile head breaking method that is efficient, precise, and provides good protection for the pile body and reinforcing steel is of great practical significance. Summary of the Invention

[0006] The technical problem to be solved by this invention is how to efficiently, accurately, and effectively protect the pile body and reinforcing steel bars when breaking the pile head. The purpose is to provide a controlled and rapid construction method for breaking pile heads in a row of piles to solve the above-mentioned problem.

[0007] This invention is achieved through the following technical solution:

[0008] A method for controlled and rapid demolition of pile heads in a pile foundation includes the following steps:

[0009] Pile head reinforcement sleeve;

[0010] Cleaning of soil around piles;

[0011] Eliminate elevation measurement and double control line markings: Set the pile top design elevation control line and circumferential cutting joint control line at intervals from bottom to top;

[0012] Circumferential cutting: Cutting based on the circumferential cutting control line to obtain a continuous closed circumferential cutting along the circumference of the pile body;

[0013] Layered pile breaking construction: breaking in layers until the circumferential cutting joint is reached;

[0014] Manual finishing and shaping control of pile heads: The cross-section of the pile head is finished to the design elevation control line of the pile top;

[0015] Quality inspection and finished product protection.

[0016] In one possible design, based on the circumferential cut, the following steps are included:

[0017] Positioning: Shallow cutting positioning with a concrete cutter;

[0018] Continuous cutting: The concrete cutting machine cuts the concrete to the designed depth in one go;

[0019] The design dimensions of the circumferential cutting slit are as follows: the slit width is controlled between 8 and 12 mm, and the slit position deviation is no greater than ±5 mm.

[0020] In one possible design, the layered demolition construction based on a pile breaker includes the following steps:

[0021] Upper layer operation: Layered compression and shearing from top to bottom, causing the concrete to crack and peel off layer by layer;

[0022] Lower layer operation: When breaking near the circumferential cut, control the breaking force and operation rhythm to allow the pile head concrete to fracture naturally along the cut.

[0023] In one possible design, during upper-level operations, the thickness of a single layer is controlled at 200–300 mm;

[0024] In the lower-level operations, the breaking force includes working pressure and single-module breaking force, and the operation rhythm includes the duration of each pressurization, the holding time, and the number of cycles.

[0025] In one possible design, based on the pile head reinforcement sleeve, the following is included: before the reinforcement cage is fabricated and lowered into the pile hole, the pile head reinforcement section above the designed elevation of the pile top is fitted with a sleeve.

[0026] Based on the clearing of the soil around the pile, including: excavating the soil around the pile until the pile head and surrounding area form an operating space that meets the requirements of equipment operation, the excavation depth is controlled to be 50-100mm below the design elevation of the pile top.

[0027] In one possible design, based on breaking the elevation measurement and double control line markings, the following steps are included:

[0028] The design elevation of the pile head is transferred to the surface of the pile body;

[0029] Mark two control lines around the circumference of the pile;

[0030] Among them, the two control lines are the pile top design elevation control line used to control the final cross-sectional position of the pile head, and the circumferential cutting joint control line used for circumferential cutting joint construction positioning and confirmation of the pile head breaking interface.

[0031] In one possible design, a total station or level is used to transfer the design breaking elevation of the pile head to the surface of the pile body.

[0032] The design elevation control line of the pile top is moved 20-30mm upwards to set the circumferential cutting joint control line.

[0033] In one possible design, based on manual finishing and shaping control of the pile head, the following steps are taken: removing residual concrete; adjusting local elevation differences until the final elevation deviation of the pile top is controlled within the range of +0 to -10 mm.

[0034] In one possible design, based on manual trimming and shaping control of the pile head, residual concrete is cleaned using electric picks, pneumatic picks, or concrete cutters, and local height differences are adjusted using chisels, hammers, angle grinders, or fine grinders.

[0035] In one possible design, based on quality acceptance and finished product protection, the following steps are included:

[0036] Quality acceptance: Based on the control of pile top elevation, pile top flatness and integrity, reinforcement condition, protection and marking of sonic logging tubes and / or low strain testing, the construction quality is accepted.

[0037] Finished product protection: Protect the constructed pile heads by using temporary covering protection, impact protection, drainage management, steel reinforcement rust prevention treatment and / or process connection.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] With the controllability of pile head breaking height and range as the core, this method effectively solves the problems of low efficiency, poor construction quality stability and high construction cost of existing technologies by combining circumferential cutting and positioning, mechanical layered breaking and manual fine finishing, thus achieving efficient, safe and controllable breaking of pile head concrete. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0041] Figure 1 This is a flowchart illustrating a method for the controlled and rapid demolition of pile heads in a row of piles. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0043] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other embodiments, well-known structures, circuits, materials, or methods have not been specifically described in order to avoid obscuring the invention.

[0044] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0045] In the description of this invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "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 this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0046] Example:

[0047] In existing technologies, the demolition of pile heads in pile retaining structures is mainly carried out manually or semi-mechanized. Typical technical solutions include the following:

[0048] 1) Direct Chipping Method: Without effective isolation and control of the pile head breaking interface, this method involves directly chiseling away the concrete at the pile head using manual pneumatic hammers, pneumatic hammers combined with electric hammers, or partial hydraulic breakers combined with manual trimming. This method relies heavily on manual experience to control the breaking height and range. During construction, the breaking stress is difficult to effectively isolate and is easily transmitted to the lower part of the pile, potentially causing concrete cracking, spalling, and bending or damage to the main reinforcement bars, among other quality hazards. The Ministry of Housing and Urban-Rural Development's "Catalogue of Prohibited and Restricted Technologies" issued in August 2025 explicitly prohibits the direct chiseling method for cast-in-place pile head construction. Therefore, this method no longer meets current engineering quality and safety management requirements.

[0049] 2) Double-ring cutting method with rebar isolation: This is currently the most widely used method for breaking pile heads. The construction process involves: rebar sleeve → manual ring cutting of the pile head → stripping the rebar → driving in steel rods → lifting the pile head → finishing the pile top. This method achieves a certain degree of isolation and control of the breaking interface through the ring cut, reducing the adverse impact on the pile structure compared to direct chiseling. However, in practical applications, this method is still mainly manual. A pneumatic pick is used to chisel a groove between the two ring cuts, then the main rebar is exposed, and finally, a steel rod is driven in manually to cut the pile head. This method has low construction efficiency, and the construction quality is greatly affected by human factors, making it difficult to achieve efficient and stable construction under conditions of a large number of piles and tight schedules.

[0050] Based on this, existing technologies mainly rely on the double-ring cutting method with rebar isolation, but this method has the following drawbacks:

[0051] 1) The process is mainly manual, which is inefficient, labor-intensive, and time-consuming for single pile construction.

[0052] 2) Manual operation is highly dependent on the technical level of the operators, and there are obvious differences in construction quality among different operators, making it difficult to achieve standardized and large-scale construction. The quality of pile head breaking is inconsistent and the construction quality is unstable.

[0053] 3) If the operation is not properly controlled during the process of grooving, stripping the reinforcing bars and driving in the steel rods, the stress may still be transmitted to the lower part of the pile body, causing the concrete of the pile body to crack and peel off or the main reinforcement to bend and be damaged, affecting the structural safety and durability.

[0054] 4) The total cost is approximately 450-550 yuan per pile, resulting in high construction costs.

[0055] In response to the existing double-ring cutting method for reinforcing steel isolation, this embodiment provides a controlled and rapid demolition method for pile heads. With controllable demolition height and range as its core, it combines ring cutting joint positioning, mechanical layered demolition, and manual finishing to achieve efficient, safe, and controllable demolition of the pile head concrete. This method replaces the double-ring cutting method for reinforcing steel isolation and overcomes its shortcomings. Specifically:

[0056] like Figure 1 As shown, a method for controlled and rapid demolition of pile heads in a row of piles includes the following steps:

[0057] S100 pile head reinforcement sleeve;

[0058] S200 pile perimeter soil removal;

[0059] S300 Elevation Measurement and Double Control Line Marking: The pile top design elevation control line and the circumferential cutting joint control line are set at intervals from bottom to top;

[0060] S400 circumferential cutting joint: Based on the circumferential cutting joint control line, a circumferential cutting joint is obtained that is set along the circumference of the pile body and is continuously closed;

[0061] S500 pile breaker layered demolition construction: layered demolition up to the circumferential cutting joint;

[0062] S600 Pile Head Manual Trimming and Shaping Control: Pile head cross-section trimmed to the pile top design elevation control line;

[0063] S700 Quality Acceptance and Finished Product Protection.

[0064] In step S100, the pile head reinforcement is protected by a sleeve to prevent bending or damage during the demolition operation. At the same time, it helps to improve the efficiency and quality of the demolition operation, that is, the demolition only requires circumferential cutting, separation and lifting, which greatly shortens the construction period, makes the top surface of the pile head flat, reduces residual loose concrete, and ensures construction quality while reducing dust pollution.

[0065] Step S200 is used to clear the space around the piles, thereby making room for subsequent equipment operations; at the same time, it also ensures that the pile heads have sufficient exposed height to facilitate subsequent operations; in addition, when there are many piles, especially when the pile spacing is dense, the soil clearing of multiple piles can be carried out in a unified operation, which helps to improve the overall operation efficiency.

[0066] Step S300 involves marking the piles. On one hand, the relevant elevations are accurately transferred and marked onto the piles on site through elevation measurement, thereby accurately controlling the termination position of pile head breaking. On the other hand, a dual control system is formed using two control lines (i.e., the pile top design elevation control line and the circumferential cutting joint control line). The pile top design elevation control line is used to mark the top boundary of the effective pile body. All breaking operations must stop at this line to ensure the accuracy of the pile top elevation and meet the subsequent depth and structural stress requirements. The circumferential cutting joint control line serves as an isolation and protection function to facilitate rapid breaking operations above it, improving the efficiency of the operation.

[0067] Step S400 uses the marking line from step S300 as a reference to achieve positioning, thereby accurately machining a circumferential cut on the pile body. The circumferential cut is used to form a breaking isolation interface to limit the transmission of breaking stress to the lower part of the pile body.

[0068] Step S500 involves using a pile breaker to break up the pile, replacing manual labor and greatly improving construction efficiency. The layered breaking method is adopted, which can gradually release the internal stress of the concrete and prevent the impact load from being transmitted to the main structure and main reinforcement of the pile, thereby ensuring the integrity of the pile structure.

[0069] Step S600 is carried out after mechanical demolition, and the cross-section of the pile head is promptly manually trimmed to ensure that the quality of the pile head meets the design requirements and satisfies the requirements for subsequent retaining structure construction.

[0070] Step S700 involves inspecting the construction quality to ensure that the work quality meets the design requirements; at the same time, the processed pile heads are also protected to prevent damage to the pile heads during the process transition stage.

[0071] Based on this, compared with the existing double-ring cutting method for steel reinforcement isolation, the controlled and rapid demolition method for pile heads achieves the following technical effects:

[0072] 1) High breaking efficiency: The use of a pile breaking machine for overall breaking operation results in fast breaking speed and significantly shortens the construction time of a single pile. It is particularly suitable for engineering conditions with a large number of piles and concentrated operations.

[0073] 2) Precise positioning of the breaking elevation and controllable forming quality: By performing circumferential cutting operations at the designed breaking elevation position of the pile head in advance, a clear and continuous breaking interface is formed, which provides accurate height positioning and breaking boundary for subsequent mechanical breaking, effectively ensuring that the breaking elevation of the pile head is consistent with the design requirements.

[0074] 3) Strong control over the demolition range: The pile breaking machine demolishes the concrete of the pile head above the cut in layers. The demolition process is advanced layer by layer with uniform force. The demolition force of the pile breaking machine is concentrated on the concrete above the cut, preventing the damage from being transmitted to the lower part of the pile body during the demolition process, and reducing the adverse effects on the integrity and bearing capacity of the pile body.

[0075] 4) Good protection effect for reinforcing bars, and neat exposure of reinforcing bars: The pile breaking machine acts on the concrete by squeezing and shearing. Under the control of the cutting, the concrete is peeled off as a whole, the main reinforcing bars are naturally exposed, the risk of bending and damage to the reinforcing bars is small, which is conducive to the construction of subsequent processes such as the cap beam.

[0076] 5) Wide range of applications and high degree of standardization: It is applicable to pile retaining structures with different pile diameters and different concrete strength grades. The process flow is clear and easy to promote, apply and manage in a standardized manner.

[0077] 6) Significant economic benefits: The comprehensive cost of a single pile using this technology is approximately RMB 140 to 180, which can save approximately 60% to 74.5% of the cost compared to the traditional pile breaking process (RMB 450 to 550 per pile).

[0078] Therefore, the controlled and rapid demolition method for pile heads effectively solves the problems of low efficiency, poor construction quality stability and high construction cost of existing technologies, and achieves efficient, safe and controllable demolition of pile head concrete.

[0079] In one possible implementation, based on S400 circumferential cutting, the following steps are included:

[0080] S410 positioning: Using the circumferential cutting joint control joint as a reference, the concrete cutting machine performs shallow cutting positioning;

[0081] S420 Continuous Cutting: Concrete cutting machine cuts to the designed depth in one go;

[0082] The design dimensions of the circumferential cutting slit are as follows: the slit width is controlled between 8 and 12 mm, and the slit position deviation is no greater than ±5 mm.

[0083] Based on the above design scheme, the cutting construction adopts the method of "first positioning, then continuous cutting". After shallow positioning, the cutting is completed in one go, avoiding the chipping or inconsistent depth of the cut edge caused by repeated cutting, thus improving the processing quality. As for the design size of the circumferential cut, an appropriate value can be selected from the given range according to the specific construction conditions. This invention does not impose any restrictions on this.

[0084] In one possible implementation, the layered demolition construction based on the S500 pile breaker includes the following steps:

[0085] S510 upper layer operation: layered compression and shearing from top to bottom, causing the concrete to crack and peel off layer by layer;

[0086] S520 Lower Layer Operation: When breaking down near the circumferential cut, control the breaking force and operation rhythm to allow the pile head concrete to naturally fracture along the cut.

[0087] Based on the above design scheme, the closer the demolition work is to the circumferential cut, the more likely the demolition force is to affect the main structure of the pile. Therefore, S500 is divided into upper-level and lower-level operations. The upper-level operation focuses on efficiency and rapid demolition, while the lower-level operation focuses on controlling and protecting the pile body to avoid the impact load being transmitted to the main structure and main reinforcement of the pile body, thereby ensuring the integrity of the pile body structure.

[0088] It is worth noting that while efficiency is paramount in upper-layer operations, the working parameters should also be designed to achieve the effect of causing the concrete to fracture and naturally peel off layer by layer. This allows the pile head concrete to separate spontaneously along the predetermined interface without strong external impact, maximizing the protection of the effective pile integrity and improving construction accuracy and safety. During lower-layer operations, parameters should be adjusted promptly (i.e., controlling the breaking force and work pace) to allow the pile head concrete to fracture naturally along the cut joint, thus achieving effective separation of the pile head from the lower pile body.

[0089] Optionally, during the upper layer operation of S510, the thickness of a single layer is controlled between 200 and 300 mm. Based on this, in actual construction, when the pile diameter is large or the concrete strength is high, a smaller thickness value is adopted.

[0090] Optionally, in the S520 lower-level operation, the breaking force includes the working pressure and the single-module jacking force, and the operation rhythm includes the duration of each pressurization cycle, the holding time, and the number of cycles. Based on this, in addition to the above parameters, any other suitable parameters can be controlled to achieve the purpose of controlling the breaking force and the operation rhythm.

[0091] In one possible implementation, based on the S100 pile head reinforcement sleeve, the sleeve is installed on the pile head reinforcement section above the designed elevation of the pile top before the reinforcement cage is fabricated and lowered into the pile hole.

[0092] Based on the above design scheme, the sleeve is made of plastic, pearl cotton or any other suitable existing material. The sleeve and the reinforcing bar are tightly fitted without any looseness, and the sleeve end can be sealed by binding wire or any other suitable existing sealing method to prevent grout from seeping into the gap between the sleeve and the reinforcing bar during concrete pouring.

[0093] It is worth noting that the sleeve is installed straight and of uniform length. On the one hand, it prevents the reinforcing bars above the pile top elevation from getting stuck with the concrete, so there is no adhesive resistance when breaking it, which makes it easy to peel off or lift it as a whole. On the other hand, it can effectively protect the main reinforcing bars and avoid bending, deformation and damage to the reinforcing bars caused by chiseling and impact during the pile breaking process.

[0094] In one possible implementation, the soil around the S200 pile is cleared, including: excavating the soil around the pile until the pile head and surrounding area form an operating space that meets the requirements of equipment operation, and the excavation depth is controlled to be 50-100mm below the design elevation of the pile top.

[0095] Based on the above design scheme, the backfilling and excavation can be completed using any suitable existing equipment or manually, depending on the actual construction situation. At the same time, the excavation depth should be carefully controlled to avoid excessive excavation that could affect the stability of the surrounding soil.

[0096] In one possible implementation, the process of removing elevation measurements and double control line markers based on the S300 includes the following steps:

[0097] S30 pile head design breaks the elevation transfer to the pile body surface;

[0098] S320 marks two control lines around the circumference of the pile;

[0099] Among them, the two control lines are the pile top design elevation control line used to control the final cross-sectional position of the pile head, and the circumferential cutting joint control line used for circumferential cutting joint construction positioning and confirmation of the pile head breaking interface.

[0100] Based on the above design scheme, in S310, a total station or level is used to transfer the designed breaking elevation of the pile head to the surface of the pile body. In S320, the control line of the designed elevation of the pile top is moved 20-30mm upwards to set the control line of the circumferential cutting joint.

[0101] In one possible implementation, based on the manual trimming and shaping control of the S600 pile head, the following steps are taken: removing residual concrete; adjusting local elevation differences until the final allowable deviation of the pile top elevation is controlled within the range of +0 to -10 mm.

[0102] Based on the above design scheme, after mechanical demolition, the pile head cross-section should be manually trimmed in a timely manner to remove residual concrete and adjust local elevation differences, ensuring a smooth and dense pile head cross-section. The allowable deviation of the final pile top elevation should be controlled within the range of +0 to -10mm to meet the requirements of subsequent retaining structure construction.

[0103] Optionally, in the S600, based on the manual trimming and shaping control of the pile head, electric picks, pneumatic picks, or concrete cutters are used to remove residual concrete, and chisels, hammers, angle grinders, or fine grinders are used to adjust local height differences. Therefore, workers can freely choose and combine any of the tools listed above to complete the trimming work better, faster, and more effectively; in addition to the tools listed above, workers can also use any other suitable existing equipment to complete the manual trimming of the pile head.

[0104] In one possible implementation, based on S700 quality acceptance and finished product protection, the following steps are included:

[0105] S710 Quality Acceptance: Based on pile top elevation control, pile top flatness and integrity, reinforcement condition, sonic logging tube protection and marking and / or low strain testing, the construction quality is accepted.

[0106] S720 Finished Product Protection: Based on the selection of temporary covering protection, impact protection, drainage management, steel reinforcement rust prevention treatment and / or process connection, protect the constructed pile heads.

[0107] Based on the above design scheme, at least one of the acceptance items should be selected for quality acceptance, and at least one protection scheme should be selected for finished product protection. If sonic logging tubes are installed inside the pile, it is necessary to align and inspect them to ensure they are intact and not blocked. Collision protection can be achieved by setting up warning signs and rigid barriers around the pile body to prevent collisions from causing deformation of the reinforcing steel or damage to the pile top. Process coordination refers to the timely commencement of subsequent construction to avoid prolonged exposure of the pile head.

[0108] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlled and rapid demolition of pile heads in a pile drive system, characterized in that, Includes the following steps: Pile head reinforcement sleeve; Clear the soil around the piles; Eliminate elevation measurement and double control line markings: Set the pile top design elevation control line and circumferential cutting joint control line at intervals from bottom to top; Circumferential cutting: Cutting based on the circumferential cutting control line to obtain a continuous closed circumferential cutting along the circumference of the pile body; Layered pile breaking construction: breaking in layers until the circumferential cutting joint is reached; Manual finishing and shaping control of pile heads: The cross-section of the pile head is finished to the design elevation control line of the pile top; Quality inspection and finished product protection.

2. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, Based on the circumferential cut, the following steps are included: Positioning: Shallow cutting positioning with a concrete cutter; Continuous cutting: The concrete cutting machine cuts the concrete to the designed depth in one go; The design dimensions of the circumferential cutting slit are as follows: the slit width is controlled between 8 and 12 mm, and the slit position deviation is no greater than ±5 mm.

3. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, The layered demolition construction based on pile breaking machines includes the following steps: Upper layer operation: Layered compression and shearing from top to bottom, causing the concrete to crack and peel off layer by layer; Lower layer operation: When breaking near the circumferential cut, control the breaking force and operation rhythm to allow the pile head concrete to fracture naturally along the cut.

4. The method for controlled and rapid demolition of pile heads according to claim 3, characterized in that, In the upper layer operation, the thickness of a single layer to be broken is controlled at 200-300mm; In the lower-level operations, the breaking force includes working pressure and single-module breaking force, and the operation rhythm includes the duration of each pressurization, the holding time, and the number of cycles.

5. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, Based on the pile head reinforcement sleeve, including: before the reinforcement cage is fabricated and lowered into the pile hole, the pile head reinforcement section above the design elevation of the pile top is sleeved; Based on the clearing of the soil around the pile, including: excavating the soil around the pile until the pile head and surrounding area form an operating space that meets the requirements of equipment operation, the excavation depth is controlled to be 50-100mm below the design elevation of the pile top.

6. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, Based on the removal of elevation measurement and double control line markings, the following steps are included: The design elevation of the pile head is transferred to the surface of the pile body; Mark two control lines around the circumference of the pile; Among them, the two control lines are the pile top design elevation control line used to control the final cross-sectional position of the pile head, and the circumferential cutting joint control line used for circumferential cutting joint construction positioning and confirmation of the pile head breaking interface.

7. The method for controlled and rapid demolition of pile heads according to claim 6, characterized in that, Use a total station or level to transfer the designed breaking elevation of the pile head to the surface of the pile body; The design elevation control line of the pile top is moved 20-30mm upwards to set the circumferential cutting joint control line.

8. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, Based on manual finishing and shaping control of the pile head, including: removing residual concrete; adjusting local elevation differences until the final elevation of the pile top is controlled within the range of +0 to -10mm.

9. The method for controlled and rapid demolition of pile heads according to claim 8, characterized in that, Based on manual trimming and shaping control of the pile head, electric picks, pneumatic picks or concrete cutters are used to clean up residual concrete, and chisels, hammers, angle grinders or fine grinders are used to adjust local height differences.

10. The method for controlled and rapid demolition of pile heads according to claim 1, characterized in that, Based on quality acceptance and finished product protection, the following steps are included: Quality acceptance: Based on the control of pile top elevation, pile top flatness and integrity, reinforcement condition, protection and marking of sonic logging tubes and / or low strain testing, the construction quality is accepted. Finished product protection: Protect the constructed pile heads by using temporary covering protection, impact protection, drainage management, steel reinforcement rust prevention treatment and / or process connection.

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