Construction method of variable diameter drilling and reaming pile driver

Abstract

This invention belongs to the field of engineering machinery technology and relates to a construction method for a variable-diameter drilling and reaming integrated pile driver. It solves the problem that existing drilling and reaming integrated pile drivers cannot change diameter. The construction method is based on a variable-diameter drilling and reaming integrated pile driver, which includes an active pipe, a driven pipe, an upper wing plate seat, a lower wing plate seat, and a reaming arm. The reaming arm is formed by connecting an upper wing plate and a lower wing plate. The upper wing plate is formed by connecting an upper wing plate and an upper wing plate link, and the lower wing plate is formed by connecting a lower wing plate and a lower wing plate link. The construction method determines the length of the reaming arm to be connected by adjusting the position of the upper wing plate seat on the gear key and the position of the lower wing plate seat on the driven pipe. Then, it adaptively adjusts the number of wing plate link connections. Through the coordinated cooperation between the components, it achieves reaming operations for different pile diameters, angles, and sizes, which is simple, convenient, and greatly improves construction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of engineering machinery technology, specifically a construction method for a variable-diameter drilling and reaming integrated pile driver. Background Technology

[0002] Drilled piles with one or more bearing plates are called expanded-plate (or supported-plate) piles. Because the bearing plates increase the surface area between the pile and the foundation soil, the pile's bearing capacity is significantly improved. Expanded-plate piles offer advantages such as a wide range of applicable soil layers, saving raw materials, shortening construction time, greatly reducing pollutant emissions, and significant economic benefits.

[0003] Currently, the application status of expanded-diameter cast-in-place piles is as follows:

[0004] a. Hydraulic expansion bearing pile

[0005] This process involves first drilling a pile hole using a conventional drilling rig, then using a crane to place a hydraulic expansion device into the pile hole at the required expansion depth. Utilizing hydraulic power, the device requires manual rotation after each expansion and retraction, and each cavity needs to be formed more than 10 times. This process easily generates a large amount of sediment falling to the bottom of the pile hole, and is also prone to localized diameter reduction and hole collapse, increasing the difficulty of subsequent construction processes. Furthermore, this method involves excessive manual operation, high difficulty in quality control, requires the simultaneous operation of multiple construction machines, and results in high construction costs.

[0006] b. Rotary drilling rig construction of enlarged-diameter cast-in-place piles

[0007] When rotary drilling rigs construct enlarged-diameter cast-in-place piles, a special enlargement device must be used whenever the borehole reaches the required enlargement depth. Because this device lacks a slag removal function, the slag produced during enlargement fills the borehole cavity and above. The rotary drilling rig then needs to be replaced with a slag remover to repeatedly remove the slag, and the pressure applied during slag removal easily pushes the slag back into the cavity. The slag inside the cavity severely affects the normal bearing capacity of the enlarged-diameter cast-in-place pile.

[0008] c. Integrated drilling, reaming, and cleaning reverse circulation rotary extrusion bearing pile machine

[0009] This piling machine, due to its need for mud circulation during construction, boasts excellent performance characteristics such as simultaneous operation and slag removal, minimal soil disturbance, and regular disc formation, making it a relatively ideal construction tool for expanded-disc cast-in-place piles. However, due to its inherent mechanical structure, the diameter of the expanded disc is fixed and cannot be adjusted. This makes it unable to meet the construction needs of expanded-disc cast-in-place piles with different pile diameters and disc diameters.

[0010] In summary, none of the existing pile drivers have the function of adjusting the diameter of the expansion head. Therefore, in order to facilitate operation, improve construction progress, reduce construction costs, and ensure construction quality, it is necessary to design a construction method for a variable diameter drilling and expansion integrated pile driver. Summary of the Invention

[0011] The purpose of this invention is to provide a construction method for a variable-diameter drilling and reaming integrated pile driver that features a scientifically and rationally designed structure, convenient operation, improved construction progress, reduced construction costs, guaranteed construction quality, and easy implementation.

[0012] The technical problem solved by this invention is achieved through the following technical solution:

[0013] A construction method for a variable-diameter drilling and reaming integrated pile driver is disclosed. This method is based on a variable-diameter drilling and reaming integrated pile driver, which includes a drive pipe, a driven pipe, an upper wing plate seat, a lower wing plate seat, and a rotary reaming arm. The rotary reaming arm is formed by connecting an upper wing plate and a lower wing plate. The upper wing plate is formed by connecting an upper wing plate and an upper wing plate link, and the lower wing plate is formed by connecting a lower wing plate and a lower wing plate link. The construction method for the variable-diameter drilling and reaming integrated pile driver includes the following steps:

[0014] Step 1: Obtain the pile diameter, disc diameter, and disc height values ​​of the expanded disc cast-in-place pile according to the construction drawings, and simulate and measure the actual disc height.

[0015] Step 2: Move the active tube downwards so that the distance between the center point of the pin on the upper wingplate seat and the center point of the pin on the lower wingplate seat reaches the simulated actual disc height. Then, measure whether the actual disc diameter meets the disc diameter requirements of the drawing.

[0016] Step 3: When the actual disc diameter measurement result is smaller than the disc diameter requirement in the drawing, adjust the upper wing plate seat from high to low; when the actual disc diameter measurement result is larger than the disc diameter requirement in the drawing, adjust the upper wing plate seat from low to high; at the same time, simultaneously increase or decrease the height of the upper wing plate link, lower wing plate link, and lower wing plate seat so that the diameter of the extended reaming arm of the variable diameter drilling and reaming pile driver reaches the disc diameter size in the drawing.

[0017] Step 4: Repeatedly raise and lower the active pipe to check the drilling status of the rotary expansion arm when it is retracted, so that the maximum diameter of the rotary expansion arm of the variable diameter drilling and expansion pile driver is less than the pile diameter specified on the drawing.

[0018] Step 5: When the reamer arm of the variable diameter drilling and reaming machine is extended and the reamer is in the reamer's completed state, measure whether the reamer height matches the simulated reamer height; whether the reamer diameter meets the reamer diameter requirements in the drawing; and in this state, fix the stop key on the driven pipe to restrict the downward movement of the driven pipe.

[0019] Step 6: Measure and record the vertical travel values ​​of the upper wing plate pin center point from the drilling state to the expanded plate completion state of the variable diameter drilling and reaming integrated pile driver.

[0020] Step 7: When the variable diameter drilling and reaming machine reaches the depth of the disc position during forward drilling, the machine reverses. Due to the clutch and the switching between drilling and reaming functions, the drill bit remains stationary. The main tube of the variable diameter drilling and reaming machine descends, and the upper and lower wing plates gradually open to expand the disc. When the main tube descends to the stop key, the expansion operation of the disc cavity under concealed engineering conditions ends. Subsequently, the main tube is raised. When it is raised beyond the expansion stroke value, the variable diameter drilling and reaming machine continues to drill in the forward direction, and so on.

[0021] Furthermore, the variable diameter drilling and reaming integrated pile driver includes an active pipe, a driven pipe, and a rotary reaming arm. An active pipe that can telescopically move on the driven pipe is sleeved on it. An upper wing plate seat is installed on the outer wall of the active pipe, and a lower wing plate seat is installed on the lower outer wall of the driven pipe. The two ends of the rotary reaming arm are respectively connected to the upper wing plate seat and the lower wing plate seat. A stop key is provided at a lower position on the outer wall of the active pipe. The upper wing plate seat achieves upper and lower limit on the stop key through the cooperation of a limit block and a retaining ring. A stop key is provided on the lower driven pipe of the active pipe. Limit blocks are provided at intervals on the lower outer wall of the driven pipe. A lower wing plate seat is installed between the two limit blocks.

[0022] The aforementioned swivel arm consists of an upper wing plate, a lower wing plate, an upper wing plate link, and a lower wing plate link. The upper wing plate is mounted on the upper wing plate seat, and an upper wing plate link is connected to the upper wing plate. The lower wing plate is mounted on the lower wing plate seat, and a lower wing plate link is connected to the lower wing plate. The upper wing plate link and the lower wing plate link are hinged together.

[0023] Furthermore, the gear selector is composed of a high gear selector group and a low gear selector group arranged sequentially from top to bottom on the drive tube. The high gear selector group consists of upper gear selector blocks evenly distributed circumferentially on the outer wall of the drive tube and high gear selector blocks spaced apart directly below each upper gear selector block. The low gear selector group consists of low gear selector blocks spaced apart directly below each high gear selector block and lower gear selector blocks spaced apart directly below each low gear selector block.

[0024] Limit block connection holes are provided on the upper stop key, high stop key, low stop key and lower stop key, and the limit blocks are fixed on the limit block connection holes by screws;

[0025] The gaps between the upper stop key, the high stop key, the low stop key, and the lower stop key form a retaining ring groove.

[0026] Furthermore, the retaining ring includes a ring body and an inner groove provided on the inner wall of the ring body. The position of each inner groove corresponds to the position of the stop key on the active tube. An internal threaded hole for connecting the limiting block is provided between the inner grooves on the ring body.

[0027] Moreover, the limiting block is composed of a horizontal plate and a vertical plate. The vertical plate is vertically arranged on the inner side of the horizontal plate. The inner surfaces of both the horizontal and vertical plates are arc surfaces. The horizontal plate is provided with a retaining ring connection hole for connecting to the retaining ring, and the vertical plate is provided with a stop key connection hole for connecting to the stop key.

[0028] Furthermore, both the upper and lower wing plate seats have internal key blocks spaced apart on their inner walls. The space between the internal key blocks on the upper wing plate seat forms a sliding groove for the stop key, and the space between the internal key blocks on the lower wing plate seat forms an external key lifting groove for the driven tube. The driven tube has an external key that is evenly distributed on its outer wall. The external key is adapted to the external key lifting groove of the driven tube. The driving tube is rotatably mounted on the upper wing plate seat, and the driven tube is slidably mounted up and down on the lower wing plate seat.

[0029] Furthermore, the stop key is located on the external key of the driven tube.

[0030] Furthermore, both the upper wing plate link and the lower wing plate link include mounting blocks.

[0031] The mounting block consists of a block body, a central pin hole head set in the middle of the upper end of the block body, and side pin holes heads symmetrically set on both sides of the lower end of the block body. An upper wing plate connecting piece is set at the end of the central pin hole head of the upper wing plate link, and a lower wing plate connecting piece is set at the end of the side pin holes head of the lower wing plate link.

[0032] Both the upper wing plate connecting piece and the lower wing plate connecting piece are provided with wing plate connecting holes.

[0033] The upper wing plate link is connected to the upper wing plate screw through the wing plate connecting hole on the upper wing plate connecting piece, and is pinned to the upper wing plate through the central pin hole head on the upper wing plate link. The central pin hole head of the lower wing plate link is inserted between the two end pin holes of the upper wing plate link and connected by a pin shaft. The lower wing plate link is connected to the lower wing plate screw through the wing plate connecting hole on the lower wing plate connecting piece, and is pinned to the lower wing plate through the side end pin hole head on the lower wing plate link.

[0034] The advantages and beneficial effects of this invention are as follows:

[0035] 1. The construction method of this variable diameter drilling and reaming integrated pile driver determines the length of the reaming arm to be connected by adjusting the position of the upper wing plate seat on the stop key and the position of the lower wing plate seat on the driven pipe. Then, the number of wing plate chain links is adjusted adaptively. Through the coordinated cooperation between the components, the reaming operation for different pile diameters, angles and sizes can be realized. It is simple and convenient and greatly improves the construction efficiency.

[0036] 2. In this variable-diameter drilling and reaming integrated pile driver construction method, during drilling, the rotating reaming arm can refine the soil particles. Under the action of centrifugal force and electrostatic charge, the refined soil is adsorbed onto the pile hole wall, thereby enhancing the mud wall protection effect of the expanded-plate cast-in-place pile.

[0037] 3. The present invention has a scientific and reasonable structural design, and has the advantages of convenient operation, improved construction progress, reduced construction costs, guaranteed construction quality, and easy implementation. It is a highly innovative construction method for a variable diameter drilling and reaming integrated pile driver. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the present invention;

[0039] Figure 2 This is a schematic diagram of the active tube structure of the present invention;

[0040] Figure 3 This is a schematic diagram of the assembly of the upper wing plate seat and the active tube of the present invention;

[0041] Figure 4 This is a schematic diagram of the retaining ring of the present invention;

[0042] Figure 5 This is a schematic diagram of the assembly of the active tube and the retaining ring of the present invention;

[0043] Figure 6 This is a schematic diagram of the structure of the limiting block of the present invention;

[0044] Figure 7 This is a schematic diagram of the assembly of the lower wing plate seat and the driven tube of the present invention;

[0045] Figure 8 This is a schematic diagram of the structure of the rotary expander arm of the present invention;

[0046] Figure 9 This is an exploded structural diagram of the upper wing plate link and the lower wing plate link of the present invention;

[0047] Figure 10 This is a schematic diagram of the structure of the pile type with equal compressive and tensile strength as described in this invention;

[0048] Figure 11 This is a schematic diagram of the structure of the pile type with compressive strength as the main component and tensile strength as the secondary component, as described in this invention.

[0049] Figure 12 This is a schematic diagram of the structure of the expanded pile type with tensile strength as the main component and compressive strength as the secondary component in this invention;

[0050] Figure 13 This is a schematic diagram of the movement trajectory of the upper wing plate of the pile type of the present invention, which is mainly based on compressive strength and secondarily on tensile strength;

[0051] Figure 14This is a schematic diagram of the movement trajectory of the upper wing plate of the pile type with equal compressive and tensile strength according to the present invention;

[0052] Figure 15 This is a schematic diagram of the movement trajectory of the upper wing plate of the pile type of the present invention, which is mainly designed to resist pull-out and secondarily to resist compressive stress.

[0053] Attached Figure

[0054] 1. Active tube, 2. Limit block, 3. Retaining ring, 4. Upper wingplate seat, 5. Low gear key, 6. Lower stop key, 7. Driven tube, 8. External key, 9. Cut-off key, 10. Rotary expansion arm, 11. Lower wingplate seat, 12. Upper stop key, 13. High gear key, 14. Screw, 15. Limit block connecting hole, 16. Retaining ring groove, 17. Position key, 18. Position key sliding groove, 19. Inner key block, 2 0-Inner groove, 21-Internal threaded hole, 22-Vertical plate, 23-Stop key connection hole, 24-Horizontal plate, 25-Sticker ring connection hole, 26-Upper wing plate, 27-Upper wing plate link, 28-Lower wing plate link, 29-Lower wing plate, 30-Upper wing plate connecting piece, 31-Middle pin hole head, 32-Block, 33-Side pin hole head, 34-Wing plate connection hole, 35-Lower wing plate connecting piece. Detailed Implementation

[0055] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0056] The innovative aspect of the variable-diameter drilling and reaming integrated pile driver construction method lies in its ability to construct expanded-diameter cast-in-place piles with different shapes, sizes, and stress characteristics based on adjusting the structural dimensions of the variable-diameter drilling and reaming integrated pile driver. This method includes adjusting the position of the upper wing plate seat on the drive pipe, adjusting the lengths of the upper and lower auxiliary wing plates, and adjusting the position of the lower wing plate seat.

[0057] The construction method for the variable diameter drilling and reaming integrated pile driver includes the following steps:

[0058] Step 1: Obtain the pile diameter, disc diameter, and disc height values ​​of the expanded disc cast-in-place pile according to the construction drawings, and simulate and measure the actual disc height.

[0059] Step 2: Move the active tube downwards so that the distance between the center point of the pin on the upper wingplate seat and the center point of the pin on the lower wingplate seat reaches the simulated actual disc height. Then, measure whether the actual disc diameter meets the disc diameter requirements of the drawing.

[0060] Step 3: When the actual disc diameter measurement result is smaller than the disc diameter requirement in the drawing, adjust the upper wing plate seat from high to low; when the actual disc diameter measurement result is larger than the disc diameter requirement in the drawing, adjust the upper wing plate seat from low to high; at the same time, simultaneously increase or decrease the height of the upper wing plate link, lower wing plate link, and lower wing plate seat so that the diameter of the extended reaming arm of the variable diameter drilling and reaming pile driver reaches the disc diameter size in the drawing.

[0061] Step 4: Repeatedly raise and lower the active pipe to check the drilling status of the rotary expansion arm when it is retracted. Ensure that the maximum diameter of the rotary expansion arm of the variable diameter drilling and expansion pile driver is less than the pile diameter specified in the drawings, and ensure that the rotary expansion arm is retracted in place.

[0062] Step 5: When the reamer arm of the variable diameter drilling and reaming machine is extended and the reamer is in the reamer's completed state, measure whether the reamer height matches the simulated reamer height; whether the reamer diameter meets the reamer diameter requirements in the drawing; and in this state, fix the stop key on the driven pipe to restrict the downward movement of the driven pipe.

[0063] Step 6: Measure and record the vertical travel values ​​of the upper wing plate pin center point from the drilling state to the expanded plate completion state of the variable diameter drilling and reaming integrated pile driver.

[0064] Step 7: When the variable diameter drilling and reaming machine reaches the depth of the disc position during forward drilling, the machine reverses. Due to the clutch and the switching between drilling and reaming functions, the drill bit remains stationary. The main tube of the variable diameter drilling and reaming machine descends, and the upper and lower wing plates gradually open to expand the disc. When the main tube descends to the stop key, the expansion operation of the disc cavity under concealed engineering conditions ends. Subsequently, the main tube is raised. When it is raised beyond the expansion stroke value, the variable diameter drilling and reaming machine continues to drill in the forward direction, and so on.

[0065] The applicant had previously filed a patent application for an integrated drilling and reaming pile driver, application number 2023102147885, prior to this invention. Its contents are as follows:

[0066] A drilling and reaming integrated pile driver includes a drill rod, a drilling-reaming conversion unit, wing plates, and a drill bit. The drill rod and drill bit are connected to the upper and lower ends of the drilling-reaming conversion unit, respectively. Wing plates are spaced along the length of the outer periphery of the conversion unit. The wing plates are helical wing plates, comprising an upper wing plate and a lower wing plate. The upper end of the upper wing plate is connected to a wing plate sleeve via a wing plate seat. The wing plate sleeve is mounted on the active pipe of the drilling-reaming conversion unit. The lower end of the upper wing plate is hinged to the upper end of the lower wing plate. The lower end of the lower wing plate is fixed to the clutch of the drilling-reaming conversion unit via a wing plate seat. The connection point between the helical wing plate and the upper wing plate seat forms an upper fixed point, and the connection point between the helical wing plate and the lower wing plate seat forms a lower fixed point. The drilling-reaming conversion unit enables the conversion between drilling and reaming functions. The existing straight wing plate structure with fixed points on one side is redesigned into a spiral wing plate structure with fixed points at 180 degrees. This achieves angled compression and cutting of the soil in the pile hole, thereby reducing disturbance to the soil in the pile hole. The spiral wing plate forms a stable triangular structure, which extends the service life of the drilling and reaming machine.

[0067] This variable-diameter drilling and reaming machine is an improvement on the existing drilling and reaming machine.

[0068] The variable diameter drilling and reaming integrated pile driver includes an active pipe 1, a driven pipe 7, and a rotary reaming arm 10. An active pipe that can telescopically move on the driven pipe is sleeved on it. An upper wing plate seat 4 is installed on the outer wall of the active pipe, and a lower wing plate seat 11 is installed on the lower outer wall of the driven pipe. The two ends of the rotary reaming arm are respectively connected to the upper wing plate seat and the lower wing plate seat. Its innovation lies in the following: a stop key is set at a lower position on the outer wall of the active pipe. The upper wing plate seat achieves upper and lower limit on the stop key through the cooperation of the limiting block 2 and the retaining ring 3. A stop key 9 is set on the lower driven pipe of the active pipe. Limiting blocks are set at intervals on the lower outer wall of the driven pipe. The lower wing plate seat is installed between the two limiting blocks.

[0069] The expanding arm is composed of an upper wing plate 26, a lower wing plate 29, an upper wing plate link 27, and a lower wing plate link 28. An upper wing plate is mounted on an upper wing plate seat, and an upper wing plate link is connected to the upper wing plate. A lower wing plate is mounted on a lower wing plate seat, and a lower wing plate link is connected to the lower wing plate. The upper wing plate link and the lower wing plate link are hinged together.

[0070] By redesigning the existing structure with non-adjustable upper and lower wing plate seats and fixed expansion arm length into a structure with adjustable wing plate seat positions and adjustable expansion arm length, a single pile driver can be used to expand the discs of different diameters.

[0071] The upper wingplate seat is an adjustable structure on the driving tube, and its position is determined by limiting blocks positioned vertically. The lower wingplate seat is fixed to the driven tube and is also limited by limiting blocks positioned vertically. Specifically:

[0072] The gear selector 17 consists of a high gear selector group and a low gear selector group arranged sequentially from top to bottom on the drive tube. The high gear selector group consists of upper gear selector keys 12 evenly distributed circumferentially on the outer wall of the drive tube and high gear selector keys 13 spaced apart directly below each upper gear selector key. The low gear selector group consists of low gear selector keys 5 spaced apart directly below each high gear selector key and lower gear selector keys 6 spaced apart directly below each low gear selector key.

[0073] Limit block connection holes 15 are provided on the upper stop key, high stop key, low stop key and lower stop key, and the limit block is fixed on the limit block connection hole by screws 14;

[0074] The gaps between the upper stop key, the high stop key, the low stop key and the lower stop key form a retaining ring groove 16.

[0075] The retaining ring includes a ring body and an inner groove 20 provided on the inner wall of the ring body. The position of each inner groove corresponds to the position of the stop key on the active tube. An internal threaded hole 21 for connecting the limiting block is provided between the inner grooves on the ring body.

[0076] The limiting block is composed of a horizontal plate 24 and a vertical plate 22. The vertical plate is vertically arranged on the inner side of the horizontal plate. The inner surfaces of both the horizontal and vertical plates are arc surfaces. The horizontal plate is provided with a retaining ring connecting hole 25 for connecting to the retaining ring, and the vertical plate is provided with a stop key connecting hole 23 for connecting to the stop key.

[0077] Both the upper and lower wing plate seats have an inner key block 19 spaced apart on their inner walls. The space between the inner key blocks on the upper wing plate seat forms a sliding groove 18 for the stop key. The space between the inner key blocks on the lower wing plate seat forms an external key lifting groove for the driven tube. The driven tube has an external key 8 spaced evenly on its outer wall. The external key is adapted to the external key lifting groove of the driven tube. The driving tube is rotatably mounted on the upper wing plate seat, and the driven tube is slidably mounted up and down on the lower wing plate seat.

[0078] The cut-off key is located on the external key of the driven tube and is used to limit the extension and retraction of the driving tube.

[0079] The overall length of the expander arm can be adjusted by increasing or decreasing the number of links on the upper and lower wing plates.

[0080] Both the upper wing plate link and the lower wing plate link include mounting blocks.

[0081] The mounting block consists of a block body 32, a central pin hole head 31 located in the middle of the upper end of the block body, and side pin hole heads 33 symmetrically located on both sides of the lower end of the block body. An upper wing plate connecting piece 30 is provided at the end of the central pin hole head of the upper wing plate link, and a lower wing plate connecting piece 35 is provided at the ends of the side pin hole heads of the lower wing plate link.

[0082] Both the upper wing plate connecting piece and the lower wing plate connecting piece are provided with wing plate connecting holes 34.

[0083] The upper wing plate link is connected to the upper wing plate screw via the wing plate connecting hole on the upper wing plate connecting plate, and is pinned to the upper wing plate via the central pin hole on the connecting female head. The central pin hole of the lower wing plate link is inserted between the two end pin holes of the upper wing plate link and connected by a pin shaft. The lower wing plate link is connected to the lower wing plate screw via the wing plate connecting hole on the lower wing plate connecting plate, and is pinned to the lower wing plate via the side pin hole on the lower wing plate link. The rotation and extension of the drive tube enables the rotation and extension of the expanding arm.

[0084] The lengths of the upper and lower wing plate links are 0.3-0.9 meters.

[0085] Expanded-diameter cast-in-place piles, after expansion, have different angles at the upper and lower edges of the cavity, giving them different stress characteristics such as compressive and tensile strength. Variable-diameter drilling and reaming rigs, by adjusting the height and low gears of the upper wing plate seat and the fixed position of the lower wing plate seat on the driven pipe, and by adding or removing appropriate lengths of wing plate links (including swapping the positions of the upper and lower wing plates), can form expanded-diameter cast-in-place piles as follows: Figure 10 The pile type shown has equal compressive and tensile strength. Figure 11 The pile type shown is primarily designed for compressive strength with secondary tensile strength. Figure 12 The pile type shown is mainly designed for tensile strength and secondarily for compressive strength, thus enabling the construction of expanded-disk cast-in-place piles with different shapes, angles, sizes, and stress characteristics.

[0086] Example 1: Pile type with equal compressive and tensile strength

[0087] like Figure 14 As shown, under the premise that the disc diameter R is 2 or 2.5 times the pile diameter r as specified in the standard, for drill-expanded cast-in-place piles with equal vertical tensile and compressive strength, the actual disc height h of this type of variable-diameter drill-expanded pile driver is simulated due to the height of the disc cavity generated by the movement trajectory of the upper flange. This h is the disc height dimension indicated on the drawing divided by 2. The length of the lower flange is 1 / 4 longer than the length of the upper flange, and the length of the upper flange is greater than or equal to the pile diameter.

[0088] Example 2: Pile type with compressive strength as the primary factor and tensile strength as a secondary factor

[0089] like Figure 13As shown, for drill-expanded cast-in-place piles with vertical compressive strength as the main resistance and tensile strength as the secondary resistance, the actual disc height of this type of pile with variable diameter drilling and expanding integrated pile driver is simulated due to the height of the disc cavity generated by the movement trajectory of the upper flange. Actual disc height = (disc height marked on the drawing / 3) * 2.

[0090] Example 3: Pile type with tensile strength as the primary factor and compressive strength as a secondary factor

[0091] like Figure 15 As shown, for a drill-expanded cast-in-place pile with vertical tensile strength as the main resistance and compressive strength as the secondary resistance, the lower flange is twice as long as the upper flange, and the length of the upper flange is greater than or equal to the pile diameter. Due to the height of the disc cavity generated by the running trajectory of the upper flange, the actual disc height of this type of variable diameter drill-expanded pile driver is simulated. Actual disc height = (disc height marked on the drawing / 3.5) * 2.5.

[0092] This invention achieves its purpose by adjusting its own structure and adding small accessories without changing or replacing the main components:

[0093] a. Construction and shaping of enlarged-diameter cast-in-place piles with different pile diameters and disc diameters;

[0094] b. Operations for expanded-diameter cast-in-place piles with different shapes and stress characteristics;

[0095] c. Applicable to both forward and reverse circulation processes of mud.

[0096] The different angles and sizes mentioned refer to different angles and sizes that can be adjusted within a certain range.

[0097] After drilling and enlarging the borehole of the enlarged-diameter cast-in-place pile, the subsequent procedures such as primary hole cleaning, lowering the reinforcing cage, placing the guide pipe, secondary hole cleaning, and underwater concrete pouring to form the pile are all well-known technologies stipulated in national standards, and will not be elaborated upon in this article.

[0098] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A construction method for a variable-diameter drilling and reaming integrated pile driver, characterized by: The construction method of the variable diameter drilling and reaming integrated pile driver is based on the variable diameter drilling and reaming integrated pile driver, which includes an active pipe, a driven pipe and a rotary reaming arm. The active pipe, which can be telescopically moved on the driven pipe, is sleeved on the driven pipe. An upper wing plate seat is installed on the outer wall of the active pipe, and a lower wing plate seat is installed on the lower outer wall of the driven pipe. The two ends of the rotary reaming arm are respectively connected to the upper wing plate seat and the lower wing plate seat. A stop key is set at the lower position on the outer wall of the active pipe. The upper wing plate seat achieves upper and lower limit on the stop key through the cooperation of the limit block and the retaining ring. A stop key is set on the lower driven pipe of the active pipe. Limit blocks are set at intervals on the lower outer wall of the driven pipe. The lower wing plate seat is installed between the two limit blocks. The swivel arm consists of an upper wing plate, a lower wing plate, an upper wing plate link, and a lower wing plate link. The upper wing plate is mounted on the upper wing plate seat, and the upper wing plate link is connected to the upper wing plate. The lower wing plate is mounted on the lower wing plate seat, and the lower wing plate link is connected to the lower wing plate. The upper wing plate link and the lower wing plate link are hinged together. The gear selector consists of a high gear selector group and a low gear selector group arranged sequentially from top to bottom on the drive tube. The high gear selector group consists of upper stop keys evenly spaced circumferentially on the outer wall of the drive tube and high gear keys spaced apart directly below each upper stop key. The low gear selector group consists of low gear keys spaced apart directly below each high gear key and lower stop keys spaced apart directly below each low gear key. Limit block connection holes are provided on the upper stop key, high gear key, low gear key and lower stop key, and the limit blocks are fixed on the limit block connection holes by screws; The gaps between the upper stop key, the high gear key, the low gear key, and the lower stop key form a retaining ring groove; The retaining ring includes a ring body and an inner groove provided on the inner wall of the ring body. The position of each inner groove corresponds to the position of the stop key on the active tube. An internal threaded hole for connecting the limit block is provided between the inner grooves on the ring body. The limiting block is composed of a horizontal plate and a vertical plate. The vertical plate is vertically arranged on the inner side of the horizontal plate. The inner surfaces of both the horizontal plate and the vertical plate are arc surfaces. The horizontal plate is provided with a retaining ring connection hole for connecting with the retaining ring, and the vertical plate is provided with a stop key connection hole for connecting with the stop key. Both the upper and lower wing plate seats have internal key blocks spaced apart on their inner walls. The space between the internal key blocks on the upper wing plate seat forms a sliding groove for the stop key, and the space between the internal key blocks on the lower wing plate seat forms an external key lifting groove for the driven tube. The driven tube has an external key that is evenly distributed on its outer wall. The external key is adapted to the external key lifting groove of the driven tube. The driving tube is rotatably installed on the upper wing plate seat, and the driven tube is slidably installed up and down on the lower wing plate seat. The stop key is located on the external key of the driven tube; Both the upper wing plate link and the lower wing plate link include a mounting block. The mounting block consists of a block body, a central pin hole head provided in the middle of the upper end of the block body, and side pin holes heads symmetrically provided on both sides of the lower end of the block body. An upper wing plate connecting piece is provided at the end of the central pin hole head of the upper wing plate link, and a lower wing plate connecting piece is provided at the ends of the side pin holes heads of the lower wing plate link. Both the upper and lower wingplate connecting pieces are provided with wingplate connecting holes. The upper wing plate link is connected to the upper wing plate screw through the wing plate connecting hole on the upper wing plate connecting piece, and is pinned to the upper wing plate through the central pin hole head on the upper wing plate link. The central pin hole head of the lower wing plate link is inserted between the two end pin holes of the upper wing plate link and connected by a pin shaft. The lower wing plate link is connected to the lower wing plate screw through the wing plate connecting hole on the lower wing plate connecting piece, and is pinned to the lower wing plate through the side end pin hole head on the lower wing plate link. The construction method for a variable-diameter drilling and reaming integrated pile driver includes the following steps: Step 1: Obtain the pile diameter, disc diameter, and disc height values ​​of the expanded disc cast-in-place pile according to the construction drawings, and simulate and measure the actual disc height. Step 2: Move the active tube downwards so that the distance between the center point of the pin on the upper wingplate seat and the center point of the pin on the lower wingplate seat reaches the simulated actual disc height. Then, measure whether the actual disc diameter meets the disc diameter requirements of the drawing. Step 3: When the actual disc diameter measurement result is smaller than the disc diameter requirement in the drawing, adjust the upper wing plate seat from high to low; when the actual disc diameter measurement result is larger than the disc diameter requirement in the drawing, adjust the upper wing plate seat from low to high; at the same time, simultaneously increase or decrease the height of the upper wing plate link, lower wing plate link, and lower wing plate seat so that the diameter of the extended reaming arm of the variable diameter drilling and reaming pile driver reaches the disc diameter size in the drawing. Step 4: Repeatedly raise and lower the active pipe to check the drilling status of the rotary expansion arm when it is retracted, so that the maximum diameter of the rotary expansion arm of the variable diameter drilling and expansion pile driver is less than the pile diameter specified on the drawing. Step 5: When the reamer arm of the variable diameter drilling and reaming machine is extended and the reamer is in the reamer's completed state, measure whether the reamer height matches the simulated reamer height; whether the reamer diameter meets the reamer diameter requirements in the drawing; and in this state, fix the stop key on the driven pipe to restrict the downward movement of the driven pipe. Step 6: Measure and record the vertical travel values ​​of the upper wing plate pin center point from the drilling state to the expanded plate completion state of the variable diameter drilling and reaming integrated pile driver. Step 7: When the variable diameter drilling and reaming machine reaches the depth of the disc position during forward drilling, the machine reverses direction. Due to the clutch and the switching between drilling and reaming functions, the drill bit remains stationary. The main tube of the variable diameter drilling and reaming machine descends, and the upper and lower wing plates gradually open to expand the disc. When the main tube descends to the stop key, the disc expansion operation under concealed engineering conditions ends. Subsequently, the main tube is raised. When it is raised beyond the expansion stroke value, the variable diameter drilling and reaming machine continues to drill in the forward direction, and so on.

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