CN112761139A - Cast-in-place pile with diameter-expanding conical pile section, drill bit for pile forming and pile forming construction method - Google Patents

Cast-in-place pile with diameter-expanding conical pile section, drill bit for pile forming and pile forming construction method Download PDF

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Publication number
CN112761139A
CN112761139A CN202110023397.6A CN202110023397A CN112761139A CN 112761139 A CN112761139 A CN 112761139A CN 202110023397 A CN202110023397 A CN 202110023397A CN 112761139 A CN112761139 A CN 112761139A
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pile
diameter
enlarged
section
drill bit
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刘守进
张喜才
赵世范
方光秀
赵越
杨延君
金成彬
吴建祥
金光男
安志宏
李俊阳
高峰
黄健
张夏枭
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/22—Piles
    • E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/26—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers
    • E21B10/32—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers with expansible cutting tools
    • E21B10/322—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers with expansible cutting tools cutter shifted by fluid pressure
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/44—Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
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  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Structural Engineering (AREA)
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  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Piles And Underground Anchors (AREA)

Abstract

The invention relates to a cast-in-place pile with an enlarged-diameter conical pile section, a drill bit for pile forming and a pile forming construction method. The cast-in-place pile with the enlarged-diameter conical body pile section comprises a main cylindrical cast-in-place pile and a conical pile bottom, wherein a plurality of sections of the enlarged-diameter conical body pile sections with integrated structures are manufactured on the outer edge of the main cylindrical cast-in-place pile; the structure of the diameter-enlarged conical body screw tooth pile section is that the outer edge of a main cylindrical cast-in-place pile is provided with a screw tooth I with an integral structure, and the outer edge of the integral screw tooth I forms a conical body; the structure of the diameter-enlarging conical body multiple-compaction pile section is that the upper part of the integral structure is a multiple-compaction column pile section and the lower part is a multiple-compaction cone pile section, and the outer edges of the multiple-compaction column pile section and the multiple-compaction cone pile section are wrapped with a layer of multiple-compaction reinforcing layer. The cast-in-place pile created by the invention has high bearing capacity, is energy-saving and environment-friendly.

Description

Cast-in-place pile with diameter-expanding conical pile section, drill bit for pile forming and pile forming construction method
Technical Field
The invention belongs to the field of construction of foundation piles in building construction, and particularly relates to a grouting pile with an enlarged-diameter conical pile section, a drill bit for pile forming and a pile forming method.
Background
In the construction of pile foundation, cast-in-place concrete cast-in-place pile has wide applicable geological conditions, the pile diameter and the pile length can be determined according to the requirements of engineering geology and bearing capacity of foundation pile, and mainly rotary drilling cast-in-place pile and long spiral drilling cast-in-place pile are mainly used. The method has the advantages of good pile forming quality, high construction efficiency, higher bearing capacity and the like. However, the foundation pile is simple in pile type, stress action among pile soil is not sufficiently exerted, so that the bearing capacity is not very high, and meanwhile, a large amount of residual soil is discharged, so that the environment is not protected.
Disclosure of Invention
In view of the above problems, it is an object of the present invention to provide a new pile type with high bearing capacity, energy saving and environmental protection, i.e. a bored concrete pile with an enlarged diameter conical section.
The invention also aims to provide a drill bit for forming the cast-in-place pile with the enlarged-diameter conical pile section.
The invention also aims to provide a pile-forming construction method of the cast-in-place pile with the enlarged-diameter conical pile section.
The invention adopts the technical scheme that: a bored concrete pile with enlarged diameter conical body pile section, including the cylindrical bored concrete pile of the body, the bottom of the cylindrical bored concrete pile of the said body is a conical pile bottom, form several sections of integrally constructed enlarged diameter conical body pile sections on the outer fringe of the cylindrical bored concrete pile of the said body, the said enlarged diameter conical body pile section includes enlarging one or two of conical body screw tooth pile section and enlarged diameter conical body and crowding the pile section again; the diameter-enlarged conical body screw tooth pile section is structurally characterized in that screw teeth I which are integrally structured, spirally wound around the outer edge of the main cylindrical cast-in-place pile and gradually increased in outer diameter from bottom to top are formed on the outer edge of the main cylindrical cast-in-place pile, the outer edge of the integral screw teeth I forms a conical body, and the section of the screw teeth I is of a trapezoidal structure; the structure of the diameter-enlarged conical body composite-compaction pile section is that the upper part of an integral structure is a composite-compaction cylinder pile section and the lower part of the integral structure is a composite-compaction cone pile section, the outer edge of the composite-compaction cone pile section forms a conical body, and the outer edges of the composite-compaction cylinder pile section and the composite-compaction cone pile section are wrapped with a layer of composite-compaction reinforcing layer.
Furthermore, the bored concrete pile with the enlarged-diameter conical pile section is characterized in that a plurality of sections of enlarged-diameter cylindrical body thread pile sections with an integrated structure are manufactured on the outer edge of the main cylindrical bored concrete pile, the enlarged-diameter cylindrical body thread pile sections are structurally characterized in that threads II which are integrated with an integrated structure and spirally wound around the outer edge of the main cylindrical bored concrete pile are manufactured on the outer edge of the main cylindrical bored concrete pile, and the outer edge of each integral thread II forms a cylindrical body.
Further, the aforesaid bored concrete pile with enlarge footpath conical body stake section establishes main part cylindricality bored concrete pile diameter and is D, and it is D to enlarge footpath cylindricality body thread stake section external diameter, and it is D1 to compound compaction cylinder stake section external diameter, and the biggest external diameter of compound compaction enhancement layer is D4, enlarges footpath conical body thread stake section minimum end external diameter and is D2, the biggest end external diameter is D3, and I pitch of thread is T1, and II pitches of thread are T2, then: d is 400-800 mm, D > D, D1> D, D3> D2> D, D4> D1, and D/T2 is 1.1-1.5; the thread pitch T1 of the enlarged diameter conical body thread pile section is increased along with the increase of the outer diameter of the thread, and the ratio of the diameter formed by the outer edge of the thread I at any point in the enlarged diameter conical body thread pile section around the center of the main cylindrical cast-in-place pile and the thread pitch T1 between the adjacent threads I (201) at the upper part and the lower part of the diameter conical body thread pile section is 1.1-1.5.
Further, in the above cast-in-place pile with the enlarged diameter tapered pile section, the thread i and the thread ii have the structure that the thread height is h, the outer side thickness of the thread is b1, and the inner side thickness is b2, and then: h is 50-200 mm, b1 is 50-80 mm, and b2 is 100-200 mm.
A drill bit for forming a cast-in-place pile with an enlarged-diameter conical body pile section comprises a joint, a spiral cylinder soil squeezing blade, a cylinder core pipe, a cone core pipe, a spiral cone soil squeezing blade and a drill tip door, and is provided with an oil cylinder device, an expanding slide block device, a fixed seat, an oil cylinder lug plate, a shaft I, a shaft II and a shaft III; the fixing seat is arranged at the joint of the cylinder core pipe and the cone core pipe and penetrates through the cylinder core pipe, the cone core pipe and the spiral cylinder soil-squeezing blade; the cylinder device is arranged in an inner cavity of the cylinder core tube and comprises a main cylinder, a protection tube I, an auxiliary cylinder, a protection tube II and a push rod, wherein the extending end of a piston rod of the main cylinder is fixed with the cylinder sleeve end of the auxiliary cylinder; one end of the protective pipe II is fixed on the outer wall of the auxiliary oil cylinder sleeve, and the other end of the protective pipe II is in movable sealing fit with the outer diameter of the push rod; the exposed end of the push rod is provided with a connecting lug seat I; the exposed end of the main oil cylinder is provided with a connecting lug seat II; the diameter-expanding sliding block device is fixed into a whole by a sleeve, a sliding block and a connecting plate, the sleeve is installed in a fixed seat through a shaft III and rotates around the shaft III, an oil cylinder lug plate is fixed on the inner wall of a cylinder core pipe, one end of the oil cylinder device is hinged with the oil cylinder lug plate through a connecting lug seat II and a shaft I, the other end of the oil cylinder device is hinged with the connecting plate of the diameter-expanding sliding block device through the connecting lug seat I and the shaft II, and the sliding block is driven to rotate around the shaft III through the expansion of the oil cylinder device; the working end of the sliding block is of a trapezoidal structure.
Furthermore, the drill bit for forming the cast-in-place pile with the enlarged-diameter conical body pile section comprises a connector, a cylinder core pipe and a cone core pipe which are concentrically and sequentially fixed into a whole, wherein an inner cavity of the drill bit forms a passage for concrete to pass through, a spiral cylinder soil squeezing blade is spirally wound and fixed on the outer edges of the connector and the cylinder core pipe, the spiral cone soil squeezing blade is spirally wound and fixed on the outer edge of the cone core pipe, the upper end surface of the spiral cone soil squeezing blade is correspondingly connected with the lower end surface of the spiral cylinder soil squeezing blade, and the lower end of the spiral cone soil squeezing blade is provided with cutting teeth.
Furthermore, the drill bit for forming the cast-in-place pile with the diameter-expanding conical body pile section is characterized in that the drill tip door is arranged on the lower end face of the conical core pipe, the drill tip door is movably connected to the lower end of the conical core pipe through a pin, the drill tip door rotates downwards around the pin by a maximum angle delta which is larger than or equal to 35 degrees and smaller than or equal to 45 degrees, a discharge port of the drill bit is opened to a maximum opening, the drill tip door rotates upwards around the pin to the lower end face of the conical core pipe, and the discharge port of the drill bit is closed.
Furthermore, the joint, the spiral cylinder soil-squeezing blade and the cylinder core pipe form a cylinder structure part of the drill bit device, and the outer edge of the drill bit is a cylinder; the cone core tube, the spiral cone soil-squeezing blade and the drill tip door form a cone structure part of the drill bit device, and the outer edge of the cone structure part is a cone.
A pile-forming construction method of a cast-in-place pile with an enlarged-diameter conical pile section utilizes the drill bit and comprises the following steps:
1) the joint of the drill bit is well assembled with a spiral soil extrusion pile machine and a concrete pumping device through a soil extrusion drill rod, the oil cylinder device is connected with a hydraulic control system, a slide block of an expanding slide block device of the drill bit is in a withdrawing state, and the pile machine is aligned to a pile position;
2) starting a pile machine, driving a drill bit to drill and rotate by a power head through an earth-squeezing drill rod, slowly drilling down, normally drilling after a hole position is determined to be correct, squeezing rock soil at the hole position of the pile into a small-diameter taper hole by the drill bit, moving down along with the drilling of the drill bit, squeezing and expanding the small-diameter taper hole into a large-diameter taper hole until the hole diameter of a foundation pile, squeezing and drilling the earth until the designed hole depth, continuously rotating in situ for 2-3 minutes, and fully squeezing the rock soil at the hole bottom and the hole wall of the foundation pile;
3) and (2) lifting the drill bit and the drill rod, and simultaneously pumping concrete to fill concrete, and realizing pile formation of each pile section according to the construction sequence that the pile bottom starts to be upwards section by section:
3.1) main body cylindrical cast-in-place pile and tapered pile bottom of bottom end
Pumping concrete to the bottom of the inner cavity of the drill bit by a drill bit pump positioned at the bottom of the pile hole, then lifting the drill bit and the drill rod rotating in the drilling direction, keeping the matching degree of the drill lifting speed and the pumping pressure filling amount, lifting the drill bit and performing pressure filling until the hole diameter of the cylindrical pile is reached, and completing the filling construction of the conical pile bottom; continuously lifting the drill bit and the pressure-grouting column body pile hole to the designed height of the main body cylindrical cast-in-place pile top, completing the cast-in-place construction of the main body cylindrical cast-in-place pile, wherein the slide block of the expanding slide block device in the drill bit is in a completely retracted state in the process;
3.2) enlarging the cylindrical body screw tooth pile section
In the process of lifting and pouring a main cylindrical cast-in-place pile section, when an enlarged-diameter cylindrical body screw tooth pile section needs to be arranged, a hydraulic control system is used for driving a piston rod of an auxiliary oil cylinder in an oil cylinder device to completely extend, then driving a piston rod of a main oil cylinder in the oil cylinder device to extend, determining a fixed extension amount of the piston rod of the main oil cylinder according to the design height of screw teeth of the enlarged-diameter cylindrical body screw tooth pile section, pushing and controlling the extension amount of a sliding block in an enlarged-diameter sliding block device, rotating a drill bit and a drill rod in the drilling direction for one rotation, lifting a screw pitch upwards, matching with pump pressure pouring, pouring concrete into a spiral screw tooth groove extruded by the sliding block in the wall of a pile hole and the pile hole together, lifting and pouring to the design height, and finishing the pouring construction of the enlarged-diameter cylindrical body screw tooth pile section;
3.3) enlarging diameter conical body multiple extruding dense pile section
In the process of lifting and drilling and pouring the pile section of the main cylindrical cast-in-place pile, when the section of the enlarged-diameter conical body and the section of the enlarged-diameter conical body are required to be arranged, the poured main cylindrical cast-in-place pile is spun downwards again, concrete in a pile hole is extruded to drill, the hole wall of the rock and soil is extruded and expanded by the extruded concrete, a multiple compaction reinforcing layer is formed in the extruded and expanded hole wall, a small part of the concrete in the pile hole is extruded into the multiple compaction reinforcing layer, a large part of the concrete is remained in the hole cavity of the extruded and expanded rock and soil, the pile is drilled until the designed depth of the enlarged-diameter conical body and the section of the enlarged-diameter conical body is expanded, then the concrete is pumped to the bottom of the inner cavity of the drill bit, a drilling tool rotating in the drilling direction is lifted, the matching degree of the lifting speed and the pumping filling quantity is kept, the newly poured concrete is fused with the concrete remained in the hole cavity of the extruded and expanded rock and soil, the drill is lifted and pressed to be, in the process, the slide block of the drill bit inner diameter-expanding slide block device is in a completely retracted state;
3.4) enlarging diameter conical body screw tooth pile section
In the process of lifting and drilling a cylindrical cast-in-place pile section of a cast-in-place main body, when an enlarged-diameter conical body screw pile section needs to be arranged, a hydraulic control system is used for driving a secondary oil cylinder piston rod in an oil cylinder device to completely extend out to drive a sliding block part in an enlarged-diameter sliding block device to extend out, then a main oil cylinder piston rod in the oil cylinder device to extend out at a constant speed, the length of the enlarged-diameter conical body screw pile section is matched with the total amount of the main oil cylinder piston rod extending out at a constant speed, a drill bit and a drill rod are rotated in the drilling direction one rotation to lift a screw pitch upwards, the drill bit and the drill rod are matched with pump pressure casting, a gradually deepened screw groove is extruded by the sliding block into the wall of a pile hole to be cast with the pile hole together with cast-in-place concrete;
4) and (5) placing the prefabricated reinforcement cage or the prefabricated member into the poured pile hole to form the pile.
The beneficial effects of the invention are as follows:
1. the bored concrete pile with the enlarged-diameter conical pile section has strong bearing capacity. The primary soil-squeezing pile hole is formed by squeezing soil through the cone-shaped drill bit, the soil squeezing is sufficient, the standard value of the resistance of the rock-soil layer at the extreme side of the wall of the pile hole is improved, the primary soil-squeezing cone pile bottom has a wedge-shaped squeezing effect, and the end bearing capacity is good; the composite compaction cylinder pile section and the composite compaction cone pile section are externally provided with the composite compaction reinforcing layer, so that on one hand, the lateral resistance surface area of the pile section is increased, on the other hand, the composite compaction reinforcing layer changes the slip crack surface of the pile section damaged by stress, the pile (concrete) -soil interaction is changed into the soil-soil interaction, the bearing capacity is improved, meanwhile, the composite compaction reinforcing layer outside the composite compaction cone pile section effectively increases the geometric dimension of the cone, and the wedge-shaped squeezing and expanding effect is enhanced; the pile section of the enlarged diameter cylindrical body screw thread is in a specified screw pitch range, the outer contour surface of the screw thread is a damaged interface, the side resistance value of the pile section is the friction force (shearing resistance force of soil) value of a soil-soil interface, and the cost among the screw threads of the pile section is reasonably reduced under the condition of meeting high bearing capacity; the enlarged diameter conical body screw tooth pile section is a combination of the advantages of the enlarged diameter cylindrical body screw tooth pile section and the multiple compaction conical body pile section, the damage slip crack surface is the outer contour of the screw tooth and is reflected on a soil-soil interface, the damage interface is conical, a wedge-shaped squeezing and expanding effect is achieved, and the bearing capacity of the pile section is higher.
2. The bored concrete pile with the enlarged-diameter conical pile section, which is created by the invention, is suitable for different soil properties, and has high efficiency by designing and implementing the adaptive pile section. According to different rock-soil layers, pile types of different pile section combinations are selected and designed, the stress effect among pile soils is fully exerted, the bearing capacity of the pile is improved, and the pile forming cost is reduced. Soft soil layers such as cohesive soil, silt, sandy soil and the like are suitable for the diameter-enlarged cylindrical screw tooth pile section and the diameter-enlarged conical screw tooth pile section, particularly soft soil layers with gradually increased compressibility of rock soil from bottom to top and are more suitable for the diameter-enlarged conical screw tooth pile section; hard rock-soil layers such as compact gravels, garden gravels, angle gravels, broken stones, pebbles, completely weathered rocks and the like are suitable for the multiple-compaction pile section of the enlarged-diameter conical body; hard rock soil layers such as strongly weathered rock, moderately weathered rock and the like are suitable for the conical pile bottom of primary soil extrusion and the main cylindrical pile section of primary soil extrusion.
3. The cast-in-place pile with the enlarged-diameter conical pile section is energy-saving and environment-friendly, and the pile forming quality and reliability are good. The construction has no mud, vibration and noise, less residual soil discharge, simple operation, strong controllability and high efficiency, and can be formed by single-machine operation.
4. The drill bit for forming the cast-in-place pile with the diameter-expanding conical pile section has a simple structure and good reasonableness. The cone structure part in the drill bit extrudes soil (containing concrete) to form a hole reasonably, the soil (containing concrete) is extruded fully, the penetration capacity is good, and the lower parts of the primary soil-extruded pile bottom, the multiple compaction pile section and the multiple compaction reinforcing layer are all in a cone shape, have a wedge-shaped extrusion-expansion effect and are beneficial to improving the bearing capacity; the expanding slide block device for extruding the thread groove is arranged at the lower end of the drill bit cylinder structure part, and is also arranged below a drill bit buried interface when concrete is poured, so that the pouring of the concrete in the thread groove is facilitated, the adverse effect of underground water is avoided, and meanwhile, the smoothness of a concrete channel in an inner cavity of the drill bit is also met.
Drawings
Fig. 1 is a schematic structural diagram of a pile-forming drill bit for a cast-in-place pile with an enlarged-diameter conical pile section.
Fig. 2 is a side view (slide block retracted state) of the drill bit for forming the cast-in-place pile with the enlarged-diameter conical pile section of the invention.
Fig. 3 is a side view (with the slide block partially extended) of the pile-forming drill bit for the cast-in-place pile of the present invention with the enlarged-diameter conical pile section.
Fig. 4 is a side view (slide block fully extended state) of the pile-forming drill bit for the cast-in-place pile of the present invention with an enlarged diameter conical pile section.
Fig. 5 is a schematic structural diagram of the oil cylinder device.
Fig. 6 is a schematic view of the first construction of the bored concrete pile with the enlarged-diameter tapered pile section according to the present invention.
Fig. 7 is a schematic view of a second construction of the inventive bored concrete pile with an enlarged-diameter conical pile section.
Fig. 8 is a third construction of the inventive bored concrete pile with an enlarged-diameter conical pile section.
Fig. 9 is a fourth construction of the inventive bored concrete pile with an enlarged-diameter conical pile section.
Fig. 10 is a fifth construction of the bored concrete pile with the enlarged-diameter tapered pile section according to the present invention.
Fig. 11 is a sixth construction of the bored concrete pile with an enlarged-diameter tapered pile section according to the present invention.
FIG. 12 is a schematic view of the wedge-shaped squeezing action of the cone.
Fig. 13 is a pile-forming construction diagram of the cast-in-place pile with the enlarged-diameter conical pile section created by the invention.
Detailed Description
Example 1
As shown in fig. 1-5, a drill bit for forming a cast-in-place pile with an enlarged diameter conical body pile section comprises a joint (1), a spiral cylinder soil squeezing blade (2), a cylinder core pipe (3), a cone core pipe (4), a spiral cone soil squeezing blade (5), a drill tip door (6), an oil cylinder device (7), an enlarged diameter sliding block device (8), a fixed seat (9), an oil cylinder lug plate (10), a shaft I (11), a shaft II (12) and a shaft III (13).
The joint (1), the cylinder core pipe (3) and the cone core pipe (4) are coaxially and sequentially fixed into a whole, and an inner cavity of the joint forms a channel for concrete to pass through. The spiral soil squeezing blade (2) is spirally wound and fixed on the outer edges of the joint (1) and the cylinder core pipe (3), the spiral cone soil squeezing blade (5) is spirally wound and fixed on the outer edge of the cone core pipe (4), the upper end face of the spiral cone soil squeezing blade (5) is correspondingly connected with the lower end face of the spiral cylinder soil squeezing blade (2), and the lower end of the spiral cone soil squeezing blade (5) is provided with cutting teeth (5-1).
The drill point door (6) is arranged on the lower end face of the cone core pipe (4), the drill point door (6) is movably connected to the lower end of the cone core pipe (4) through a pin (6-1), the drill point door (6) rotates downwards around the pin (6-1) for a maximum angle delta, delta is larger than or equal to 35 degrees and smaller than or equal to 45 degrees, a drill bit discharge hole is opened to the maximum opening, the drill point door (6) rotates upwards around the pin (6-1) to the lower end face of the cone core pipe (4), and the drill bit discharge hole is closed.
The joint (1), the spiral cylinder soil-squeezing blade (2) and the cylinder core pipe (3) form a cylinder structure part of the drill bit, and the outer edge of the cylinder structure part is a cylinder and plays roles in assisting soil squeezing and diameter keeping; the cone core tube (4), the spiral cone soil squeezing blade (5) and the drill tip door (6) form a cone structure part of the drill bit device, and the outer edge of the cone structure part is a cone and plays a role of main soil squeezing.
As shown in FIG. 5, the cylinder device (7) comprises a main cylinder (7-1), a protection pipe I (7-2), an auxiliary cylinder (7-3), a protection pipe II (7-4) and a push rod (7-5). The extending end of the main oil cylinder piston rod (7-1A) is fixed with the cylinder sleeve end of the auxiliary oil cylinder (7-3), and the extending end of the auxiliary oil cylinder piston rod (7-3A) is fixed with one end of the push rod (7-5). One end of the protective pipe I (7-2) is fixed on the outer wall of the cylinder sleeve of the auxiliary oil cylinder (7-3), and the other end is in movable sealing fit with the outer diameter of the cylinder sleeve of the main oil cylinder (7-1). One end of the protective pipe II (7-4) is fixed on the outer wall of the cylinder sleeve of the auxiliary oil cylinder (7-3), and the other end is in movable sealing fit with the outer diameter of the push rod (7-5). The exposed end of the push rod (7-5) is provided with a connecting lug seat I (7-5A). The exposed end of the main oil cylinder (7-1) is provided with a connecting lug seat II (7-1B).
The fixing seat (9) is arranged at the joint of the cylinder core pipe (3) and the cone core pipe (4) and penetrates through the cylinder core pipe (3), the cone core pipe (4) and the spiral cylinder soil-squeezing blade (2). The oil cylinder device (7) is arranged in the inner cavity of the cylinder core pipe (3). The expanding slide block device (8) is fixed into a whole by a sleeve (8-1), a slide block (8-2) and a connecting plate (8-3), the sleeve (8-1) is installed in a fixed seat (9) through a shaft III (13) and rotates around the shaft III (13), an oil cylinder lug plate (10) is fixed on the inner wall of the cylinder core pipe (3), one end of the oil cylinder device (7) is hinged with the oil cylinder lug plate (10) through a connecting lug seat II (7-1B) and a shaft I (11), the other end of the oil cylinder device (7) is hinged with the connecting plate (8-3) of the expanding slide block device (8) through a connecting lug seat I (7-5A), a shaft II (12) and the expanding slide block device (8), and the slide block (8-2) is driven to rotate around the shaft III (13) through the expansion of the oil cylinder device (7); the working end of the sliding block (8-2) is of a trapezoidal structure and corresponds to the trapezoidal structures of the sections of the screw teeth I (201) and the screw teeth II (401) of the cast-in-place pile with the enlarged-diameter conical pile section.
The working principle of the drill bit for forming the cast-in-place pile with the diameter-expanding conical pile section is as follows:
when drilling holes, the discharge hole of the drill bit is closed, the piston rod of the main oil cylinder and the piston rod of the auxiliary oil cylinder are all in a withdrawing state, and the sliding block 8-2 is arranged in the fixed seat 9, as shown in figure 2.
When the drill bit is lifted and concrete is pumped to form the enlarged-diameter cylindrical threaded pile section, firstly, oil is supplied to a rodless cavity of the auxiliary oil cylinder 7-3 through a hydraulic control system, a piston rod 7-3A of the auxiliary oil cylinder is driven to completely extend out, then oil is supplied to a rodless cavity of the main oil cylinder 7-1, the extension amount of a piston rod 7-1A of the main oil cylinder is determined according to the design height of threads of the enlarged-diameter cylindrical threaded pile section, and the extension of the piston rods of the two oil cylinders pushes the connecting plate 8-3 to rotate downwards to drive the sliding block 8-2 to rotate outwards, as shown in figure 4. The extended slide block 8-2 rotates along with the drill bit in the drilling direction and is lifted upwards to extrude the wall rock of the cylinder pile into a spiral thread groove.
When the drill bit is lifted and concrete is pumped to form the threaded pile section with the enlarged diameter conical body, firstly, oil is supplied to a rodless cavity of the auxiliary oil cylinder 7-3 through the hydraulic control system, a piston rod 7-3A of the auxiliary oil cylinder is driven to completely extend out, the sliding block 8-2 is driven to rotate downwards by pushing the connecting plate 8-3, and the sliding block 8-2 is driven to rotate outwards until the maximum diameter formed by the outermost edge of the sliding block 8-2 around the center of the drill bit reaches the outer diameter of the structure of the drill bit cylinder, as shown in figure 3, or slightly exceeds the outer diameter of the structure of the drill bit. Then, the oil supply speed of a rodless cavity of the main oil cylinder 7-1 is adjusted and determined through a hydraulic control system according to the rotating speed and the lifting speed of the drill bit and the length of the constructed expanded-diameter conical-body thread pile section, the matching degree of the length of the expanded-diameter conical-body thread pile section and the rotating extension amount of the sliding block 8-2 is met, the piston rod 7-1A of the main oil cylinder stretches out at a constant speed, the connecting plate 8-3 is pushed to rotate downwards, the sliding block 8-2 is driven to rotate outwards at a constant speed and extend out, and therefore the sliding block 8-2 forms a gradually deepened spiral thread groove in rock soil on the wall of a pile hole until the maximum outer diameter of a thread is reached, and construction of the expanded-diameter conical-body thread pile section is completed.
The cone structure part of the drill bit bears the main extrusion function in the drilling process of extruding soil into a pile hole and extruding concrete in a repeated extruding and compacting way, and rock soil at the pile hole position or the concrete in the pile hole directly bears the radial downward rotary extrusion force of the cone structure part. When the soil-squeezing hole-forming drill is used for squeezing soil, the squeezed soil and soil are forced to move downwards in the radial direction, and the soil and soil on the wall of the pile hole are squeezed; when the composite compaction extrusion concrete is drilled, the bottom surface of a drill point door is subjected to an upward acting force of the pressure concrete in a pile hole, the upward acting force moves downwards along with the drilling of a drill bit, the upward acting force rotates around a pin to close a discharge hole until the discharge hole of the drill bit is closed, the mutual circulation of the concrete inside and outside a drilling tool is blocked, the concrete extruded by the drill bit serves as a medium, force is transferred to rock soil on the adjacent hole wall, the hole diameter of the rock soil is squeezed and expanded again to form a rock soil hole wall with an expanded diameter, and meanwhile, part of the concrete is extruded into the hole wall of the rock soil to form a mixture layer of the concrete and the soil, namely. After the cone structure part of the drill bit extrudes soil or concrete to the designed depth, the outer contour of the formed rock-soil bottom hole or the lower part of the multiple compaction reinforcing layer is in a cone structure and is similar to the outer contour of the cone structure part of the drill bit.
Example 2
Filling pile with enlarged diameter conical body pile section
The cast-in-place pile with the enlarged-diameter conical pile section comprises a main cylindrical cast-in-place pile (100), wherein the bottom end of the main cylindrical cast-in-place pile (100) is a conical pile bottom (101).
The outer edge of the main cylindrical cast-in-place pile (100) is provided with a plurality of sections of enlarged diameter conical body pile sections of an integrated structure, and the enlarged diameter conical body pile sections comprise one or two of enlarged diameter conical body screw tooth pile sections (200) and enlarged diameter conical body multiple-compaction pile sections (300).
The diameter-enlarged conical body screw tooth pile section (200) is structurally characterized in that a screw tooth I (201) which is of an integral structure, spirally winds the outer edge of the main cylindrical cast-in-place pile (100) and gradually increases in outer diameter from bottom to top is manufactured on the outer edge of the main cylindrical cast-in-place pile (100), the outer edge of the integral screw tooth I (201) forms a conical body, and the section of the screw tooth I (201) is of a trapezoidal structure. The diameter of the outer edge of the screw thread I around the center of the pile is gradually increased from bottom to top. The outer edge surface of the screw tooth pile section of the enlarged diameter conical body is a conical body, and the small diameter of the conical body is arranged at the lower end.
The diameter-enlarged conical body multiple-compaction pile section (300) is structurally characterized in that the outer edge of a main cylindrical cast-in-place pile (100) is provided with an integrated structure, the upper part of the integrated structure is a multiple-compaction cylindrical pile section (301), the lower part of the integrated structure is a multiple-compaction conical pile section (302), the outer edge of the multiple-compaction conical pile section (302) forms a conical body, and the outer edges of the multiple-compaction cylindrical pile section (301) and the multiple-compaction conical pile section (302) are wrapped with a layer of multiple-compaction reinforcing layer (303). The multiple compaction reinforcing layer (303) is a mixture of concrete and soil formed by extruding concrete into rock soil, and wraps the multiple compaction pile sections in the inner part, the outer edge of the multiple compaction pile section is similar to the shape of the multiple compaction pile sections, the lower part of the multiple compaction pile section is a cone, and the upper part of the multiple compaction pile section is a cylinder.
Furthermore, the cast-in-place pile with the enlarged-diameter conical pile section is characterized in that a plurality of sections of the enlarged-diameter cylindrical body thread pile sections (400) which are of an integrated structure are arranged on the outer edge of the main cylindrical cast-in-place pile (100).
The structure of the enlarged-diameter cylindrical body screw tooth pile section (400) is that screw teeth II (401) which are of an integral structure and spirally wound around the outer edge of the main cylindrical cast-in-place pile (100) are manufactured at the outer edge of the main cylindrical cast-in-place pile (100), and the outer edge of the integral screw teeth II (401) forms a cylindrical body.
Furthermore, above-mentioned bored concrete pile with enlarge footpath conical body stake section establishes main part cylindricality bored concrete pile (100) diameter and is D, enlarges footpath cylindricality thread stake section (400) external diameter and is D, and compound compaction cylinder stake section (301) external diameter is D1, and compound compaction enhancement layer (303) maximum external diameter is D4, enlarges footpath conical body thread stake section (200) minimum end external diameter and is D2, maximum end external diameter is D3, and thread I (201) pitch is T1, and thread II (401) pitch is T2, then: d is 400-800 mm, D > D, D1> D, D3> D2> D, D4> D1, and D/T2 is 1.1-1.5; the thread pitch T1 of the enlarged diameter conical body thread pile section (200) is increased along with the increase of the outer diameter of the thread, and the ratio of the diameter formed by the outer edge of the thread I (201) at any point in the enlarged diameter conical body thread pile section (200) around the center of the main cylindrical cast-in-place pile (100) to the thread pitch T1 between the adjacent threads I (201) above and below the diameter is 1.1-1.5.
Further, in the above cast-in-place pile with an enlarged diameter tapered pile section, the thread i (201) and the thread ii (401) have a structure in which the height of the thread is h, the thickness of the outer side of the thread is b1, and the thickness of the inner side of the thread is b2, and then: h is 50-200 mm, b1 is 50-80 mm, and b2 is 100-200 mm.
Preferably, as shown in fig. 6, in one embodiment, a cast-in-place pile with an enlarged diameter conical body pile section includes a main cylindrical cast-in-place pile (100), a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), and the conical pile bottom (101) is provided with an enlarged diameter conical body re-compaction pile section (300), an enlarged diameter cylindrical body thread pile section (400), an enlarged diameter conical body re-compaction pile section (300) and an enlarged diameter cylindrical body thread pile section (400) which are integrally formed in sequence on the outer edge of the main cylindrical cast-in-place pile (100).
Preferably, as shown in fig. 7, in an embodiment, a cast-in-place pile with an enlarged diameter conical body pile section includes a main cylindrical cast-in-place pile (100), a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), and an enlarged diameter conical body re-compaction pile section (300), an enlarged diameter cylindrical body thread pile section (400) and an enlarged diameter conical body re-compaction pile section (300) are sequentially arranged on the conical pile bottom (101) and upward on the outer edge of the main cylindrical cast-in-place pile (100) in an integrated structure.
Preferably, in one embodiment, as shown in fig. 8, the cast-in-place pile with the enlarged-diameter conical pile section comprises a main cylindrical cast-in-place pile (100), wherein a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), and the enlarged-diameter conical multiple-compaction pile section (300) of an integral structure is partially manufactured at the conical pile bottom (101). The conical pile bottom (101) is upwards provided with an integral cylindrical body screw tooth pile section (400) at the outer edge of the middle part of the main cylindrical cast-in-place pile (100).
Preferably, as shown in fig. 9, in one embodiment, a cast-in-place pile with an enlarged diameter conical body pile section includes a main cylindrical cast-in-place pile (100), a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), and the conical pile bottom (101) is provided with an enlarged diameter conical body re-extrusion dense pile section (300), an enlarged diameter conical body screw pile section (200), an enlarged diameter conical body re-extrusion dense pile section (300) and an enlarged diameter cylindrical body screw pile section (400) which are integrally formed on the outer edge of the main cylindrical cast-in-place pile (100) in sequence.
Preferably, in an embodiment, as shown in fig. 10, a cast-in-place pile with an enlarged diameter conical body pile section comprises a main cylindrical cast-in-place pile (100), a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), an integrally structured enlarged diameter conical body thread pile section (200) is sequentially arranged on the outer edge of the main cylindrical cast-in-place pile (100) at the conical pile bottom (101) upwards, and the enlarged diameter conical body thread pile section (200) is arranged at the top end.
Preferably, in one embodiment, as shown in fig. 11, a cast-in-place pile with an enlarged-diameter conical pile section comprises a main cylindrical cast-in-place pile (100), wherein a conical pile bottom (101) is arranged at the bottom end of the main cylindrical cast-in-place pile (100), and an enlarged-diameter conical multiple-compaction pile section (300) of an integrated structure is partially manufactured at the conical pile bottom (101). The conical pile bottom (101) is upwards provided with an enlarged diameter conical body composite compaction pile section (300) and an enlarged diameter conical body screw tooth pile section (200) which are of an integrated structure on the outer edge of the middle part of the main cylindrical cast-in-place pile (100).
Pile-forming construction method for cast-in-place pile with enlarged diameter conical pile section
1) A joint (1) of a drill bit is assembled with a spiral soil extrusion pile machine and a concrete pumping device through a soil extrusion drill rod, an oil cylinder device (7) is connected with a hydraulic control system, a slide block (8-2) of an expanding slide block device (8) of the drill bit is in a withdrawing state, and the pile machine is aligned to a pile position.
2) And starting the pile machine, driving the drill bit to drill and rotate by the power head through the soil extrusion drill rod, slowly drilling down, normally drilling after the hole position is determined to be correct, extruding rock soil at the pile hole position into a small-diameter taper hole by the drill bit, moving the small-diameter taper hole downwards along with the drilling of the drill bit, extruding and expanding the small-diameter taper hole into a large-diameter taper hole until the hole diameter of the foundation pile, extruding and drilling the soil until the designed hole depth, continuously rotating in situ for 2-3 minutes, and fully extruding the rock soil at the hole bottom and the hole wall of the foundation pile as shown in figure 13 (a).
3) And (2) lifting the drill bit and the drill rod, and simultaneously pumping concrete to fill concrete, and realizing pile formation of each pile section according to the construction sequence that the pile bottom starts to be upwards section by section:
3.1) main body cylindrical cast-in-place pile (100) and tapered pile bottom (101) at bottom end
Concrete is pumped into the bottom of the inner cavity of the drill bit by a drill bit pump positioned at the bottom of the pile hole, then the drill bit and the drill rod rotating in the drilling direction are lifted, the matching degree of the drill lifting speed and the pump pressure filling amount is kept, the drill is lifted and pressure filled to the aperture of the column pile, and the filling construction of the conical pile bottom (101) is completed; and (3) continuously lifting the drill bit and the pressure-grouting column pile hole to the designed height of the top of the main cylindrical grouting pile (100), and completing the grouting construction of the main cylindrical grouting pile (100), wherein the slide block of the expanding slide block device in the drill bit is in a completely retracted state as shown in fig. 13 (b).
3.2) enlarged diameter cylindrical screw tooth pile section (400)
In the process of lifting and pouring the pile section of the main cylindrical cast-in-place pile (100), when an enlarged-diameter cylindrical body thread pile section (400) needs to be arranged, a hydraulic control system is used for driving a piston rod of an auxiliary oil cylinder in an oil cylinder device to completely extend, driving a piston rod of a main oil cylinder in the oil cylinder device to extend, determining a fixed extension amount of the piston rod of the main oil cylinder according to the designed depth of threads of the enlarged-diameter cylindrical body thread pile section to push and control the extension amount of a sliding block in an enlarged-diameter sliding block device, rotating a drill bit and a drill rod in one rotation in the drilling direction to lift a screw pitch upwards, matching with pump pouring, pouring concrete into a spiral groove extruded by the sliding block in the wall of a pile hole together with the pile hole, lifting and pouring to the designed height, and finishing the pouring construction of the enlarged-diameter cylindrical body thread pile section (400), as shown in fig. 13 (c).
3.3) enlarged diameter conical body multiple extruding density pile section (300)
In the process of lifting and drilling and pouring the pile section of the main cylindrical cast-in-place pile (100), when the diameter-enlarged conical body re-extrusion pile section (300) needs to be arranged, downward spinning is carried out in the poured main cylindrical cast-in-place pile (100) again, concrete in an extrusion pile hole is drilled, the hole wall of the rock and soil of the pile is extruded and expanded through the extruded concrete, a re-extrusion density reinforcing layer is formed in the extruded and expanded hole wall, a small part of the concrete in the pile hole is extruded into the re-extrusion density reinforcing layer, the majority of the concrete is remained in the hole cavity of the rock and soil which is extruded and expanded, the drilling is carried out until the designed depth of the diameter-enlarged conical body re-extrusion pile section (300) is reached, then the concrete is firstly pumped and poured to the bottom of the inner cavity of the drill bit, then a drilling tool rotating in the drilling direction is lifted, the rock and soil with the matching degree of drilling speed and pumping pressure filling quantity is kept, the newly poured concrete and the concrete is integrated with the concrete remained in the, the pouring construction of the enlarged diameter conical body recompression pile section (300) is completed, as shown in fig. 13(d), (e), (f) and (g), in the process, the slide block of the inner diameter expansion slide block device of the drill bit is in a complete retraction state.
3.4) enlarged diameter conical screw pile section (200)
In the process of lifting and drilling the pile section of the main cylindrical cast-in-place pile (100) and when an enlarged-diameter conical body thread pile section (200) needs to be arranged, a hydraulic control system is used for driving a piston rod of an auxiliary oil cylinder in an oil cylinder device to completely extend out to drive a sliding block in an expanding sliding block device to partially extend out, then a piston rod of a main oil cylinder in the oil cylinder device to extend out at a constant speed, the length of the enlarged-diameter conical body thread pile section is matched with the total amount of the piston rod of the main oil cylinder extending out at a constant speed, a drill bit and a drill rod are rotated in the drilling direction one rotation to lift a thread pitch upwards, and are matched with pump pressure filling, the sliding block extrudes a gradually deepened spiral groove in the wall of a pile hole to fill concrete together with the pile hole, the concrete is lifted and filled to the designed height, and the filling construction of the.
The filling of the filling pile with the conical body adopts a mode of upward filling section by section from the bottom end of the pile, and the structural requirements of each pile section of the designed foundation pile are met. After the pile hole is formed, the drill bit is always kept in the effective buried depth of the concrete in the pile hole in the processes of lifting drilling, pouring and re-extruding dense drilling, and a certain amount of concrete is kept in the inner cavity of the drilling tool, so that the pile forming quality is ensured. The expanding slide block device is arranged at the upper end of the drill bit cone structure, namely the maximum outer edge of the bottom of the drill bit, and is positioned in the effective burial depth of pressure concrete in a pile hole when the drill bit is lifted and poured, and a spiral groove extruded by the slide block in the wall of the pile hole is immediately filled with the pressure concrete and is pressed and poured together with the main cylindrical pile hole, so that the strength between the screw teeth and the main cylindrical pile body is ensured.
4) And (5) placing the prefabricated reinforcement cage or the prefabricated member into the poured pile hole to form the pile, as shown in fig. 13 (i).
Bearing mechanism of pile (III)
The tapered pile bottom (101) and the main cylindrical cast-in-place pile (100) are formed by once extruding soil through a drill bit to form a hole, concrete is pumped and poured during drill lifting, the main cylindrical cast-in-place pile formed by once extruding soil is stressed to destroy a slip crack surface on the outer surface of the main cylindrical cast-in-place pile, namely on a concrete pile-soil interface, the lateral resistance of the pile section is the friction force between the outer surface of the concrete pile and the soil around the pile, and because the soil around the pile is compacted in a compaction manner, the limit lateral resistance standard value of the soil around the pile is improved, and the bearing capacity of the pile side is enhanced; the pile bottom is in a cone structure, the surrounding soil is compacted, the wedge-shaped squeezing effect is achieved, and the bearing capacity of the pile bottom can be effectively improved.
The pile section of the enlarged-diameter cylindrical screw tooth is formed by extruding a screw tooth groove into a rock soil with an extruded cylindrical hole wall again and pumping and pouring concrete together with a primary soil extrusion pile hole, the pile section is damaged along the outer contour of the screw tooth by stress, the outer contour surface of the screw tooth is formed by the outer side surface of the concrete screw tooth with a small proportion and soil, a stress damage sliding surface is mainly reflected on a soil-soil interface, the side resistance value of the pile section is the friction force (the shearing resistance force of the soil) of the soil-soil interface and is higher than the side resistance force of the pile-soil interface, and according to Berum calculation formula and related expert research results, the friction force of the soil-soil interface is 1.3-1.6 times of the side resistance force of the pile-soil interface.
The diameter-enlarging conical body multiple-extrusion-compaction pile section is formed by extruding and enlarging once again and performing pressure irrigation once again (or extruding and enlarging many times and performing pressure irrigation many times). The method comprises the following steps that a drill bit is used, concrete in a pile hole is used as a medium to extrude and expand the wall of a rock-soil hole, during extrusion, part of concrete is extruded into the rock-soil wall after the diameter is expanded, a mixture layer of the concrete and the soil is formed, namely a composite extrusion enhancement layer, and in the layer, the concrete content on the side close to the center of the pile hole is high, and the content on the far side is low; most of the extruded concrete is reserved in an inner cavity of the wall of the rock-soil hole which is extruded and expanded, the profile of the rock-soil hole which is extruded and expanded is similar to the appearance of the drill bit under the control of the appearance structure of the drill bit, namely the upper part is in a cylindrical shape, and the lower part is in a conical shape; lifting the drill and pumping and pouring concrete again, wherein the newly poured concrete and the concrete remained in the inner cavity of the expanded hole wall are integrated into a whole to form an expanded diameter conical body multiple-extrusion dense pile section with a conical body at the lower part and a cylindrical body at the upper part; the outer contour of the re-compaction reinforcing layer is similar to the outer contours of the re-compaction column pile section and the re-compaction cone pile section, and the re-compaction column pile section and the re-compaction cone pile section are wrapped by the re-compaction reinforcing layer. Because the combination strength of the composite compaction reinforcing layer and the concrete pile bodies in the composite compaction column pile section and the composite compaction cone pile section is high, the stress failure interface of the pile section is generated on the outer contour surface of the composite compaction reinforcing layer, the composition of the inner part of the composite compaction reinforcing layer close to the outer contour surface is that the re-compacted rock soil contains a small amount of concrete, and the soil occupies most part, therefore, the stress failure slip crack surface of the pile section is mainly embodied on the soil-soil interface, and the side resistance value of the pile section is the friction force (the shearing resistance force of the soil) of the soil-soil interface; meanwhile, the peripheral rock soil of the re-compaction enhancement layer is further compacted, and a foundation is laid for improving the bearing capacity; the externally wrapped multiple compaction reinforcing layer of the multiple compaction cone pile section is in a cone shape, so that the action volume of the multiple compaction cone is effectively increased, and the wedge-shaped squeezing and expanding effect is obvious.
The enlarged diameter conical body thread pile section is the advantageous combination of the enlarged diameter cylindrical body thread pile section and the conical pile section, the pile section is damaged along the outer contour of the thread due to stress damage, a damaged slip crack surface appears on a soil-soil interface, the damaged interface is conical, the wedge-shaped squeezing effect is achieved, and the bearing capacity is improved.
The wedge squeezing and expanding action of the conical body is shown in fig. 12, when a building (structure) applies force P to the pile body conical body, the action direction of the force P is changed on the outer surface of the conical body, the force P is decomposed into a normal force P1 and a tangential force P2 on the outer surface of the conical body, rock and soil around the outer surface of the conical body are radially extruded by the P1, the rock and soil are further compacted, and the action of the P2 is overcome by the friction force of a conical surface soil-soil interface (the surface of the conical body which is squeezed once is a pile-soil interface). The cone reduces the vertical effect of the force P and reduces the pile settlement. A large amount of research, experiments and application of professionals at home and abroad provide an empirical calculation formula of the side resistance of a conical pile section (wedge-shaped pile):
Pn＝∑Uili(ficosα+tisinα)
in the formula, Pn-allowable value of resistance (kN) on the side of the conical pile section; u shapei-perimeter (m) of pile at mid-waist of the pile section in the ith layer; li-in the ith layer, the pile section length (m); f. ofi-friction (kPa) of the ith soil layer against piles of equal section; t is ti-normal pressure (kPa) of ith soil layer against the tapered side; alpha-cone angle of the conical pile section.
From the above formula, Ui、fiThe value is taken according to the sliding crack surface of the cone-shaped pile section damaged by stress, and the geometric size U is calculated for the multiple compaction cone in the multiple compaction pile section according to the appearance of the multiple compaction enhancement layeriIs increased by fiThe friction force value is calculated according to the soil-soil interface, and is higher than the calculation of the pile-soil interface; for the diameter-enlarged cone screw-thread pile section, f is calculated according to the surface of the screw-thread outer contouriThe friction force of the soil-soil interface is taken, so that the material cost (the material between the threads) for forming the pile is saved under the condition of ensuring high bearing capacity of the pile. The rock soil around the primary extrusion cone pile bottom and the multiple extrusion enhancement layer outside the multiple extrusion cone body are compacted through extrusion, and particularly, the rock soil around the multiple extrusion enhancement layer outside the multiple extrusion cone body is compacted again or repeatedly, tiThe value will increase. Therefore, the cast-in-place pile with the enlarged-diameter conical pile section is a pile type with high bearing capacity, energy conservation and environmental protection.

Claims (9)

1. The cast-in-place pile with the enlarged-diameter conical body pile section comprises a main cylindrical cast-in-place pile (100), wherein the bottom end of the main cylindrical cast-in-place pile (100) is a conical pile bottom (101), and is characterized in that a plurality of sections of enlarged-diameter conical body pile sections of an integrated structure are manufactured on the outer edge of the main cylindrical cast-in-place pile (100), and each enlarged-diameter conical body pile section comprises one or two of an enlarged-diameter conical body thread pile section (200) and an enlarged-diameter conical body composite compaction pile section (300); the diameter-enlarged conical body screw tooth pile section (200) is structurally characterized in that screw teeth I (201) which are integrally structured, spirally wound around the outer edge of the main cylindrical cast-in-place pile (100) and gradually increased in outer diameter from bottom to top are formed on the outer edge of the main cylindrical cast-in-place pile (100), the outer edge of the integral screw teeth I (201) forms a conical body, and the section of the screw teeth I (201) is of a trapezoidal structure; the structure of the enlarged-diameter conical body multiple-compaction pile section (300) is that the outer edge of a main cylindrical cast-in-place pile (100) is provided with an integrated structure, the upper part of the integrated structure is a multiple-compaction cylindrical pile section (301), the lower part of the integrated structure is a multiple-compaction conical pile section (302), the outer edge of the multiple-compaction conical pile section (302) forms a conical body, and the outer edges of the multiple-compaction cylindrical pile section (301) and the multiple-compaction conical pile section (302) are wrapped with a layer of multiple-compaction reinforcing layer (303).
2. The bored concrete pile with an enlarged diameter tapered pile section according to claim 1, wherein the enlarged diameter cylindrical body screw pile section (400) is formed in a plurality of integrated structures on the outer periphery of the main cylindrical bored concrete pile (100), the enlarged diameter cylindrical body screw pile section (400) is formed in a structure in which a screw ii (401) is formed in an integrated structure on the outer periphery of the main cylindrical bored concrete pile (100) and spirally wound around the outer periphery of the main cylindrical bored concrete pile (100), and the outer periphery of the integrated screw ii (401) is formed in a cylindrical body.
3. The bored concrete pile with an enlarged diameter tapered pile section according to claim 2, wherein assuming that the diameter of the main cylindrical bored concrete pile (100) is D, the outer diameter of the enlarged diameter cylindrical threaded pile section (400) is D, the outer diameter of the multiple compacted cylindrical pile section (301) is D1, the maximum outer diameter of the multiple compacted reinforcement layer (303) is D4, the minimum outer diameter of the enlarged diameter tapered threaded pile section (200) is D2, the maximum outer diameter of the enlarged diameter tapered threaded pile section is D3, the thread pitch of the thread i (201) is T1, and the thread pitch of the thread ii (401) is T2, then: d is 400-800 mm, D > D, D1> D, D3> D2> D, D4> D1, and D/T2 is 1.1-1.5; the thread pitch T1 of the enlarged diameter conical thread pile section (200) is increased along with the increase of the outer diameter of the thread, and the ratio of the diameter formed by the outer edge of the thread I (201) at any point in the enlarged diameter conical thread pile section (200) around the center of the main cylindrical cast-in-place pile (100) to the thread pitch T1 between the adjacent threads I (201) above and below the diameter is 1.1-1.5.
4. A bored concrete pile with an enlarged-diameter tapered pile section according to claim 2, wherein the screw thread i (201) and the screw thread ii (401) have a configuration in which the height of the screw thread is h, the thickness of the outer side of the screw thread is b1, and the thickness of the inner side is b2, and further comprising: h is 50-200 mm, b1 is 50-80 mm, and b2 is 100-200 mm.
5. A drill bit with an enlarged-diameter conical body pile section for forming a cast-in-place pile comprises a joint (1), a spiral cylinder soil squeezing blade (2), a cylinder core pipe (3), a cone core pipe (4), a spiral cone soil squeezing blade (5) and a drill point door (6), and is characterized by being provided with an oil cylinder device (7), an enlarged-diameter sliding block device (8), a fixed seat (9), an oil cylinder lug plate (10), a shaft I (11), a shaft II (12) and a shaft III (13); the fixing seat (9) is arranged at the joint of the cylinder core pipe (3) and the cone core pipe (4) and penetrates through the cylinder core pipe (3), the cone core pipe (4) and the spiral cylinder soil-squeezing blade (2) at the joint; the cylinder device (7) is arranged in an inner cavity of the cylinder core tube (3), the cylinder device (7) comprises a main cylinder (7-1), a protection tube I (7-2), an auxiliary cylinder (7-3), a protection tube II (7-4) and a push rod (7-5), the extending end of a piston rod (7-1A) of the main cylinder is fixed with the cylinder sleeve end of the auxiliary cylinder (7-3), the extending end of a piston rod (7-3A) of the auxiliary cylinder is fixed with one end of the push rod (7-5), one end of the protection tube I (7-2) is fixed on the outer wall of the cylinder sleeve of the auxiliary cylinder (7-3), and the other end of the protection tube I is movably matched with the outer diameter of the cylinder sleeve of the main cylinder (7-1) in a; one end of the protective pipe II (7-4) is fixed on the outer wall of the cylinder sleeve of the auxiliary oil cylinder (7-3), and the other end is in movable sealing fit with the outer diameter of the push rod (7-5); the exposed end of the push rod (7-5) is provided with a connecting lug seat I (7-5A); the exposed end of the main oil cylinder (7-1) is provided with a connecting lug seat II (7-1B); the expanding slide block device (8) is fixed into a whole by a sleeve (8-1), a slide block (8-2) and a connecting plate (8-3), the sleeve (8-1) is installed in a fixed seat (9) through a shaft III (13) and rotates around the shaft III (13), an oil cylinder lug plate (10) is fixed on the inner wall of the cylinder core pipe (3), one end of the oil cylinder device (7) is hinged with the oil cylinder lug plate (10) through a connecting lug seat II (7-1B) and a shaft I (11), the other end of the oil cylinder device (7) is hinged with the connecting plate (8-3) of the expanding slide block device (8) through a connecting lug seat I (7-5A), a shaft II (12) and the connecting plate (8-3) of the expanding slide block device (8), and the slide block (8-2) is driven to rotate around the shaft III (13) through; the working end of the sliding block (8-2) is of a trapezoidal structure.
6. The drill bit for forming the cast-in-place pile with the enlarged-diameter conical pile section is characterized in that the joint (1), the cylinder core pipe (3) and the cone core pipe (4) are concentrically and sequentially fixed into a whole, a channel for concrete to pass through is formed in an inner cavity of the joint, the spiral cylinder soil squeezing blade (2) is spirally wound and fixed on the outer edges of the joint (1) and the cylinder core pipe (3), the spiral cone soil squeezing blade (5) is spirally wound and fixed on the outer edge of the cone core pipe (4), the upper end face of the spiral cone soil squeezing blade (5) is correspondingly connected with the lower end face of the spiral cylinder soil squeezing blade (2), and the lower end of the spiral cone soil squeezing blade (5) is provided with cutting teeth (5-1).
7. The drill bit for forming the cast-in-place pile with the enlarged-diameter conical pile section is characterized in that the drill tip gate (6) is installed on the lower end face of the conical core tube (4), the drill tip gate (6) is movably connected to the lower end of the conical core tube (4) through a pin (6-1), the drill tip gate (6) rotates downwards around the pin (6-1) by a maximum angle delta which is more than or equal to 35 degrees and less than or equal to 45 degrees, a drill bit discharge port is opened to the maximum opening, the drill tip gate (6) rotates upwards around the pin (6-1) to the lower end face of the conical core tube (4), and the drill bit discharge port is closed.
8. The pile-forming drill bit for the cast-in-place pile with the enlarged-diameter conical pile section is characterized in that the joint (1), the spiral cylinder soil-squeezing blade (2) and the cylinder core tube (3) form a cylinder structure part of a drill bit device, and the outer edge of the cylinder structure part is a cylinder; the cone core tube (4), the spiral cone soil squeezing blade (5) and the drill tip door (6) form a cone structure part of the drill bit device, and the outer edge of the cone structure part is a cone.
9. A pile-forming construction method for a cast-in-place pile with an enlarged-diameter conical pile section, characterized in that the drill bit of any one of claims 5 to 8 is used, comprising the steps of:
1) the joint (1) of the drill bit is assembled with a spiral soil extrusion pile machine and a concrete pumping device through a soil extrusion drill rod, an oil cylinder device (7) is connected with a hydraulic control system, a slide block (8-2) of an expanding slide block device (8) of the drill bit is in a withdrawing state, and the pile machine is aligned to a pile position;
2) starting a pile machine, driving a drill bit to drill and rotate by a power head through an earth-squeezing drill rod, slowly drilling down, normally drilling after a hole position is determined to be correct, squeezing rock soil at the hole position of the pile into a small-diameter taper hole by the drill bit, squeezing and expanding the small-diameter taper hole into a large-diameter taper hole along with the drilling down of the drill bit until the hole diameter of a foundation pile, squeezing and drilling the earth until the designed hole depth, continuously rotating in situ for 2-3 minutes, and fully squeezing the rock soil at the hole bottom and the hole wall of the foundation pile;
3) and (2) lifting the drill bit and the drill rod, and simultaneously, in the process of pumping concrete, realizing the pile formation of each pile section according to the construction sequence that the pile bottom is upwards section by section:
3.1) main body cylindrical cast-in-place pile (100) and tapered pile bottom (101) at bottom end
Concrete is pumped into the bottom of a drill bit inner cavity by a drill bit pump positioned at the bottom of a pile hole, then the drill bit and a drill rod rotating in the drilling direction are lifted, the matching degree of the drill lifting speed and the pump pressure filling amount is kept, the drill is lifted and pressure filled to the column pile aperture, and the filling construction of the conical pile bottom (101) is completed; continuously lifting the drill bit and the pressure-grouting column body pile hole to the design height of the top of the main body column-shaped grouting pile (100), completing the grouting construction of the main body column-shaped grouting pile (100), wherein in the process, the slide block of the expanding slide block device in the drill bit is in a completely retracted state;
3.2) enlarged diameter cylindrical screw tooth pile section (400)
In the process of lifting and pouring a pile section of a main cylindrical cast-in-place pile (100), when an enlarged-diameter cylindrical thread pile section (400) needs to be arranged, a hydraulic control system is used for driving a piston rod of an auxiliary oil cylinder in an oil cylinder device to completely extend out, driving a piston rod of a main oil cylinder in the oil cylinder device to extend out, determining a fixed extension amount of the piston rod of the main oil cylinder according to the designed height of threads of the enlarged-diameter cylindrical thread pile section to push and control the extension amount of a sliding block in an enlarged-diameter sliding block device, rotating a drill bit and a drill rod in the drilling direction for one rotation, lifting a screw pitch upwards, matching with pump pressure pouring, pouring concrete into a spiral thread groove extruded by the sliding block in the wall of a pile hole together with the pile hole, lifting and pouring to the designed height, and finishing the pouring construction of the enlarged-diameter cylindrical thread pile section (400);
3.3) enlarged diameter conical body multiple extruding density pile section (300)
In the process of lifting and drilling and pouring the pile section of the main cylindrical cast-in-place pile (100), when an enlarged-diameter conical body re-compaction pile section (300) needs to be arranged, downward spinning is carried out in the poured main cylindrical cast-in-place pile (100) again, concrete in a pile hole is extruded to drill, the hole wall of the rock and soil of the pile is extruded and expanded through the extruded concrete, a re-compaction reinforcing layer is formed in the extruded and expanded hole wall, a small part of the concrete in the pile hole is extruded into the re-compaction reinforcing layer, the majority of the concrete is remained in the hole cavity of the rock and soil which is extruded and expanded, drilling is carried out until the designed depth of the enlarged-diameter conical body re-compaction pile section (300) is reached, then concrete is pumped to the bottom of the inner cavity of a drill bit, a drilling tool rotating in the drilling direction is lifted, the matching degree of the drilling speed and the pumping pressure filling quantity is kept, the newly poured concrete is integrated with the concrete remained in the hole cavity of the extruded and expanded rock and soil, the pouring construction of the diameter-expanding conical body recompression pile section (300) is completed, and in the process, the slide block of the diameter-expanding slide block device in the drill bit is in a completely retracted state;
3.4) enlarged diameter conical screw pile section (200)
In the process of lifting and pouring a pile section of a main cylindrical pouring pile (100), when an enlarged-diameter conical body thread pile section (200) needs to be arranged, a hydraulic control system is used for driving a piston rod of an auxiliary oil cylinder in an oil cylinder device to completely extend out to drive a sliding block in an expanding sliding block device to partially extend out, then a piston rod of a main oil cylinder in the oil cylinder device to extend out at a constant speed, the length of the enlarged-diameter conical body thread pile section is matched with the total amount of the extending out of the piston rod of the main oil cylinder at a constant speed, a drill bit and a drill rod are rotated in the drilling direction for one rotation, a thread pitch is lifted upwards and matched with pump pressure pouring, a gradually deepened spiral thread groove is extruded by the sliding block in the wall of a pile hole to be poured with the pile hole together with concrete, the concrete is lifted and poured to the designed height, and pouring construction of;
4) and (5) placing the prefabricated reinforcement cage or the prefabricated member into the poured pile hole to form the pile.
CN202110023397.6A 2021-01-08 2021-01-08 Cast-in-place pile with diameter-expanding conical pile section, drill bit for pile forming and pile forming construction method Pending CN112761139A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113175303A (en) * 2021-05-27 2021-07-27 城地建设集团有限公司 Dry-method rotary extrusion-expansion drill bit and construction method
CN114109279A (en) * 2021-12-22 2022-03-01 西北民航机场建设集团有限责任公司 Pore-forming device and pore-forming method for concrete drilling cast-in-place threaded pile
CN115125938A (en) * 2022-07-05 2022-09-30 刘守进 Composite pile construction method with built-in precast tubular pile

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113175303A (en) * 2021-05-27 2021-07-27 城地建设集团有限公司 Dry-method rotary extrusion-expansion drill bit and construction method
CN114109279A (en) * 2021-12-22 2022-03-01 西北民航机场建设集团有限责任公司 Pore-forming device and pore-forming method for concrete drilling cast-in-place threaded pile
CN115125938A (en) * 2022-07-05 2022-09-30 刘守进 Composite pile construction method with built-in precast tubular pile
CN115125938B (en) * 2022-07-05 2023-12-29 刘守进 Composite pile construction method for built-in prefabricated pipe pile

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