CN110952552A

CN110952552A - Large-diameter PHC precast tubular pile construction method and pile driver for implementing same

Info

Publication number: CN110952552A
Application number: CN201911303798.6A
Authority: CN
Inventors: 冯欣华; 庞国达; 杨树金
Original assignee: GUANGDONG LIYUAN HYDRAULIC MACHINERY Co Ltd
Current assignee: GUANGDONG LIYUAN HYDRAULIC MACHINERY Co Ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-04-03

Abstract

The invention discloses a construction method of a large-diameter PHC precast tubular pile, which comprises the following steps: the pile driver takes place, the inclination angle is adjusted, the large-diameter PHC prefabricated pipe pile is put into place, the soft soil layer is hammered and sent, the guide hole is aligned, the guide hole is drilled in the pile driver, the pile driver is hammered and aligned, and the hard soil layer is hammered and sent. The invention discloses a piling device for implementing the method. The invention adopts a hammering mode for the construction of the foundation soft soil layer pile foundation, and the large-diameter PHC pipe pile is sunk into the soft soil layer, thereby ensuring the side friction between the upper part of the pile foundation and the soft soil layer and improving the bearing capacity of the pile foundation; the mode of firstly guiding holes and then hammering the hard soil layer of the foundation is adopted, the soil plug effect of the hard soil layer on the large-diameter PHC tubular pile is solved, the large-diameter PHC tubular pile smoothly sinks into the hard soil layer, the inclination angle of the large-diameter PHC tubular pile is accurately controlled by adjusting the inclination angle of the tower, and accurate and efficient construction of the large-diameter PHC tubular pile with the set inclination angle is realized.

Description

Large-diameter PHC precast tubular pile construction method and pile driver for implementing same

Technical Field

The invention relates to the technical field of pile foundation construction equipment, in particular to a large-diameter PHC precast tubular pile construction method and a pile driver for implementing the method.

Background

Pile foundation construction in the prior art generally comprises steel piles, cast-in-situ bored piles and PHC (prestressed high-strength concrete) pipe piles.

The steel pile adopts steel materials, so that the hardness and the toughness of the steel pile are good, the pile materials cannot be damaged by large hammering force, meanwhile, the steel material has high strength and small section, the penetrating capability of the steel pile to a soil layer is good, and the quality of the steel pile penetrating through a thick sandy soil layer is guaranteed. However, the steel piles are expensive in manufacturing cost, so that more expensive steel materials are driven under the ground, which is difficult to bear by general owners, and the steel piles are less and less adopted in the current engineering foundation treatment.

The cast-in-situ bored pile can penetrate through most soil layers, and is a solution scheme which is most used for penetrating through thick sandy soil layers and the like at present. However, the cast-in-situ bored pile has the following disadvantages:

1) and because the soil squeezing effect is not generated, the bearing capacity of a single pile with the same diameter is lower compared with that of a PHC pile.

2) The pile sinking quality is restricted by the site construction conditions, the site pore-forming, the reinforcement cage manufacturing and the concrete pouring procedures are complex, the construction is complicated, and the pile-forming quality control is difficult.

3) The construction cost is lower than that of a steel pipe pile and is obviously higher than that of a PHC pile.

4) The construction speed is limited by equipment, and the pile sinking speed of each pile to each pile foundation is slower than that of a PHC pile.

5) The dirty condition of mud full flow can appear in drilling bored concrete pile building site, and the building site is drawn water everywhere and the busy scene of mound fortune soil.

6) If a karst cave or an underground river and the like appear in a pile foundation soil layer, a large amount of concrete is over-poured, and great economic loss is caused.

Compared with the traditional concrete cast-in-place pile, the PHC tubular pile has the advantages of visual quality, convenience in inspection, low manufacturing cost, easiness in ensuring of pile forming process quality, short construction period, environmental friendliness and the like, and becomes the main force and development direction of the existing pile for construction.

In practical engineering, a soft soil layer (weak subjacent layer) exists in a soil layer, and because the engineering has high requirements on settlement control, a soil layer below the soft soil layer is required to be used as a bearing layer, so that the PHC pipe pile generally needs to penetrate through a soft soil layer and a hard soil layer above the soft soil layer, and is generally a sandy soil layer. When the thickness of the sandy soil layer is large (generally more than 10m), particularly for the PHC tubular pile with a large diameter (generally more than 120 cm), due to the soil plug effect, pile sinking of the PHC precast tubular pile with the large diameter is very difficult no matter hammering and static pressure pile sinking processes are adopted. For projects which generally need to penetrate through thicker sandy soil layers (generally more than 10m) and have longer pile lengths (generally more than 40m), most of the traditional foundation treatment methods adopt steel piles or cast-in-situ bored piles.

The invention patent with application number of CN200710156471.1 in the prior art discloses a construction process for hammering a PHC tubular pile into rock through whole process pre-leading holes, which adopts a rotary pile machine with a long spiral drill rod, firstly pre-leading holes on the pile foundation in the whole process, then injecting yellow mud into the pre-leading holes, forming a mud protective wall in the holes, and finally hammering the PHC tubular pile to a designed depth by using a hammering pile machine; in actual engineering, in particular large-scale railway bridge engineering, a single-pier bearing platform pile group pile foundation is mostly adopted, a plurality of piles are arranged below a bearing platform, and some piles have inclination, so that the method has the following defects:

1) because the whole-course pre-leading hole is adopted, the upper part of the pile foundation has no soil squeezing effect, the side friction between the upper part of the pile foundation and a soil layer is lost, and the bearing capacity is lower.

2) Because two equipment of a rotary pile machine and a hammering pile machine are adopted, hole leading and hammering construction of the PHC tubular pile are respectively completed, the same inclination is difficult to ensure, and construction of the inclined pile is difficult to complete.

3) Due to the fact that a site for pile group construction is narrow, a rotary pile driver and a hammering pile driver are adopted, the coordination difficulty of the two devices is high, and influences on construction cost, quality, safety, progress and the like are large.

Therefore, it is necessary to design a new large-diameter PHC precast tubular pile construction apparatus and a large-diameter PHC precast tubular pile sinking construction method to solve the above problems.

Disclosure of Invention

The invention aims to provide a construction method and equipment of a large-diameter PHC precast tubular pile, aiming at the defects, the construction method adopts a hammering mode to a soft soil layer of a foundation, and the large-diameter PHC precast tubular pile is sunk into the soft soil layer, so that the side friction between the upper part of a pile foundation and the soft soil layer is ensured, and the bearing capacity of the pile foundation is improved; the method that the holes are led firstly and then the holes are hammered is adopted for the hard soil layer of the foundation, the soil plug effect of the hard soil layer on the large-diameter PHC prefabricated pipe pile is solved, the large-diameter PHC prefabricated pipe pile is smoothly sunk into the hard soil layer, the inclination angle of the large-diameter PHC prefabricated pipe pile is accurately controlled by adjusting the inclination angle of the tower, and the precise construction of the large-diameter PHC prefabricated pipe pile with the set inclination angle is realized; this major diameter PHC precast tubular pile driver utilizes the flexible control of two flexible diagonal braces, realizes the slope angle control to major diameter PHC precast tubular pile, with hammering and the design of draw hole integral type, makes the draw hole keep higher same gradient with the hammering in the work progress, can accomplish the batter pile construction smoothly, saves the construction site simultaneously, improves efficiency of construction, quality, security.

The technical scheme is as follows:

a construction method of a large-diameter PHC precast tubular pile comprises the following steps:

(1) the pile driver is in place, the large-diameter PHC precast tubular pile driver is moved to a to-be-constructed area, and the pile driver is provided with a hammering drilling center which is integrally arranged, so that the hammering drilling center on the front side of a tower frame of the large-diameter PHC precast tubular pile driver is positioned right above the pile position of the to-be-constructed pile foundation; the large-diameter PHC precast tubular pile driver comprises a host platform, a tower frame, a moving mechanism, a hole guiding device, a pile driving hammer, a first telescopic diagonal brace and a second telescopic diagonal brace;

(2) adjusting the inclination angle, namely adjusting the lengths of the first telescopic diagonal brace and the second telescopic diagonal brace to enable the inclination angle of the tower frame of the large-diameter PHC precast tubular pile driver to correspond to the designed inclination angle of the tubular pile to be constructed;

(3) the large-diameter PHC precast tubular pile is lifted to the front end of the tower frame, and the center of the large-diameter PHC precast tubular pile to be constructed is superposed with the center of the pile position of the pile foundation to be constructed; the top of the large-diameter PHC precast tubular pile to be constructed is arranged in a pile cap at the lower end of the pile hammer;

(4) the pile driving hammer is used for driving the large-diameter PHC precast tubular pile to be constructed into a foundation soil layer and penetrates through the soft soil layer of the foundation soil layer to the top surface of the hard soil layer of the foundation soil layer, wherein the foundation soil layer comprises the soft soil layer and the hard soil layer;

(5) aligning the guide holes, and lifting the pile hammer upwards to separate a pile cap at the lower end of the pile hammer from the top of the large-diameter PHC precast tubular pile to be constructed; utilizing a moving mechanism of a large-diameter PHC prefabricated pipe pile driver to move a tower on the host platform forward, and enabling a hole guiding and drilling center of a hole guiding device in the tower to correspond to a pile center of the large-diameter PHC prefabricated pipe pile to be constructed;

(6) drilling a guide hole inside, namely drilling a soil body in the large-diameter PHC precast tubular pile to be constructed by using the guide hole device, and discharging the soil body; drilling a hard soil layer pre-guide hole below the large-diameter PHC precast tubular pile to be constructed to the design depth of the pile foundation;

(7) hammering and aligning, and lifting the hole guiding device upwards to enable the lower end of the hole guiding device to slide to the position above the top of the large-diameter PHC precast tubular pile to be constructed; moving a tower on the host platform backwards by using a moving mechanism of the large-diameter PHC precast tubular pile driver, and enabling the center of a pile driving hammer on the front side of the tower to correspond to the pile center of the large-diameter PHC precast tubular pile to be constructed;

(8) hard soil layer hammering pile delivery, the lapse makes the top of treating the major diameter PHC precast tubular pile of construction is installed in the pile cap of pile hammer lower extreme, utilize the pile hammer will treat the major diameter PHC precast tubular pile of construction and send to the hard soil in situ, until the design depth of arriving the pile foundation.

The large-diameter PHC precast tubular pile to be constructed comprises a plurality of sections of large-diameter PHC precast tubular piles; the pile can be formed by combining a plurality of sections according to the designed pile length, and is combined into a whole by welding or other connection modes.

Treat the major diameter PHC precast tubular pile of being under construction and include that first festival PHC tubular pile includes tubular pile, stake point fixer, the tubular pile bottom is equipped with the bottom steel sheet of stake, the stake point fixer install on the tubular pile bottom face.

The large-diameter PHC precast tubular pile to be constructed further comprises a first-section follow-up PHC tubular pile, and the step (8) further comprises the following steps:

when will the top hammering of first section PHC tubular pile is sent to liftoff 50CM to 100CM, stops the hammering and send a stake, and will the lower extreme of the follow-up PHC tubular pile of first section with the top of first section PHC tubular pile is connected, connects after accomplishing, continues to carry out the hammering again and send a stake until reaching the design depth of pile foundation.

The first section of subsequent PHC tubular pile at least comprises a second section of PHC tubular pile and a third section of PHC tubular pile, the lengths of the second section of PHC tubular pile and the third section of PHC tubular pile are selected according to the soil property of a hard soil layer, the pre-lead holes at least comprise a second section of tubular pile pre-lead hole and a third section of tubular pile pre-lead hole, the depth of the second section of tubular pile pre-lead hole is larger than the length of the second section of PHC tubular pile, the depth of the third section of tubular pile pre-lead hole is larger than the length of the third section of PHC tubular pile, and the method further comprises the following steps after the step (5):

(61) the pile foundation of the first section of PHC tubular pile is drilled by the hole guiding device, and a hard soil layer below the first section of PHC tubular pile is subjected to second section of tubular pile pre-guiding hole;

(62) hammering and aligning the second PHC tubular pile, and sliding the hole guiding device upwards to enable the lower end of the hole guiding device to slide to the upper part of the top of the first PHC tubular pile; moving the tower on the host platform backwards by using the moving mechanism of the large-diameter PHC precast tubular pile driver, and enabling the center of a pile hammer on the front side of the tower to correspond to the pile center of the first PHC tubular pile;

(63) the pile driving hammer is used for driving the first PHC tubular pile to move downwards, the top of the first PHC tubular pile is installed in a pile cap at the lower end of the pile driving hammer, the first PHC tubular pile is conveyed into the hard soil layer by the pile driving hammer, when the top of the first PHC tubular pile is lifted to 50CM to 100CM, the pile driving hammer stops driving and conveying the pile, the lower end of the second PHC tubular pile is connected with the top of the first PHC tubular pile, and after the connection is completed, the pile driving hammer is continued until the pile driving and conveying of the second PHC tubular pile are completed;

(64) aligning the guide holes of the third PHC tubular pile, and sliding the pile driving hammer upwards to separate the pile cap at the lower end of the pile driving hammer from the top of the second PHC tubular pile when hammering and pile feeding of the second PHC tubular pile are completed; utilizing a moving mechanism of the large-diameter PHC precast tubular pile driver to move a tower on a host platform forward, and enabling a hole guiding and drilling center of a hole guiding device in the tower to correspond to a pile center of the second PHC tubular pile;

(65) drilling soil in the first section of PHC tubular pile and the second section of PHC tubular pile by using the hole-drilling device, performing third section of tubular pile pre-drilling on a hard soil layer below the first section of PHC tubular pile, and drilling the pre-drilling hole to the design depth of the pile foundation;

(66) and (4) repeating the steps (62) to (63) to complete the hammering and pile feeding of the third section of PHC tubular pile until the design depth of the pile foundation is reached.

The large-diameter PHC precast tubular pile driver for implementing the construction method is characterized in that the pile driver is provided with an integrally arranged hammering and drilling center and comprises a host platform, a tower frame, a moving mechanism, a hole guiding device, a pile driving hammer, a first telescopic diagonal brace and a second telescopic diagonal brace, the lower end of the tower frame is hinged with the front end of the host platform, the upper ends of the first telescopic diagonal brace and the second telescopic diagonal brace are respectively hinged with the middle parts of two sides of the tower frame, the lower ends of the first telescopic diagonal brace and the second telescopic diagonal brace are respectively hinged with the rear ends of two sides of the host platform, the first telescopic diagonal brace and the second telescopic diagonal brace are respectively positioned on two opposite sides of the tower frame, the pile driving hammer is vertically and slidably connected with the front side surface of the tower frame, the tower frame is hollow and forms a vertical sliding cavity, the hole guiding device is arranged in the vertical sliding cavity, the lower end of the front side surface of the tower is provided with a tubular pile outlet, the height of the tubular pile outlet is more than 500CM, and the tubular pile outlet is communicated with the vertical sliding cavity; the moving mechanism is installed at the bottom of the host platform.

The pile driving device is characterized by further comprising a pulley block, a hanging hammer winch and a hanging hammer steel wire rope, wherein the hanging hammer winch is installed on the host platform and comprises a plurality of guide pulleys, the pulley block is installed at the top end of the tower, one end of the hanging hammer steel wire rope is connected with the hanging hammer winch, and the other end of the hanging hammer steel wire rope is connected with the upper end of the pile driving hammer through the pulley block.

The hole guiding device comprises a power head, a top supporting frame, a telescopic drill rod, a spiral drilling tool, a drilling tool traction winch, a power head traction winch, a drilling tool telescopic traction steel wire rope and a power head traction steel wire rope, wherein the power head and the top supporting frame are vertically and slidably connected with the vertical sliding cavity, the top supporting frame is positioned above the power head, the power head is provided with a guide sleeve, the telescopic drill rod comprises an outer layer rod and an inner layer rod, the inner layer rod is telescopically nested in the outer layer rod, the upper end of the outer layer rod is rotatably connected with the top supporting frame, the lower end of the outer layer rod penetrates through the power head guide sleeve and is rotatably connected with the power head guide sleeve, and the inner layer rod telescopically penetrates through the guide sleeve and is connected with; the drilling tool traction winch and the power head traction winch are respectively installed on the host platform, one end of a power head traction steel wire rope is connected with the power head traction winch, the other end of the power head traction steel wire rope is connected with the power head through the guide pulley, one end of the drilling tool telescopic traction steel wire rope is connected with the drilling tool traction winch, and the other end of the drilling tool telescopic traction steel wire rope is connected with the upper end of the inner layer rod through the guide pulley.

The first telescopic inclined support rod comprises a first support rod and a first inclined support oil cylinder, the second telescopic inclined support rod comprises a second support rod and a second inclined support oil cylinder, the upper ends of the first inclined support oil cylinder and the second inclined support oil cylinder are hinged to the middle portions of the two sides of the tower frame through the first support rod and the second support rod respectively, and the lower ends of the first inclined support oil cylinder and the second inclined support oil cylinder are hinged to the rear ends of the two sides of the host platform respectively.

The moving mechanism comprises a longitudinal moving mechanism, the longitudinal moving mechanism comprises two long ships, four supporting leg oil cylinders, two longitudinal telescopic oil cylinders and four longitudinal travelling wheels, the four supporting leg oil cylinders are respectively installed at the front end and the rear end of two sides of the host platform, each longitudinal travelling wheel is respectively installed at the lower end of each supporting leg oil cylinder, the front end and the rear end of each long ship are respectively connected with the longitudinal travelling wheels in a longitudinal sliding mode, one end of each longitudinal telescopic oil cylinder is hinged to the middle of each long ship, and the other end of each longitudinal telescopic oil cylinder is hinged to the longitudinal travelling wheels.

It should be noted that:

the foregoing references to "first and second …" do not denote any particular quantity or order, but rather are used to distinguish one name from another.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", and the like refer to orientations or positional relationships based on those shown in the drawings, or orientations or positional relationships that are conventionally used to place products of the present invention, or orientations or positional relationships that are conventionally understood by those skilled in the art, and are used for convenience of description and simplicity of description only, and do not refer to or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

The soft soil layer refers to a soil layer which is easy to hammer and penetrate through the large-diameter PHC prefabricated pipe pile, and is located on the upper portion of the foundation soil layer, the hard soil layer refers to a soil layer which is difficult to hammer and penetrate through the large-diameter PHC prefabricated pipe pile, generally refers to a soil layer with hardness higher than that of a sandy soil layer, and is located on the lower portion of the foundation soil layer.

The following illustrates the advantages or principles of the invention:

1. the construction method of the large-diameter PHC prefabricated tubular pile is provided with the integrally arranged hammering drilling center, the pile driver is put in place firstly, the equipment adopting the construction method is moved to a to-be-constructed area, the pile driving hammer center of the equipment is opposite to the pile position of a pile foundation to be constructed, then the extension lengths of the first telescopic diagonal brace and the second telescopic diagonal brace are adjusted, so that the inclination of an equipment tower frame is adjusted to correspond to the designed inclination of the pile foundation to be constructed, the inclination angle of the large-diameter PHC prefabricated tubular pile is accurately controlled by adjusting the inclination angle of the tower frame, and the precise construction of the large-diameter PHC prefabricated tubular pile with the set inclination angle is realized; then hammering the large-diameter PHC precast tubular pile into the soft soil layer to reach the top surface of the hard soil layer, so that the side friction between the upper part of the pile foundation and the soft soil layer is ensured, and the bearing capacity of the pile foundation is improved; then, a hole guiding device is used for guiding holes in the hard soil layer, so that the problems of soil plug effect of hammering and pile sinking of the large-diameter tubular pile and difficulty in pile sinking of the large-diameter PHC precast tubular pile in the hard soil layer are solved, and then the large-diameter PHC precast tubular pile is hammered and sent into the hard soil layer to complete construction of the large-diameter PHC precast tubular pile; due to the integral design of hammering and leading holes, two kinds of construction conversion of the leading holes and hammering in the construction process are rapid, and the coaxiality of the hammering and the leading holes can be effectively ensured. Especially when the inclined piles are driven, the effect is more obvious, and the construction of the inclined piles (including rows of inclined piles) can be smoothly completed; meanwhile, the construction site is saved, and the construction efficiency, quality and safety are improved.

2. According to the depth distribution of the soft soil layer and the hard soil layer and the design requirement of the pile foundation, the large-diameter PHC precast tubular pile to be constructed is divided into a plurality of sections, so that the construction is convenient.

3. The first-section PHC tubular pile comprises a tubular pile and a pile tip fixer, wherein the pile tip fixer is arranged at the front end of the first-section PHC tubular pile, so that the pile head of the first-section PHC tubular pile can be protected when the PHC tubular pile is hammered to sink the pile, and the pile tip fixer can also have a cutting effect on a soil layer.

4. The large-diameter PHC precast tubular pile to be constructed further comprises a first section of subsequent PHC tubular pile, the first section of subsequent PHC tubular pile is connected when the top of the first section of PHC tubular pile is hammered and sent to a position 50CM to 100CM away from the ground, hammering and sending are continuously carried out after pile connection, and connection quality of the first section of subsequent PHC tubular pile and the first section of PHC tubular pile is guaranteed.

5. The first section of subsequent PHC tubular pile at least comprises a second section of PHC tubular pile and a third section of PHC tubular pile, the hole depth of the second section of PHC tubular pile is firstly led, then the second section of PHC tubular pile is hammered and sunk into the soil layer, then the hole depth of the third section of PHC tubular pile is led until the design depth of the pile foundation, finally the third section of PHC tubular pile is hammered and sunk into the soil layer, the construction operation of punching and hammering pile sinking of each section of PHC tubular pile is carried out alternately, the phenomenon that one-time punching is too deep to cause hole collapse in the midway is avoided, and the construction quality and the safety of the pile foundation are improved.

6. The invention provides a large-diameter PHC precast tubular pile driver, which is provided with an integrally arranged hammering and drilling center, and comprises a host platform, a tower frame, a moving mechanism, a hole guiding device, a pile driving hammer, a first telescopic diagonal brace rod and a second telescopic diagonal brace rod, wherein when the pile driver is used, the pile driving hammer is moved to a to-be-constructed area, the hammering and drilling center of the pile driver is aligned to the pile position of a pile foundation to be constructed, and the extension lengths of the two telescopic diagonal brace rods are adjusted, so that the inclination of the tower frame of the pile driver is adjusted to correspond to the designed inclination of the pile foundation to be constructed, and the inclination angle of the tower frame is adjusted, so that the inclination angle of a large-diameter PHC precast tubular pile is accurately controlled, and the accurate construction of the large-; then hammering the large-diameter PHC precast tubular pile into the soft soil layer to reach the top surface of the hard soil layer, so that the side friction between the upper part of the pile foundation and the soft soil layer is ensured, and the bearing capacity of the pile foundation is improved; then, a hole guiding device is used for guiding holes in the hard soil layer, the soil plugging effect of the hard soil layer on the large-diameter PHC precast tubular pile is solved, the large-diameter PHC precast tubular pile is hammered and sent into the hard soil layer, and the construction of the large-diameter PHC precast tubular pile is completed; the lower end of the tower is hinged with the front end of the host platform, two telescopic diagonal braces are conveniently utilized to adjust the inclination of the tower by taking the hinged position as a rotation center, the control of the inclination angle of the large-diameter PHC prefabricated tubular pile is realized, and the hole guiding device and the pile hammer are vertically and slidably connected with the tower, so that the hole guiding device and the pile hammer complete the construction of the large-diameter PHC prefabricated tubular pile along the same inclination direction of the tower, and the same inclination of the construction of the large-diameter PHC prefabricated tubular pile is ensured; the hole guiding device is arranged in the vertical sliding cavity in the tower, when the PHC tubular pile is subjected to hole guiding construction, the upper section of the PHC tubular pile exposed out of the ground is positioned in the vertical sliding cavity, the pile driving hammer is arranged on the front side surface of the outer side of the tower, and when the PHC tubular pile is subjected to hammering pile sinking construction, the upper section of the PHC tubular pile exposed out of the ground is required to be moved out of the vertical sliding cavity, so that a tubular pile outlet is arranged at the lower end of the front side surface of the tower, a moving penetrating channel is provided for the upper section of the PHC tubular pile exposed out of the ground to be moved out of the vertical sliding cavity in the tower or moved into the vertical sliding cavity in the tower from the outside of the tower, and the tubular pile outlet is convenient for the tower to move in or out of the upper section of the PHC tubular pile exposed out of; this major diameter PHC precast tubular pile driver utilizes the flexible control of two flexible diagonal braces, realizes the slope angle control to the prefabricated tubular pile of major diameter PHC, with hammering and the design of draw hole integral type, makes draw hole and hammering keep higher same gradient in the work progress, saves the construction site simultaneously, improves the construction speed.

7. The large-diameter PHC precast tubular pile driver further comprises a pulley block, a hanging hammer winch and a hanging hammer steel wire rope, wherein the hanging hammer winch and the hanging hammer steel wire rope provide power for vertical sliding of the pile hammer, and the pulley block facilitates guiding of the hanging hammer steel wire rope.

8. The hole guiding device comprises a power head, a top supporting frame, a telescopic drill rod, a spiral drilling tool, a drilling tool traction winch, a power head traction winch, a drilling tool telescopic traction steel wire rope and a power head traction steel wire rope, wherein the power head provides hole guiding power for the spiral drilling tool, and the power head traction winch and the power head traction steel wire rope provide power for vertical sliding of the power head; due to the arrangement of the telescopic drill rod, the design height of the tower frame is saved, and the telescopic drilling of a lead hole with a longer depth is realized for equipment with the same tower frame height; the drilling tool traction winch and the drilling tool telescopic traction steel wire rope provide power for the telescopic drill rod to stretch.

9. According to the equipment provided by the invention, the first inclined support oil cylinder and the second inclined support oil cylinder are respectively connected in an elongated manner by utilizing the first support rod and the second support rod, so that the first telescopic inclined support rod and the second telescopic inclined support rod are conveniently in support connection with the tower frame.

10. The moving mechanism comprises a longitudinal moving mechanism, wherein the longitudinal moving mechanism comprises two long ships, four supporting leg oil cylinders, two longitudinal telescopic oil cylinders and four longitudinal travelling wheels, the two long ships are lifted through the four supporting leg oil cylinders, the two long ships are longitudinally and slidably connected with the longitudinal travelling wheels at the lower ends of the four supporting leg oil cylinders respectively, and the longitudinal travelling wheels are driven to roll on steel rails of the long ships respectively through the stretching of the two longitudinal telescopic oil cylinders, so that the host platform and the tower are driven to move back and forth.

Drawings

Fig. 1 is a schematic view showing the overall external three-dimensional structure of a pile driver according to an embodiment of the invention.

Fig. 2 is a schematic external three-dimensional structure diagram of the pile driver in the embodiment of the invention.

Fig. 3 is a schematic external perspective view of a hole guiding device of a tubular pile driver according to an embodiment of the invention.

Description of reference numerals:

10. the device comprises a host platform, 20, a tower, 21, a tubular pile outlet, 22, a guide hole vertical guide rail, 30, a moving mechanism, 31, a long ship, 32, a support oil cylinder, 33, a longitudinal telescopic oil cylinder, 34, a longitudinal travelling wheel, 40, a guide hole device, 41, a power head, 411, a guide sleeve, 42, a top support frame, 43, a telescopic drill rod, 431, an outer layer rod, 432, an inner layer rod, 44, a spiral drilling tool, 45, a drilling tool traction winch, 46, a power head traction winch, 50, a pile hammer, 51, a hanging hammer winch, 60, a first telescopic inclined support rod, 61, a first support rod, 62, a first inclined support oil cylinder, 70, a second telescopic inclined support rod, 71, a second support rod, 72, a second inclined support oil cylinder, 80, a pulley block, 81, a guide pulley, 91, an operation room, 92 and a hydraulic power station.

Detailed Description

The following provides a detailed description of embodiments of the invention.

Referring to fig. 1 to 3, the construction method of the large-diameter PHC precast tubular pile provided by the invention comprises the following steps:

(1) the pile driver is in place, the large-diameter PHC precast tubular pile driver is moved to a to-be-constructed area, the pile driver is provided with a hammering drilling center which is integrally arranged, and the hammering drilling center on the front side of a tower frame 20 of the large-diameter PHC precast tubular pile driver is positioned right above the pile position of the to-be-constructed pile foundation; the large-diameter PHC precast tubular pile driver comprises a host platform 10, a tower 20, a moving mechanism 30, a hole guiding device 40, a pile driving hammer 50, a first telescopic diagonal brace 60 and a second telescopic diagonal brace 70;

(2) adjusting the inclination angle, namely adjusting the lengths of the first telescopic inclined stay bar 60 and the second telescopic inclined stay bar 70 to enable the inclination angle of the tower frame 20 of the large-diameter PHC precast tubular pile driver to correspond to the designed inclination angle of the tubular pile to be constructed;

(3) the large-diameter PHC precast tubular pile is arranged, the large-diameter PHC precast tubular pile to be constructed is hoisted to the front end of the tower 20, and the center of the large-diameter PHC precast tubular pile to be constructed is superposed with the center of the pile position of the pile foundation to be constructed; the top of the large-diameter PHC precast tubular pile to be constructed is arranged in a pile cap at the lower end of the pile hammer 50;

(4) hammering and pile feeding on the soft soil layer, feeding the large-diameter PHC precast tubular pile to be constructed into the foundation soil layer by using a pile hammer 50, and penetrating the soft soil layer of the foundation soil layer to the top surface of the hard soil layer of the foundation soil layer, wherein the foundation soil layer comprises the soft soil layer and the hard soil layer;

(5) aligning the guide holes, and lifting the pile hammer 50 upwards to separate the pile cap at the lower end of the pile hammer 50 from the top of the large-diameter PHC precast tubular pile to be constructed; utilizing a moving mechanism 30 of the large-diameter PHC precast tubular pile driver to move a tower 20 on a host platform 10 forwards, and enabling a hole guiding and drilling center of a hole guiding device 40 in the tower 20 to correspond to the pile center of a large-diameter PHC precast tubular pile to be constructed;

(6) drilling a guide hole inside, drilling a soil body in the PHC precast tubular pile with the large diameter to be constructed by using a guide hole device 40, and discharging the soil body; drilling a hard soil layer pre-guide hole below the large-diameter PHC precast tubular pile to be constructed to the design depth of the pile foundation;

(7) hammering and aligning, and lifting the hole guiding device 40 upwards to enable the lower end of the hole guiding device 40 to slide to the position above the top of the large-diameter PHC precast tubular pile to be constructed; moving the tower 20 on the host platform 10 backwards by using the moving mechanism 30 of the large-diameter PHC precast tubular pile driver, and enabling the center of a pile driving hammer on the front side of the tower 20 to correspond to the pile center of the large-diameter PHC precast tubular pile to be constructed;

(8) and hammering and pile feeding in the hard soil layer, sliding the pile hammer 50 downwards to enable the top of the large-diameter PHC precast tubular pile to be constructed to be installed in a pile cap at the lower end of the pile hammer 50, and feeding the large-diameter PHC precast tubular pile to be constructed into the hard soil layer by utilizing the pile hammer 50 until the design depth of the pile foundation is reached.

The construction method comprises the steps that firstly, a pile driver is put in place, equipment adopting the construction method is moved to a to-be-constructed area, the center of a pile hammer of the equipment faces the pile position of a pile foundation to be constructed, then the extension lengths of a first telescopic diagonal brace 60 and a second telescopic diagonal brace 70 are adjusted, so that the inclination of an equipment tower frame 20 is adjusted to correspond to the designed inclination of the pile foundation to be constructed, the inclination angle of a large-diameter PHC prefabricated tubular pile is accurately controlled by adjusting the inclination angle of the tower frame 20, and the precise construction of the large-diameter PHC prefabricated tubular pile with the set inclination angle is realized; then hammering the large-diameter PHC precast tubular pile into the soft soil layer to reach the top surface of the hard soil layer, so that the side friction between the upper part of the pile foundation and the soft soil layer is ensured, and the bearing capacity of the pile foundation is improved; then, the hole guiding device 40 is used for guiding holes in the hard soil layer, so that the problems of soil plug effect of hammering and pile sinking of the large-diameter tubular pile and difficulty in pile sinking of the large-diameter PHC precast tubular pile in the hard soil layer are solved, and then the large-diameter PHC precast tubular pile is hammered and sent into the hard soil layer to complete construction of the large-diameter PHC precast tubular pile; due to the integral design of hammering and leading holes, two kinds of construction conversion of the leading holes and hammering in the construction process are rapid, and the coaxiality of the hammering and the leading holes can be effectively ensured. Especially, when the inclined pile is driven, the effect is more obvious; meanwhile, the construction site is saved, and the construction efficiency, quality and safety are improved.

The large-diameter PHC precast tubular pile to be constructed comprises a plurality of sections of large-diameter PHC precast tubular piles; the pile can be formed by combining a plurality of sections according to the designed pile length, and is combined into a whole by welding or other connection modes. According to the depth distribution of the soft soil layer and the hard soil layer and the design requirement of the pile foundation, the large-diameter PHC precast tubular pile to be constructed is divided into a plurality of sections, so that the construction is convenient.

The large-diameter PHC precast tubular pile to be constructed comprises a first section of PHC tubular pile, a tubular pile bottom steel plate and a pile tip fixer, wherein the pile tip fixer is arranged on the bottom end face of the tubular pile. The pile tip fixer is arranged at the front end of the first-section PHC tubular pile, so that when the PHC tubular pile is hammered and sunk, the pile head of the first-section PHC tubular pile can be protected, and the pile tip fixer can also have a penetrating and cutting effect on a soil layer.

The large-diameter PHC precast tubular pile to be constructed further comprises a first-section subsequent PHC tubular pile, and the step (8) further comprises the following steps:

when the top of the first-section PHC tubular pile is hammered and sent to 50-100 CM above the ground, the hammering and pile sending are stopped, the lower end of the first-section subsequent PHC tubular pile is connected with the top of the first-section PHC tubular pile, and after the connection is completed, the hammering and pile sending are continued until the design depth of the pile foundation is reached.

The large-diameter PHC precast tubular pile to be constructed further comprises a first section of subsequent PHC tubular pile, the first section of subsequent PHC tubular pile is connected when the top of the first section of PHC tubular pile is hammered and sent to a position 50CM to 100CM away from the ground, hammering and sending are continuously carried out after pile connection, and connection quality of the first section of subsequent PHC tubular pile and the first section of PHC tubular pile is guaranteed.

The first section of subsequent PHC tubular pile at least comprises a second section of PHC tubular pile and a third section of PHC tubular pile, the lengths of the second section of PHC tubular pile and the third section of PHC tubular pile are selected according to the soil layer properties of a hard soil layer, the pre-leading holes at least comprise a second section of tubular pile pre-leading hole and a third section of tubular pile pre-leading hole, the depth of the second section of tubular pile pre-leading hole is larger than the length of the second section of PHC tubular pile, the depth of the third section of tubular pile pre-leading hole is larger than the length of the third section of PHC tubular pile, and the method further comprises the following steps after the step (:

(61) drilling a soil body in the first section of PHC tubular pile by using a hole guiding device 40, and pre-guiding the second section of tubular pile in a hard soil layer below the first section of PHC tubular pile;

(62) hammering and aligning the second PHC tubular pile, and sliding the hole guiding device 40 upwards to enable the lower end of the hole guiding device 40 to slide to the upper part of the top of the first PHC tubular pile; the moving mechanism 30 of the large-diameter PHC precast tubular pile driver is utilized to move the tower 20 on the host platform 10 backwards, and the center of a pile driving hammer on the front side of the tower 20 corresponds to the pile center of the first PHC tubular pile;

(63) the second PHC tubular pile is hammered and fed in the hard soil layer, the pile hammer 50 is slid downwards, the top of the first PHC tubular pile is installed in a pile cap at the lower end of the pile hammer 50, the pile hammer 50 feeds the first PHC tubular pile into the hard soil layer, when the top of the first PHC tubular pile is lifted to 50CM to 100CM, the hammering and feeding are stopped, the lower end of the second PHC tubular pile is connected with the top of the first PHC tubular pile, and after the connection is finished, the hammering and feeding are continued until the hammering and feeding of the second PHC tubular pile are finished;

(64) aligning the guide holes of the third PHC tubular pile, and when hammering and pile feeding of the second PHC tubular pile are completed, sliding the pile driving hammer 50 upwards to enable the pile cap at the lower end of the pile driving hammer 50 to be separated from the top of the second PHC tubular pile; utilizing a moving mechanism 30 of the large-diameter PHC precast tubular pile driver to move the tower 20 on the host platform 10 forwards, and enabling the hole guiding and drilling center of a hole guiding device 40 in the tower 20 to correspond to the pile center of the second PHC tubular pile;

(65) drilling soil in the first section of PHC tubular pile and the second section of PHC tubular pile by using a hole drilling device 40, pre-drilling the third section of the tubular pile in a hard soil layer below the first section of the PHC tubular pile, and drilling the pre-drilled holes to the design depth of the pile foundation;

The first section of subsequent PHC tubular pile at least comprises a second section of PHC tubular pile and a third section of PHC tubular pile, the hole depth of the second section of PHC tubular pile is firstly led, then the second section of PHC tubular pile is hammered and sunk into the soil layer, then the hole depth of the third section of PHC tubular pile is led until the design depth of the pile foundation, finally the third section of PHC tubular pile is hammered and sunk into the soil layer, the construction operation of punching and hammering pile sinking of each section of PHC tubular pile is carried out alternately, the phenomenon that one-time punching is too deep to cause hole collapse in the midway is avoided, and the construction quality and the safety of the pile foundation are improved.

As shown in fig. 1 to 3, the large-diameter PHC precast tubular pile driver for implementing the above construction method includes a main machine platform 10, a tower 20, a moving mechanism 30, a hole guiding device 40, a pile hammer 50, a first telescopic diagonal brace 60 and a second telescopic diagonal brace 70, wherein a lower end of the tower 20 is hinged to a front end of the main machine platform 10, upper ends of the first telescopic diagonal brace 60 and the second telescopic diagonal brace 70 are respectively hinged to middle portions of two sides of the tower 20, lower ends of the first telescopic diagonal brace 60 and the second telescopic diagonal brace 70 are respectively hinged to rear ends of two sides of the main machine platform 10, the first telescopic diagonal brace 60 and the second telescopic diagonal brace 70 are respectively located on two opposite sides of the tower 20, the pile hammer 50 is vertically slidably connected to a front side of the tower 20, the tower 20 is hollow and forms a vertical sliding cavity, the hole guiding device 40 is installed in the vertical sliding cavity and is vertically slidably connected to the vertical sliding cavity, a tubular pile outlet 21 is provided at a lower end of the front side of the tower 20, the height of the tubular pile outlet 21 is more than 500CM, and the tubular pile outlet 21 is communicated with the vertical sliding cavity; the moving mechanism 30 is installed at the bottom of the host platform 10.

When the device is used, the device is moved to a to-be-constructed area, a hammering drilling center of the device is aligned to the pile position of a pile foundation to be constructed, then the extension lengths of the two telescopic diagonal braces are adjusted, so that the inclination of the device tower frame 20 is adjusted to correspond to the designed inclination of the pile foundation to be constructed, the inclination angle of the large-diameter PHC prefabricated pipe pile is accurately controlled by adjusting the inclination angle of the tower frame 20, and the accurate construction of the large-diameter PHC prefabricated pipe pile with the set inclination angle is realized; then hammering the large-diameter PHC precast tubular pile into the soft soil layer to reach the top surface of the hard soil layer, so that the side friction between the upper part of the pile foundation and the soft soil layer is ensured, and the bearing capacity of the pile foundation is improved; then, the hole guiding device 40 is used for guiding holes in the hard soil layer, the soil plugging effect of the hard soil layer on the large-diameter PHC precast tubular pile is solved, and then the large-diameter PHC precast tubular pile is hammered and sent into the hard soil layer, so that the construction of the large-diameter PHC precast tubular pile is completed; the lower end of the tower frame 20 is hinged with the front end of the host platform 10, two telescopic diagonal braces are conveniently utilized to adjust the inclination of the tower frame 20 by taking the hinged position as a rotation center, so that the inclination angle control of the large-diameter PHC prefabricated tubular pile is realized, the hole guiding device 40 and the pile hammer 50 are vertically and slidably connected with the tower frame 20, the hole guiding device 40 and the pile hammer 50 complete the construction of the large-diameter PHC prefabricated tubular pile along the same inclination direction of the tower frame 20, and the same inclination of the construction of the large-diameter PHC prefabricated tubular pile is ensured; because the hole guiding device 40 is installed in the vertical sliding cavity inside the tower 20, when the PHC pipe pile is subjected to hole guiding construction, the upper section of the PHC pipe pile exposed to the ground is located in the vertical sliding cavity, and because the pile driving hammer 50 is installed on the front side surface outside the tower 20, when the PHC pipe pile is subjected to hammering pile sinking construction, the upper section of the PHC pipe pile exposed to the ground needs to be moved out of the vertical sliding cavity, therefore, the pipe pile outlet 21 is arranged at the lower end of the front side surface of the tower 20, so that the upper section of the PHC pipe pile exposed to the ground is moved out of the tower 20 from the vertical sliding cavity in the tower 20 or moved into the vertical sliding cavity in the tower 20 from the outside of the tower 20, and a moving penetrating channel is provided, and the pipe pile outlet 21 not only facilitates the tower 20 to move in or out of the upper section of the PHC pipe pile exposed to the ground; this major diameter PHC precast tubular pile driver utilizes the flexible control of two flexible diagonal braces, realizes the slope angle control to the prefabricated tubular pile of major diameter PHC, with hammering and the design of draw hole integral type, makes draw hole and hammering keep higher same gradient in the work progress, saves the construction site simultaneously, improves the construction speed.

The large-diameter PHC precast tubular pile driver further comprises a pulley block 80, a hanging hammer winch 51, a hanging hammer steel wire rope and a guide hole vertical guide rail 22, wherein the hanging hammer winch 51 is installed on the host platform 10, the pulley block 80 comprises a plurality of guide pulleys 81, the pulley block 80 is installed at the top end of the tower frame 20, one end of the hanging hammer steel wire rope is connected with the hanging hammer winch 51, and the other end of the hanging hammer steel wire rope is connected with the upper end of the pile driving hammer 50 through the guide pulleys 81. The hanging hammer winch 51 and the hanging hammer steel wire rope provide power for the vertical sliding of the pile driving hammer 50, and the pulley block 80 facilitates the guiding of the hanging hammer steel wire rope.

The hole guiding device 40 comprises a power head 41, a top support frame 42, a telescopic drill rod 43, a spiral drill 44, a drill traction winch 45, a power head traction winch 46, a drill telescopic traction wire rope and a power head traction wire rope, wherein the power head 41 and the top support frame 42 are vertically and slidably connected with a vertical sliding cavity, the top support frame 42 is positioned above the power head 41, the power head 41 is provided with a guide sleeve 411, the telescopic drill rod 43 comprises an outer layer rod 431 and an inner layer rod 432, the inner layer rod 432 is telescopically nested in the outer layer rod 431, the upper end of the outer layer rod 431 is rotatably connected with the top support frame 42, the lower end of the outer layer rod 431 penetrates through the guide sleeve 411 of the power head 41 and is rotatably connected with the power head, and the inner layer rod 432 telescopically; the drilling tool traction winch 45 and the power head traction winch 46 are respectively installed on the host platform 10, one end of a power head traction steel wire rope is connected with the power head traction winch 46, the other end of the power head traction steel wire rope is connected with the power head 41 through a guide pulley 81, one end of the drilling tool telescopic traction steel wire rope is connected with the drilling tool traction winch 45, and the other end of the drilling tool telescopic traction steel wire rope is connected with the upper end of the inner layer rod 432 through the guide pulley 81. The power head 41 provides hole guiding power for the spiral drilling tool 44, and the power head traction winch 46 and the power head traction steel wire rope provide power for vertical sliding of the power head 41; due to the arrangement of the telescopic drill rod 43, the design height of the tower frame 20 is saved, and a longer-depth guide hole is drilled in a telescopic mode for equipment with the same height as the tower frame 20; the drilling tool traction winch 45 and the drilling tool telescopic traction steel wire rope provide power for the telescopic drill rod 43 to stretch.

The guide hole vertical guide rail 22 is installed on the rear side surface in the vertical sliding cavity, and the power head 41 and the top support frame 42 are vertically and slidably connected with the vertical sliding cavity through the guide hole vertical guide rail 22. The vertical sliding of the hole guiding device 40 is smoother.

The drilling tool traction winch 45 and the power head traction winch 46 are respectively installed on the host platform 10, one end of a power head traction steel wire rope is connected with the power head traction winch 46, the other end of the power head traction steel wire rope is connected with the power head 41 through a guide pulley 81, one end of the drilling tool telescopic traction steel wire rope is connected with the drilling tool traction winch 45, and the other end of the drilling tool telescopic traction steel wire rope is connected with the upper end of the inner layer rod 432 through the guide pulley 81. The power head traction winch 46 and the power head traction steel wire rope provide power for the vertical sliding of the power head 41; the drilling tool traction winch 45 and the drilling tool telescopic traction steel wire rope provide power for the expansion of the telescopic drill rod 43

The first telescopic diagonal brace 60 comprises a first support rod 61 and a first diagonal brace oil cylinder 62, the second telescopic diagonal brace 70 comprises a second support rod 71 and a second diagonal brace oil cylinder 72, the upper ends of the first diagonal brace oil cylinder 62 and the second diagonal brace oil cylinder 72 are respectively hinged with the middle parts of the two sides of the tower 20 through the first support rod 61 and the second support rod 71, and the lower ends of the first diagonal brace oil cylinder 62 and the second diagonal brace oil cylinder 72 are respectively hinged with the rear ends of the two sides of the host platform 10. The first inclined support oil cylinder 62 and the second inclined support oil cylinder 72 are respectively connected in an lengthening manner by the first support rod 61 and the second support rod 71, so that the first telescopic inclined support rod 60 and the second telescopic inclined support rod 70 can be conveniently connected with the tower 20 in a supporting manner.

The moving mechanism 30 comprises a longitudinal moving mechanism, the longitudinal moving mechanism comprises two long boats 31, four supporting leg oil cylinders 32, two longitudinal telescopic oil cylinders 33 and four longitudinal traveling wheels 34, the four supporting leg oil cylinders 32 are respectively installed at the front end and the rear end of two sides of the host platform 10, each longitudinal traveling wheel 34 is respectively installed at the lower end of each supporting leg oil cylinder 32, the front end and the rear end of each long boat 31 are respectively connected with the longitudinal traveling wheels 34 in a longitudinal sliding mode, one end of each longitudinal telescopic oil cylinder 33 is hinged to the middle of each long boat 31, and the other end of each longitudinal telescopic oil cylinder 33 is hinged to the longitudinal traveling wheels 34. The two long ships 31 are respectively connected with longitudinal walking wheels 34 at the lower ends of the four supporting leg oil cylinders 32 in a longitudinal sliding mode, and the longitudinal walking wheels 34 are respectively driven to roll on the steel rails of the long ships 31 through the extension and contraction of the two longitudinal telescopic oil cylinders 33, so that the host platform 10 and the tower 20 are driven to move back and forth.

The large-diameter PHC pile driver further comprises a control chamber 91 and a hydraulic power station 92, wherein the hydraulic power station 92 is installed at the rear end of the main machine platform 10, and the control chamber 91 is installed in the middle of the main machine platform 10 and is close to the rear side of the tower 20. The control cabin 91 is used for controlling the operation of the all-in-one machine, and the hydraulic power station 92 can adopt the modes of motor driving, diesel engine driving and the like to provide hydraulic sources for a winch, the power head 41 and the like.

The above are merely specific embodiments of the present invention, and the scope of the present invention is not limited thereby; any alterations and modifications without departing from the spirit of the invention are within the scope of the invention.

Claims

1. A construction method of a large-diameter PHC precast tubular pile is characterized by comprising the following steps:

2. The construction method of the large-diameter PHC precast tubular pile according to claim 1, wherein the large-diameter PHC precast tubular pile to be constructed comprises a plurality of sections of large-diameter PHC precast tubular piles; the pile can be formed by combining a plurality of sections according to the designed pile length, and is combined into a whole by welding or other connection modes.

3. The construction method of the large-diameter PHC precast tubular pile according to claim 2, wherein the large-diameter PHC precast tubular pile to be constructed comprises a first section PHC tubular pile including a tubular pile and a pile tip fixer, the bottom end of the tubular pile is provided with a pile bottom steel plate, and the pile tip fixer is installed on the bottom end face of the tubular pile.

4. The construction method of a large-diameter PHC precast tubular pile according to any one of claims 1 to 3, wherein the large-diameter PHC precast tubular pile to be constructed further comprises a first-joint subsequent PHC tubular pile, and the step (8) further comprises the steps of:

5. The construction method of the large-diameter PHC precast tubular pile according to claim 4, wherein the first section of subsequent PHC tubular pile at least comprises a second section of PHC tubular pile and a third section of PHC tubular pile, the lengths of the second section of PHC tubular pile and the third section of PHC tubular pile are selected according to soil layer properties of a hard soil layer, the pre-guiding holes at least comprise a second section of tubular pile pre-guiding hole and a third section of tubular pile pre-guiding hole, the depth of the second section of tubular pile pre-guiding hole is greater than the length of the second section of PHC tubular pile, the depth of the third section of tubular pile pre-guiding hole is greater than the length of the third section of PHC tubular pile, and the step (5) is followed by the following steps:

6. The large-diameter PHC precast tubular pile driver adopting the construction method as claimed in any one of claims 1 to 5, characterized in that the pile driver is provided with an integrally arranged hammering and drilling center, and comprises a host platform, a tower frame, a moving mechanism, a hole guiding device, a pile hammer, a first telescopic diagonal brace and a second telescopic diagonal brace, wherein the lower end of the tower frame is hinged with the front end of the host platform, the upper ends of the first telescopic diagonal brace and the second telescopic diagonal brace are respectively hinged with the middle parts of two sides of the tower frame, the lower ends of the first telescopic diagonal brace and the second telescopic diagonal brace are respectively hinged with the rear ends of two sides of the host platform, the first telescopic diagonal brace and the second telescopic diagonal brace are respectively positioned on two opposite sides of the tower frame, the pile hammer is vertically and slidably connected with the front side of the tower frame, the inside of the tower frame is hollow and forms a vertical sliding cavity, the hole guiding device is installed in the vertical sliding cavity and is vertically and slidably connected with the vertical sliding cavity, a tubular pile outlet is formed in the lower end of the front side face of the tower frame, the height of the tubular pile outlet is larger than 500CM, and the tubular pile outlet is communicated with the vertical sliding cavity; the moving mechanism is installed at the bottom of the host platform.

7. The large-diameter PHC precast tubular pile driver of claim 6, further comprising a pulley block, a hammer hoist, a hammer wire rope, the hammer hoist being mounted on the host platform, the pulley block including a plurality of guide pulleys, the pulley block being mounted at the top end of the tower, one end of the hammer wire rope being connected to the hammer hoist, the other end of the hammer wire rope being connected to the upper end of the pile driver through the pulley block.

8. The large-diameter PHC precast tubular pile driver of claim 7, wherein the hole guiding device comprises a power head, a top support frame, a telescopic drill rod, a spiral drilling tool, a drilling tool traction winch, a power head traction winch, a drilling tool telescopic traction wire rope and a power head traction wire rope, the power head, the top support frame and the vertical sliding cavity are vertically and slidably connected, the top support frame is located above the power head, the power head is provided with a guide sleeve, the telescopic drill rod comprises an outer layer rod and an inner layer rod, the inner layer rod is telescopically nested inside the outer layer rod, the upper end of the outer layer rod is rotatably connected with the top support frame, the lower end of the outer layer rod penetrates through the power head guide sleeve and is rotatably connected with the power head guide sleeve, and the inner layer rod telescopically penetrates through the guide sleeve and is connected with the upper end of the spiral drilling; the drilling tool traction winch and the power head traction winch are respectively installed on the host platform, one end of a power head traction steel wire rope is connected with the power head traction winch, the other end of the power head traction steel wire rope is connected with the power head through the guide pulley, one end of the drilling tool telescopic traction steel wire rope is connected with the drilling tool traction winch, and the other end of the drilling tool telescopic traction steel wire rope is connected with the upper end of the inner layer rod through the guide pulley.

9. The large-diameter PHC precast tubular pile driver of any one of claims 6 to 8, wherein the first telescopic diagonal brace comprises a first support rod and a first diagonal brace cylinder, the second telescopic diagonal brace comprises a second support rod and a second diagonal brace cylinder, the upper ends of the first diagonal brace cylinder and the second diagonal brace cylinder are hinged to the middle portions of two sides of the tower frame through the first support rod and the second support rod respectively, and the lower ends of the first diagonal brace cylinder and the second diagonal brace cylinder are hinged to the rear ends of two sides of the host platform respectively.

10. The large-diameter PHC precast tubular pile driver as recited in any one of claims 1 to 5, wherein the moving mechanism comprises a longitudinal moving mechanism, the longitudinal moving mechanism comprises two long boats, four leg cylinders, two longitudinal telescopic cylinders and four longitudinal travelling wheels, the four leg cylinders are respectively mounted at the front end and the rear end of two sides of the host platform, each longitudinal travelling wheel is respectively mounted at the lower end of each leg cylinder, the front end and the rear end of each long boat are respectively connected with the longitudinal travelling wheels in a longitudinal sliding manner, one end of each longitudinal telescopic cylinder is hinged with the middle part of each long boat, and the other end of each longitudinal telescopic cylinder is hinged with the longitudinal travelling wheel.