CN116988460A - Extrusion-expansion supporting disc screw pile, construction method thereof and pile forming device used in construction - Google Patents

Abstract

The invention discloses an extrusion-expansion support disc screw pile, a construction method thereof and a pile forming device used in construction. Constructing a screw pile, descending a drill rod by one screw pitch, rotating clockwise for more than two weeks, and drilling a straight rod section; forming pile end enlarging heads after reaching the pile end bearing layer; the drill rod rises by one screw pitch and rotates anticlockwise by one circle, and grouting is carried out; the construction branch bearing frame and the expansion bearing disc are grouted in the lifting process of the drill rod, the reinforcement cage is placed, and the reinforcement cage is solidified, so that the extrusion expansion bearing disc screw pile is built. The pile forming device comprises an upper section of drill rod, a rotary section of drill rod and a lower section of drill rod, wherein a spiral blade is arranged outside the lower section of drill rod, and a bottom expanding drill bit is arranged at the bottom end of the lower section of drill rod; a driving motor is arranged in the upper section of drill rod, a supporting arm is arranged in the rotating section of drill rod, and a strip-shaped hole is formed in the side wall of the rotating section of drill rod. The screw pile enhances the biting force between the pile and the soil body, improves the bearing capacity, the compression resistance and the pulling resistance, and effectively reduces the settlement of the foundation.

Description

Extrusion-expansion supporting disc screw pile, construction method thereof and pile forming device used in construction

Technical Field

The invention belongs to the technical field of pile foundation engineering construction, relates to a novel extrusion-expansion supporting disc screw pile and a construction method thereof, and also relates to a pile forming device used in the construction process of the screw pile.

Background

The screw pile as a novel foundation reinforcing structure has the advantages of high bearing capacity, low manufacturing cost and the like, is widely applied to projects such as high-rise buildings, railways, bridges and the like, and achieves good engineering benefit. But large-scale projects are built in places with poor engineering geological conditions, and the bearing capacity of common screw piles is insufficient. Therefore, how to optimize the bearing performance of the common screw pile becomes a hot spot problem. Therefore, in the prior art, the screw pile with the pile types such as full thread type, half thread type, positive and negative thread type, enlarged body type and the like is designed, and the bearing capacity of the screw pile is enhanced to a certain extent. The bearing capacity of these pile-type screw piles is still difficult to meet in some projects requiring high bearing capacity foundations.

Disclosure of Invention

The invention aims to provide a novel extruding and expanding support disc screw pile with stronger bearing performance.

A second object of the present invention is to provide a method of constructing a screw pile as described above.

A third object of the present invention is to provide a piling device for use in the above construction method.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the screw pile comprises a straight rod section, an expansion bearing disc, a thread section and an expansion bottom head which are fixedly connected in sequence from top to bottom, wherein the thread section comprises a cylindrical pile body, a plurality of branch bearing frames are uniformly distributed on the side wall of the middle part of the pile body, and threads are fixedly connected on the pile body above and below the branch bearing frames; the outer diameter of the thread is the same as that of the straight rod section; the enlarged bottom head is a round table, the diameter of the smaller end of the enlarged bottom head is the same as the diameter of the pile body, and the enlarged bottom head is fixedly connected with the bottom end of the pile body; the branch bearing frame is a regular triangular prism, and one side surface of the regular triangular prism is fixedly connected with the pile body; the expanding bearing disc is formed by vertically overlapping and fixedly connecting two truncated cones, and the diameter of the top surface of the truncated cone positioned above is the same as that of the straight rod section and is fixedly connected with the straight rod section; the diameter of the bottom surface of the truncated cone positioned below is the same as the diameter of the pile body and is fixedly connected with the top end of the pile body.

The second technical scheme adopted by the invention is as follows: the construction method of the extruded and expanded support disc screw pile comprises the following steps:

1) The pile forming device comprises a concrete pump truck and a spiral pile driver, wherein a control system, a pile frame and drilling equipment arranged on the pile frame are arranged on the spiral pile driver, and the drilling equipment comprises a drill rod and a rotary driving mechanism for driving the drill rod to rotate; the lower end of the drill rod is provided with a hole drilling tool through a connecting mechanism, and the control system is respectively connected with drilling equipment and the hole drilling tool through signals;

the hole forming drilling tool comprises an upper section drill rod, a rotary section drill rod and a lower section drill rod which are sequentially connected from top to bottom, wherein the upper section drill rod, the rotary section drill rod and the lower section drill rod form a cylindrical main body drill rod, and the rotary section drill rod is respectively connected with the upper section drill rod and the lower section drill rod through bearings;

the outer wall of the lower section drill rod is fixedly connected with a helical blade, and a cutting edge is arranged on the helical blade; the bottom end of the lower section of drill rod is provided with a bottom expanding drill bit; the top end of the upper section of drill rod is fixedly connected with the drill rod through a fixing frame; the lower end of the drill rod is provided with a first driving motor, the first driving motor is positioned in an inner hole of the drill rod at the upper end, a motor shaft of the first driving motor is provided with a driving gear, the driving gear stretches into the drill rod at the rotating section, the inner wall of the drill rod at the rotating section is provided with an inner gear ring, and the inner gear ring is meshed with the driving gear;

two strip-shaped holes are symmetrically formed in the side wall of the rotary section drill rod, and openable and closable automatic plugging mechanisms are respectively arranged in the two strip-shaped holes and are in signal connection with a control system; a supporting arm which can be opened and retracted is arranged in the rotary section drill rod, and a first electric push rod is arranged on the inner wall of the rotary section drill rod; the first electric push rod drives the supporting arms to open and retract;

the bottom end of the lower section of drill rod is fixedly connected with a barrel-shaped bottom-expanding drill bit through a flange, a plurality of seepage holes communicated with the inside of the main body drill rod are formed in the bottom plate of the bottom-expanding drill bit, and the inner holes of the main body drill rod, the inner holes of the flange and the inside of the bottom-expanding drill bit are communicated to form a concrete channel which is communicated with all seepage holes;

the first electric push rod and the bottom expanding drill bit are in signal connection with a control system;

moving the pile forming device to a construction site, and moving a spiral pile driver to enable a hole forming drilling tool in the pile forming device to be aligned with a pile position;

the guide pipe is communicated with a concrete channel in the pore-forming drilling tool through a rotary joint;

2) Starting the spiral pile driver, and controlling the descending speed and the rotating speed of the drill rod by the control system, wherein the drill rod descends by one screw pitch and simultaneously rotates clockwise for more than two weeks to drill the straight rod section;

after the drilling depth reaches the design depth of the straight rod section, the descending speed and the rotating speed of the drill rod are controlled to be: the drill rod descends by one screw pitch and simultaneously rotates clockwise for one circle, threads are formed in the rock-soil body, and drilling of the thread sections is carried out;

3) After the hole forming drilling tool drills down to the pile end bearing layer, a pile end expanding head is formed through the control system bottom expanding drill bit;

4) The control system is used for controlling the retraction of the bottom expanding drill bit, then, the drill rod is lifted, and the lifting speed and the rotating speed of the drill rod are controlled as follows: the drill rod rises by one screw pitch and simultaneously rotates anticlockwise by one circle, a pouring device on the concrete pump truck is started, concrete slurry is sent into a concrete channel through a guide pipe and flows out through a plurality of seepage holes, and grouting of the enlarged bottom head and the thread section is performed;

5) When the hole forming drilling tool is lifted to the design depth of the branch bearing frame, a pouring device on the concrete pump truck is closed, grouting is stopped temporarily, an automatic plugging mechanism is started by a control system, the automatic plugging mechanism is opened, a first electric push rod is started, the first electric push rod drives the supporting arm, two working parts of the driving supporting arm extend out of the rotating sections from the two strip-shaped holes respectively, surrounding soil is extruded, and cavities of the two branch bearing frames are formed; then, controlling the first electric push rod to drive the supporting arm, enabling two working parts of the driving supporting arm to retract into the rotating section, starting the first driving motor by the control system, enabling the first driving motor to drive the driving gear to rotate, enabling the driving gear to drive the annular gear to rotate, enabling the annular gear to drive the rotating section drill rod to rotate around the axis of the rotating section drill rod by a set angle, starting the first electric push rod to drive the supporting arm again, enabling the two working parts of the driving supporting arm to extend out of the rotating section from the two strip-shaped holes respectively, extruding surrounding soil bodies, and forming cavities of the other two branch bearing frames; performing operation for a set number of times according to the operation process to form cavities of the branch bearing frames with designed numbers; then, the supporting arm is retracted into the rotary section drill rod, and an automatic blocking mechanism is started through a control system to block the strip-shaped hole; lifting the drill rod again, and controlling the lifting speed and the rotating speed of the drill rod to be as follows: the drill rod rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts the pouring device to perform grouting on the part of the screw thread section, the cavity of the branch bearing frame and the straight rod section;

6) After the hole forming drilling tool is lifted to the design depth of the expansion bearing disc, lifting and rotating of a drill rod are stopped, a pouring device on a concrete pump truck is closed, grouting is temporarily stopped, an automatic plugging mechanism is started through a control system, two strip-shaped holes are opened, a first electric push rod is started, the first electric push rod drives a supporting arm, two working parts of the supporting arm extend out of a rotating section from the two strip-shaped holes, surrounding soil is extruded, and a cavity is formed; controlling a first electric push rod, wherein the first electric push rod drives the supporting arm, so that two working parts of the supporting arm retract into the rotating section, a first driving motor is started, the first driving motor drives a driving gear to rotate, the driving gear drives an inner gear ring to rotate, the inner gear ring drives a rotating section drill rod to rotate around the axis of the rotating section drill rod by a set angle, the first electric push rod drives the supporting arm, and the two working parts of the supporting arm extend out of the rotating section from two strip-shaped holes to squeeze surrounding soil bodies to form two other cavities; performing multiple operations according to the operation steps to form a disc-shaped expanding bearing disc cavity in the soil body; then, the supporting arm is retracted into the rotary section drill rod, and an automatic blocking mechanism is started through a control system to block the two strip-shaped holes; lifting a drill rod, and controlling the lifting speed and the rotating speed of the drill rod to be as follows: the drill rod rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts the pouring device to perform grouting on the part, which is not grouted, of the thread section above the branch bearing frame, the cavity of the expansion bearing disc and the straight rod section;

7) And after the whole pore-forming drilling tool is lifted to the ground, placing a reinforcement cage, and after solidification, completing the construction of the extruded and expanded support disc screw pile.

The third technical scheme adopted by the invention is as follows: the pile forming device used in the construction method comprises a concrete pump truck and a spiral pile driver, wherein a control system, a pile frame and drilling equipment arranged on the pile frame are arranged on the spiral pile driver, and the drilling equipment comprises a drill rod and a rotary driving mechanism for driving the drill rod to rotate; the lower end of the drill rod is provided with a hole drilling tool through a connecting mechanism, and the control system is respectively connected with drilling equipment and the hole drilling tool through signals; the drill rod can move up and down, and the control system can control the rotation speed and the telescopic speed of the drill rod; the concrete pump truck is connected with one end of a guide pipe, and the other end of the guide pipe is connected with a pore-forming drilling tool through a rotary joint;

the hole drilling tool comprises a cylindrical upper section drill rod, a cylindrical rotary section drill rod and a cylindrical lower section drill rod which are sequentially connected from top to bottom, wherein the upper section drill rod, the rotary section drill rod and the lower section drill rod form a cylindrical main body drill rod, and the upper section drill rod and the lower section drill rod are connected with a rotary section drill rod bearing;

the outer wall of the lower section drill rod is fixedly connected with a helical blade, and a cutting edge is arranged on the helical blade; the bottom end of the lower section of drill rod is provided with a bottom expanding drill bit; the top end of the upper section of drill rod is fixedly connected with the drill rod through a fixing frame; the lower end of the drill rod is provided with a first driving motor, the first driving motor is positioned in an inner hole of the drill rod at the upper end, a motor shaft of the first driving motor is provided with a driving gear, the driving gear stretches into the drill rod at the rotating section, and the inner wall of the drill rod at the rotating section is provided with an inner gear ring meshed with the driving gear;

two strip-shaped holes are symmetrically formed in the side wall of the rotary section drill rod, automatic plugging mechanisms are arranged in the two strip-shaped holes, the automatic plugging mechanisms can seal the strip-shaped holes which can be opened, and the automatic plugging mechanisms are in signal connection with a control system; the rotary section drill rod is internally provided with a supporting arm and a first electric push rod, and the first electric push rod drives the working part of the supporting arm to extend out of the rotary section drill rod or retract into the rotary section drill rod.

The screw pile with the extruding and expanding support disc is provided with the expanding support disc and the branch bearing frame at different positions in the middle of the pile body, and the expanding body structure is arranged at the bottom of the pile, so that the screw pile has excellent bearing performance and anti-sedimentation capacity. The characteristics of various special-shaped piles are integrated, the bearing capacity is further increased, the compression resistance and the pulling resistance are optimized, the pile forming quality is good, the construction method is simple and convenient, the cost is saved, and the method is particularly suitable for foundation engineering with high bearing capacity and has important popularization and application values.

The novel extrusion-expansion supporting disc screw pile has the following advantages:

1) The pile side soil body is extruded and encrypted under the combined action of the screw threads, the extruding and expanding support disc and the branch bearing frame, so that the biting force between the pile and the soil body is enhanced, and the bearing capacity of the pile body is improved; the pile bottom is provided with the enlarged footing to strengthen the pile end resistance, and forms a structure similar to a bolt with the upper expansion support plate, so that the compression resistance and the pulling resistance of the screw pile are greatly improved, and the foundation settlement is effectively reduced.

2) The number and the positions of the branch bearing frames can be changed according to different engineering geological conditions, and the method is suitable for reinforcing various foundations.

3) The construction processes of drilling, rotary expanding the bottom head, hydraulic extruding and expanding the supporting plate or the supporting frame of the branch, pouring and the like are completed at one time, the pile forming speed is high, the automation degree is high, the construction is quick and convenient, the quality is good, the installation of each device is simple and convenient, the required manpower is small, and the device has great application value.

Drawings

Fig. 1 is a schematic view of a screw pile according to the present invention.

Fig. 2 is a schematic view of a pile forming apparatus used in constructing the screw pile of fig. 1.

Fig. 3 is a schematic view of a hole forming drill in the piling device of the present invention.

Fig. 4 is a schematic view of the hole drilling tool of fig. 3 with the arms extending out of the drill pipe.

Fig. 5 is an enlarged schematic view of the stay in the hole drilling tool.

Fig. 6 is a schematic view of the automatic plugging mechanism mounted on the rotary section drill pipe in the piling device of the present invention.

Fig. 7 is an enlarged view at P in fig. 3.

In the figure: 1. the hydraulic pile comprises a straight rod section, a threaded section, a 3 part, an enlarged bottom head, a 4 part branch bearing frame, a 5 part pile body, a 6 part expansion bearing disc, a 7 part hole drilling tool, a 8 part concrete pump truck, a 9 part pipe, a 10 part spiral pile driver, a 11 part fixing device, a 12 part drill rod, a 13 part first driving motor, a 14 part fixing frame, a 15 part upper part drill rod, a 16 part rotating drill rod, a 17 part automatic plugging mechanism, a 18 part lower part drill rod, a 19 part spiral blade, a 20 part bottom expanding drill bit, a 21 part annular gear, a 22 part driving gear, a 23 part supporting arm, a 24 part first electric push rod, a 25 part strip-shaped hole, a 26 part first pin roll, a 27 part first pin roll, a 28 part second pin roll, a 29 part second pin roll, a 30 part third pin roll pin, a 31 part third pin roll pin, a 32 part fourth pin roll pin, a 33 part fourth pin roll pin, a 34 part chute, a 35 part sliding cover, a 36 part flange, a 37 part connecting flange, a 38 part mounting seat, a 39 part expandable drill bit, a 40 part, a small drill bit, a 41 part expanding hole, a 41 part mechanism, a 42 part and a guide sleeve, a 44.

Detailed Description

The invention will be described in detail below with reference to the drawings and the detailed description.

As shown in fig. 1, the extrusion-expansion supporting disc screw pile comprises a straight rod section 1, an expansion bearing disc 6, a thread section 2 and an expansion bottom head 3 which are fixedly connected in sequence from top to bottom, wherein the thread section 2 comprises a cylindrical pile body 5, a plurality of branch bearing frames 4 are uniformly distributed on the side wall of the middle part of the pile body 5, and threads are fixedly connected on the pile body 5 above and below the branch bearing frames 4; the outer diameter of the thread is the same as the outer diameter of the straight rod section 1.

The pitch of the thread in the thread section 2 is 0.2m, and the cross section of the thread is not isosceles trapezoid. The thread pitch and the section shape of the thread greatly improve the biting force of the thread and soil body at the pile side, and enhance the bearing capacity.

The diameter of the straight rod section 1 is consistent with the outer diameter of the threads in the thread section 2, so that the construction of the straight rod section 1 is facilitated, the diameter of the pile body 5 is smaller than that of the straight rod section 1, and the material cost is saved.

The enlarged footing 3 is a round table, the diameter of the smaller end is the same as the diameter of the pile body 5, and is fixedly connected with the bottom end of the pile body 5.

The branch bearing frame 4 is a regular triangular prism, and one side surface of the regular triangular prism is fixedly connected with the pile body 5. The number of the branch bearing frames 4 is preferably six, and all the branch bearing frames 4 are distributed on the pile body 5 in a shape of a Chinese character 'mi', so that the bearing capacity of the pile body is improved, the pile forming time is shortened, and the cost is reduced.

The expanding bearing disc 6 is formed by vertically overlapping and fixedly connecting two truncated cones, and the diameter of the top surface of the truncated cone positioned above is the same as the diameter of the straight rod section 1 and is fixedly connected with the straight rod section 1; the diameter of the bottom surface of the lower round table body is the same as the diameter of the pile body 5 and is fixedly connected with the top end of the pile body 5.

In order to construct the screw pile, the invention provides a construction method of the screw pile, and a pile forming device shown in fig. 2 is required to be used in the construction process of the screw pile.

The pile forming device comprises a concrete pump truck 8 and a spiral pile driver 10, wherein a control system, a pile frame and drilling equipment arranged on the pile frame are arranged on the spiral pile driver 10, and the drilling equipment comprises a drill rod 12 and a rotary driving mechanism for driving the drill rod 12 to rotate; the lower end of the drill rod 12 is provided with a hole forming drilling tool 7 through a connecting mechanism, and the control system is respectively connected with drilling equipment and the hole forming drilling tool 7 through signals;

the drill pipe 12 may be moved up and down and the control system may control the rotational speed and the telescoping speed of the drill pipe 12.

The concrete pump truck 8 is connected with one end of a guide pipe 9, and the other end of the guide pipe 9 is connected with a pore-forming drilling tool 7.

As shown in fig. 3 and 4, the hole drilling tool 7 in the pile forming device of the present invention comprises a cylindrical upper section drill rod 15, a cylindrical rotary section drill rod 16 and a cylindrical lower section drill rod 18 which are sequentially connected from top to bottom, wherein the upper section drill rod 15, the rotary section drill rod 16 and the lower section drill rod 18 form a cylindrical main body drill rod, the rotary section drill rod 16 is connected with an upper section drill rod 15 bearing, and the rotary section drill rod 16 is connected with a lower section drill rod 18 bearing.

The outer wall of the lower section drill rod 18 is fixedly connected with a helical blade 19, and a cutting edge is arranged on the helical blade 19. A bottom-expanding drill bit 20 is arranged at the bottom end of the lower section of drill rod 18. The top end of the upper section of drill rod 15 is fixedly connected with the drill rod 12 through a fixing frame 14; the lower end of the drill rod 12 is provided with a first driving motor 13, the first driving motor 13 is positioned in an inner hole of the drill rod 15 at the upper end, a motor shaft of the first driving motor 13 is provided with a driving gear 22, the driving gear 22 stretches into the drill rod 16 at the rotating section, the inner wall of the drill rod 16 at the rotating section is provided with an annular gear 21, and the annular gear 21 is meshed with the driving gear 22;

two strip-shaped holes 25 are symmetrically formed in the side wall of the rotary section drill rod 16, an automatic blocking mechanism 17 is arranged in each strip-shaped hole, and the automatic blocking mechanism 17 is in signal connection with a control system. The rotary section drill rod 16 is internally provided with a supporting arm 23, and the inner wall of the rotary section drill rod 16 is provided with a first electric push rod 24. The supporting arm 23 is an annular structure formed by movably connecting four supporting rods, and comprises a first supporting rod 27, a second supporting rod 29, a third supporting rod 31 and a fourth supporting rod 33, wherein one end of the first supporting rod 27 and one end of the fourth supporting rod 33 are movably connected with a first pin shaft 26, the first pin shaft 26 is fixedly connected to the side wall of the rotary section drill rod 16, one end of the first supporting rod 27 and one end of the second supporting rod 29 are movably connected with a second pin shaft 28, one end of the fourth supporting rod 33 and one end of the third supporting rod 31 are movably connected with a fourth pin shaft 32, and the other end of the third supporting rod 31 and the other end of the second supporting rod 29 are movably connected with a third pin shaft 30, as shown in fig. 5.

The third pin shaft 30 is fixedly connected with the first electric push rod 24, the first electric push rod 24 can drive the first pin shaft 30 to reciprocate up and down, the third pin shaft 30 is positioned below the first pin shaft 26, and the first pin shaft 26 is positioned

Below the ring gear 21.

The automatic plugging mechanism 17 comprises a sliding cover 35 and a second driving motor, a sliding groove 34 is arranged in the bar-shaped hole 25, the sliding groove 34 extends into the side wall of the rotary section drill rod 16 at two sides of the bar-shaped hole 25, and the sliding cover 35 is arranged in the sliding groove 34 and can reciprocate along the sliding groove 34, as shown in fig. 6. The second driving motor is installed in the rotary section drill rod 16, and drives the sliding cover 35 to reciprocate through the reciprocating mechanism, and the sliding cover 35 can also be driven by an electric cylinder. The second driving motor is in signal connection with the control system.

An annular flange 36 with an inner hole communicated with the inner hole of the lower section drill rod 18 is arranged at the bottom end of the lower section drill rod 18, and the flange 36 is fixedly connected with the bottom expanding drill bit 20 through bolts, as shown in fig. 7. The bottom expanding drill bit 20 comprises an annular connecting flange 37, the connecting flange 37 is fixedly connected with a flange 36 through a plurality of bolts, an inner hole of the connecting flange 37 is communicated with an inner hole of the flange 36, a barrel-shaped mounting seat 38 is fixedly connected below the connecting flange 37, an inner cavity of the mounting seat 38 is communicated with an inner hole of the connecting flange 37, a guide sleeve 43 is arranged on a bottom plate of the mounting seat 38, the lower end of the guide sleeve 43 extends out of the mounting seat 38, a second electric push rod is arranged at the upper end of the guide sleeve 43, a push rod 42 capable of moving up and down along the guide sleeve 43 is arranged at the upper end of the guide sleeve 43, the upper end of the push rod 42 is connected with the second electric push rod, the lower end of the push rod 42 extends out of the guide sleeve 43, an expanding mechanism 41 is arranged at the lower end of the push rod 42, and a small drill bit 40 is arranged at the bottom of the lower end of the push rod 42; the second electric push rod is in signal connection with the control system.

The bottom plate of the mounting seat 38 is provided with an outward-expandable drill bit 39, the outward-expandable drill bit 39 consists of three cutting rods uniformly distributed around the guide sleeve 43, the upper ends of the cutting rods are movably connected with the bottom plate of the mounting seat 38, and the cutting rods are sealed with the bottom plate of the mounting seat 38. The cutting rod is formed by fixedly connecting a quadrangular straight rod and a bottom rod which is obliquely arranged, the upper end of the bottom rod is fixedly connected with the bottom end of the supporting rod, the lower end of the bottom rod faces the small drill bit 40, and the outer side wall of the supporting rod and the outer side wall of the bottom rod are respectively provided with a cutting blade; the lower part of the straight rod is movably connected with the expansion mechanism 41, namely, the lower part of one straight rod is movably connected with one expansion claw in the expansion mechanism 41.

The bottom plate of the mounting seat 38 is also provided with a plurality of seepage holes 44, all seepage holes 44 penetrate through the bottom plate of the mounting seat 38 and are communicated with the inner cavity of the mounting seat 38, and the diameter of each seepage hole 44 is preferably 10cm.

The inner hole of the upper drill rod 15, the inner hole of the rotary drill rod 16, the inner hole of the lower drill rod 18, the inner hole of the flange 36, the inner hole of the connecting flange 37 and the inner cavity of the mounting seat 38 are sequentially communicated to form a concrete channel, and the concrete channel is communicated with all seepage holes 44.

The invention also provides a method for constructing the novel extrusion expansion supporting disc screw pile by using the pile forming device, which comprises the following steps:

1) Taking a pile forming device, moving the pile forming device to a construction site, and moving the spiral pile driver 10 to align the hole forming drilling tool 7 with a pile position;

the conduit 9 is in communication with the concrete passage in the hole drilling tool 7 via a swivel.

2) The screw pile driver 10 is started, and the control system controls the lowering speed and the rotating speed of the drilling tool 7 by controlling the lowering speed and the rotating speed of the drill rod 12: the drill rod 12 descends by one screw pitch and simultaneously rotates clockwise for more than two weeks to drill the straight rod section 1;

after the drilling depth reaches the design depth of the straight rod section 1, the descending speed and the rotating speed of the drill rod 12 are controlled to be: the drill rod 12 descends by one screw pitch and simultaneously rotates clockwise by one circle, threads are formed in the rock-soil body, and drilling of the thread section 2 is carried out;

3) After the hole forming drilling tool 7 drills down to the pile end bearing layer, a control system starts a second electric push rod, a power piece of the second electric push rod drives a push rod 42 to move upwards along a guide sleeve 43, in the upward moving process of the push rod 42, an expansion mechanism 41 is driven to move upwards, expansion claws in the expansion mechanism 41 are outwards opened to push the lower end of a cutting rod to outwards expand, the lower end of the cutting rod is outwards expanded, and meanwhile, the hole forming drilling tool 7 rotates to enable an outwards expanded drill 39 to outwards "peel off a surrounding rock and soil layer to form a pile end expansion head;

4) The power piece of the second electric push rod is controlled to move downwards through the control system, so that the outer expanding drill bit 39 is retracted to the initial pile head, then the drill rod 12 is lifted, and the lifting speed and the rotating speed of the drill rod 12 are controlled to be: the drill rod 12 rises by one screw pitch and simultaneously rotates anticlockwise by one circle, a pouring device on the concrete pump truck 8 is started, concrete slurry is sent into a concrete channel through the guide pipe 9 and flows out through the plurality of seepage holes 44, and grouting of the expansion head 3 and the thread section 2 is carried out;

5) When the hole forming drilling tool 7 is lifted to the designed depth of the branch bearing frame 4, a pouring device on the concrete pump truck 8 is closed, grouting is temporarily stopped, a second driving motor is started by a control system, a sliding cover 35 is driven by the second driving motor to move into the side wall of the rotary section drill rod 16 along a sliding groove 34, the outside is communicated with the inner hole of the rotary section 16, a first electric push rod 24 is started, a power piece of the first electric push rod 24 moves upwards, the power piece drives a third pin shaft 30 to move upwards, one end of a third support rod 31 connected with a fourth pin shaft 32 and one end of a fourth support rod 33 connected with the fourth pin shaft 32 extend out of the rotary section drill rod 16 from one strip-shaped hole 25, one end of a first support rod 27 connected with a second pin shaft 28 and one end of a second support rod 29 connected with the second pin shaft 28 extend out of the rotary section drill rod 16 from the other strip-shaped hole 25, and the part of the support arm 23 extending out of the rotary section drill rod 16 extrudes surrounding soil bodies to form cavities of the two branch bearing frames; the power piece of the first electric push rod 24 is controlled to move downwards, the part of the supporting arm 23 extending out of the rotary section drill rod 16 is retracted into the rotary section drill rod 16, the control system starts the first driving motor 13, the first driving motor 13 drives the driving gear 22 to rotate, the driving gear 22 drives the annular gear 21 to rotate, the annular gear 21 drives the rotary section drill rod 16 to rotate 60 degrees around the axis (the process does not lift the drill rod), the first electric push rod 24 is started again, the power piece of the first electric push rod 24 is enabled to move upwards, one end of the first supporting rod 27 connected with the second pin shaft 28 and one end of the second supporting rod 29 connected with the second pin shaft 28 extend out of the rotary section drill rod 16 from the other strip-shaped hole 25, and the part of the supporting arm 23 extending out of the rotary section drill rod 16 extrudes surrounding soil bodies to form cavities of other two branch bearing frames; performing the operation twice according to the step to form cavities of 8 branch bearing frames, wherein the cavities of the 8 branch bearing frames form a 'rice' -shape; then, the supporting arm 23 is retracted into the rotary section drill rod 16, a second driving motor is started through the control system, and the second driving motor drives the sliding cover 35 to move along the sliding groove 34 so as to seal the strip-shaped hole 25; lifting the drill rod 12 again, and controlling the lifting speed and the rotating speed of the drill rod 12 to be as follows: the drill rod 12 rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts a pouring device to perform pouring on the non-poured part of the screw thread section 2, the cavity of the branch bearing frame and the straight rod section;

the operation time of constructing the cavities of the 8 branch bearing frames is less than the initial setting time of the concrete slurry.

6) After the hole forming drilling tool 7 is lifted to the designed depth of the expansion bearing disc 6, lifting and rotating of the drill rod 12 are stopped, a pouring device on the concrete pump truck 8 is closed, grouting is temporarily stopped, a second driving motor is started through a control system, the second driving motor drives a sliding cover 35 to move inwards along a sliding groove 34 towards the side wall of the rotating section drill rod 16, the outside is communicated with the inner hole of the rotating section 16, a first electric push rod 24 is started, a power piece of the first electric push rod 24 moves upwards, the power piece drives a third pin shaft 30 to move upwards, one end of the third pin shaft 31 connected with a fourth pin shaft 32 and one end of the fourth pin shaft 33 connected with the fourth pin shaft 32 extend out of the rotating section drill rod 16 from one strip-shaped hole 25, one end of the first pin shaft 27 connected with the second pin shaft 28 and one end of the second pin shaft 29 connected with the second pin shaft 28 extend out of the rotating section drill rod 16 from the other strip-shaped hole 25, and the part of the supporting arm 23 extending out of the rotating section drill rod 16 extrudes surrounding soil body to form a cavity; the power piece of the first electric push rod 24 is controlled to move downwards, the part of the supporting arm 23 extending out of the rotary section drill rod 16 is retracted into the rotary section drill rod 16, the control system starts the first driving motor 13, the first driving motor 13 drives the driving gear 22 to rotate, the driving gear 22 drives the annular gear 21 to rotate, the annular gear 21 drives the rotary section drill rod 16 to rotate around the axis of the annular gear by a set angle (the drill rod is not lifted in the process), the first electric push rod 24 is started again, the power piece of the first electric push rod 24 is enabled to move upwards, one end of the first supporting rod 27 connected with the second pin shaft 28 and one end of the second supporting rod 29 connected with the second pin shaft 28 extend out of the rotary section drill rod 16 from the other strip-shaped hole 25, and the part of the supporting arm 23 extending out of the rotary section drill rod 16 extrudes surrounding soil bodies to form two other cavities; performing multiple operations according to the step to form a disc-shaped expanding bearing disc cavity in the soil body; then, the supporting arm 23 is retracted into the rotary section drill rod 16, a second driving motor is started through the control system, and the second driving motor drives the sliding cover 35 to move along the sliding groove 34 so as to seal the strip-shaped hole 25; lifting the drill rod 12, and controlling the lifting speed and the rotating speed of the drill rod 12 to be: the drill rod 12 rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts the pouring device to perform grouting on the non-grouted part of the thread section 2 above the branch bearing frame, the cavity of the expansion bearing disc and the straight rod section;

in step 5) and step 6), the portion of the arm 23 extending beyond the rotary section drill pipe 16 to compress the surrounding soil mass is referred to as the working site.

7) After the hole forming drilling tool 7 is lifted to the ground integrally, a reinforcement cage (a method of pouring concrete and then placing the reinforcement cage is adopted at home and abroad at present, such as a long spiral drilling pile pressing and pouring technology). After the concrete is poured to the designed elevation, the reinforcement cage is inserted into the concrete pile body to the designed elevation at one time by means of the dead weight of the reinforcement cage or by utilizing a vibration device, so that the reinforced concrete pouring pile is formed.

The expansion head 3 in the extrusion expansion support disc screw pile is positioned in a better bearing layer in a foundation, the threaded section 2 is arranged in hard soil or soft rock stratum, the expansion bearing disc 6 and the branch bearing frame 4 can be designed according to different engineering geological conditions, and the straight rod section 1 is generally arranged in a softer soil layer. The arms 23 resist outward expansion by 0 deg. to 90 deg..

Claims (7)

1. The extruding and expanding support disc screw pile is characterized by comprising a straight rod section (1), an expanding bearing disc (6), a thread section (2) and an expanding bottom head (3) which are fixedly connected in sequence from top to bottom, wherein the thread section (2) comprises a cylindrical pile body (5), a plurality of branch bearing frames (4) are uniformly distributed on the side wall of the middle part of the pile body (5), and threads are fixedly connected on the pile body (5) above and below the branch bearing frames (4); the outer diameter of the thread is the same as the outer diameter of the straight rod section (1); the enlarged bottom head (3) is a round table, the diameter of the smaller end of the enlarged bottom head is the same as the diameter of the pile body (5), and the enlarged bottom head is fixedly connected with the bottom end of the pile body (5); the branch bearing frame (4) is a regular triangular prism, and one side surface of the regular triangular prism is fixedly connected with the pile body (5); the expanding bearing disc (6) is formed by vertically overlapping and fixedly connecting two truncated cones, the diameter of the top surface of the truncated cone positioned above is the same as the diameter of the straight rod section (1), and the expanding bearing disc is fixedly connected with the straight rod section (1); the diameter of the bottom surface of the lower round table body is the same as the diameter of the pile body (5) and is fixedly connected with the top end of the pile body (5).

2. The extruded and expanded branch disc screw pile according to claim 1, characterized in that the pitch of the screw thread is 0.2m and the cross-sectional shape of the screw thread is "not isosceles trapezoid".

3. A method of constructing an extruded disc screw pile according to claim 1, comprising the steps of:

1) The pile forming device comprises a concrete pump truck (8) and a spiral pile driver (10), wherein a control system, a pile frame and drilling equipment arranged on the pile frame are arranged on the spiral pile driver (10), and the drilling equipment comprises a drill rod (12) and a rotary driving mechanism for driving the drill rod (12) to rotate; the lower end of the drill rod (12) is provided with a hole forming drilling tool (7) through a connecting mechanism, and the control system is respectively connected with drilling equipment and the hole forming drilling tool (7) through signals;

the hole forming drilling tool (7) comprises an upper section drill rod (15), a rotary section drill rod (16) and a lower section drill rod (18) which are sequentially connected from top to bottom, wherein the upper section drill rod (15), the rotary section drill rod (16) and the lower section drill rod (18) form a cylindrical main body drill rod, and the rotary section drill rod (16) is respectively connected with the upper section drill rod (15) and the lower section drill rod (18) through bearings;

the outer wall of the lower section drill rod (18) is fixedly connected with a helical blade (19), and a cutting edge is arranged on the helical blade (19); the bottom end of the lower section drill rod (18) is provided with a bottom expanding drill bit (20); the top end of the upper section drill rod (15) is fixedly connected with the drill rod (12) through a fixing frame (14); the lower end of the drill rod (12) is provided with a first driving motor (13), the first driving motor (13) is positioned in an inner hole of the drill rod (15) at the upper end, a motor shaft of the first driving motor (13) is provided with a driving gear (22), the driving gear (22) stretches into the rotating section drill rod (16), the inner wall of the rotating section drill rod (16) is provided with an inner gear ring (21), and the inner gear ring (21) is meshed with the driving gear (22);

two strip-shaped holes (25) are symmetrically formed in the side wall of the rotary section drill rod (16), openable and closable automatic plugging mechanisms (17) are arranged in the two strip-shaped holes (25), and the automatic plugging mechanisms (17) are in signal connection with a control system; a supporting arm (23) which can be opened and retracted is arranged in the rotary section drill rod (16), and a first electric push rod (24) is arranged on the inner wall of the rotary section drill rod (16); the first electric push rod (24) drives the supporting arm (23) to open and retract;

the bottom end of the lower section drill rod (18) is fixedly connected with a barrel-shaped bottom-expanding drill bit (20) through a flange plate (36), a plurality of seepage holes (44) communicated with the inside of the main body drill rod are formed in the bottom plate of the bottom-expanding drill bit (20), and the inner holes of the main body drill rod, the inner holes of the flange plate (36) and the inside of the bottom-expanding drill bit (20) are communicated to form a concrete channel, and the concrete channel is communicated with all the seepage holes (44);

the first electric push rod (24) and the bottom expanding drill bit (20) are in signal connection with a control system;

moving the pile forming device to a construction site, and moving a spiral pile driver (10) to enable a hole forming drilling tool (7) in the pile forming device to be aligned with a pile position;

the guide pipe (9) is communicated with a concrete channel in the pore-forming drilling tool (7) through a rotary joint;

2) Starting the spiral pile driver (10), and controlling the descending speed and the rotating speed of the drill rod (12) by the control system, wherein the drill rod (12) descends by one pitch and simultaneously rotates clockwise for more than two weeks to drill the straight rod section (1);

after the drilling depth reaches the design depth of the straight rod section (1), controlling the descending speed and the rotating speed of the drill rod (12) to be as follows: the drill rod (12) descends by one screw pitch and simultaneously rotates clockwise for one circle to form threads in a rock-soil body so as to drill the thread section (2);

3) After the hole forming drilling tool (7) drills down to the pile end bearing layer, a pile end expanding head is formed through the control system bottom expanding drill bit (20);

4) The control system controls the retraction of the bottom expanding drill bit (20), then, the drill rod (12) is lifted, and the lifting speed and the rotating speed of the drill rod (12) are controlled as follows: the drill rod (12) rises by one screw pitch and simultaneously rotates anticlockwise by one circle, a pouring device on the concrete pump truck (8) is started, concrete slurry is sent into a concrete channel through a guide pipe (9) and flows out through a plurality of seepage holes (44), and grouting of the enlarged bottom head (3) and the threaded section (2) is performed;

5) When the hole forming drilling tool (7) is lifted to the design depth of the branch bearing frame (4), a pouring device on the concrete pump truck (8) is closed, grouting is stopped temporarily, an automatic plugging mechanism (17) is started through a control system, the automatic plugging mechanism (17) is opened, a first electric push rod (24) is started, the first electric push rod (24) drives a supporting arm (23), two working parts of the driving supporting arm (23) extend out of a rotating section (16) from two strip-shaped holes (25) respectively, surrounding soil is extruded, and cavities of the two branch bearing frames are formed; then, the first electric push rod (24) is controlled to drive the supporting arm (23), two working parts of the driving supporting arm (23) retract into the rotating section (16), the control system starts the first driving motor (13), the first driving motor (13) drives the driving gear (22) to rotate, the driving gear (22) drives the annular gear (21) to rotate, the annular gear (21) drives the rotating section drill rod (16) to rotate around the axis by a set angle, the first electric push rod (24) is started again to drive the supporting arm (23), and the two working parts of the driving supporting arm (23) extend out of the rotating section (16) from the two strip-shaped holes (25) respectively to squeeze surrounding soil bodies to form cavities of the other two branch bearing frames; performing operation for a set number of times according to the operation process to form cavities of the branch bearing frames with designed numbers; then, the supporting arm (23) is retracted into the rotary section drill rod (16), and the automatic plugging mechanism (17) is started through the control system to close the strip-shaped hole (25); lifting the drill rod (12) again, and controlling the lifting speed and the rotating speed of the drill rod (12) to be as follows: the drill rod (12) rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts a pouring device to perform pouring on the non-poured part of the threaded section (2), the cavity of the branch bearing frame and the straight rod section;

6) After the hole forming drilling tool (7) is lifted to the design depth of the expansion bearing disc (6), lifting and rotation of the drill rod (12) are stopped, a pouring device on the concrete pump truck (8) is closed, grouting is temporarily stopped, an automatic plugging mechanism (17) is started through a control system, two strip-shaped holes (25) are opened, a first electric push rod (24) is started, the first electric push rod (24) drives the supporting arm (23), so that two working parts of the supporting arm (23) extend out of the rotating section (16) from the two strip-shaped holes (25), surrounding soil is extruded, and a cavity is formed; controlling a first electric push rod (24), wherein the first electric push rod (24) drives the supporting arm (23), two working parts of the supporting arm (23) retract into the rotating section (16), starting a first driving motor (13), the first driving motor (13) drives a driving gear (22) to rotate, the driving gear (22) drives an inner gear ring (21) to rotate, the inner gear ring (21) drives a rotating section drill rod (16) to rotate around the axis of the rotating section drill rod by a set angle, the first electric push rod (24) drives the supporting arm (23), and two working parts of the supporting arm (23) extend out of the rotating section (16) from two strip-shaped holes (25) to squeeze surrounding soil bodies to form two other cavities; performing multiple operations according to the operation steps to form a disc-shaped expanding bearing disc cavity in the soil body; then, the supporting arm (23) is retracted into the rotary section drill rod (16), and the automatic plugging mechanism (17) is started through the control system to close the two strip-shaped holes (25); lifting the drill rod (12), and controlling the lifting speed and the rotating speed of the drill rod (12) to be as follows: the drill rod (12) rises by one screw pitch, simultaneously rotates anticlockwise for more than two weeks, and starts the pouring device to perform grouting on the non-grouted part of the thread section (2) above the branch bearing frame, the cavity of the expansion bearing disc and the straight rod section;

7) And (3) after the hole forming drilling tool (7) is integrally lifted to the ground, placing a reinforcement cage, and after solidification, completing the construction of the extruded and expanded support disc screw pile.

4. A piling device for use in a method of constructing a squeeze-and-expand branch disc screw pile as claimed in claim 3, comprising a concrete pump truck (8) and a screw pile driver (10), the screw pile driver (10) being provided with a control system, a pile frame and drilling equipment mounted on the pile frame, the drilling equipment comprising a drill pipe (12) and a rotary drive mechanism for driving the drill pipe (12) in rotation; the lower end of the drill rod (12) is provided with a hole forming drilling tool (7) through a connecting mechanism, and the control system is respectively connected with drilling equipment and the hole forming drilling tool (7) through signals; the drill rod (12) can move up and down, and the control system can control the rotation speed and the expansion speed of the drill rod (12); the concrete pump truck (8) is connected with one end of a guide pipe (9), and the other end of the guide pipe (9) is connected with the pore-forming drilling tool (7) through a rotary joint;

the hole forming drilling tool (7) comprises a cylindrical upper section drill rod (15), a cylindrical rotary section drill rod (16) and a cylindrical lower section drill rod (18) which are sequentially connected from top to bottom, wherein the cylindrical main body drill rod is formed by the upper section drill rod (15), the rotary section drill rod (16) and the lower section drill rod (18), and the upper section drill rod (15) and the lower section drill rod (18) are connected with the rotary section drill rod (16) through bearings;

the outer wall of the lower section drill rod (18) is fixedly connected with a helical blade (19), and a cutting edge is arranged on the helical blade (19); the bottom end of the lower section drill rod (18) is provided with a bottom expanding drill bit (20); the top end of the upper section drill rod (15) is fixedly connected with the drill rod (12) through a fixing frame (14); the lower end of the drill rod (12) is provided with a first driving motor (13), the first driving motor (13) is positioned in an inner hole of the drill rod (15) at the upper end, a motor shaft of the first driving motor (13) is provided with a driving gear (22), the driving gear (22) stretches into the rotating section drill rod (16), and the inner wall of the rotating section drill rod (16) is provided with an inner gear ring (21) meshed with the driving gear (22);

two strip-shaped holes (25) are symmetrically formed in the side wall of the rotary section drill rod (16), automatic plugging mechanisms (17) are arranged in the two strip-shaped holes, the automatic plugging mechanisms (17) can seal the strip-shaped holes (25) which can be opened, and the automatic plugging mechanisms (17) are in signal connection with a control system; the rotary section drill rod (16) is internally provided with a supporting arm (23) and a first electric push rod (24), and the first electric push rod (24) drives the working part of the supporting arm (23) to extend out of the rotary section drill rod (16) or retract into the rotary section drill rod (16).

5. Piling device according to claim 4, wherein the brace (23) comprises a first brace (27), one end of the first brace (27) and one end of a fourth brace (33) are both movably connected with the first pin (26), the first pin (26) is fixedly connected to the side wall of the rotary section drill rod (16), the other end of the first brace (27) and one end of the second brace (29) are both movably connected with the second pin (28), the other end of the fourth brace (33) and one end of the third brace (31) are both movably connected with the fourth pin (32), and the other end of the third brace (31) and the other end of the second brace (29) are both movably connected with the third pin (30); the third pin shaft (30) is positioned below the first pin shaft (26), the first pin shaft (26) is positioned below the inner gear ring (21), the third pin shaft (30) is fixedly connected with the first electric push rod (24), and the first electric push rod (24) can drive the first pin shaft (30) to reciprocate up and down.

6. Pile forming device according to claim 4, characterized in that the automatic plugging mechanism (17) comprises a sliding cover (35) and a second driving motor, a sliding groove (34) is arranged in the bar-shaped hole (25), the sliding groove (34) extends into the side wall of the rotary section drill rod (16) at two sides of the bar-shaped hole (25), the sliding cover (35) is arranged in the sliding groove (34) and can reciprocate along the sliding groove (34), the second driving motor is arranged in the rotary section drill rod (16), the second driving motor drives the sliding cover (35) to reciprocate through the reciprocating mechanism, and the second driving motor is in signal connection with the control system.

7. Pile forming device according to claim 4, characterized in that the bottom expanding drill bit (20) comprises an annular connecting flange (37), the connecting flange (37) is fixedly connected with the lower section drill rod (18), an inner hole of the connecting flange (37) is communicated with an inner hole of the main section drill rod, a barrel-shaped inner cavity is fixedly connected below the connecting flange (37) and is communicated with a mounting seat (38) of the inner hole of the connecting flange (37), a guide sleeve (43) is arranged on a bottom plate of the mounting seat (38), the lower end of the guide sleeve (43) extends out of the mounting seat (38), a second electric push rod is arranged at the upper end of the guide sleeve (43), a push rod (42) capable of moving up and down along the guide sleeve (43) is arranged in the guide sleeve (43), the upper end of the push rod (42) is connected with the second electric push rod, the lower end of the push rod (42) extends out of the guide sleeve (43), an expanding mechanism (41) is arranged, and a small drill bit (40) is arranged at the bottom of the lower end of the push rod (42); the second electric push rod is in signal connection with the control system;

the bottom plate of the mounting seat (38) is provided with an outward-expandable drill bit (39), the outward-expandable drill bit (39) is composed of three cutting rods uniformly distributed around the guide sleeve (43), the upper ends of the cutting rods are movably connected with the bottom plate of the mounting seat (38), and the cutting rods are sealed with the bottom plate of the mounting seat (38); the cutting rod is formed by fixedly connecting a quadrangular straight rod and a bottom rod which is obliquely arranged, the upper end of the bottom rod is fixedly connected with the bottom end of the supporting rod, the lower end of the bottom rod faces to the small drill bit (40), and the outer side wall of the supporting rod and the outer side wall of the bottom rod are respectively provided with a cutting blade; the lower part of one straight rod is movably connected with one expansion claw in the expansion mechanism (41);

the bottom plate of the mounting seat (38) is also provided with a plurality of seepage holes (44), and all seepage holes (44) penetrate through the bottom plate of the mounting seat (38) and are communicated with the inner cavity of the mounting seat (38).