High-strength hard rock rotary drilling hole-forming pile foundation and construction method

Abstract

The invention relates to a high-strength hard rock rotary drilling hole-forming pile foundation and a construction method. The high-strength hard rock rotary drilling hole-forming pile foundation comprises a high-strength hard rock rotary drilling hole-forming drill bit system, a positioning platform reinforcement cage sinking system, a deformation steel casing detachable inner support reinforcing system and a steel casing limiting platform. The high-strength hard rock rotary excavating hole-forming drill bit system has the beneficial effects that sediment at the bottom of a hole can be conveniently cleaned, the sediment is prevented from falling, one-time hole cleaning can be achieved, the sediment cleaning efficiency and effect are improved, and the drilling efficiency is improved; the positioning platform reinforcement cage sinking system can quickly and accurately determine the center of the pile foundation, reworking caused by deviation of the pile foundation in the later period is avoided, it is guaranteed that the pile foundation construction progress is not affected, and a safe and reliable construction platform is provided. The detachable inner support reinforcing system for the deformed steel casing is convenient to construct, simple to operate and reasonable in stress form, and has better technical and economic benefits; the steel pile casing limiting platform can prevent the pile casing from sinking in the construction process.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation pits and pile foundations, and particularly relates to a high-strength hard-rock rotary drilling pile foundation and a construction method thereof. Background Technique

[0002] A pile foundation is a foundation form that transfers the load of a building through the pile body to a deep and stable soil layer or rock stratum. In subway construction, the pile foundation serves as the main load-bearing foundation for structures such as subway stations and ventilation shafts. By transferring the load through the pile foundation to the deep and stable soil layer or rock stratum, the bearing capacity of the foundation is significantly improved, and the pile foundation has good anti-settlement performance, which can effectively reduce the settlement deformation of the subway structure during construction and operation. Through pile foundation construction, the safety and stability of the subway structure can be effectively ensured, meeting various requirements during subway operation.

[0003] At present, many technologies involved in pile foundation construction at home and abroad have their certain advantages. Among them, the static pressure pile technology uses a static pressure pile machine to press precast piles into the soil, with advantages such as low construction noise and little impact on the surrounding environment; the bored cast-in-place pile technology forms a pile body by drilling a hole with a drilling machine and then pouring concrete into the hole, which is suitable for various complex geological conditions; the steel pipe pile construction technology uses steel pipes as the pile body material, with advantages such as high bearing capacity and strong lateral pressure resistance. However, with the development of cities, subway stations are becoming larger and deeper, and the disadvantages of slow construction speed and low construction efficiency of traditional pile foundation construction methods are gradually emerging, making it difficult to meet the existing requirements.

[0004] For high-strength hard-rock rotary drilling pile foundations and construction, there is an urgent need to propose a construction method that can improve construction efficiency while ensuring project quality and safety. Summary of the Invention

[0005] The purpose of the invention is to overcome the deficiencies in the prior art and provide a high-strength hard-rock rotary drilling pile foundation and a construction method thereof.

[0006] This high-strength hard-rock rotary drilling pile foundation construction system includes a high-strength hard-rock rotary drilling bit system, a positioning platform steel cage sinking system, a deformable steel casing detachable internal support reinforcement system, and a steel casing limiting platform; a steel casing is provided in the drilling direction; the high-strength hard-rock rotary drilling bit system includes a drill body; there is a connection bayonet at the top of the drill body, and a drill bit at the bottom; a screw rod is connected to the drill body on the upper side of the drill bit; the positioning platform steel cage sinking system penetrates through a steel cage and is arranged on the ground; the positioning platform steel cage sinking system includes a positioning platform; micro-concave arc-shaped limiters are symmetrically provided on the side wall of the positioning platform facing the steel cage; there is a karst cave between the deformed steel casing and the drilling hole wall and a grouting pipe is inserted, and high-fluidity concrete is in the grouting pipe; the deformable steel casing detachable internal support reinforcement system includes a steel section column, and detachable telescopic rods are symmetrically connected to the side wall of the steel section column, and the detachable telescopic rods support on the inner wall of the deformed steel casing; the center of the steel casing limiting platform is fixedly penetrated with a steel casing.

[0007] Preferably, the high-strength hard-rock rotary drilling hole-forming bit system includes a drill body; a movable block is welded to the top of the steel casing; the drill body penetrates through the steel casing; a connecting bayonet is provided at the top of the drill body, and a drill bit is provided at the bottom; an external mechanical component is connected to the top of the connecting bayonet; an upper stop block is welded to the drill body below the connecting bayonet, and a lower stop block is welded to the drill body above the screw rod; a limiting spring is installed between the upper stop block and the lower stop block, one end of the limiting spring is connected to the bottom of the upper stop block, and the other end is connected to the top of the movable block.

[0008] Preferably, the positioning platform steel reinforcement cage sinking system includes a positioning platform; the positioning platform is in a cube shape, and platform legs are provided at the four corners of the bottom of the positioning platform; positioning support devices are provided at the central positions around the positioning platform; the positioning support device includes a positioning clamping plate; the positioning clamping plate is provided at the central position of the side wall around the positioning platform, and a clamping hole penetrates through the positioning clamping plate; clamping holes corresponding to the positioning clamping plates are provided at the central positions around the top surface of the positioning platform; a positioning pin is fixedly penetrated in the clamping hole, and the positioning clamping plate is fixed to the periphery of the positioning platform through the positioning pin; a sliding groove is provided on the side wall of the positioning clamping plate facing the steel reinforcement cage; a clamping tongue and a micro-concave arc-shaped limiter are sequentially connected in the sliding groove, and the micro-concave arc-shaped limiter is attached to the side wall of the steel reinforcement cage.

[0009] Preferably, the deformable steel casing detachable internal support reinforcement system includes a steel casing repair system and a karst cave filling system; the steel casing repair system includes a steel section column; the steel section column is placed in the deformed steel casing, several rod bases are symmetrically and vertically connected horizontally to the side wall of the steel section column, a detachable telescopic rod is connected to the rod base, and the other end of the detachable telescopic rod supports on the inner wall of the deformed steel casing; the karst cave filling system includes a grouting pipe, the grouting pipe is inserted between the hole wall and the karst cave, and high-fluidity concrete is filled between the hole wall and the karst cave.

[0010] Preferably, the steel casing limiting platform is erected on the ground, a high-strength concrete base is provided at the bottom, a limiting protrusion is connected to the bottom of the high-strength concrete base, and the limiting protrusion is inserted into the ground; a stacking layer is provided around the top of the high-strength concrete base; a steel casing penetrates through the center of the steel casing limiting platform, a filling layer is filled between the steel casing and the stacking layer, a limiting cap is provided at the top of the steel casing, and reinforcing diagonal bars are symmetrically provided in the filling layer, one end of the reinforcing diagonal bar is connected to the connection part of the stacking layer and the high-strength concrete base, and the other end is connected to the top of the filling layer.

[0011] The construction method of this high-strength hard-rock rotary drilling hole-forming pile foundation includes the following steps:

[0012] S1. Connect the high-strength hard-rock rotary drilling hole-forming bit system to the external mechanical component through the connecting bayonet, and while the screw rod breaks the hard rock, the soil and gravel are carried out as the steel casing moves up and down.

[0013] S2. After installing the positioning platform steel cage sinking system, adjust the micro-concave arc limiter back and forth through the sliding groove to complete the limiting and sinking of the steel cage.

[0014] S3. Insert a profiled steel column into the deformed steel casing, adjust the detachable telescopic rod to perform a jacking repair on the deformed steel casing; then insert a grouting pipe between the hole wall and the karst cave and inject high-fluidity concrete to repair the karst cave.

[0015] S4. After erecting the steel casing limiting platform, insert the steel casing and perform limiting and fixing.

[0016] Preferably, there is a connecting bayonet at the top of the drill body and a drill bit at the bottom; an upper stop block is welded to the drill body below the connecting bayonet, and a lower stop block is welded to the drill body above the screw rod; a limiting spring is installed between the upper stop block and the lower stop block, one end of the limiting spring is connected to the bottom of the upper stop block, and the other end is connected to the top of the movable block; an external mechanical component is connected to the top of the connecting bayonet; in step S1, the external mechanical component drives the drill bit to rise and fall, the movable block drives the steel casing to rise and fall between the upper stop block and the lower stop block, and while the screw rod breaks hard rock, it takes out the soil and crushed stones as the steel casing moves up and down.

[0017] The beneficial effects of the present invention are:

[0018] 1) In the high-strength hard rock rotary drilling hole-forming drill bit system, a screw rod is connected to the drill body on the upper side of the drill bit. While the screw rod breaks hard rock, it takes out the soil and crushed stones as the steel casing moves up and down. It has the advantages of facilitating the cleaning of bottom sediment in the hole, preventing sediment from falling, being able to achieve primary hole cleaning, improving the efficiency and effect of sediment cleaning, and improving the drilling efficiency.

[0019] 2) The positioning platform steel cage sinking system can quickly and accurately determine the pile foundation center according to the pile diameter after the steel cage is lowered, avoiding rework caused by pile foundation deviation in the later stage, ensuring that the pile foundation construction progress is not affected, and at the same time providing a safe and reliable construction platform throughout the process from steel cage hoisting to pile foundation pouring.

[0020] 3) In the deformable steel casing detachable internal support reinforcement system, several detachable telescopic rods are symmetrically and vertically cross-connected to the side wall of the profiled steel column. The detachable telescopic rods support the inner wall of the deformed steel casing. The construction is convenient, the operation is simple, and the stress form is reasonable, having good technical and economic benefits.

[0021] 4) The steel casing limiting platform can support the limiting cap at the top of the casing through the reinforced platform, avoiding the sinking of the casing caused by too low friction during construction. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the high-strength hard rock rotary drilling hole-forming drill bit system;

[0023] Figure 2 This is a top view of the steel cage sinking system of the positioning platform;

[0024] Figure 3 This is the side view of the steel cage sinking system of the positioning platform;

[0025] Figure 4 It is a schematic diagram of the structure of the deformed steel casing detachable internal support reinforcement system;

[0026] Figure 5 It is a schematic diagram of the steel casing limiting platform structure.

[0027] Explanation of the accompanying drawings: 1 upper stop block, 2 drill body, 3 lower stop block, 4 drill bit, 5 connecting bayonet, 6 limit spring, 7 movable block, 8 spiral rod, 9 steel casing, 10 clamping hole, 11 clamping tongue, 12 positioning pin, 13 steel cage, 14 positioning clamping plate, 15 sliding groove, 16 slightly concave arc limiter, 17 positioning platform, 18 platform support leg, 19 hole wall, 20 rod base, 21 steel column, 22 grouting pipe, 23 detachable telescopic rod, 24 cave, 25 high-flow concrete, 26 steel casing limit platform, 27 filling layer, 28 limit protrusion, 29 limit cap, 30 reinforced diagonal reinforcement, 31 masonry layer, 32 high-strength concrete base. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0029] Embodiment 1

[0030] As an embodiment, a construction system for bored piles with high-strength hard rock rotary drilling is proposed, which includes a high-strength hard rock rotary drilling bit system, a positioning platform steel reinforcement cage sinking system, a deformable steel casing detachable internal support reinforcement system, and a steel casing limiting platform 26; a steel casing 9 is provided in the drilling direction; the high-strength hard rock rotary drilling bit system includes a drill body 2; at the top of the drill body 2, there is a connection bayonet 5, and at the bottom is a drill bit 4; on the upper side of the drill bit 4, a screw rod 8 is connected to the drill body 2; the positioning platform steel reinforcement cage sinking system penetrates through a steel reinforcement cage 13 and is arranged on the ground; the positioning platform steel reinforcement cage sinking system includes a positioning platform 17; on the side wall of the positioning platform 17 centered towards the steel reinforcement cage 13, micro concave arc limiters 16 are symmetrically provided; there is a karst cave 24 between the deformed steel casing 9 and the drilling hole wall 19, and a grouting pipe 22 is inserted, and high-fluidity concrete 25 is inside the grouting pipe 22; the deformable steel casing detachable internal support reinforcement system includes a steel column 21, and on the side wall of the steel column 21, detachable telescopic rods 23 are symmetrically connected, and the detachable telescopic rods 23 support on the inner wall of the deformed steel casing 9; the center of the steel casing limiting platform 26 is fixedly penetrated with the steel casing 9.

[0031] As Figure 1 shown, the high-strength hard rock rotary drilling bit system includes a drill body 2; a movable block 7 is welded on the top of the steel casing 9; the drill body 2 penetrates through the steel casing 9; at the top of the drill body 2, a connection bayonet 5 is provided, and at the bottom, a drill bit 4 is provided; at the top of the connection bayonet 5, an external mechanical component is connected; on the drill body 2 below the connection bayonet 5, an upper stop block 1 is welded, and on the drill body 2 above the screw rod 8, a lower stop block 3 is welded; a limiting spring 6 is installed between the upper stop block 1 and the lower stop block 3, one end of the limiting spring 6 is connected to the bottom of the upper stop block 1, and the other end is connected to the top of the movable block 7.

[0032] The high-strength hard rock rotary drilling bit system includes a limiting spring 6, an upper stop block 1, a lower stop block 3, and a connection buckle 9 arranged on the drill body 2, and a screw rod 8 is provided on the drill bit 4, which can crush high-strength hard rock. During the ascending and descending process of the drill bit 4, the movable block 7 and the steel casing 9 are fixed between the upper stop block 1 and the lower stop block 3 through the limiting spring 6, playing a role in collecting soil and crushed stones.

[0033] Embodiment Two

[0034] As another embodiment, this Embodiment Two is proposed based on Embodiment One, and a more specific construction system for bored piles with high-strength hard rock rotary drilling.

[0035] As Figure 2 and Figure 3As shown in the figure, the positioning platform steel cage sinking system includes a positioning platform 17. The positioning platform 17 is in the shape of a cube, and platform legs 18 are provided at the four corners of the bottom of the positioning platform 17. Positioning support devices are provided at the central positions around the positioning platform 17. The positioning support device includes a positioning card 14. The positioning card 14 is provided at the central position of the side walls around the positioning platform 17, and a card hole 10 runs through the positioning card 14. Card holes 10 corresponding to the positioning card 14 are provided at the central positions around the top surface of the positioning platform 17. A positioning pin 12 is fixedly penetrated in the card hole 10, and the positioning card 14 is fixed around the positioning platform 17 through the positioning pin 12. A sliding groove 15 is provided on the side wall of the positioning card 14 facing the steel cage 13. A card tongue 11 and a microconcave arc-shaped limiter 16 are sequentially connected in the sliding groove 15, and the microconcave arc-shaped limiter 16 is attached to the side wall of the steel cage 13.

[0036] The positioning platform 17 is in the shape of a cube, and platform legs 18 are provided at the four corners of the bottom of the platform for support; positioning support devices are provided at the central positions around the platform. The positioning support device is composed of a positioning card 14, a card hole 10, a card tongue 11, a sliding groove 15, a microconcave arc-shaped limiter 16 and a positioning pin 12. By adjusting the positioning support device, the fixing and sinking of the steel cage 13 can be realized.

[0037] As Figure 4 As shown in the figure, the deformable steel casing detachable internal support reinforcement system includes a steel casing repair system and a karst cave filling system. The steel casing repair system includes a steel section column 21. The steel section column 21 is placed in the deformed steel casing 9, and several rod bases 20 are symmetrically and vertically connected horizontally on the side wall of the steel section column 21. The rod base 20 is connected with a detachable telescopic rod 23, and the other end of the detachable telescopic rod 23 supports on the inner wall of the deformed steel casing 9. The karst cave filling system includes a grouting pipe 22. The grouting pipe 22 is inserted between the hole wall 19 and the karst cave 24, and high-fluidity concrete 25 is filled between the hole wall 19 and the karst cave 24.

[0038] As Figure 5 As shown in the figure, the steel casing limit platform includes a limit cap 29 arranged on the steel casing 9. The steel casing limit platform 26 is composed of a high-strength concrete base 32, a stacking layer 31, a filling layer 27, reinforcing diagonal bars 30 and a limit protrusion 28. The function of the limit protrusion 28 is to enhance the overall stability of the platform structure by increasing the contact area with the soil.

[0039] The steel casing limiting platform 26 is erected on the ground, and a high-strength concrete base 32 is provided at the bottom. A limiting protrusion 28 is connected to the bottom of the high-strength concrete base 32, and the limiting protrusion 28 is inserted into the ground; a stacking layer 31 is provided around the top of the high-strength concrete base 32; a steel casing 9 passes through the center of the steel casing limiting platform 26, and a filling layer 27 is filled between the steel casing 9 and the stacking layer 31. A limiting cap 29 is provided at the top of the steel casing 9, and reinforcing diagonal bars 30 are symmetrically arranged in the filling layer 27. One end of the reinforcing diagonal bar 30 is connected to the connection between the stacking layer 31 and the high-strength concrete base 32, and the other end is connected to the top of the filling layer 27.

[0040] It should be noted that the same or similar parts in this embodiment and the first embodiment can be referred to each other, and will not be described in detail in this application.

[0041] Embodiment III

[0042] As another embodiment, this Embodiment III is proposed on the basis of Embodiment II. A construction method for a high-strength hard rock rotary drilling pile foundation includes the following steps;

[0043] S1. Install the high-strength hard rock rotary drilling bit system: As Figure 1 shown, a movable block 7 is welded to the steel casing 9 in advance, and then a limiting spring 6 is installed on the drill body 2, and a stop block 1 and a lower stop block 3 are welded to the head and tail respectively as the movable limits at both ends of the movable block 7. A connecting bayonet 5 is provided at the head of the drill body 2 and can be connected to an external mechanical component; a screw rod 8 is provided on the drill bit 4, which can take out the soil and gravel while breaking the hard rock as the steel casing 9 moves up and down, playing the role of integrating rock breaking and mud discharging.

[0044] S2. Install the positioning platform steel cage sinking system: As Figure 2 and Figure 3 shown, multiple rows of card holes 10 are made on the positioning card plate 14 in advance, and the tongue 11 and the slightly concave arc-shaped limiter 16 can be freely adjusted back and forth through the sliding groove 15 to complete the limiting and sinking of the steel cage 13. The positioning card plate 14 is fixed to the cubic positioning platform 17 through a positioning pin 12 inserted into the card hole 10, and platform legs 18 are provided at the four corners of the bottom of the platform.

[0045] S3. Install the deformable steel casing detachable internal support reinforcement system: As Figure 4 shown, first, a section steel column 21 is inserted into the deformed steel casing 9. A detachable telescopic rod 23 and a corresponding rod base 20 are pre-set on the section steel column 21, and the opposite top repair of the deformed steel casing 9 can be realized by adjusting the detachable telescopic rod 23. Then, a grouting pipe 22 is inserted between the hole wall 19 and the karst cave 24, and high-fluidity concrete 25 is injected into the foundation pit for filling to complete the repair of the karst cave 24.

[0046] S4. Install the steel casing limiting platform: Figure 5 As shown, firstly, a high-strength concrete base 32 is cast and a masonry layer 31 is applied on one side of the base, then the strengthening diagonal reinforcement 30 is supported and a filling layer 27 is applied, and finally, a limiting protrusion 28 is installed at the bottom of the high-strength concrete base 32 to penetrate into the soil and improve the stability of the overall structure. After the steel casing limiting platform 26 is set up, the steel casing 9 is inserted and fixed by the limiting cap 29.

[0047] It should be noted that the parts in this embodiment that are the same or similar to those in the second embodiment can be referenced to each other and will not be described in detail in this application.

[0048] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A high-strength hard rock rotary drilling pile foundation construction system, characterized in that: include: A high-strength hard rock rotary drilling drill bit system, a positioning platform steel cage sinking system, a deformed steel casing detachable internal support reinforcement system and a steel casing limiting platform; a steel casing is provided in the drilling direction; the high-strength hard rock rotary drilling drill bit system includes a drill body; a connecting socket is provided on the top of the drill body, and a drill bit is provided at the bottom; a spiral rod is connected to the drill body on the upper side of the drill bit; a steel cage is penetrated by the positioning platform steel cage sinking system and is arranged on the ground; the positioning platform steel cage sinking system includes a positioning platform; a slightly concave arc limiter is symmetrically provided on the side wall of the positioning platform facing the steel cage; there is a cave between the deformed steel casing and the wall of the borehole and a grouting pipe is inserted, and high-flow concrete is contained in the grouting pipe; the deformed steel casing detachable internal support reinforcement system includes a steel column, and the side wall of the steel column is symmetrically connected with a detachable telescopic rod, and the detachable telescopic rod is supported on the inner wall of the deformed steel casing; a steel casing is penetrated and fixed at the center of the steel casing limiting platform.

2. The high-strength hard rock rotary drilling pile foundation construction system according to claim 1 is characterized in that: The high-strength hard rock rotary drilling drill bit system includes a drill body; a movable block is welded on the top of a steel casing; the drill body runs through the steel casing; a connecting socket is provided on the top of the drill body, and a drill bit is provided on the bottom; an external mechanical component is connected to the top of the connecting socket; an upper stop block is welded on the drill body at the lower side of the connecting socket, and a lower stop block is welded on the drill body at the upper side of a spiral rod; a limit spring is installed between the upper stop block and the lower stop block, one end of the limit spring is connected to the bottom of the upper stop block, and the other end is connected to the top of the movable block.

3. The high-strength hard rock rotary drilling pile foundation construction system according to claim 1 is characterized in that: The positioning platform steel cage sinking system includes a positioning platform; the positioning platform is in a cubic shape, and platform legs are provided at the four corners of the bottom of the positioning platform; positioning support devices are provided at the center positions around the positioning platform; the positioning support devices include a positioning card plate; the positioning card plate is provided at the center position of the side walls around the positioning platform, and the positioning card plate is penetrated by a card hole; card holes corresponding to the positioning card plate are provided at the center of the top surface of the positioning platform; positioning pins are penetrated and fixed in the card holes, and the positioning card plate is fixed to the surrounding of the positioning platform by the positioning pins; the positioning card plate is provided with a sliding groove facing the side wall of the steel cage; the sliding groove is sequentially connected with a card tongue and a slightly concave arc limiter, and the slightly concave arc limiter is attached to the side wall of the steel cage.

4. The high-strength hard rock rotary drilling pile foundation construction system according to claim 1 is characterized in that: The detachable inner support reinforcement system of the deformed steel casing includes a steel casing repair system and a cave filling system; the steel casing repair system includes steel columns; the steel columns are placed in the deformed steel casing, and the side walls of the steel columns are symmetrically vertically and horizontally connected with several rod bases, and the rod bases are connected with detachable telescopic rods, and the other ends of the detachable telescopic rods are supported on the inner wall of the deformed steel casing; the cave filling system includes a grouting pipe, which is inserted between the hole wall and the cave, and the hole wall and the cave are filled with high-flow concrete.

5. The high-strength hard rock rotary drilling pile foundation construction system according to claim 1 is characterized in that: The steel casing limiting platform is erected on the ground, with a high-strength concrete base at the bottom, and a limiting protrusion is connected to the bottom of the high-strength concrete base, and the limiting protrusion is inserted into the ground; there are masonry layers around the top of the high-strength concrete base; a steel casing runs through the center of the steel casing limiting platform, and a filling layer is filled between the steel casing and the masonry layer, a limiting cap is provided on the top of the steel casing, and reinforcing oblique bars are symmetrically arranged in the filling layer, one end of the reinforcing oblique bar is connected to the connection between the masonry layer and the high-strength concrete base, and the other end is connected to the top of the filling layer.

6. The construction method of high-strength hard rock rotary drilling pile foundation according to claim 1 is characterized in that: The following steps are involved: S1. Connect the high-strength hard rock rotary drilling drill system to the external mechanical component through the connecting bayonet. The spiral rod breaks the hard rock and brings out the soil and gravel as the steel casing moves up and down; S2. After installing the steel cage sinking system on the positioning platform, the slightly concave arc stopper is adjusted forward and backward through the sliding groove to complete the positioning and sinking of the steel cage; S3, inserting a steel column into the deformed steel casing, adjusting the detachable telescopic rod to repair the deformed steel casing; then inserting a grouting pipe between the hole wall and the cave and injecting high-flow concrete to repair the cave; S4. After setting up the steel casing limiting platform, insert the steel casing and fix it in position.

7. The construction method of high-strength hard rock rotary drilling pile foundation according to claim 6 is characterized in that: There is a connecting bayonet on the top of the drill body and a drill bit at the bottom; an upper stop block is welded on the drill body at the lower side of the connecting bayonet, and a lower stop block is welded on the drill body at the upper side of the spiral rod; a limit spring is installed between the upper stop block and the lower stop block, one end of the limit spring is connected to the bottom of the upper stop block, and the other end is connected to the top of the movable block; an external mechanical component is connected to the top of the connecting bayonet; in step S1, the external mechanical component drives the drill bit to rise and fall, and the movable block drives the steel casing to rise and fall between the upper stop block and the lower stop block, and the spiral rod breaks the hard rock and brings out the soil and gravel as the steel casing moves up and down.

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