CN112012199A

CN112012199A - Novel BNT carrier pile and construction equipment construction method thereof

Info

Publication number: CN112012199A
Application number: CN201910454154.0A
Authority: CN
Inventors: 白洁; 白大泉; 徐莉
Original assignee: Zhangye Longyuan Foundation Engineering Co ltd
Current assignee: Zhangye Longyuan Foundation Engineering Co ltd
Priority date: 2019-05-29
Filing date: 2019-05-29
Publication date: 2020-12-01

Abstract

The invention relates to the field of civil engineering, in particular to a novel BNT carrier pile and a construction method of construction equipment thereof. The high-quality potential with high bearing capacity of the carrier pile is fully developed, and the advantages of high pile forming quality and strong applicability are realized by utilizing the BNT technology; the problems existing in the pile forming concept and construction of the original carrier pile are solved; the design and construction can be based by the diversification of construction forms and equipment and the requirement of three-stroke penetration as a criterion; the method is simple, optimizes the process, and finally realizes the BNT carrier pile with high bearing capacity, good effect, high speed, low cost and wider application range so as to meet different requirements of engineering construction on higher pile foundations.

Description

Novel BNT carrier pile and construction equipment construction method thereof

Technical Field

The invention relates to the field of civil engineering, in particular to a novel BNT carrier pile and a construction method of construction equipment thereof.

Background

When the bearing capacity of the natural foundation cannot meet the requirement, foundation treatment is required or a pile foundation is adopted, and how to improve the bearing capacity of a single pile by adopting the pile foundation becomes a general concern. The invention relates to a carrier pile which is invented on the basis of a rammed pile. However, the area of the pile end expanding head and the area of the pile end soil body affected by the concept and the process of the tamping-expanding pile are limited, so that the bearing capacity is improved to a limited extent. The carrier pile is a product combining a dynamic compaction replacement technology and tamping pile expansion construction in foundation treatment; the pile end bearing body which is more compact, has higher bearing capacity and is artificially reinforced is obtained by adding fillers into a pile end natural soil layer and tamping the fillers, and the load is transferred to a carrier through a pile body and is diffused to a bearing layer below the carrier, so that the improvement effect of the bearing capacity is more obvious.

The BNT pile is also called a full-casing cast-in-place pile, and is a French technology introduced in the last 70 th century. MZ series shaking type full casing pile driver, called 'pile driver' for short, was developed by Kunming engineering piling company in the end of 90 s. The advantages are that:

(1) the problem that the hole is easy to collapse due to the sand flowing in the stratum is solved, the quality problems caused by necking, mud clamping, pile breaking, segregation and the like are avoided, and the quality reliability of hole forming and pile forming is high;

(2) the construction method can be applied to construction under almost any geological conditions, and has wide adaptability;

(3) the soil condition can be checked at any time according to the soil sampling condition, so that the real conditions of a pile body soil layer and a pile end bearing layer can be conveniently researched and judged, the pile length can be reasonably selected, and the design is optimized;

(4) the full sleeve is used for forming the hole to form the pile, so that the size and the shape of the section of the pile are easy to control, the filling magnitude is small, and materials are saved;

(5) no slurry pollution, neat and civilized construction site and good environmental protection effect.

The BNT technology in the prior art has the greatest advantages of high pile-forming quality and strong adaptability, but the problems of slow construction, high cost and large equipment are difficult to overcome, and the BNT technology also becomes the biggest obstacle to popularization and application. The BNT pile utilizes the shaking or the rotation of the hydraulic device to reduce the side resistance between the steel sleeve and the soil layer, and the punching grab bucket is used for digging and taking soil while shaking or rotating until the steel sleeve sinks to the pile end bearing layer. After the steel reinforcement cage is placed and concrete is poured, the steel sleeve is slowly pulled out in a sinking mode.

Both the prior art carrier piles and BNT piles have their limitations and cognitive differences, as well as a number of problems to be improved, perfected and developed:

(1) when the underground water level is high or the pressure-bearing water is encountered, the standard column hammer cannot be constructed due to the fact that water enters the pipe and mud enters the pipe; even when no underground water is used for construction of a wet and soft soil layer, the standard column hammer is very difficult to pull up under the double action of negative pressure and viscous force generated by pulling up the standard column hammer, and particularly in saturated sandy soil, the phenomenon of water inflow or sand gushing in a pipe is very easy to cause if the standard column hammer is forcibly pulled up, so that the construction is difficult to continue; more serious is the influence of factors such as the clearance between the true diameter of the standard column hammer and the inner diameter of the outer pipe, and when the standard column hammer falls freely to tamp the filler, the generated air resistance, water resistance, mud resistance and the like can directly cause the distortion of the actual tamping force effect and are difficult to be found, the bearing capacity of the pile is discrete, and the reliability of the construction quality is not high. Therefore, the original carrier pile can only be constructed under the condition of no underground water and dryness;

(2) partial potential of soil layer can not be fully utilized: the pile foundation generally selects a soil layer with higher bearing capacity and larger thickness and continuity as a bearing layer, but when no better natural bearing layer exists or the better natural bearing layer is buried deeper and is not easy to use, the soil layer with relatively good bearing capacity can also reach higher bearing capacity after reinforcement treatment, so that the great potential advantage of the carrier pile is ignored. But also one of the reasons for limited applicability;

(3) the pile diameter and the pile length have small selectable range and are also the important factors with limited applicability: the diameter of the standard column hammer determines the diameter range of the pile; the effective height of the pile frame limits the maximum length of the pile. Due to the restriction of process and equipment, the general carrier pile can only be used for the construction of a short pile with a small diameter;

(4) the construction of the carrier pile by using the standard column hammer has lower ramming frequency and lower construction efficiency, and the work efficiency is lower when meeting stratum conditions, the construction is carried out by using double hammers, the pile hammer or a vibration hammer in the prior art to improve the construction efficiency, but the vertical arrangement of the double hammers occupies most of the effective height of a pile frame, so that the actual pile length is limited, and the construction can only adapt to the construction of small pile diameter and short piles; because the requirement that the length of the inner pipe is greater than that of the outer pipe is met, the construction water-proof and silt-blocking measures are difficult to implement under the condition of high water level, and the pile-forming quality is difficult to control; in the double-hammer operation, the total mass and the height of the hammer form a challenge to the stability of the pile machine in the construction process, and the operation difficulty is increased, so that more technicians are required;

(5) in the prior art, the three-strike penetration is a key index for determining the bearing capacity of a carrier, and when a pile hammer or a vibration hammer is used as power to construct a carrier pile, the actual striking force of the pile hammer or the vibration hammer is different due to the fact that the models of the pile hammer or the vibration hammer are not uniform, but the requirements of the three-strike penetration are not easy to keep consistent, so that the design and construction are not dependent, and the construction quality is difficult to control;

(6) the special construction equipment has large investment amount, single function and limited equipment utilization rate, thereby causing investment waste;

(7) the construction efficiency is low: the hole is formed by hydraulic shaking or rotating, and the pipe sinking and drawing speed is slow; the small soil taking amount of the flushing grab bucket each time is low in frequency; the pile machine wastes time and labor when being in place and moved;

(8) the cost is big, the selectable specification of stake footpath is few: due to the investment of equipment and steel sleeves, common construction units lack economic strength and are difficult to prepare sleeves with various diameter specifications, so the pile diameter is limited to a certain extent; the method cannot be applied to small pile construction due to the limitation of processes and equipment;

(9) the equipment is huge: the construction needs a larger construction site, the distance from the boundary of the construction site to the center of the side pile also needs to be larger, and the construction site is difficult to maintain today with small dimension and gold.

Disclosure of Invention

The invention aims to provide a novel BNT carrier pile, a construction method of construction equipment of the novel BNT carrier pile and a construction method of the novel BNT carrier pile, which fully explores the advantages of high quality potential with high bearing capacity of the carrier pile, high pile quality and adaptability of the BNT technology, high bearing capacity, good effect, high speed, low cost and wider application range, and further improves the comprehensive bearing capacity by taking the BNT carrier pile as a platform.

In order to solve the technical problems, the novel BNT carrier pile comprises a pile body and a pile end carrier, wherein the pile body is a concrete column body, the cross section of the pile body is round, square or rectangular, and a reinforcement cage is arranged inside the pile body; the pile end carrier comprises a filler ramming entity and a compacted soil body; the reinforced soil layer is a natural bearing layer; the ramming body of the filling material is arranged in the natural bearing layer. The bearing capacity of the natural bearing layer serving as the bearing layer of the reinforced soil layer is increased from low to high, and the bearing capacity is increased from high to high; not only utilizes the advantage of high bearing capacity of the natural bearing layer, but also ensures that the reinforcement treatment is simple and easy, thereby obviously improving the bearing capacity and effectively improving the construction efficiency.

Furthermore, the cement mixture comprises anhydrous concrete, dry hard concrete, concrete with the same strength as the pile body and concrete or concrete fragments scattered on a construction site. When the bearing capacity characteristic value of the natural bearing layer is larger than or equal to 300Kpa, the pile end carrier is not provided with a filler tamping entity, and the natural bearing layer is directly tamped and reinforced. The filler variety is reasonably selected according to geological conditions to achieve the optimal compaction effect, so that the method is an important link which is not neglected and ensures half the effort, the materials are available, and the construction is convenient.

Furthermore, the pile body is an extruded and expanded pile, and the cross section of the pile body is three limbs or more. The comprehensive bearing capacity of the BNT carrier pile after the pile body is subjected to squeezing and expanding treatment by using the squeezing and expanding device can be obviously improved in compressive resistance, horizontal resistance, pulling resistance and the like.

Furthermore, the pile body is an occlusive pile, the pile body and the pile body are transversely overlapped and occluded, and the pile distance between the pile bodies is smaller than the pile diameter of the pile body. In the deep pit support with shallow underground water, the secant pile can well play roles of supporting, waterproofing and impermeability, can also be used as a part of a permanent structure to have good effect, and is a better process for replacing an underground continuous wall; compared with the underground continuous wall, the construction method can greatly reduce the equipment investment and the engineering cost, and has the characteristics of high construction speed, good quality and environmental protection.

Further, the pile body strength should satisfy the formula: q_u=KR_a<f_ckA_p(ii) a In the formula Q_u: a vertical bearing capacity limit value KN; k: a safety factor; r_a: a single-pile vertical bearing capacity characteristic value KN; f. of_ck: standard value of the compressive strength of the concrete axle center; a. the_p: square meter with pile body cross-sectional area.

A novel BNT carrier pile construction device comprises a pile frame system, a pile hammer, a hoisting system and a steel wire rope guide system, wherein the hoisting system is connected to the pile frame system; the method is characterized in that: the pile frame system comprises a working platform, the working platform is provided with a vertical rod and a pressurizing cantilever, the vertical rod is arranged at the front end of the working platform, the vertical rod is vertical to the working platform, and the pressurizing cantilever is arranged at the front end of the working platform; the inclined supports are arranged on the working platform and are obliquely connected between the working platform and the upright stanchions, the inclined supports are two, the two inclined supports are respectively connected to two sides of the upright stanchions, and the upright stanchions and the two inclined supports form a triangular stable structure; the top end of the vertical rod is also provided with a top pulley, and the front end of the vertical rod is also provided with a slideway. The hoisting system comprises a pressurization hoist, a main hoist and a hopper hoist, the main hoist is arranged on the upper side of the working platform and is arranged behind the vertical rod, the main hoist comprises a main hoist A cylinder and a main hoist B cylinder, the main hoist A cylinder is arranged on the front side of the main hoist B cylinder, and the hopper hoist is arranged below the main hoist; the upper end of the pile hammer is connected with a cylinder A of the main winch through a steel wire rope, and the steel wire rope is connected to the pulley block in a sliding manner; the hopper winch is also connected with a hopper, the hopper winch is connected with the hopper through a steel wire rope, and the steel wire rope is connected to the top pulley block in a sliding manner; a walking crawler, a chassis and a slewing bearing are further arranged below the working platform, the slewing bearing is connected to the lower side of the working platform, the chassis is connected between the walking crawler and the slewing bearing, and a slewing reducer is further arranged on the side surface of the slewing bearing; the working platform is also provided with a plurality of hydraulic support legs; the working platform is also provided with a hydraulic oil pump, a distribution board and an operating platform; the walking pedrail, the chassis and the slewing bearing can lead the working platform to do slewing movement in all directions and 360 degrees.

Furthermore, when the diameter of the pile body is less than or equal to 500mm and the length of the pile body is less than or equal to 15M, and soil squeezing and hole forming construction is adopted due to the limitation of the height of a pile frame, the lower end of the pile hammer is also connected with a force transfer rod, the lower end of the force transfer rod is also connected with a tamping head, the force transfer rod and the tamping head are also connected in a sleeve in a sliding manner, the upper end of the sleeve is also connected with a steel wire rope, the steel wire rope is connected on a top pulley block in a sliding manner, and the steel wire rope is; the hopper winch is connected with a steel wire rope which is connected to the top pulley block in a sliding manner, and the steel wire rope is connected with a hopper; the upper end of the sleeve is provided with a filling port; the dowel bar is a steel cylinder, the total length of the dowel bar and the tamper head is 80-120 mm smaller than the length of the sleeve, the length-to-diameter ratio of the dowel bar is 55-65, the tamper head is a flat bottom, and the diameter ratio of the tamper head is 20-40mm smaller than the inner diameter of the sleeve.

The upper end of the pile hammer is connected with a steel wire rope of a cylinder A of the main winch, the steel wire rope suspends the pile hammer on a vertical rod through a pulley block at the top and is in sliding connection with the vertical rod through a slideway, the lower end of the steel wire rope is connected with a force transmission rod and then is connected with a tamping head, the force transmission rod and the tamping head are inserted into a sleeve, and the force transmission rod and the tamping head can move up and down in the sleeve along the slideway of the vertical rod under the action of the steel wire rope of the cylinder A of the main winch; the upper end of the sleeve is connected with a steel wire rope and is connected with a B cylinder of a main winch through a pulley block at the top of the vertical rod, and the dowel bar, the tamping head and the sleeve can respectively move up and down; the construction material is hoisted, a hopper or a hook is connected with a hopper steel wire rope, and the hopper or the hook is connected with a hopper winch through a top pulley block, so that the construction material can be vertically transported.

The dowel bar replaces a standard column hammer and has the advantages that: the problems of air resistance, mud resistance and water resistance generated during the construction of the standard column hammer are well solved; the length of the force transmission rod is shorter than that of the sleeve, a waterproof and siltation-resistant pipe plug can be formed when the force transmission rod synchronously sinks, and muddy water can be effectively prevented from entering the sleeve; the length of the sleeve is 80mm-120mm longer than that of the force transmission rod, if the thickness of the pipe plug formed by exceeding 120mm is too large, the filling material is difficult to knock out the sleeve, and if the thickness of the pipe plug is short and 80mm, the thickness of the pipe plug is small, so that the waterproof performance is not facilitated; the diameter of the tamping head of the dowel bar is 20-40mm smaller than the inner diameter of the sleeve, so that the tamping head of the dowel bar can be ensured to move up and down smoothly in the sleeve without causing overlarge gap; the ratio of the length to the diameter of the force transmission rod is preferably 55-65, the rigidity of the force transmission rod is mainly ensured under the action of hammering, if the ratio is more than 65, the deflection of the force transmission rod is increased under the action of hammering, so that the hammering force cannot be truly reflected at the pile end, and if the ratio is less than 55, the diameter of the sleeve is restricted; the force transmission rod is used for replacing a standard column hammer, so that the important measures of realizing diversification of construction methods and construction equipment, expanding the application range and ensuring the construction quality are achieved, and meanwhile, the important link for improving the construction efficiency is achieved.

In the construction equipment, the sleeve is round or rectangular or square, the upper end of the sleeve is provided with a material port, and construction materials can be fed through the material port at the upper end of the sleeve by connecting a steel wire rope of a hopper winch on the pile frame with the hopper. The material opening is a main channel for feeding fillers, placing a reinforcement cage and pouring concrete, and is also an important measure for simplifying the filling process and improving the work efficiency.

Furthermore, when the diameter of the pile body is larger than 500mm and the length of the pile body is larger than 15M, the pile hammer is subjected to soil sampling hole forming construction, the lower end of the pile hammer is connected with a sleeve chuck and a dowel bar chuck, a sleeve is clamped on the sleeve chuck, a dowel bar is clamped on the dowel bar chuck, and the lower end of the dowel bar is connected with a soil sampler; the cylinder B of the main winch is connected with a steel wire rope, the steel wire rope is also connected with a column hammer, and the steel wire rope is connected to a top pulley block in a sliding manner; the length of the soil sampler is 1.5M longer than that of the tamper head, and the cross section of the sleeve is circular, rectangular or square; the sleeve is provided with a plurality of sections, and the lower end of the first section of sleeve is in a sawtooth shape.

When the soil taking and hole forming construction is carried out, the connection of the upper end of the pile hammer is the same as that of the upper end of the pile hammer during the soil squeezing and hole forming construction, the lower end of the pile hammer is connected with the sleeve chuck and the dowel bar chuck, the sleeve chuck is firstly used for clamping the first section of sleeve and sinking into the soil according to requirements, then the sleeve chuck is loosened, if the length of the sleeve cannot meet the design requirements, the lower end of the second section of sleeve can be connected with the upper end of the first section of sleeve, and the upper end of the second section of sleeve is clamped by the sleeve chuck and continues sinking, so that the process is repeated until the design requirements. Replacing the dowel bar and clamping the dowel bar by using a dowel bar chuck, wherein the lower end of the dowel bar is connected with a special soil sampler, and when the length of the dowel bar cannot meet the construction requirement, the dowel bar can be lengthened according to a sleeve connection method to carry out soil sampling operation; when the standard or non-standard column hammer is used for implementing the filling material tamping, the upper end of the column hammer is connected with a steel wire rope of a cylinder B of a main winch, the steel wire rope is hung on a vertical rod through a top pulley block, and can be lifted upwards and fall freely under the action of the steel wire rope of the cylinder B of the main winch, and the loading and unloading of heavy or large objects with small radius can be realized; the vertical transportation connection mode of construction materials or small objects is the same as that of soil extrusion hole forming construction.

Furthermore, the pile hammer is a diesel pile hammer, a vibrating pile hammer or a non-standard pile hammer,

according to JG/T5109-1999 guide rod type diesel pile hammer, the diesel pile hammer reaches the medium jump standard, namely the cylinder stroke is 80% of the maximum stroke of the cylinder:

N₁=P_b/A_b/Z_jP_c=2654A_g/P_c

in the formula N₁: hammering energy P of one stroke of standard column hammer_aHammering energy P with diesel pile hammer_cEquivalent of (2) converting the hit number; p_b: the standard column hammer one-shot peening energy is 210 KN; a. the_b: bottom area of standard column hammer is square meter; z_j: the reduction coefficient of hammering energy of the diesel pile hammer is 0.8; p_c: the used diesel pile hammer hammering energy KN/M; a. the_g: a casing pipe cross-sectional area of a square meter;

the vibratory pile hammer meets the requirements that the current A and the voltage V accord with relevant national regulations:

S₁≦280A_g/N_rHA_bZ_j=5660A_g/NrH

in the formula S₁: hammering energy P of one stroke of standard column hammer_aThe time equivalent value of hammering energy of the vibration hammer; 280: a standard column hammer hammering energy value KN.M/second; a. the_g: the bottom area of the vibration hammer is square meter; n: the vibration hammer exciting force KN; a. the_b: bottom area of standard column hammer is square meter; r: vibrating at the second rotation speed of the hammer; z_j: the reduction amount is 0.5; p_c: the used diesel pile hammer hammering energy KN/M; h: vibration hammer amplitude m;

the nonstandard column hammer meets the condition that the free falling distance of the column hammer is 6 meters:

G<354A_f

in the formula, G: a non-standard ram weight kN; a. the_f: cross sectional area of non-standard columnm²；

The novel BNT carrier pile construction method comprises the following steps:

1) selecting a hole forming mode, wherein the hole forming mode is selected according to the diameter of the pile body and the length of the pile body;

1.1) the diameter of a pile body is less than or equal to 500mm, the length of the pile body is less than or equal to about 15M, and a soil extrusion hole forming mode is preferably selected;

1.2) the diameter of the pile body is more than 500mm, and the length of the pile body is more than 15M, preferably adopting a soil taking and hole forming mode;

2) the pile driver is in place, the sleeve pipe is aligned with the pile position, the pile frame is adjusted, and the pipe is sunk;

2.1) soil extrusion pore-forming mode: connecting the upper end of a dowel bar with a pile hammer, connecting the lower end of the dowel bar with a rammer head, placing the connected dowel bar, the pile hammer and the rammer head in a sleeve, and synchronously sinking the sleeve and the dowel bar into the soil until reaching a natural bearing stratum;

2.2) a soil taking and hole forming mode: sinking the sleeve into the bearing stratum by a pile hammer, connecting the upper end of a dowel bar with the pile hammer, connecting the lower end of the dowel bar with a soil sampler, and synchronously sinking the sleeve and the dowel bar into the soil until the bearing stratum;

3) pulling out the dowel bar, putting the filler into the sleeve, and tamping and reinforcing the filler by using the dowel bar to form a filler tamping body; when the bearing capacity characteristic value of the natural bearing layer is larger than or equal to 300kpa, directly tamping and reinforcing the natural bearing layer without adding fillers;

4) placing a steel reinforcement cage in the sleeve, and pouring concrete;

5) pulling out the sleeve and forming a pile;

5.1) extruding soil to form holes: firstly pressing a dowel bar on concrete in a sleeve, slowly pulling out the sleeve, and compacting the concrete on the pile top within the range of 2-4m by using a vibrating rod;

when soil is taken out and holes are formed: the casing is slowly pulled out by the pile hammer vibration force when the pile hammer is started.

When the natural bearing stratum is deeply buried in the step 2), sinking the first section of sleeve by using a pile hammer, connecting the second section with the first section, and continuing to sink to the bearing stratum; then the upper end and the lower end of the dowel bar are respectively connected with the pile hammer and the soil sampler, and soil is sampled until reaching a bearing stratum; when a hard interlayer is encountered, the sleeve can be continuously sunk after soil is taken out in advance, and the alternate operation is repeated until a bearing stratum is reached; when the soil layer is well formed, is not easy to collapse and has no underground water, the first section of the sleeve can be sunk, and then the soil sampler is used for directly sampling soil to the bearing stratum.

The novel BNT carrier pile and the construction equipment thereof can not only diversify construction equipment and modes and achieve the purposes of high pile forming quality, large bearing capacity and high construction speed, but also can adapt to changeable geological conditions, greatly expand the application range, have good universality and high utilization rate of the construction equipment, and can meet the increasingly high requirements of various geological conditions and engineering construction by replacing other construction power devices to carry out pile foundation construction of different pile types and different processes.

The invention has the beneficial effects that:

1. the pile forming concept of the original carrier pile and the error area in the construction method are changed, and the high-quality potential of the bearing capacity is effectively excavated; the safety of the pile under the high-load condition is ensured; according to the criterion of three-strike penetration, conditions are created for diversification of construction equipment and methods, and the design and construction can be based on the following steps:

2. the pile forming quality can be guaranteed; the problems that the original carrier body pile is not suitable for construction in a high water level and soft and wet soil layer and the applicability is limited due to the conditions of pile diameter, pile length and the like are solved; the method has the advantages of simple removal and storage, and optimized process, so that the construction efficiency is effectively improved:

3. the pile body is squeezed and expanded, so that the comprehensive capabilities of the pile such as compression resistance, horizontal resistance, pulling resistance and the like are improved; provides material guarantee and technical support for the construction of the occlusive piles, and lays a foundation for meeting different requirements of various projects on pile foundations.

Drawings

Fig. 1 is a schematic structural view of the novel BNT carrier pile of the present invention;

FIG. 2 is a schematic structural view of the novel occlusive pile body;

FIG. 3 is a schematic structural view of an extruded and expanded pile according to the present invention;

FIG. 4 is a cross-sectional view A-A of FIG. 3 according to the present invention;

FIG. 5 is a front view of a first embodiment of the construction apparatus of the present invention;

FIG. 6 is a left side view of a first embodiment of the construction apparatus of the present invention;

FIG. 7 is a top view of a first embodiment of the apparatus of the present invention;

FIG. 8 is a front view of a second embodiment of a construction apparatus according to the present invention;

FIG. 9 is a left side view of a second embodiment of the construction apparatus of the present invention;

FIG. 10 is a schematic flow chart of the soil-extruding hole-forming construction method of the present invention;

FIG. 11 is a schematic flow chart of the construction method for taking soil and forming holes.

In the figure: 1. walking is carried out; 2. a chassis; 3. a slewing bearing; 4. a slewing reducer; 5. a working platform; 6. a hydraulic leg; 7. a pressurized winch; 8. a main winch A drum; 9. a main winch B drum; 10. a hopper; 11. a hydraulic oil pump; 12. a switchboard; 13. a hopper winch; 14. an operation table; 15. a dowel bar; 16. a sleeve; 17. pressurizing the cantilever; 18. a pile hammer; 19. obliquely supporting; 20. erecting a rod; 21. a top pulley block; 22. tamping a head; 23. a filling opening; 24. a sleeve chuck; 25. a dowel bar clamp; 26. a column hammer; 27. a soil sampler; 28. a pile frame system; 29. a main hoist; 30. a hoisting system; 31. a wire rope guide system; 3501. a pile body; 3502. a pile end carrier; 3503. tamping a filling material into a solid body; 3504. compacting soil; 3505. reinforcing a soil layer; 3506; a natural strength layer.

Detailed Description

As shown in fig. 1, the novel BNT carrier pile of the present invention comprises a pile body 3501 and a pile end carrier 3502, wherein the pile body 3501 is a concrete column, the cross-sectional shape of the pile body 3501 is circular, square or rectangular, and a reinforcement cage is arranged inside the pile body 3501; the pile end carrier 3502 comprises a filler ramming body 3503 and a compacted soil body 3504; the reinforced soil layer 3505 is a natural bearing layer 3506; the stuffing ramming mass 3503 is arranged in the natural bearing layer 3506; the filling material of the filling material ramming entity 3503 comprises broken stones, pebbles and cement mixture, and the cement mixture comprises anhydrous concrete, dry hard concrete, concrete with the same strength as the pile body 3501, and concrete or concrete fragments scattered on a construction site.

As shown in fig. 3 and 4, the pile 3501 is an extruded pile, and the cross section of the pile 3501 is three limbs or more.

As shown in fig. 2, the pile bodies 3501 are snap piles, the pile bodies 3501 and the pile bodies 3501 are transversely overlapped and snapped, and the pile distance between the pile bodies 3501 is smaller than the pile diameter of the pile bodies 3501.

As shown in fig. 5, 6, and 7, the construction equipment for a novel BNT carrier according to the present invention is a structural schematic diagram of an embodiment i.e. a pile 3501 with a diameter less than or equal to 500mm and a pile 3501 with a diameter less than or equal to 15M, and adopts a soil extrusion hole-forming construction due to the limitation of the pile height, and uses the power of the hammer position of a diesel pile, and as shown in the figure, the construction equipment further includes a pile frame system 28, a pile hammer 18, a hoisting and hoisting system 30, and a steel wire rope guiding system 31, the hoisting and hoisting system 30 is connected to the pile frame system 28, and the pile frame system 28 is moved up and down by the hoisting and hoisting system 30; the steel wire rope guide system 31 is connected between the hoisting system 30 and the pile hammer 18, and the pile hammer 18 moves up and down through the hoisting system 30; the method is characterized in that: the pile frame system 28 comprises a working platform 5, the working platform 5 is provided with an upright 20 and a pressurizing cantilever 17, the upright 20 is arranged at the front end of the working platform 5, the upright 20 is vertical to the working platform 5, and the pressurizing cantilever 17 is arranged at the front end of the working platform 101; the working platform 5 is also provided with two inclined supports 19, the inclined supports 19 are arranged at the rear end of the working platform 5, the inclined supports 19 are obliquely connected between the working platform 5 and the upright 20, the two inclined supports 19 are respectively connected to two sides of the upright 20, and the two inclined supports 19 and the upright 20 form a triangular stable structure; the top end of the upright rod 20 is also provided with a top pulley 21, and the front end of the upright rod 20 is also provided with a slideway. The hoisting and hoisting system 30 comprises a pressurizing hoisting machine 7, a main hoisting machine 29 and a hopper hoisting machine 13, wherein the main hoisting machine 29 is arranged on the upper side of the working platform 5, the main hoisting machine 29 is arranged behind the upright stanchion 20, the main hoisting machine 29 comprises a main hoisting machine A cylinder 8 and a main hoisting machine B cylinder 9, the main hoisting machine A cylinder 8 is arranged on the front side of the main hoisting machine B cylinder 9, and the hopper hoisting machine 13 is arranged below the main hoisting machine 29; the upper end of the pile hammer 18 is connected with the main winch A cylinder 8 through a steel wire rope, and the steel wire rope is connected to the top pulley block 21 in a sliding mode. The lower end of the pile hammer 18 is also connected with a dowel bar 15, the lower end of the dowel bar 15 is also connected with a tamping head 22, the dowel bar 15 and the tamping head 22 are also connected in a sleeve 16 in a sliding manner, the upper end of the sleeve 16 is also connected with a steel wire rope (marked in the attached drawing), the steel wire rope is connected on a top pulley block 21 in a sliding manner, and the steel wire rope is connected with a B cylinder 9 of a main winch; the hopper winch 13 is connected with a steel wire rope which is connected on the top pulley block 21 in a sliding way, and the steel wire rope is connected with a hopper 10; the upper end of the sleeve 16 is provided with a filling opening 23; the hopper 10 for vertical transportation of small articles or construction materials is connected with a steel wire rope, and then connected with the hopper winch 13 through the top pulley block 21, so that the vertical transportation of the construction materials can be realized.

The dowel bar 15 is a steel cylinder, the total length of the dowel bar 15 and the tamper head 22 is 80mm-120mm smaller than the length of the sleeve 16, the length-to-diameter ratio of the dowel bar 15 to the tamper head 22 is 55-65, the tamper head 22 is a flat bottom, and the diameter of the tamper head 22 is 20mm-40mm smaller than the inner diameter of the sleeve 16. A walking crawler 1, a chassis 2 and a slewing bearing 3 are further arranged below the working platform 5, the slewing bearing 3 is connected to the lower side of the working platform 5, the chassis 2 is connected between the walking crawler 1 and the slewing bearing 3, and a slewing reducer 4 is further arranged on the side surface of the slewing bearing 3; the working platform 5 is also provided with a plurality of hydraulic support legs 6; the working platform 5 is also provided with a hydraulic oil pump 11, a distribution board 12 and an operation platform 14, and the walking 1, the chassis 2 and the slewing bearing 3 can make the working platform 5 perform slewing movement in all directions and 360 degrees.

Fig. 8 and 9 show a schematic structural diagram of a second embodiment of the novel BNT carrier construction equipment of the present invention, which is different from the first embodiment in that a casing chuck 24 and a dowel bar chuck 25 are connected to the lower end of a pile hammer 18, a casing 16 is clamped on the casing chuck 24, a dowel bar 15 is clamped on the dowel bar chuck 25, and a soil sampler 27 is connected to the lower end of the dowel bar 15, wherein the diameter of the pile body 3501 is greater than 500mm, the length of the pile body 3501 is greater than 15M, and a hole is formed by soil sampling; the B cylinder of the main winch is connected with a steel wire rope, the steel wire rope is also connected with a column hammer 26, and the steel wire rope is connected to the top pulley block 21 in a sliding manner; the length of the soil sampler (27) is 1.5M longer than that of the tamper head (22), and the cross section of the sleeve (16) is circular, rectangular or square; the sleeve (16) is provided with a plurality of sections, and the lower end of the first section of sleeve (16) is in a sawtooth shape; during construction, a first section of sleeve 16 is clamped by a sleeve chuck 24, and is sunk into soil according to requirements, then the chuck is loosened, if the length of the sleeve cannot meet the design requirements, the lower end of a second section of sleeve 16 can be connected with the upper end of the first section of sleeve 16, the upper end of the second section of sleeve 16 is clamped by the sleeve chuck 24 to continue sinking, if the length of the sleeve cannot meet the design requirements, a dowel bar 15 is replaced and clamped by a dowel bar chuck 25, the lower end of the dowel bar 15 is connected with a soil sampler 27, and when the dowel bar 15 cannot meet the construction requirements, the dowel bar 15 can be lengthened according to the connection mode of the sleeve 16; the geological condition permits that the standard or non-standard column hammer 26 can be used for tamping the filling material, the upper end of the column hammer 26 is connected with the steel wire rope of the main winding machine B cylinder 9 and is hung on the vertical rod through the top pulley block 21, the vertical rod can be lifted upwards and fall freely under the action of the steel wire rope of the main winding machine B cylinder 9, and the loading and unloading of heavy and large objects with small radius can be realized.

The construction method comprises the following steps:

1) selecting a hole forming mode, wherein the hole forming mode is selected according to the diameter of the pile body 3501 and the length of the pile body 3501;

1.1) the diameter of a pile body 3501 is less than or equal to 500mm, the length of the pile body 3501 is less than or equal to 15M, and a soil extrusion pore-forming mode is preferably adopted;

1.2) the diameter of the pile body 3501 is more than 500mm, and the length of the pile body 3501 is more than 15M, preferably selecting a mode of taking earth and forming holes;

2) the construction equipment is in place, the sleeve 16 is aligned with the pile position, the working platform 5 is adjusted, and the pipe is sunk;

2.1) soil extrusion pore-forming mode: connecting the upper end of a dowel bar 15 with a pile hammer 18, connecting the lower end of the dowel bar 15 with a tamper head 22, placing the connected dowel bar 15, pile hammer 18 and tamper head 22 in a sleeve 16, and synchronously sinking the sleeve 16 and dowel bar 15 into the soil until a natural bearing stratum 3506;

2.2) a soil taking and hole forming mode: sinking the sleeve 16 into the natural bearing stratum 3506 by using the pile hammer 18, connecting the upper end of the dowel bar 15 with the pile hammer 18, connecting the lower end of the dowel bar 15 with the soil sampler 27, and synchronously sinking the sleeve 16 and the dowel bar 15 into the soil until reaching the natural bearing stratum 3506;

3) pulling out the dowel bar 15, putting the filler into the sleeve 16, and tamping and reinforcing the filler by using the dowel bar 15 to form a filler tamping body 3503; when the bearing capacity characteristic value of the natural bearing layer 3506 is not less than 300kpa, the natural bearing layer 3506 is directly tamped without adding filler;

4) placing a steel reinforcement cage in the sleeve 16 and pouring concrete;

5) pulling out the sleeve 16 to form a pile;

5.1) extruding soil to form holes: firstly, pressing a dowel bar 15 on concrete in a sleeve 16, slowly pulling out the sleeve 16, and compacting the concrete on the pile top within the range of 2-4m by using a vibrating rod;

when soil is taken out and holes are formed: starting the hammer 18 to slowly pull out the casing 16 by the vibration force of the hammer 18;

in the step 2, when the natural bearing stratum 3506 is deeply buried, the first casing 16 is sunk by the pile hammer 18, and then the second casing 16 is connected with the first casing 16 and then sinks to the natural bearing stratum 3506; then the upper end and the lower end of the dowel bar 15 are respectively connected with the pile hammer 18 and the soil sampler 27, and soil is sampled until the natural bearing stratum 3506 is reached; when a hard interlayer is encountered, the casing 16 can be continuously sunk after soil is taken out in advance, and the alternate operation is repeated until the natural bearing stratum 3506 is reached; when the soil layer is well formed, is not easy to collapse and has no underground water, the first section of the sleeve 16 can be sunk and then the soil sampler 27 can be used for directly sampling soil to the bearing stratum.

FIG. 10 is a flow chart of a construction method of a first embodiment of the novel BNT carrier construction equipment for soil extrusion and hole forming and using a diesel pile hammer position power: as shown in the figure, the lower end of the transmission rod 15 is connected with the rammer head 22 and inserted into the sleeve 16, then the transmission rod 15 and the sleeve 16 are synchronously sunk into the natural bearing layer 3506, at this time, a waterproof siltation pipe plug is formed, then the transmission rod 15 is pulled out, the filler is put into the sleeve 16 and then inserted into the transmission rod 15, the filler is beaten out of the sleeve 16 by the transmission rod 15, when the bearing characteristic value of the natural bearing layer 3506 is not less than 300KPa, the filler can not be thrown, and the step can be reduced, the transmission rod 15 and the sleeve 16 are simultaneously tamped repeatedly by a pile hammer until the requirement of three-stroke penetration degree is met, and a filler ramming entity 3503 is formed; placing a steel reinforcement cage, and filling concrete in the sleeve 16; the tamper head 22 is pressed against the concrete in the sleeve 16, the sleeve 16 is slowly pulled out, and finally the concrete in the range of 2-4m of the pile top is compacted by the vibrator.

FIG. 11 is a flow chart of a construction method of a second embodiment of the present invention in which a novel BNT carrier construction device is used for taking soil and forming a hole and using a vibratory pile hammer as power, wherein as shown in the figure, a first section of casing 16 is first sunk into the soil; when the bearing stratum is deeply buried, the lower end of the second section of sleeve 16 can be connected with the upper end of the first section of sleeve 16 and then continuously subsided, and the process is repeated until the natural bearing stratum 3506 is reached; then the lower end of the dowel bar 15 is connected with a soil sampler 27 for soil sampling operation, and when the natural bearing stratum 3506 is buried deeply, the dowel bar 15 is lengthened to take soil in a manner similar to the casing 16; when encountering a hard soil layer, the first section of casing 16 can be sunk firstly, then the dowel bar 15 is connected with the soil sampler 27 for taking soil in advance, and then the casing 16 is sunk, and the operation is crossed until the natural bearing layer 3506 is reached; when the soil layer forming effect is good, the soil layer is not easy to collapse and no underground water exists, the first section of sleeve 16 can be sunk and then is connected with the soil sampler 27 through the dowel bar 15 for direct soil sampling) until reaching the bearing stratum C; as shown in fig. 11, pulling out the dowel 15, removing the geotome 27, replacing the tamper head 22, and throwing the filling material into the casing 16, when the characteristic value of the bearing capacity of the natural bearing layer 3506 is greater than 300KPa, the filling material can be not thrown, and the step can be omitted; tamping the filling material by using the dowel bar 15 and the tamping head 22 according to the requirement of three-stroke penetration, and when no water exists in the sleeve 16, tamping by using a standard or non-standard column hammer; placing a steel reinforcement cage and pouring concrete in the sleeve 16, and then, if water enters the sleeve, performing underwater concrete pouring by using a guide pipe; finally the casing 16 is extracted by the vibration of the hammer 18.

In 2017, different carrier pile structures are adopted under the same conditions of geology, pile diameter and pile length, and different results are obtained: the bearing capacity characteristic values of the carrier pile in the prior art and the novel BNT carrier pile are 1100KN and 2000KN respectively through detection tests, the construction efficiency of the carrier pile is several times that of the carrier pile in the prior art and the novel BNT carrier pile, and the effect is obvious. In a certain cell project in 6 months in 2018, due to the fact that the buried depth of the better natural bearing layer 3506 is deeper, powder clay with the buried depth of about 13 meters is selected as the natural bearing layer 3506 for cost reasons, and the bearing capacity characteristic value of the project is only 110 KPa; the pile diameter is adopted, the thickness is 450 mm, the pile length is 13.5-14M, and after the natural bearing layer 3506 is subjected to reinforcement treatment, the vertical bearing capacity characteristic value of the single pile is Ra =1750KN through detection.

The novel BNT carrier pile and the construction method of the construction equipment thereof can not only diversify the construction equipment and the construction mode and achieve the purposes of high pile-forming quality, large bearing capacity and high construction speed, but also can adapt to changeable geological conditions, greatly expand the application range, simultaneously have good universality of the construction equipment and high utilization rate, and can meet the increasingly high requirements of various geological conditions and engineering construction by replacing other construction power devices to carry out pile foundation construction of different pile types and different processes.

Claims

1. The utility model provides a novel BNT carrier pile which characterized in that: the pile comprises a pile body (3501) and a pile end carrier (3502), wherein the pile body (3501) is a concrete column, the cross section of the pile body (3501) is round, square or rectangular, and a reinforcement cage is arranged in the pile body (3501); the pile end carrier (3502) comprises a filler ramming entity (3503) and a compacted soil body (3504); the reinforced soil layer (3505) is a natural bearing layer (3506); the ramming mass of the filling material (3503) is arranged in the natural bearing layer (3506).

2. The novel BNT carrier pile according to claim 1, wherein: the filling material of the filling material ramming entity (3503) comprises broken stones, pebbles and cement mixture, and the cement mixture comprises anhydrous concrete, dry hard concrete, concrete with the same strength as the pile body (3501), concrete scattered on a construction site or concrete fragments; when the bearing capacity characteristic value of the natural bearing layer (3506) is not less than or equal to 300Kpa, the pile end carrier (3502) is not provided with the filler tamping body (3503), and the natural bearing layer (3506) is directly tamped and reinforced.

3. The novel BNT carrier pile according to claim 1, wherein: the pile body (3501) is an extruded and expanded pile, and the cross section of the pile body (3501) is three limbs or more.

4. The novel BNT carrier pile according to claim 1, wherein: the pile body (3501) is an engaged pile, the pile body (3501) and the pile body (3501) are transversely overlapped and engaged, and the pile distance between the pile bodies (3501) is smaller than the pile diameter of the pile body (3501).

5. The novel BNT carrier pile according to claim 1, wherein: the strength of the pile body (3501) meets the formula:

Q_u=KR_a<f_ckA_p；

in the formula, Qu: a vertical bearing capacity limit value KN; k: a safety factor; r_a: a single-pile vertical bearing capacity characteristic value KN; fck: standard value of the compressive strength of the concrete axle center; a. the_p: square meter with pile body cross-sectional area.

6. A novel BNT carrier pile construction device comprises a pile frame system (28), a pile hammer (18), a hoisting system (30) and a steel wire rope guide system (31), wherein the hoisting system (30) is connected to the pile frame system (28), the steel wire rope guide system (31) is connected between the hoisting system (30) and the pile hammer (18), and the pile hammer (18) moves up and down through the hoisting system (30); the method is characterized in that: the pile frame system (28) comprises a working platform (5), wherein the working platform (5) is provided with an upright rod (20) and a pressurizing cantilever (17), the upright rod (20) is arranged at the front end of the working platform (5), the upright rod (20) is vertical to the working platform (5), and the pressurizing cantilever (17) is arranged at the front end of the working platform (101); the working platform (5) is also provided with inclined supports (19), the inclined supports (19) are arranged at the rear end of the working platform (5), the inclined supports (19) are obliquely connected between the working platform (5) and the upright stanchion (20), the number of the inclined supports (19) is two, and the two inclined supports (19) are respectively connected to two sides of the upright stanchion (20); the top end of the upright rod (20) is also provided with a top pulley block (21), and the front end of the upright rod (20) is also provided with a slideway; the hoisting and hoisting system (30) comprises a pressurization hoist (7), a main hoist (29) and a hopper hoist (13), wherein the main hoist (29) is arranged on the upper side of the working platform (5), the main hoist (29) is arranged behind the vertical rod (20), the main hoist (29) comprises a main hoist A cylinder (8) and a main hoist B cylinder (9), the main hoist A cylinder (8) is arranged on the front side of the main hoist B cylinder (9), and the hopper hoist (13) is arranged below the main hoist (29); the upper end of the pile hammer (18) is connected with a main winch A cylinder (8) through a steel wire rope, and the steel wire rope is connected to a top pulley block (21) in a sliding manner; the hopper winch (13) is also connected with a hopper (10), the hopper winch (13) is connected with the hopper (10) through a steel wire rope, and the steel wire rope is connected to the top pulley block (21) in a sliding manner; a walking crawler (1), a chassis (2) and a slewing bearing (3) are further arranged below the working platform (5), the slewing bearing (3) is connected to the lower side of the working platform (5), the chassis (2) is connected between the walking crawler (1) and the slewing bearing (3), and a slewing reducer (4) is further arranged on the side surface of the slewing bearing (3); the working platform (5) is also provided with a plurality of hydraulic support legs (6), and the hydraulic support legs (6) are arranged; the working platform (5) is also provided with a hydraulic oil pump (11), a distribution board (12) and an operation table (14).

7. The construction equipment of the BNT carrier pile according to claim 6, wherein: the lower end of the pile hammer (18) is further connected with a force transmission rod (15), the lower end of the force transmission rod (15) is further connected with a tamping head (22), the force transmission rod (15) and the tamping head (22) are further connected in a sleeve (16) in a sliding mode, the upper end of the sleeve (16) is further connected with a steel wire rope, the steel wire rope is connected to a top pulley block (21) in a sliding mode, and the steel wire rope is connected with a B cylinder (9) of a main winch; the hopper winch (13) is connected with a steel wire rope which is connected to the top pulley block (21) in a sliding manner, and the steel wire rope is connected with a hopper (10); the upper end of the sleeve (16) is provided with a filling opening (23); the dowel bar (15) is a steel cylinder, the total length of the dowel bar (15) and the tamper head (22) is 80-120 mm smaller than the length of the sleeve (16), the length-to-diameter ratio of the dowel bar (15) is 55-65, the tamper head (22) is a flat bottom, and the diameter of the tamper head (22) is 20-40mm smaller than the inner diameter of the sleeve (16).

8. The construction equipment of the BNT carrier pile according to claim 6, wherein: the lower end of the pile hammer (18) is connected with a sleeve chuck (24) and a dowel bar chuck (25), a sleeve (16) is clamped on the sleeve chuck (24), a dowel bar (15) is clamped on the dowel bar chuck (25), and the lower end of the dowel bar (15) is connected with a soil sampler (27); the B cylinder of the main winch is connected with a steel wire rope, the steel wire rope is also connected with a column hammer (26), and the steel wire rope is connected to a top pulley block (21) in a sliding manner; the length of the soil sampler (27) is 1.5M longer than that of the tamper head (22), and the cross section of the sleeve (16) is circular, rectangular or square; the casing (16) is provided with a plurality of sections, and the lower end of the first section of casing (16) is in a sawtooth shape.

9. The construction equipment of the BNT carrier pile according to claim 6, wherein: the pile hammer (18) is a diesel pile hammer, a vibrating pile hammer or a non-standard pile hammer, the diesel pile hammer is configured according to JG/T5109-1999 guide rod type diesel pile hammer standard, the diesel pile hammer reaches the medium jump standard, and the cylinder stroke is 80% of the maximum stroke of the cylinder:

N₁=P_b/A_b/Z_jP_c=2654A_g/P_c

S₁≦280A_g/N_rHA_bZ_j=5660A_g/NrH

in the formula S₁: hammering energy P of one stroke of standard column hammer_aThe time equivalent value of hammering energy of the vibration hammer; 280: a standard column hammer hammering energy value KN.M/second; a. the_g: the bottom area of the vibration hammer is square meter; n is a radical of: the vibration hammer exciting force KN; a. the_b: bottom area of standard column hammer is square meter; r: vibrating at the second rotation speed of the hammer; z_j: the reduction amount is 0.5; p_c: the used diesel pile hammer hammering energy KN/M; h: vibration hammer amplitude m;

G<354A_f

in the formula, G: a non-standard ram weight kN; a. the_f: cross-sectional area m of non-standard column hammer²。

10. A construction method of a novel BNT carrier pile is characterized in that: the construction method comprises the following steps:

1) selecting a hole forming mode, wherein the hole forming mode is selected according to the diameter of the pile body (3501) and the length of the pile body (3501);

1.1) the diameter of the pile body (3501) is less than or equal to 500mm, the length of the pile body (3501) is less than or equal to 15M, and a soil extrusion pore-forming mode is preferably adopted;

1.2) the diameter of the pile body (3501) is more than 500mm, and the length of the pile body (3501) is more than 15M, preferably adopting a soil-taking hole-forming mode;

2) the construction equipment is in place, the sleeve (16) is aligned with the pile position, the working platform (5) is adjusted, and the pipe is sunk;

2.1) soil extrusion pore-forming mode: connecting the upper end of a dowel bar (15) with a pile hammer (18), connecting the lower end of the dowel bar (15) with a tamper head (22), placing the connected dowel bar (15), pile hammer (18) and tamper head (22) in a casing (16), and synchronously sinking the casing (16) and the dowel bar (15) into the soil until a natural bearing stratum (3506);

2.2) a soil taking and hole forming mode: sinking the sleeve (16) into a natural bearing stratum (3506) by using a pile hammer (18), connecting the upper end of a dowel bar (15) with the pile hammer (18), connecting the lower end of the dowel bar (15) with a soil sampler (27), and synchronously sinking the sleeve (16) and the dowel bar (15) into the soil until the natural bearing stratum (3506);

3) pulling out the dowel bar (15), putting the filler into the sleeve (16), and tamping and reinforcing the filler by using the dowel bar (15) to form a filler tamping body (3503); when the bearing capacity characteristic value of the natural bearing layer (3506) is larger than 300kpa, the natural bearing layer (3506) is directly tamped and reinforced without adding fillers;

4) placing a steel reinforcement cage in the sleeve (16) and pouring concrete;

5) the sleeve (16) is pulled out to form a pile;

5.1) extruding soil to form holes: firstly, pressing a dowel bar (15) on concrete in a sleeve (16), slowly pulling out the sleeve (16), and compacting the concrete on the pile top within the range of 2-4m by using a vibrating rod;

when soil is taken out and holes are formed: starting the pile hammer (18) and slowly pulling out the sleeve (16) by using the vibration force of the pile hammer (18);

when the step 2) is carried out, when the natural bearing stratum (3506) is buried deeply, sinking the first section of casing pipe (16) by using a pile hammer (18), connecting the second section of casing pipe (16) with the first section of casing pipe (16), and then continuing sinking to the natural bearing stratum (3506); then the upper end and the lower end of the dowel bar (15) are respectively connected with the pile hammer (18) and the soil sampler (27) to carry out soil sampling until the natural bearing stratum (3506); when a hard interlayer is encountered, the sleeve (16) can be sunk continuously after soil is taken out in advance, and the alternate operation is repeated until the natural bearing stratum (3506); when the soil layer is well formed, is not easy to collapse and has no underground water, the first section of sleeve (16) can be sunk and then the soil sampler (27) is used for directly sampling soil to the bearing stratum.