CN108330973B - Pile pulling equipment and quick pile pulling method under low clearance height - Google Patents

Abstract

The invention discloses pile pulling equipment and a quick pile pulling method under low clearance height. The invention has the advantages that: the position of the pulley is controlled to convert the vertical force of the jack into the drawing force of the pile axis to realize pile pulling of the inclined pile body, so that pile breakage can be prevented, and the condition that the diameter of the pile body is not uniform along the length of the pile can be self-adapted; the method for grouting, friction reducing and rapid pile pulling aiming at different pile shapes under the condition of low clearance in the channel greatly improves the operation efficiency of pulling out the obstacle piles in the tunnel crossing range.

Description

Pile pulling equipment and quick pile pulling method under low clearance height

Technical Field

The invention relates to pile pulling equipment, in particular to pile pulling equipment and a quick pile pulling method under low headroom.

Background

In the building engineering, especially in the underground engineering, the construction of the subsequent building is not considered in the prior construction structure, so that the subsequent construction is influenced, and particularly, the cast-in-situ bored pile for removing the existing structure is very common in the tunnel construction. In the construction process of subways and municipal tunnels, a shield machine often needs to penetrate through pile foundation groups below existing buildings or bridges, and barrier piles increase the construction difficulty of shield tunneling, so that pile bodies in a tunnel penetrating range need to be removed. The obstacle clearing construction is often carried out under the conditions of low clearance height, short construction period requirement, high environmental protection requirement and the like, when the situation that barriers are arranged around a bored pile or a pile body bulges and an inclined pile cannot be subjected to casing construction, flushing cannot be adopted to ensure that soil around the pile is extruded to the pile body again so as to realize pile-soil separation, the traditional pile pulling process has limitation, a steel sleeve needs to be selected and customized according to the size of the pile diameter, and the operations of sinking the steel sleeve and pulling out the steel sleeve again are also needed, so that the construction process and the construction difficulty are increased; the problem that the foundation soil extrudes the pile body from the side direction from bottom to top to increase the frictional resistance and the problem that the soil body on the upper part of the inclined pile extrudes the upper part of the pile body to increase the side wall resistance under the action of self weight due to the stress release of the soil body on the lower part of the pile hole in the pile pulling process cannot be thoroughly solved by the high-pressure flushing separation soil body.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide pile pulling equipment with low clearance height; the invention also provides a rapid pile pulling method using the pile pulling equipment on the basis of not dismantling the channel or damaging the main structure of the channel.

The technical scheme is as follows: the utility model provides a pile pulling equipment under low headroom height, includes the base, be equipped with the jack on the base, the jack top even has the roof, the roof even has the steel wire, the steel wire is connected through the assembly pulley and is embraced the staple bolt on stake top, jack-up the roof produces the drawing force to the stake.

In order to better support the extracted pile, the pile pulling equipment further comprises a pile supporting mechanism, the pile supporting mechanism comprises a movable arc-shaped supporting plate for supporting the pile and a supporting rod for supporting the supporting plate, and the supporting rod is used for adjusting the inclination of the guide plate; the face of the supporting plate contact pile is provided with a guide wheel and a groove for placing the guide wheel, and a spring support matched with the guide wheel is arranged in the groove.

The pulley block comprises a first pulley and a second pulley, the first pulley is arranged below the end part of the steel wire, and the corresponding support of the first pulley is a first support; the second pulley is arranged in the axial direction of the pile, and the corresponding support of the second pulley is a second support.

The supporting rod is divided into an upper supporting rod and a lower supporting rod, wherein the upper supporting rod is telescopic, and the lower supporting rod is movably connected to the base; one end of the upper supporting rod is movably connected with the supporting plate, the other end of the upper supporting rod is provided with a plurality of screw holes, the upper supporting rod is detachably connected with the second support through bolts, the telescopic function of the upper supporting rod is realized, and the inclination of the supporting plate is adjusted through the upper supporting rod and the lower supporting rod together when the pile is pulled out, so that the requirements of different inclinations when the pile is pulled out are met; the friction force is reduced through the guide wheel in the supporting plate, and the inclination fine adjustment is carried out by utilizing the scalability of the upper supporting rod and the elasticity of the spring support, so that the change of the gravity in the pile pulling process is adapted.

The invention discloses a quick pile pulling method using pile pulling equipment with low clearance height, which comprises the following steps: excavating a pile head, and judging the condition of the pile: when the pile is in the vertical direction, drilling grouting holes on the periphery of the pile body by using a drilling machine, injecting slurry into the grouting holes at high pressure, and gradually pulling out the whole pile by using the pile pulling equipment and then cutting the whole pile in sections; when the pile is in the inclined direction, the inclined direction and the inclination of the pile body are determined, the inclination of the drilling machine and the high-pressure rotary spraying equipment is adjusted to be the same as the inclination of the pile body, grouting holes are drilled on the periphery of the pile body through the drilling machine, the mud is injected into the grouting holes at high pressure, and the whole pile is gradually pulled out through the pile pulling equipment and then is cut off in sections.

Preferably, the mud is bentonite mud, and the bentonite mud comprises the following components in percentage by mass: 100 parts of water, 12.5-15.5 parts of bentonite, 0.4-0.6 part of soda ash and 0.15-0.3 part of CMC, wherein the CMC is an abbreviation of carboxymethyl cellulose, and a large value is recommended for a soft soil with a large specific gravity.

In the method for quickly pulling out a pile of the present invention, a first method for judging the condition of a pile comprises the following steps:

selecting a diameter at the radial direction of the pile head, taking A, B points at the position d cm away from the pile edge on the extension line at the two ends of the diameter, wherein d is more than or equal to 20cm and less than or equal to 50cm, vertically drilling a hole at the point A by using a small rotary drilling machine, and recording the depth h of an obstacle when the hole meets the obstacle₁；

(ii) drilling vertically at point B using a small rotary drill, if at depth h₁When the obstacle is met, the drum pile is the drum pile; if no obstacle exists in the pile length range, the pile body is an inclined pile, then a hole is drilled at a position 0.5-1m away from the point A on the extension line of BA, and the depth h is recorded when the obstacle is met₂Thus, the inclination i of the pile body is calculated to be 1/(h)₂-h₁)。

In the method for quickly pulling out a pile of the present invention, the second method for judging the condition of the pile comprises the following steps:

selecting a diameter at the radial direction of the pile head, taking A, B two points at the position d cm away from the pile edge on the extension line at the two ends of the diameter, wherein d is more than or equal to 20cm and less than or equal to 50cm, vertically drilling a hole at the point A by using a small rotary drilling machine, vertically drilling a hole at the point B in the pile length range without an obstacle, and recording the depth h of the obstacle if the obstacle meets the obstacle₃Drilling a hole 0.5-1m away from the point B on the extension line of the AB, and recording the depth h when meeting an obstacle₄Thus, the inclination i of the pile body is calculated to be 1/(h)₄-h₃)；

(ii) if the hole is drilled vertically at point B, with no obstacle over the length of the pile, then another hole orthogonal to the diameter AB is chosen in the radial direction of the pile headThe diameter CD is vertically drilled at the point C by using a small rotary drilling machine, and when meeting an obstacle, the depth h of the obstacle is recorded₅；

(iii) drilling vertically at D with a small rotary drill, if at depth h₅When the obstacle is met, the drum pile is the drum pile; if no obstacle exists in the pile length range, the pile body is an inclined pile, then a hole is drilled at a position 0.5-1m away from the point C on the extension line of the DC, and the depth h is recorded when the pile body meets the obstacle₆Thus, the inclination i of the pile body is calculated to be 1/(h)₆-h₅)。

Has the advantages that: compared with the prior art, the invention has the beneficial effects that: (1) the position of the pulley is controlled to convert the vertical force of the jack into the drawing force of the pile axis to realize pile pulling of the inclined pile body, so that pile breakage can be prevented, and the condition that the pile body is not uniform in diameter along the pile can be self-adaptive. (2) On the basis of not dismantling the channel or destroying the main structure of the channel, the grouting friction-reducing rapid pile pulling method aiming at different pile shapes under the condition of low clearance in the channel can complete pile pulling operation under the condition of inclined pile, pile body bulging phenomenon or obstacles around the pile, so that the efficiency of pile pulling operation of obstacle piles in the tunnel crossing range is greatly improved, the adaptability is improved, compared with the traditional hoisting equipment, the method has no noise and pollution, can adapt to different channel clearance heights, is convenient to operate, and has controllable pile pulling force. (3) And bentonite slurry is injected around the pile, and the components of the bentonite are adjusted to adapt to different conditions in the actual engineering, so that the separation of the drag reduction retaining wall and the pile soil is realized.

Drawings

FIG. 1 is a schematic structural diagram of the pile pulling equipment of the present invention;

FIG. 2 is a schematic structural view of a guide plate in the pile pulling equipment of the present invention;

FIG. 3 is a schematic diagram of a pile head excavated by the rapid pile pulling method according to the present invention;

FIG. 4a is a radial cross-sectional view illustrating the determination of the pile forming condition in the rapid pile pulling method according to the present invention;

FIG. 4b is a schematic diagram of an inclined pile for determining the forming condition of the pile body in the rapid pile pulling method according to the present invention;

FIG. 4c is a schematic view of determining pile bulging in the rapid pile pulling method according to the present invention;

FIG. 4d is a schematic diagram of a normal pile for determining the forming condition of the pile body in the rapid pile pulling method according to the present invention;

FIG. 5 is a schematic sectional view of a pile body in the rapid pile pulling method according to the present invention;

FIG. 6 is a diagram of in-place drilling of a small rotary drilling machine in the rapid pile pulling method of the invention;

FIG. 7 is a high-pressure jet grouting diagram in the rapid pile pulling method of the present invention;

FIG. 8 is a drawing of an apparatus for low clearance pile pulling in the method for rapid pile pulling of the present invention;

FIG. 9 is a drawing of the anchor ear embracing the pile head in the rapid pile pulling method of the present invention;

FIG. 10a is a schematic view of sectional pile pulling in the rapid pile pulling method of the present invention;

FIG. 10b is a schematic view of a cut pile in the rapid pile pulling method according to the present invention;

FIG. 11 is a schematic view illustrating the whole pile being completely pulled out in the rapid pile pulling method according to the present invention;

FIG. 12 is a schematic diagram of a middle-layer backfilled pile hole and tamped to a designed elevation in the rapid pile pulling method of the present invention;

FIG. 13a is a drawing of the pile head of the inclined pile held by the hoop in the rapid pile pulling method of the present invention;

FIG. 13b is a schematic view of an inclined pile being pulled out by the rapid pile pulling method according to the present invention;

fig. 13c is a schematic view of the method for rapidly pulling a pile according to the present invention.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

As shown in fig. 1-2, a pile pulling apparatus with low clearance height comprises a base 101, a top plate 103, a guide mechanism 108 and a weight 109, wherein a jack 102 is arranged between the base 101 and the top plate 103, the lower part of the top plate 103 is fixedly connected with a steel wire rope end 104, the steel wire rope end 104 is connected with a steel wire, the steel wire is connected with a hoop 107 through a first pulley 105 and a second pulley 106, the first pulley 105 is arranged right below the steel wire rope end 104, the corresponding bracket is a first bracket, and the first pulley 105 is fixedly connected to the top of the first bracket; the second pulley 106 is arranged in the axial direction of the pile, the corresponding support of the second pulley 106 is a second support, and the second pulley 106 is fixedly connected to the top of the second support; the guide mechanism 108 comprises a movable arc-shaped guide plate 108A for placing a pile, an upper positioning rod 108B and a lower positioning rod 108C for supporting the guide plate, the upper positioning rod 108B can stretch, and the lower positioning rod 108C is movably connected to the base 101; one end of the upper positioning rod 108B is movably connected with the guide plate, the other end of the upper positioning rod is provided with a plurality of screw holes, and the upper positioning rod is detachably connected with the second bracket through bolts, so that the telescopic function of the upper positioning rod is realized; the surface of the guide plate 108A contacting the pile is provided with a groove for placing a guide wheel, and the groove is internally provided with a guide wheel 108A-1, a shaft 108A-2 of the guide wheel and a spring support 108A-3 matched with the guide wheel; the position of the pulley is controlled to convert the vertical force of the jack into the drawing force of the pile axis to realize pile pulling of the inclined pile body, so that pile breakage can be prevented, and the weight 109 is placed as required.

When the pile is pulled out, the inclination of the guide plate is adjusted through the upper positioning rod and the lower positioning rod together, so that the requirements of different inclinations during pile pulling are met; the friction force is reduced through the guide wheel in the guide plate, and the inclination fine adjustment is carried out by utilizing the scalability of the upper positioning rod and the elasticity of the spring support, so that the device is suitable for the change of gravity in the pile pulling process.

The grouting resistance-reducing rapid pile pulling method for different pile shapes under the condition of low headroom comprises the following specific steps:

firstly, excavating a pile head, and judging a drum pile, an inclined pile and a normal pile.

(1) As shown in fig. 3, excavating a pile head, chiseling a channel bottom plate at the upper part of the pile 1, preparing for construction, and measuring and positioning a pile foundation to be pulled out, wherein the measurement and positioning comprise determining the diameter and the length L of the pile 1 and the distance S between adjacent piles, the general pile length is known, and if no pile length design value exists, the pile head can be measured by a sound wave method or a small strain method after being excavated;

(2) selecting A, B points on the extension lines of two ends of the diameter and d cm from the edge of the pile, wherein d is not less than 20cm and not more than 50cm, as shown in figure 4 a; a small rotary drilling machine 2 is used for vertically drilling holes at the point A, if an obstacle is encountered and the core sample in the figure is concrete, the depth h of the obstacle is recorded₁As shown in fig. 4 b;

(3) vertically drilling at B point by using a small rotary drilling machine, wherein ① is drilled at depth h₁When meeting with an obstacle, the pile body has a bulging phenomenon, as shown in fig. 4c, when the point ② B has no obstacle in the pile length range, the pile body is an inclined pile, the inclined direction is A to B, a hole can be drilled on the extension line of BA at the position 0.5-1m away from the point A, and when meeting with the obstacle, the depth h is recorded₂Thus, the inclination i of the pile body is calculated to be 1/(h)₂-h₁)；

Wherein, in the step (2), if the A point is drilled vertically and no obstacle exists in the pile length range, drilling is continued at the B point, ① if the A point meets the obstacle, the pile body inclines in the BA direction, and the depth h of the obstacle is recorded₃Drilling a hole 0.5-1m away from the point B on the extension line of the AB, and recording the depth h when meeting an obstacle₄Thus, the inclination i of the pile body is calculated to be 1/(h)₄-h₃) ② drilling hole vertically at B point, selecting another diameter CD orthogonal to AB diameter in pile head radial direction if there is no obstacle in pile length range, drilling hole vertically at C point by small rotary drilling machine, and recording obstacle depth h if meeting obstacle₅Then vertically drilling at a D point by using a small rotary drilling machine if the depth is h₅When the obstacle is met, the drum pile is the drum pile; if no obstacle exists in the pile length range, the pile body is an inclined pile, then a hole is drilled at a position 0.5-1m away from the point C on the extension line of the DC, and the depth h is recorded when the pile body meets the obstacle₆Thus, the inclination i of the pile body is calculated to be 1/(h)₆-h₅)。

If no obstacle of concrete is found in the A, B, C, D drilled hole, the pile is illustrated as a normal formed pile, as shown in fig. 4 d;

the method for simply judging the drum pile, the inclined pile and the normal pile can further utilize the drilled holes to carry out the sound wave method to find the actual situation of the pile according to the engineering requirements.

Pile pulling steps of piles in the vertical direction, such as normal piles and drum piles, are as follows:

(1) segmenting the pile body, namely segmenting the pile body according to the depth of the pile body and the clearance height I of the channel, and determining the length of each segment, wherein in the actual engineering, the length H of each segment of the pile body is H-1.5m, as shown in fig. 5;

(2) removing obstacles and forming holes, drilling holes on the periphery of a pile body 1 by using a small rotary drilling machine 2 to remove obstacles such as boulders and the like in the pile length range, separating a bulged part of the pile body from the pile body by using the drilling machine, and forming grouting holes 3 on the periphery of the pile, as shown in fig. 6;

(3) and (2) slurry injection, wherein for weak soil or sandy soil, as the stress of foundation soil at the bottom of the pile is released in the pile pulling process, soil around the pile is extruded from the bottom to the pile body again to form larger pile soil resistance, so that bentonite slurry 4 is injected into the grouting hole 3 by adopting high-pressure jet grouting equipment 5, and the proportion range is selected as water according to different stratum suggestions: bentonite: soda ash: CMC is 100: 12.5-15.5: 0.4-0.6: 0.15-0.35, the soft soil with large specific gravity is recommended to be selected to have a large value, and actually can be determined according to experiments, the foundation soil and the pile body are thoroughly separated by taking the maintenance of the stability of the hole wall as a control target, as shown in fig. 7, the mud is used for lubrication, and simultaneously, the mud can play a role in protecting the wall of the pile hole after pile pulling to prevent the hole from collapsing and influencing the safety of the upper structure, and the consistency ratio of the mud ensures that the mud is not taken out by the pile body in the pile pulling process and plays a role in protecting the wall;

(4) installing low-clearance pile pulling equipment 6, wherein the low-clearance pile pulling equipment 6 consists of a group of 4 jacks, a bracket and a hoop, and the number of the jack groups in actual engineering can be determined according to pile pulling force and the maximum jacking force of the jacks, as shown in fig. 8;

(5) the pile head is held by the hoop 107 as shown in fig. 9;

(6) after the debugging of the low-clearance pile pulling equipment is finished, pulling is started, the first pile segment 7 is lifted out of the channel bottom plate, and the segment 1 is cut and cut by using cutting equipment, as shown in fig. 10 a-10 b;

(7) repeating the step (5), lifting the rest subsections out of the channel bottom plate in sequence, cutting and cutting off the rest subsections, and cutting off the last section of pile subsection 8 as shown in fig. 11;

(8) and backfilling pile holes in layers, tamping to the designed elevation, and repairing the bottom plate of the channel, as shown in fig. 12.

Thirdly, pile pulling steps of the inclined pile are as follows:

(1) excavating a pile head, and judging the inclination direction and inclination of the pile body by adopting the method in the first step;

(2) segmenting the pile body, namely segmenting the pile body according to the depth of the pile body and the clearance height of the channel, determining the length of each segment, and performing the step (2) in the step two;

(3) removing obstacles to form holes, adjusting the verticality of a small rotary drilling machine or high-pressure rotary spraying equipment to enable the inclination of the small rotary drilling machine or the high-pressure rotary spraying equipment to be the same as that of a pile body, and drilling holes on the periphery of the pile in the sequence of drilling holes from the top to two sides according to the inclination;

(4) the bentonite slurry is injected, and due to the influence of the inclination of the pile body, the soil body on the upper part of the pile body is extruded to the pile body again under the action of self weight, so that the bentonite slurry is injected into the hole to reduce the frictional resistance of the pile soil, realize the complete separation of the pile soil and the lubrication action during pile pulling, aim at the high hole collapse risk of the inclined pile, and play a role of protecting the wall to prevent the large-area hole collapse from influencing the safety of the upper structure;

(5) the low-clearance inclined pile pulling equipment of the invention is installed, as shown in fig. 1.

(6) As shown in fig. 13a, the anchor ear 107 is used for holding the pile head, and the guide mechanism 108 is retracted after the inclination of the guide plate 108A is preset;

(7) after the low-clearance pile pulling equipment is debugged, pulling is started, the first section of pile is lifted out of the channel bottom plate in a segmented mode, the guide mechanism 108 is erected according to the preset position, the gravity of the pulled pile body is balanced, the pile pulling resistance is reduced, the shaking of the pile body is controlled, the first section of pile is lifted to the preset height in a segmented mode, and the first section of pile is cut and cut in a segmented mode through cutting equipment, as shown in fig. 13 a-13 c;

(8) repeating the step (6), and sequentially lifting the rest segments out of the channel bottom plate for sequential cutting and cutting;

(9) and backfilling pile holes in layers, tamping to a designed elevation, repairing a bottom plate and finishing construction.

Compared with other traditional pile pulling methods such as a casing method, a flushing method and the like, the grouting friction-reducing rapid pile pulling method under low clearance height further optimizes the technical scheme, the method for judging the pile shape in the step one and the grouting friction-reducing in the steps (3) and (4) realize pile-soil separation, and a jack is used as pile pulling force; and (3) grouting in the third step to realize pile-soil separation and (4) application of inclined pile pulling equipment and pile pulling technology in the third step. The grouting antifriction rapid pile pulling method of different pile shapes under the low clearance condition can judge the pile forming condition of a pile foundation, adopts the method of injecting bentonite slurry around the pile to realize the thorough separation of the pile and the soil, simultaneously plays the role of reducing resistance and protecting the wall, can effectively treat the pile pulling problem of barriers, pile swelling and inclined piles around the pile, has simple construction equipment, simplifies the construction, improves the efficiency, has no noise and environmental pollution, reduces the influence of pile pulling construction on the surrounding environment through special slurry storage equipment, can also be applied under the condition that the clearance height is not limited, and greatly improves the operation efficiency of pulling out the obstacle piles under the low clearance condition.

Claims (5)

1. The utility model provides a pile pulling equipment under low headroom which characterized in that: the pile pulling device comprises a base (101), wherein a jack (102) is arranged on the base (101), the top end of the jack (102) is connected with a top plate (103), the top plate (103) is connected with a steel wire, the steel wire is connected with a hoop (107) embracing the top end of a pile (1) through a pulley block, and the jack (102) jacks the top plate (103) to generate pulling force on the pile (1); the pile pulling equipment further comprises a pile supporting mechanism (108), wherein the pile supporting mechanism comprises a movable arc-shaped supporting plate (108A) for supporting the pile (1) and a supporting rod for supporting the supporting plate (108A); the surface of the supporting plate (108A) contacting the pile is provided with a guide wheel (108A-1) and a groove for placing the guide wheel (108A-1), and a spring support (108A-3) matched with the guide wheel (108A-1) is arranged in the groove; the pulley block comprises a first pulley (105) and a second pulley (106), the first pulley (105) is arranged below the end part of the steel wire, and the corresponding support of the first pulley (105) is a first support; the second pulley (106) is arranged in the axial direction of the pile, and the corresponding support of the second pulley is a second support; the supporting rods are divided into an upper supporting rod (108B) and a lower supporting rod (108C), wherein the upper supporting rod (108B) is telescopic, and the lower supporting rod (108C) is movably connected to the base; one end of the upper supporting rod (108B) is movably connected with the supporting plate (108A), and the other end of the upper supporting rod is provided with a plurality of screw holes which are detachably connected with the second support.

2. A method for rapid pile extraction using low-headroom pile extraction equipment of claim 1, characterized by: the method comprises the following steps: excavating a pile head, and judging the condition of the pile: when the pile is in the vertical direction, drilling grouting holes on the periphery of the pile body by using a drilling machine, injecting slurry into the grouting holes at high pressure, and gradually pulling out the whole pile by using the pile pulling equipment and then cutting the whole pile in sections; when the pile is in the inclined direction, the inclined direction and the inclination of the pile body are determined, the inclination of the drilling machine and the high-pressure rotary spraying equipment is adjusted to be the same as the inclination of the pile body, grouting holes are drilled on the periphery of the pile body through the drilling machine, the mud is injected into the grouting holes at high pressure, and the whole pile is gradually pulled out through the pile pulling equipment and then is cut off in sections.

3. The rapid pile pulling method according to claim 2, characterized in that: the mud is bentonite mud, and the bentonite mud comprises the following components in percentage by mass: 100 portions of water, 12.5 to 15.5 portions of bentonite, 0.4 to 0.6 portion of sodium carbonate and 0.15 to 0.3 portion of CMC.

4. The rapid pile pulling method according to claim 3, wherein: the method for judging the condition of the pile comprises the following steps:

selecting a diameter at the radial direction of the pile head, taking A, B points at the position d cm away from the pile edge on the extension line at the two ends of the diameter, wherein d is more than or equal to 20cm and less than or equal to 50cm, vertically drilling a hole at the point A by using a small rotary drilling machine, and recording the depth h of an obstacle when the hole meets the obstacle₁；

(ii) drilling vertically at point B using a small rotary drill, if at depth h₁When the obstacle is met, the drum pile is the drum pile; if no obstacle exists in the pile length range, the pile body is an inclined pile, then a hole is drilled at a position 0.5-1m away from the point A on the extension line of BA, and the depth h is recorded when the obstacle is met₂Thus, the inclination i of the pile body is calculated to be 1/(h)₂-h₁)。

5. The rapid pile pulling method according to claim 4, wherein the method for judging the condition of the pile comprises the steps of:

selecting a diameter at the radial direction of the pile head, taking A, B two points at the position d cm away from the pile edge on the extension line at the two ends of the diameter, wherein d is more than or equal to 20cm and less than or equal to 50cm, vertically drilling at the point A by using a small rotary drilling machine, and having no obstacle within the pile length range,then, vertically drilling a hole at the point B, and if an obstacle is met, recording the depth h of the obstacle₃Drilling a hole 0.5-1m away from the point B on the extension line of the AB, and recording the depth h when meeting an obstacle₄Thus, the inclination i of the pile body is calculated to be 1/(h)₄-h₃)；

(ii) if the hole is vertically drilled at the point B and no obstacle exists in the pile length range, selecting another diameter CD orthogonal to the diameter AB in the radial direction of the pile head, vertically drilling the hole at the point C by using a small rotary drilling machine, and recording the depth h of the obstacle when the hole meets the obstacle₅；

(iii) drilling vertically at D with a small rotary drill, if at depth h₅When the obstacle is met, the drum pile is the drum pile; if no obstacle exists in the pile length range, the pile body is an inclined pile, then a hole is drilled at a position 0.5-1m away from the point C on the extension line of the DC, and the depth h is recorded when the pile body meets the obstacle₆Thus, the inclination i of the pile body is calculated to be 1/(h)₆-h₅)。

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