Construction method for tube-sinking rammed cast-in-place concrete pile

Abstract

The invention discloses a construction method for a tube-sinking rammed cast-in-place concrete pile, and relates to the technical field of construction of the tube-sinking rammed cast-in-place concrete pile, a special pile driver is adopted, a soil layer at the bottom end of a pile tube is rammed and drilled by applying counter force to an electric vibratory hammer, applying downward impact force to the electric vibratory hammer and repeatedly ascending and descending a columnar heavy hammer, and then the pile tube is rammed and drilled through a counter pressure device. Under the combined action of the electric vibration hammers, the pile pipe sinks to the designed elevation, no sediment exists at the bottom end of the pile, dry and hard concrete is tamped to form an expanded head, and the vertical bearing capacity and pulling resistance of a single pile are increased. Due to the fact that the pile pipe is sunk into the soil, the hole collapse phenomenon cannot occur, the construction quality of a pile foundation is guaranteed, the construction efficiency is improved by 2-3 times, the bearing capacity of a single pile is high, and the engineering cost is greatly saved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete rammed-expanded cast-in-place pile construction, in particular to a pipe-sinking rammed-expanded concrete cast-in-place pile construction method. Background Art

[0002] With the development of industrial and civil construction, mountain backfill sites, blown-fill sites, sand layers and gravel sites are often encountered. However, the biggest difficulty in using traditional bored pile technology to construct such sites is the serious collapse of the holes, which makes it impossible to guarantee the quality of the piles. If the mud wall drilling method is used, a large amount of mud pollution will be generated, the construction efficiency will be low, and the project cost will increase. Summary of the invention

[0003] The purpose of the present invention is to provide a method for constructing pipe-sunk rammed concrete bored piles to solve the problems existing in the above-mentioned prior art, so that the pile pipe can be sunk to the designed elevation. Since the pile pipe is sunk into the soil, hole collapse is impossible, thereby ensuring the quality of pile foundation construction, improving construction efficiency by 2-3 times, and having a high single pile bearing capacity, which greatly saves engineering costs.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a method for constructing a pipe-sinking rammed-expanded concrete pile, comprising the following steps:

[0005] Step 1: Drill a hole at the pile position with a drilling rig, move the pile driver to the position and ensure that the center of the pile pipe is aligned with the center of the drilled hole;

[0006] Step 2: Start the pile driver, first apply force to the electric vibration hammer and the pile pipe through the counter pressure device, so that the pile pipe sinks into the drill hole;

[0007] Step 3: Turn on the electric vibration hammer, and the impact force generated by the electric vibration hammer and the force generated by the counter-pressure device act on the pile pipe at the same time, so that the pile pipe continues to sink to the designed depth;

[0008] Step 4: Add dry hard concrete into the pile pipe from the pile pipe feeding port, tamp with a cylindrical weight while adding the concrete, until the filling amount meets the design requirements, and then remove the cylindrical weight;

[0009] Step 5: Start the winch, lift the steel cage after the steel wire rope passes through the fixed pulley on the pulley bracket at the top of the pile driver tower, and put the steel cage into the pile pipe from the upper port of the middle hole pipe of the electric vibration hammer. After the steel cage is placed, pour concrete into the pile pipe from the feeding port of the pile pipe;

[0010] Step six, turn on the electric vibratory hammer and winch, pull out the pile pipe while vibrating, and continue pouring concrete into the pile pipe from the pile pipe feeding port until the bored pile meets the designed pile top elevation, the pile pipe is completely pulled out of the ground, and the bored pile construction is completed.

[0011] Preferably, a fourth winch is provided on the pile driver platform of the pile driver, and the counter-pressure device comprises fixed pulley one, fixed pulley two, fixed pulley three, fixed pulley four, fixed pulley five and fixed pulley six. After the wire rope extends out from the fourth winch, it passes through the fixed pulley one, fixed pulley two, fixed pulley three, fixed pulley four, fixed pulley five and fixed pulley six in sequence, and the end thereof is fixed on the other side of the pile driver platform; the fixed pulley one, fixed pulley two, fixed pulley four and fixed pulley five are installed on the pile driver platform, and the fixed pulley three and fixed pulley six are symmetrically installed on both sides of the bottom of the electric vibration hammer.

[0012] Preferably, a second winch is provided on the pile driver platform of the pile driver, a third fixed pulley block is provided on the pulley bracket, and the wire rope extends from the second winch and passes around the third fixed pulley block before being connected to the cylindrical weight.

[0013] Preferably, in the step three, when the impact force generated by the electric vibration hammer and the force generated by the counter-pressure device act on the pile pipe at the same time and the pile pipe has not yet sunk to the designed depth, the second winch is turned on to lift the cylindrical weight, and the cylindrical weight is placed into the pile pipe from the upper port of the hole pipe of the electric vibration hammer, and the soil layer at the bottom end of the pile pipe is repeatedly impacted to draw a hole. While impacting the hole, the electric vibration hammer and the counter-pressure device are turned on to ensure that the pipe is sunk to the designed depth.

[0014] Preferably, a third winch is provided on the pile driver platform of the pile driver, a fourth fixed pulley block is provided on the pulley bracket, and the wire rope extends from the third winch and passes around the fourth fixed pulley block before being connected to the steel cage.

[0015] Preferably, a first winch and a fifth fixed pulley block are provided on the pile driver platform of the pile driver, a fixed pulley assembly is provided on the pulley bracket, a wire rope extends from the first winch and sequentially passes around the fifth fixed pulley block and the fixed pulley assembly and is connected to the electric vibration hammer, and the first winch is used to lift the electric vibration hammer.

[0016] Preferably, the fixed pulley assembly comprises a first fixed pulley group and a second fixed pulley group, the first fixed pulley group and the second fixed pulley group are arranged on the pulley bracket in a cross form, and the first fixed pulley group and the second fixed pulley group each include two fixed pulleys.

[0017] Preferably, a movable pulley group is arranged between the fifth fixed pulley group and the fixed pulley assembly, and the fifth fixed pulley group pulls the movable pulley to move downward along the tower of the pile driver, and the steel wire ropes on both sides of the movable pulley group pass through the first fixed pulley group and the second fixed pulley group respectively and are symmetrically connected to the two sides of the top of the electric vibration hammer.

[0018] Preferably, a track is provided on the tower of the pile driver, and the electric vibration hammer can move up and down along the track; a support rod is also provided on the pile driver, and both ends of the support rod are respectively supported and connected to the pile driver platform and the tower.

[0019] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0020] The method for constructing a pipe-sinking and tamping concrete pile in the present invention adopts a special pile driver, applies a reaction force to an electric vibrating hammer, and the electric vibrating hammer exerts downward impact force, and the column-shaped heavy hammer is repeatedly lifted and lowered to tamp the soil layer at the bottom of the pile pipe to form a hole, and then the pile pipe is sunk to the designed elevation through the combined action of the counter-pressure device and the electric vibrating hammer, and there is no sediment at the bottom of the pile, and the dry hard concrete is tamped to form an enlarged head, thereby increasing the vertical bearing capacity and anti-pullout force of the single pile. Since the pile pipe is sunk into the soil, the hole collapse phenomenon is impossible, thereby ensuring the quality of pile foundation construction, improving the construction efficiency by 2-3 times, and the single pile has a high bearing capacity, which greatly saves engineering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of a pile driver for sinking tube ramming and enlarging cast-in-place piles;

[0023] Figure 2 The figure is a schematic diagram of the pulley bracket at the top of the tower;

[0024] Figure 3 It is a schematic diagram of the composition of the counter-pressure device;

[0025] Figure 4 This is the front view of the electric vibration hammer;

[0026] Figure 5 This is a top view of the electric vibration hammer;

[0027] Figure 6 Schematic diagram of the wire rope winding direction for lifting the electric vibratory hammer and pile pipe;

[0028] Among them, 1. the first winch; 2. the second winch; 3. the third winch; 4. the fourth winch; 5. the fifth fixed pulley block; 6. the movable pulley block; 7. the electric vibration hammer; 8. the pile pipe; 9. the feeding port; 10. the pulley bracket; 11. the track; 12. the support rod; 13. the pile driver platform; 14. the tower; 15. the cylindrical weight; 16. the electric vibration device; 17. the middle hole pipe; 18. the fixed pulley seven; 19. the fixed pulley eight; 20. the fixed pulley nine; 21. the fixed pulley ten; 22. the fixed pulley eleven; 23. the fixed pulley twelve; 24. the fixed pulley thirteen; 25. the fixed pulley fourteen; A. the fixed pulley one; B. the fixed pulley two; C. the fixed pulley three; D. the fixed pulley four; E. the fixed pulley five; F. the fixed pulley six. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The purpose of the present invention is to provide a method for constructing pipe-sunk rammed concrete bored piles to solve the problems existing in the above-mentioned prior art, so that the pile pipe can be sunk to the designed elevation. Since the pile pipe is sunk into the soil, hole collapse is impossible, thereby ensuring the quality of pile foundation construction, improving construction efficiency by 2-3 times, and having a high single pile bearing capacity, which greatly saves engineering costs.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1-Figure 6 As shown, the present invention provides a method for constructing a pipe-sinking rammed concrete pile. The method is suitable for the construction of concrete rammed concrete piles in sites with large-thickness backfill, blown fill, sand layer, and gravel layer. The drilling of soil layers in the above geological conditions is prone to hole collapse. The pile driving equipment used in the method is composed of:

[0033] 1. Pile driver platform 13;

[0034] 2. A tower 14 is provided at the front end of the pile driver platform 13;

[0035] 3. A track 11 is provided on the tower 14, and the electric vibration hammer 7 can move up and down along the track 11;

[0036] 4. A pulley bracket 10 is provided at the top of the tower 14;

[0037] 5. The pile driver platform 13 is provided with a first hoist 1 for lifting the electric vibration hammer 7 and the pile pipe 8, a second hoist 2 for lifting the cylindrical weight 15, a third hoist 3 for lifting the hopper and the steel cage, and a fourth hoist 4 for applying a reaction force to the electric vibration hammer 7 and the pile pipe 8;

[0038] 6. A movable pulley block 6 that moves up and down along the tower 14;

[0039] 7. A fifth fixed pulley block 5 is provided at the connection between the tower 14 and the platform;

[0040] 8. Counter-pressure device (fixed pulley 1A, fixed pulley 2B, fixed pulley 3C, fixed pulley 4D, fixed pulley 5E and fixed pulley 6F) for applying counter-force to the electric vibration hammer 7 and the pile pipe 8;

[0041] 9. The electric vibration hammer 7 is a dual-motor vibration device type with a middle hole tube 17, and two electric vibration devices 16 are arranged on the electric vibration hammer 7;

[0042] 10. A pile pipe 8 is arranged at the lower end of the middle hole pipe 17 of the electric vibration hammer 7;

[0043] 11. The pile driver is also provided with a support rod 12, and the two ends of the support rod 12 are respectively supported and connected to the pile driver platform 13 and the tower 14.

[0044] Specific construction process steps:

[0045] Step 1: Drill holes at the pile location with a drill. The diameter and depth of the holes are determined based on the designed pile diameter and length, as well as the geological conditions. If the soil strength is low or the construction pile is short, the holes can be directly sunk.

[0046] Step 2: Move the pile driver and ensure that the center of the pile pipe 8 is aligned with the center of the drilled hole.

[0047] Step 3: Start the fourth winch 4 and the counter-pressure device to apply a counter-force to the electric vibration hammer 7 and the pile pipe 8 through fixed pulley 1 A, fixed pulley 2 B, fixed pulley 3 C, fixed pulley 4 D, fixed pulley 5 E and fixed pulley 6 F (see Figure 3), so that the pile pipe 8 sinks to a certain depth in the hole.

[0048] Step 4: Due to the friction between the drilling and the back pressure pile pipe 8 on the hole wall, the hole will inevitably collapse, and the hole at the bottom of the pile pipe 8 will be backfilled with soil. It is difficult to sink the pile pipe 8 only by the force generated by the back pressure device. When the force generated by the back pressure device cannot sink the pile pipe 8 to the designed depth, the electric vibration hammer 7 is turned on to generate the downward impact force and the force generated by the back pressure device to act on the pile pipe 8 at the same time, so that the pile pipe 8 continues to sink.

[0049] Step 5, when the impact force and counterpressure of the electric vibration hammer 7 act simultaneously and still cannot ensure that the pile pipe 8 sinks to the designed depth, the second winch 2 is turned on to lift the cylindrical weight 15 through the third fixed pulley group (fixed pulley 11 22 and fixed pulley 12 23) in the pulley bracket 10 (see Figure 2) at the top of the tower 14, and the columnar weight 15 is put into the pile pipe 8 from the upper port of the middle hole pipe 17 of the electric vibration hammer 7, and the soil layer at the bottom end of the pile pipe 8 is repeatedly impacted to draw the hole, and the electric vibration hammer 7 and the counterpressure device are turned on while impacting the drawing hole, and the fourth winch 4 (see Figure 3) ensures that the pipe is sunk to the designed depth through fixed pulley 1 A, fixed pulley 2 B, fixed pulley 3 C, fixed pulley 4 D, fixed pulley 5 E and fixed pulley 6 F.

[0050] Step 6: Add dry hard concrete into the pile pipe 8 from the feeding port 9 of the pile pipe 8, and tamp it with a cylindrical heavy hammer 15 while adding the concrete until the filling amount meets the design requirements, while ensuring that the final hammer penetration meets the design requirements.

[0051] Step 7: lift the cylindrical weight 15 out of the upper end of the middle hole tube 17 of the electric vibration hammer 7.

[0052] Step eight, start the third winch 3 and lift the steel cage through the fourth fixed pulley group (fixed pulley 13 24 and fixed pulley 14 25) in the pulley bracket 10 at the top of the tower 14 (see Figure 2) and put it into the pile pipe 8 from the upper end of the middle hole pipe 17 of the electric vibration hammer 7. The length of the steel cage meets the design requirements.

[0053] Step nine: pour concrete into the pile pipe 8 from the feeding port 9 of the pile pipe 8.

[0054] Step 10, start the electric vibration hammer 7 and the first winch 1 to pull the movable pulley block 6 through the fifth fixed pulley block 5 and move it downward along the tower 14, so that the steel wire ropes on both sides of the movable pulley block 6 respectively pass through the fixed pulley assembly (fixed pulley seven 18-fixed pulley eight 19, fixed pulley nine 20-fixed pulley ten 21) in the pulley bracket 10 at the top of the tower 14 to lift the electric vibration hammer 7 and move it upward, so as to achieve the purpose of pulling out the pile pipe 8 (see Figure 6). Pull out the pile pipe 8 while vibrating to ensure that the concrete is dense and reduce the pulling out resistance. At the same time, use the hopper to continue to pour concrete into the pile pipe 8 from the feeding port 9 until it meets the designed pile top elevation (this amount of concrete is mainly the volume occupied by the wall thickness of the pile pipe 8 and the amount of filling system), and the pile pipe 8 is completely pulled out of the ground, and the pile construction is completed.

[0055] In this embodiment, the diameter of the columnar weight is slightly smaller than the inner diameter of the pile pipe 8, and the weight of the columnar weight is 2-8 tons. The diameter of the middle hole pipe 17 of the electric vibration hammer 7 and the diameter of the pile pipe 8 are 400mm-1000mm, that is, the pile diameter is 400mm-1000mm. The length of the pile pipe 8 is 6m-100m. If it is limited by the height of the tower 14, multiple sections of pile pipes 8 can be connected to achieve the purpose of pile length, and the pile length is 6m-100m.

[0056] The mobile device of the pile driver can be walking type, crawler type, or roller type.

[0057] In this embodiment, the bottom end cap of the pile pipe 8 is divided into a common type and a water-stop type. The common type is a circular steel plate that matches the diameter of the pile pipe 8 and is spot-welded at the bottom of the pile pipe 8. The water-stop type cap is a circular ring with a height greater than 5 cm welded on the common type cap steel plate. The diameter of the circular ring is smaller than the inner diameter of the pile pipe 8, and the outer wall of the circular ring is surrounded by a water-stop material, such as hemp rope, etc. The purpose of the pile pipe 8 cap is to prevent soil and water from entering the pile pipe 8 when the pile pipe is sunk to a certain depth. When the pile pipe 8 is sunk to a certain depth, a cylindrical heavy hammer 15 is used to impact the circular pile pipe 8 cap.

[0058] Embodiment 1

[0059] The geological profile of a certain project is: from top to bottom

[0060] ① Plain fill thickness 3m ② Fine sand layer thickness 25m ③ Sandstone

[0061] Design pile foundation parameters: pile diameter 500mm, pile length 20m, pile end bearing layer ② fine sand, concrete grade C40, steel cage main reinforcement The dry hard concrete grade of the enlarged head is C30, and the volume of the pile end enlarged head is 0.7m 3 , the characteristic value of the vertical bearing capacity of a single pile is R=2500KN.

[0062] Construction steps:

[0063] ① Use a long spiral drill to drill a hole at the pile position with a diameter of 500mm and a depth of 20m. Use a pile pipe with a diameter of 8 The pile pipe 8 is 22 m long, and the bottom of the pile pipe 8 is spot welded with a circular steel plate with a thickness of 10 mm and a diameter of 500 mm. The upper end of the pile pipe 8 is connected to the lower end of the middle hole pipe 17 of the electric vibration hammer 7 by bolts.

[0064] ②, move the pile driver to ensure that the center of the pile pipe 8 is aligned with the center of the hole, start the fourth winch 4, and apply reaction force to the electric vibration hammer 7 and the pile pipe 8 through fixed pulleys A, B, C, D, E and F (see Figure 3), so that the pile pipe 8 sinks 13m into the hole (the 7m at the bottom of the hole is the collapsed hole caused by the friction of the hole wall when the drill rod of the drilling rig is lifted and the pile pipe 8 sinks into the hole).

[0065] ③. When the pile pipe 8 cannot be sunk by applying the reaction force device, the electric vibration hammer 7 is turned on again, so that the downward impact force and the applied reaction force generated by the electric vibration hammer 7 act on the pile pipe 8 at the same time, and the pile pipe 8 can continue to sink to 18m, and the pile pipe 8 can no longer sink.

[0066] ④. Start the second winch 2 to lift the diameter of the tower 14 through the third fixed pulley block (fixed pulley 11 22 and fixed pulley 12 23) in the pulley bracket 10 at the top of the tower 14 (see Figure 2). A cylindrical weight 15 weighing 4 tons is placed in the pile pipe 8 through the upper port of the middle hole pipe 17 of the electric vibration hammer 7. The cylindrical weight 15 is repeatedly lifted and lowered to impact the soil hole at the bottom of the pile pipe 8. While impacting the hole, the electric vibration hammer 7 and the fourth winch 4 are turned on to apply a reaction force, so that the pile pipe 8 sinks 20m into the soil, meeting the design requirements.

[0067] ⑤. Feed dry hard concrete into the pile pipe 8 from the feeding port 9 at the upper end of the pile pipe 8. While feeding, lift and lower the cylindrical weight 15 to tamp the feed material, so that the dry hard concrete is rammed out of the bottom end of the pile pipe 8, thereby forming an enlarged head at the bottom end of the pile pipe 8. The volume of the enlarged head is 0.7m 3 .

[0068] ⑥. Turn on the second hoist 2 and lift the cylindrical weight 15 out of the upper port of the middle hole pipe 17 of the electric vibration hammer 7 through the third fixed pulley group (fixed pulley 11 22 and fixed pulley 12 23 ) in the pulley bracket 10 at the top of the tower 14 .

[0069] ⑦. Start the third winch 3 to lift the steel cage through the fourth fixed pulley group (fixed pulley 13 24 and fixed pulley 14 25) (see Figure 2) in the pulley bracket 10 at the top of the tower 14, and put it into the pile pipe 8 through the upper port of the middle hole pipe 17 of the electric vibration hammer 7. The length of the steel cage is 20m.

[0070] ⑧. Pour concrete into the pile pipe 8 from the feeding port 9 at the upper end of the pile pipe 8.

[0071] ⑨. Start the first winch 1 to pull the movable pulley block 6 downward along the tower 14 through the fifth fixed pulley block 5, so that the steel wire rope connecting the two sides of the movable pulley block 6 passes through the fixed pulley assembly (fixed pulley seven 18-fixed pulley eight 19, fixed pulley nine 20-fixed pulley ten 21) in the pulley bracket 10 at the top of the tower 14 to pull the electric vibration hammer 7 to move upward along the track 11 on the tower 14, thereby achieving the purpose of lifting and pulling out the pile pipe 8 (see Figure 6). When lifting and pulling out the pile pipe 8, the electric vibration hammer 7 should be turned on to lift and pull out the pile pipe 8 while vibrating, and at the same time, continue to pour concrete from the feeding port 9 (this pouring amount is the volume occupied by the wall thickness of the pile pipe 8 and the volume of the filling coefficient) until the pile top elevation that meets the design requirements is poured, and the pile pipe 8 is completely pulled out of the ground, and the pile construction is completed.

[0072] Embodiment 2

[0073] A certain engineering geological profile: from top to bottom

[0074] ①. 50m of plain fill. The backfill contains coal-dried stone, strongly weathered broken rocks, and boulders with a diameter greater than 500mm. The fill is compacted in layers.

[0075] ②. Strongly weathered sandstone 5.3m.

[0076] ③. Moderately weathered sandstone, groundwater level is 30m from the ground.

[0077] Design pile foundation parameters: pile diameter 600mm, pile length 52m, concrete strength C40, main reinforcement of steel cage 8 The vertical bearing capacity characteristic value of a single pile is R = 3000KN, the dry hard concrete grade of the enlarged head is C30, and the volume of the enlarged head at the pile end is 0.5m 3 .

[0078] Construction steps:

[0079] 1. Use a rotary drilling rig to drill holes at the pile location with a diameter of The hole depth is 52m.

[0080] 2. Use pile pipe 8 diameter Since the height of the pile driver tower 14 is 35m, three sections of pile pipes 8 are used for connection. The first section is a pile pipe 8 with a feeding port 9 and a length of 3m, the second section of the pile pipe 8 is 22m long, and the third section of the pile pipe 8 is 28m long. A 10mm thick and diameter A circular steel plate is welded with a 10 cm high ring on it, the diameter of which is slightly smaller than the inner diameter of the pile pipe 8, and a hemp rope is wound around the outer wall of the ring. This structure stops water from entering the pile pipe 8. The upper end of the first section of the pile pipe 8 is connected to the lower end of the middle hole pipe 17 of the electric vibration hammer 7 by bolts.

[0081] 3. First, connect the first section of pile pipe 8 with the third section of pile pipe 8, move the pile driver to ensure that the center of pile pipe 8 is aligned with the center of the hole, turn on the fourth winch 4 of the back pressure device to apply a reaction force to the electric vibration hammer 7 and pile pipe 8 through fixed pulley 1 A, fixed pulley 2 B, fixed pulley 3 C, fixed pulley 4 D, fixed pulley 5 E and fixed pulley 6 F (see Figure 3), so that the third section of pile pipe 8 is completely sunk into the hole, remove the connector between the first section and the third section of pile pipe 8, and connect the second section of pile pipe 8. The upper end is connected to the lower end of the first pile pipe 8, the lower end of the second pile pipe 8 is connected to the upper end of the third pile pipe 8, and then the fourth winch 4 of the back pressure device is turned on to apply a reaction force to the electric vibration hammer 7 and the pile pipe 8 through fixed pulleys A, B, C, D, E and F (see Figure 3), so that the pile pipe 8 sinks 48m into the hole (the bottom of the hole 4m is the hole collapsed after drilling and the hole wall friction when the pile pipe 8 sinks into the hole).

[0082] 4. When the pile pipe 8 cannot be further sunk by the counter-pressure device (see Figure 3), the electric vibration hammer 7 is turned on so that the downward impact force and the applied reaction force generated by the electric vibration hammer 7 act on the pile pipe 8 at the same time, so that the pile pipe 8 can continue to sink to 50m, and then the pile pipe 8 can no longer sink.

[0083] 5. Start the second winch 2, and lift the diameter of the fixed pulley 11 to 12 by the third fixed pulley group (fixed pulley 11 22 and fixed pulley 12 23) in the pulley bracket 10 at the top of the tower 14. A cylindrical weight 15 weighing 5 tons is placed into the pile pipe 8 from the upper end of the middle hole pipe 17 of the electric vibration hammer 7, and the cylindrical weight 15 is repeatedly lifted and lowered to impact the soil layer lead hole at the bottom of the pile pipe 8. While impacting the lead hole, the electric vibration hammer 7 and the fourth winch 4 are turned on, and a reaction force is applied through fixed pulleys A, B, C, D, E and F (see Figure 3), so that the pile pipe 8 sinks 52m into the soil, meeting the design requirements.

[0084] 6. Feed dry hard concrete into the pile pipe 8 from the feeding port 9 at the upper end of the pile pipe 8. While feeding, lift and lower the cylindrical weight 15 and tamp the feed material to make the dry hard concrete tamp out of the bottom end of the pile pipe 8, thereby forming an enlarged head at the bottom end of the pile pipe 8. The volume of the enlarged head is 0.5m 3 .

[0085] 7. Turn on the second hoist 2 to lift the cylindrical weight 15 out of the upper port of the middle hole pipe 17 of the electric vibration hammer 7 through the third fixed pulley group (fixed pulley 11 22 and fixed pulley 12 23 ) in the pulley bracket 10 at the top of the tower 14 .

[0086] 8. Start the third hoist 3 to lift the steel cage through the fourth fixed pulley block (fixed pulley 13 24 and fixed pulley 14 25) in the pulley bracket 10 at the top of the tower 14, and put the first section of the 26m steel cage into the pile pipe 8 through the upper port of the middle hole pipe 17 of the electric vibration hammer 7, and fix the first section of the steel cage to the middle hole pipe 17 of the electric vibration hammer 7. Then align the second section of the 26mm steel cage with the first section of the steel cage, connect the steel cages by electric welding, and then put the 52mm steel cage into the pile pipe 8.

[0087] 9. Pour concrete into the pile pipe 8 from the feeding port 9 at the upper end of the pile pipe 8.

[0088] 10. Start the first winch 1, and pull the movable pulley block 6 downward along the tower 14 through the fifth fixed pulley block 5. At the same time, the steel wire ropes connected to both sides of the movable pulley block 6 pass through the fixed pulley fixed pulley assembly (fixed pulley seven 18-fixed pulley eight 19, fixed pulley nine 20-fixed pulley ten 21) in the pulley bracket 10 at the top of the tower 14 to pull the electric vibration hammer 7 upward along the track 11 on the tower 14 (see Figure 6). At the same time, start the electric vibration hammer 7 to pull out the pile pipe 8, and ensure that concrete is poured into the pile pipe 8 through the feeding port 9 while pulling out the pipe (the amount of concrete poured at this time is the volume occupied by the wall thickness of the pile pipe 8 and the volume of the filling coefficient). When the joint between the second section and the third section of the pile pipe 8 leaks out of the ground, remove the connecting piece, remove the second section of the pile pipe 8 at the same time, and then connect the first section of the pile pipe 8 with the third section of the pile pipe 8, and continue to pull out the pile pipe 8 until the pile pipe 8 is completely pulled out of the ground, and the pile construction is completed.

[0089] The phenomenon of hole collapse is easy to occur when bored piles are constructed at the sites of backfilling, blowing filling, sand, gravel, etc. at the mountain pass. In order to prevent the hole collapse, mud wall protection is generally adopted, thereby reducing the bearing capacity of the single pile, increasing the engineering cost, low construction efficiency, and difficult to ensure the quality. The method of the present invention effectively solves the problem of hole collapse of bored piles in the construction of such sites, that is, three measures such as electric vibration hammer 7, counter pressure device and column hammer impact are adopted to ensure that the pile pipe 8 enters the soil layer. Moreover, the full casing (pile pipe 8) device does not have the hole collapse phenomenon after the hole is formed, thereby ensuring the quality of the pile and reducing the project cost. The lower end of the middle hole pipe 17 electric vibration hammer 7 is connected to the pile pipe 8, and the pile pipe 8 is lifted while vibrating. The concrete of the pile body is fully vibrated, its density is improved, the integrity of the pile body is good, and there is no shrinkage or broken pile phenomenon. The construction method of the present invention replaces the traditional mud wall bored pile construction process, does not produce mud discharge, and has no pollution on site. It also effectively solves the common engineering problem of reduced friction around the pile caused by mud wall protection and reduced bearing capacity of the pile, improves the bearing capacity of a single pile, and the construction efficiency is 2-3 times that of traditional mud wall bored piles.

[0090] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and therefore it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0091] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for constructing a pipe-sinking rammed concrete pile, characterized in that: The following steps are involved: Step 1: Drill a hole at the pile position with a drilling rig, move the pile driver to the position and ensure that the center of the pile pipe is aligned with the center of the drilled hole; Step 2: Start the pile driver, first apply force to the electric vibration hammer and the pile pipe through the counter pressure device, so that the pile pipe sinks into the drill hole; Step 3: Turn on the electric vibration hammer, and the impact force generated by the electric vibration hammer and the force generated by the counter-pressure device act on the pile pipe at the same time, so that the pile pipe continues to sink to the designed depth; Step 4: Add dry hard concrete into the pile pipe from the pile pipe feeding port, tamp with a cylindrical weight while adding the concrete, until the filling amount meets the design requirements, and then remove the cylindrical weight; Step 5: Start the winch, lift the steel cage after the steel wire rope passes through the fixed pulley on the pulley bracket at the top of the pile driver tower, and put the steel cage into the pile pipe from the upper port of the middle hole pipe of the electric vibration hammer. After the steel cage is placed, pour concrete into the pile pipe from the feeding port of the pile pipe; Step six, turn on the electric vibratory hammer and winch, pull out the pile pipe while vibrating, and continue pouring concrete into the pile pipe from the pile pipe feeding port until the bored pile meets the designed pile top elevation, the pile pipe is completely pulled out of the ground, and the bored pile construction is completed.

2. The method for constructing a pipe-sinking rammed concrete pile according to claim 1, characterized in that: A fourth winch is provided on the pile driver platform of the pile driver, and the counter-pressure device comprises fixed pulley one, fixed pulley two, fixed pulley three, fixed pulley four, fixed pulley five and fixed pulley six. After the wire rope extends out from the fourth winch, it passes through the fixed pulley one, fixed pulley two, fixed pulley three, fixed pulley four, fixed pulley five and fixed pulley six in sequence, and then the end thereof is fixed on the other side of the pile driver platform; the fixed pulley one, fixed pulley two, fixed pulley four and fixed pulley five are installed on the pile driver platform, and the fixed pulley three and fixed pulley six are symmetrically installed on both sides of the bottom of the electric vibration hammer.

3. The method for constructing a pipe-sinking rammed concrete pile according to claim 1, characterized in that: A second winch is arranged on the pile driver platform of the pile driver, a third fixed pulley block is arranged on the pulley bracket, and a steel wire rope extends from the second winch and passes around the third fixed pulley block before being connected to the columnar weight.

4. The method for constructing a pipe-sinking and rammed concrete pile according to claim 3 is characterized in that: In the step three, when the impact force generated by the electric vibration hammer and the force generated by the counter-pressure device act on the pile pipe at the same time and the pile pipe still has not sunk to the designed depth, the second winch is turned on to lift the cylindrical weight, and the cylindrical weight is placed into the pile pipe from the upper port of the hole pipe of the electric vibration hammer, and the soil layer at the bottom end of the pile pipe is repeatedly impacted to draw a hole. While impacting the hole, the electric vibration hammer and the counter-pressure device are turned on to ensure that the pipe is sunk to the designed depth.

5. The method for constructing a pipe-sinking rammed concrete pile according to claim 1, characterized in that: A third winch is arranged on the pile driver platform of the pile driver, a fourth fixed pulley block is arranged on the pulley bracket, and a steel wire rope extends from the third winch and passes around the fourth fixed pulley block before being connected to the steel cage.

6. The method for constructing a pipe-sinking rammed concrete pile according to claim 1, characterized in that: The pile driver platform of the pile driver is provided with a first winch and a fifth fixed pulley block, a fixed pulley assembly is provided on the pulley bracket, a steel wire rope extends from the first winch and sequentially passes around the fifth fixed pulley block and the fixed pulley assembly and is connected to the electric vibration hammer, and the first winch is used to lift the electric vibration hammer.

7. The method for constructing a pipe-sinking and rammed concrete pile according to claim 6 is characterized in that: The fixed pulley assembly comprises a first fixed pulley group and a second fixed pulley group, wherein the first fixed pulley group and the second fixed pulley group are arranged on the pulley bracket in a cross form, and the first fixed pulley group and the second fixed pulley group each comprise two fixed pulleys.

8. The method for constructing pipe-sunk rammed concrete piles according to claim 7 is characterized in that: A movable pulley block is arranged between the fifth fixed pulley block and the fixed pulley assembly, and the fifth fixed pulley block pulls the movable pulley to move downward along the tower of the pile driver, and the steel wire ropes on both sides of the movable pulley block pass through the first fixed pulley block and the second fixed pulley block respectively and are symmetrically connected to the two sides of the top of the electric vibration hammer.

9. The method for constructing a pipe-sinking rammed concrete pile according to claim 1, characterized in that: The tower of the pile driver is provided with a track, and the electric vibration hammer can move up and down along the track; the pile driver is also provided with a support rod, and the two ends of the support rod are respectively supported and connected to the pile driver platform and the tower.

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