CN108978661B

CN108978661B - Construction method for removing cast-in-situ bored pile

Info

Publication number: CN108978661B
Application number: CN201810850225.4A
Authority: CN
Inventors: 周曙东; 周芳; 陈家冬; 尚学伟; 周浩达
Original assignee: Jiangsu Foundation Engineering Co ltd
Current assignee: Jiangsu Foundation Engineering Co ltd
Priority date: 2018-07-28
Filing date: 2018-07-28
Publication date: 2020-12-01
Anticipated expiration: 2038-07-28
Also published as: CN108978661A

Abstract

The invention discloses a construction method for pulling out a cast-in-situ bored pile, relates to the field of bearing piles in the field of buildings, and solves the technical problem that potential safety hazards are caused by the separation of an old pile and a steel wire rope lock catch when the old pile in the cast-in-situ bored pile is lifted and pulled out, wherein the key points of the technical scheme are as follows: step one, determining a pile position, excavating a groove and exposing a pile head, and determining the pile position needing to be pulled out; step two, positioning the sleeve; thirdly, vibrating and sinking the pipe, pulling out the pile body, using a steel wire rope to lift and pull out the pile body and lift the old pile out of the opening of the casing pipe, using a crane to lift the pile after the steel wire rope and the pile body are firmly fixed, and using an anti-dropping device for preventing the steel wire rope from dropping when the lifting ring is separated from the lifting hook; backfilling pile holes; step five, piling high pre-pressed soil in pile holes, observing sedimentation, regularly monitoring every day after the pile soil is piled to 2m high pre-pressed, and intensively treating the waste piles; the method has the advantage that the protection performance of lifting the old pile in the process of pulling out the cast-in-situ bored pile is improved.

Description

Construction method for removing cast-in-situ bored pile

Technical Field

The invention relates to the field of bearing piles in the field of buildings, in particular to a construction method for pulling out a cast-in-situ bored pile.

Background

In the building engineering, because the construction of the subsequent structures is not considered in the structures constructed firstly, more and more obstacles are encountered in the construction, and particularly, the cast-in-situ bored piles for removing the existing structures are very common.

Chinese patent publication No. CN107338795A discloses a construction method of a full-casing extraction column-type cast-in-situ bored pile, which mainly comprises excavating old piles at pile heads of the old piles, and effectively positioning; positioning the whole sleeve of the pile extractor, and continuously drilling until the pile bottom is 1 m; lowering the steel wire rope lock catch, and pulling out the old pile by using a crane; and backfilling the holes by adopting cement soil, and pulling out the whole casing. The drill bit of the whole sleeve is divided into an inner tooth, a middle tooth and an outer tooth, a plurality of holes are formed in the pipe body of the whole sleeve, the outer diameter of the pipe body of the 1m range of the interface part of the whole sleeve is larger than the outer diameter of the pipe body by 1-3cm, and the outer diameter of the pipe body of the 2m range of the drill bit part of the whole sleeve is larger than the outer diameter of the pipe body by 1-3 cm.

However, when the old pile is lifted, the old pile is pulled out by the steel wire rope lock catch, one end, far away from the old pile, of the steel wire rope is connected with a lifting hook of a crane through the lifting ring, the steel wire rope is prone to shaking when the old pile is lifted, the steel wire rope lifting ring is separated from the lifting hook at the moment, and certain potential safety hazards exist.

Disclosure of Invention

The invention aims to provide a cast-in-situ bored pile pulling construction method which has the advantage that the protection of lifting an old pile in the cast-in-situ bored pile pulling process is improved.

The technical purpose of the invention is realized by the following technical scheme that the construction method for pulling out the cast-in-situ bored pile comprises the following steps,

step one, determining a pile position, excavating a groove and exposing a pile head, and determining the pile position needing to be pulled out;

step two, positioning the sleeve;

thirdly, vibrating and sinking the pipe, pulling out the pile body, using a steel pipe as a sleeve, using a 120T crawler crane to lift a 150kw zero-current started vibration hammer to vibrate and sink the sleeve to a position 50-100cm below the bottom of the bored pile, starting an air compressor and a high-pressure centrifugal water pump to wash and clean soil on the outer side of the old pile in the sleeve in the sinking process of the sleeve until the pile body is independently stripped, and finally, singly starting high-pressure 6m air pressure for carrying out high-pressure 6m to carry out air pressure for fully overflowing muddy water in the sleeve along with air flow;

the pile body is pulled up by a steel wire rope, the old pile is lifted out of the opening of the casing, the steel wire rope is wound in the outer wall of the old pile, the steel wire rope is provided with a hanging ring, the pile is hung by a crane after the steel wire rope and the pile body are firmly fixed, and when the hanging ring is separated from a hanging hook, the hanging hook is provided with an anti-falling device for preventing the steel wire rope from falling;

backfilling pile holes, namely mixing the pile holes on site with cement, backfilling the pile holes into the sleeve, starting a vibration hammer fixed on the sleeve, and lifting the sleeve by using a crane;

and fifthly, piling high-prepressing soil in the pile hole, observing sedimentation, regularly monitoring every day after the pile soil is piled to 2m high prepressing, and intensively treating the waste piles.

Through the technical scheme, in the process of pulling out the cast-in-situ bored pile, the old pile is pulled out of the soil body by using the steel wire rope, the anti-dropping device plays a role in protecting the old pile during the hoisting process of the crane, so that the protection device can continue hoisting the old pile when the hoisting ring and the hoisting hook are separated, the protection performance of hoisting the old pile is enhanced, the potential safety hazard in the hoisting process is reduced, after the old pile is hoisted, the pile hole is backfilled, the crane is used for hoisting the sleeve, and the pile hole piles high pre-compaction soil and settlement observation.

The invention is further configured to: the lifting hook divide into vertical portion and crotch portion, the anti-drop device is including seting up at the annular standing groove of vertical portion outer wall, setting up the protection rope that is close to rings one end at wire rope, the one end winding that wire rope was kept away from to the protection rope is behind the standing groove, twines out the standing groove and is tied on the protection rope, vertical portion is equipped with two semicircle annular spacing rings with protection rope restriction in the standing groove, two at protection rope winding's outer wall the both ends of spacing ring all are equipped with the connecting plate, lie in two spacing rings relative connecting plate and pass through locking bolted connection, the equal threaded connection in both ends of wearing out the connecting plate of locking bolt has the latch segment, the length of protection rope is greater than the straight line position of standing groove to protection rope and wire rope tie point.

Through above-mentioned technical scheme, the length of protection rope is greater than the straight line position of standing groove to protection rope and wire rope tie point for the vertical portion at the lifting hook is fixed through the setting of two spacing rings to the protection rope in the lax state, protection rope, and when rings on wire rope and lifting hook separation, the protection rope is straightened and the atress, and the protection rope has acted as wire rope's effect this moment.

The invention is further configured to: the anti-falling device comprises a pull rope arranged on the hanging ring, and one end of the pull rope, which is far away from the hanging ring, is fixed on the lifting hook.

Through above-mentioned technical scheme, the stay cord plays the effect of continuing to lift by crane old stake after rings and lifting hook separation, reduces the possibility that old stake dropped and takes place.

The invention is further configured to: the lifting hook is characterized in that an arc-shaped rod extending to the position right below the lifting hook is arranged on the side wall of the upper end of the lifting hook, a guide cylinder distributed along the vertical direction is arranged at one end, away from the lifting hook, of the arc-shaped rod, and the guide cylinder is used for a steel wire rope to pass through.

Through above-mentioned technical scheme, the setting up of arc pole makes the guide cylinder can fix in the lifting hook below, and the wire rope of being convenient for passes, and the setting up of guide cylinder has reduced wire rope's swing range.

The invention is further configured to: the welding of sleeve pipe lower extreme has annular fixed plate, the fixed plate is kept away from sheathed tube one end and is equipped with a plurality of teeth.

Through above-mentioned technical scheme, set up the tooth on the fixed plate for the tooth just welds the sleeve pipe lower extreme when the sleeve pipe uses, reduces the damage of tooth in the sleeve pipe transportation, and the tooth utilizes the gas cutting to pull down the fixed plate from the sleeve pipe when damaging.

The invention is further configured to: and a plurality of guide chutes which are spirally upward are arranged on the outer wall of the sleeve at positions corresponding to the teeth.

Through the technical scheme, when the teeth at the lower end of the sleeve are drilled into soil due to the arrangement of the guide chute, the soil on the outer wall of the sleeve enters the guide chute and moves towards the upper end of the sleeve along the guide chute, and the resistance of the soil body to the sleeve entering the soil body is reduced.

The invention is further configured to: and cutting edges are arranged at the positions of the relative groove walls of the guide grooves, which are close to the notches of the guide grooves.

Through above-mentioned technical scheme, when the casing bored into the soil body, the cutting blade cut the peripheral soil body of casing, did benefit to the casing and got into in the soil body.

The invention is further configured to: and step four, cement slurry in the backfill pile hole is continuously and slowly stirred in the grouting process, and the cement slurry is filtered by a screen when being in the grouting hole.

Through above-mentioned technical scheme, stirring that does not stop makes cement paste get into the sleeve after the solidification even, and the screen cloth discharges cement paste with great granule in the cement paste.

The invention is further configured to: and in the fourth step, for soil layers with the same permeability coefficient, grouting and capping are firstly carried out, then grouting is carried out from bottom to top, if the permeability coefficient of the soil layers is increased along with the depth, grouting is carried out from bottom to top, and if interbedded strata, grouting is carried out on the strata with high permeability or porosity.

Through above-mentioned technical scheme, adopt different slip casting modes, be convenient for lie in the pouring of different osmotic coefficient soil horizon internal drilling.

In conclusion, the invention has the following beneficial effects: when the steel wire rope lifts by crane old pile, the lifting hook is provided with an anti-falling device for preventing the steel wire rope from falling, so that the protection performance of the old pile in the lifting process is improved, and the stability of the old pile in the lifting process is higher.

Drawings

FIG. 1 is a flowchart of the construction method of the embodiment;

FIG. 2 is a schematic structural diagram of the embodiment for embodying the function of the protective rope in the process of hoisting the old pile;

FIG. 3 is an enlarged structural view of part A in FIG. 2;

FIG. 4 is a schematic structural diagram of the anti-drop device according to the present embodiment;

FIG. 5 is a schematic structural diagram of the embodiment for showing the effect of the pull rope in the old pile hoisting process;

FIG. 6 is an enlarged structural view of a portion B in FIG. 5;

fig. 7 is a schematic structural view of the material guide chute according to the present embodiment.

Reference numerals: 1. a hook; 11. a vertical portion; 12. a hook portion; 13. an anti-drop device; 131. a placement groove; 132. a protective rope; 133. a limiting ring; 134. a connecting plate; 135. locking the bolt; 136. a locking block; 137. pulling a rope; 138. an arcuate bar; 139. a guide cylinder; 14. a wire rope; 141. a hoisting ring; 15. a sleeve; 151. a fixing plate; 152. teeth; 153. a material guide chute; 154. a cutting edge; 2. and (5) old piles.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example (b):

a construction method for pulling out a cast-in-situ bored pile, as shown in figure 1, comprising the following steps,

step two, positioning the sleeve;

step three, vibrating and sinking the pipe, pulling out the pile body, excavating the sleeve pipe by a general covering method by adopting a steel pipe, crushing and removing a steel concrete bearing platform, exposing the pile top of each pile to be pulled out in the bearing platform, and machining the sleeve pipe with the diameter of 1200mm, wherein the rigidity of the sleeve pipe comprises two water paths and two gas paths meets the requirement, and the sleeve pipe comprises two water paths and two gas paths according to the actual conditions of the site such as the diameter, the cross section, the depth and the like; and (3) hoisting the 150kw zero-current started vibration hammer to vibrate the sinking casing pipe to a position 50-100cm below the bottom of the bored pile by using a 120T crawler crane, starting an air compressor and a high-pressure centrifugal water pump to wash soil outside the old pile in the casing pipe until a pile body is independently stripped in the sinking process of the casing pipe, and finally, singly driving high-pressure 6m high-pressure gas pressure to completely overflow the casing pipe with the slurry water in the casing pipe along with the gas flow.

As shown in fig. 7, the annular fixing plate 151 is welded to the lower end of the sleeve 15, a plurality of teeth 152 are arranged at one end of the fixing plate 151, which is far away from the sleeve 15, the teeth 152 are arranged on the fixing plate 151, so that the teeth 152 can be welded to the lower end of the sleeve 15 when the sleeve 15 is used, damage to the teeth 152 in the transportation process of the sleeve 15 is reduced, and when the teeth 152 are damaged, the fixing plate 151 is detached from the sleeve 15 by gas cutting, so that the fixing plate 151 is detached from the sleeve 15 by gas cutting when the teeth 152 are damaged.

As shown in fig. 7, during the sinking process of the casing 15, a plurality of guide chutes 153 are formed in the outer wall of the casing 15 at positions corresponding to the teeth 152, and the guide chutes 153 are arranged such that when the teeth 152 at the lower end of the casing 15 drill into the soil, the soil on the outer wall of the casing 15 enters the guide chutes 153 and moves along the guide chutes 153 to the upper end of the casing 15, thereby reducing the resistance of the soil body to the casing 15 entering the soil body. The notch positions of the opposite groove walls of the material guide groove 153, which are close to the material guide groove 153, are all provided with cutting edges 154, and when the casing pipe 15 drills into the soil body, the cutting edges 154 cut the soil body around the casing pipe 15, so that the casing pipe 15 can conveniently enter into the soil body.

When the pile is pulled out by vibration, the pile is pulled out while vibrating, when the distance between the pile tip and the ground is 1-2 m, the vibration is stopped immediately, and the pile is pulled out by a crane.

As shown in fig. 2 and 3, the pile body is pulled up by using a steel wire rope 14, the old pile 2 is lifted out of the opening of the sleeve 15, the steel wire rope 14 is wound in the outer wall of the old pile 2, a hanging ring 141 is arranged on the steel wire rope 14, and the pile is hung by using a crane after the steel wire rope 14 is firmly fixed with the pile body; in the hoisting process of the old pile 2, the old pile 2 gradually moves out of the soil body along with the old pile 2, the old pile 2 is easy to shake, if the old pile 2 is influenced by gale weather or is not stably hoisted, the steel wire rope 14 is also shaken, the hoisting ring 141 is easy to separate from the lifting hook 1 at the moment, and therefore the anti-falling device 13 for preventing the steel wire rope 14 from falling is arranged on the lifting hook 1.

Referring to fig. 3 and 4, the hook 1 is divided into a vertical part 11 and a hook part 12, the drop preventing device 13 includes a ring-shaped placement groove 131 formed in an outer wall of the vertical part 11, and a protection rope 132 disposed at an end of the wire rope 14 close to the hanging ring 141, an end of the protection rope 132 far from the wire rope 14 is wound around the placement groove 131, the placement groove 131 is wound around the protection rope 132, and the protection rope 132 is embedded into the placement groove 131. In order to prevent the protection rope 132 from falling out of the placing groove 131, the outer wall of the vertical part 11 wound by the protection rope 132 is provided with two semicircular limiting rings 133 which limit the protection rope 132 in the placing groove 131, two opposite ends of the two limiting rings 133 are provided with connecting plates 134, the opposite connecting plates 134 on the two limiting rings 133 are connected through locking bolts 135, and two ends of the locking bolts 135 penetrating through the connecting plates 134 are both in threaded connection with locking blocks 136; the locking block 136 is rotated towards the connecting plate 134, so that the locking block 136 abuts against the connecting plate 134 and extrudes the two connecting plates 134, the connecting plate 134 drives the limiting ring 133 to abut against the vertical part 11, and the protection rope 132 is fixed in the placing groove 131.

As shown in fig. 4, when the lifting hook 1 is connected to the lifting ring 141, the length of the protection rope 132 is greater than the linear position from the placement groove 131 to the connection point of the protection rope 132 and the steel wire rope 14, so that the protection rope 132 is in a loose state, when the lifting ring 141 is separated from the lifting hook 1, the protection rope 132 is forced to be straightened, and at this time, the protection rope 132 serves as the steel wire rope 14, and the old pile 2 is continuously lifted.

Referring to fig. 5 and 6, the pile 2 is positioned on the hook 1, and the pull rope 137 is in a loose state, when the lifting ring 141 is moved out of the hook 1 or the lifting hook 1, the pull rope 137 applies a pulling force to the lifting ring 141, so that the old pile 2 can be lifted continuously.

As shown in fig. 3, in order to reduce the swinging of the steel wire rope 14, an arc rod 138 extending to the position right below the lifting hook 1 is arranged on the side wall of the upper end of the lifting hook 1, a guide cylinder 139 distributed along the vertical direction is arranged at one end of the arc rod 138 far away from the lifting hook 1, the steel wire rope 14 passes through the guide cylinder 139, the inner diameter of the guide cylinder 139 can also be passed through by the hanging ring 141, the inner diameter of the guide cylinder 139 limits the moving range of the steel wire rope 14, and then the swinging amplitude of the steel wire rope 14 is reduced.

Step four, backfilling pile holes, mixing the pile holes on site by cement, backfilling the pile holes into the sleeve, wherein the control of the backfilling compactness of the pile holes is a key for preventing hole collapse in construction, so that cement slurry is continuously and slowly stirred in the grouting process, the cement slurry is filtered by a screen when being injected into the holes, a vibration hammer fixed on the sleeve is started, and the sleeve is lifted by a crane; for soil layers with the same permeability coefficient, grouting and capping are firstly carried out, then grouting is carried out from bottom to top, if the permeability coefficient of the soil layers is increased along with the depth, grouting is carried out from bottom to top, and if the stratum with the same permeability coefficient or porosity is mutually layered, grouting is carried out on the stratum with the high permeability or porosity.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. A construction method for pulling out a cast-in-situ bored pile is characterized by comprising the following steps,

step two, positioning the sleeve;

step three, vibrating and sinking the pipe and pulling out the pile body, wherein the casing pipe is a steel pipe, a vibration hammer started by 150kw zero current is hung by a 120T crawler crane to vibrate and sink the casing pipe to a position 50-100cm below the bottom of the cast-in-situ bored pile, in the sinking process of the casing pipe, an air compressor and a high-pressure centrifugal water pump are started to wash and clean soil on the outer side of the old pile in the casing pipe until the pile body is independently stripped, finally, high-pressure 6m air pressure is singly started to carry out high-pressure 6m air pressure transmission, and all muddy water in the casing pipe overflows the casing pipe along with air flow;

the pile body is pulled up by a steel wire rope, the old pile is lifted out of the sleeve opening, the steel wire rope is wound in the outer wall of the old pile, a hanging ring is arranged on the steel wire rope, the pile is hung by a crane after the steel wire rope and the pile body are firmly fixed, and an anti-falling device for preventing the steel wire rope from falling is arranged on the hanging ring; an arc-shaped rod (138) extending to the position right below the lifting hook (1) is arranged on the side wall of the upper end of the lifting hook (1), a guide cylinder (139) distributed along the vertical direction is arranged at one end, far away from the lifting hook (1), of the arc-shaped rod (138), and the guide cylinder (139) is used for a steel wire rope (14) to penetrate through;

the lifting hook (1) is divided into a vertical part (11) and a hook part (12), the anti-falling device (13) comprises an annular placing groove (131) formed in the outer wall of the vertical part (11) and a protection rope (132) arranged at one end, close to the lifting ring (141), of the steel wire rope (14), one end, far away from the steel wire rope (14), of the protection rope (132) is wound on the placing groove (131) and then wound out of the placing groove (131) and tied to the protection rope (132), two semicircular limiting rings (133) limiting the protection rope (132) in the placing groove (131) are arranged on the outer wall, wound on the protection rope (132), of the vertical part (11), two connecting plates (134) are arranged at two ends of the two limiting rings (133), the opposite connecting plates (134) on the two limiting rings (133) are connected through locking bolts (135), and locking blocks (136) are in threaded connection with the two ends penetrating through the connecting plates (134) of the locking bolts (135), the length of the protection rope (132) is larger than the straight line position from the placement groove (131) to the connection point of the protection rope (132) and the steel wire rope (14);

the anti-falling device (13) comprises a pull rope (137) arranged on the hanging ring (141), and one end, far away from the hanging ring (141), of the pull rope (137) is fixed on the lifting hook (1);

2. The cast-in-situ bored pile pulling construction method according to claim 1, wherein an annular fixing plate (151) is welded to the lower end of the casing (15), and a plurality of teeth (152) are provided at one end of the fixing plate (151) far away from the casing (15).

3. The cast-in-situ bored pile pulling construction method according to claim 2, wherein the outer wall of the casing (15) is provided with a plurality of spirally upward material guiding chutes (153) at positions corresponding to the teeth (152).

4. The cast-in-situ bored pile pulling construction method according to claim 3, wherein the notch of the guide chute (153) is provided with a cutting edge (154) at a position close to the guide chute (153) relative to the wall of the guide chute.

5. The cast-in-situ bored pile pulling construction method according to claim 1, wherein the cement slurry in the holes of the fourth backfill pile is continuously and slowly stirred during the grouting process, and the cement slurry is filtered by a screen when being injected into the holes.

6. The cast-in-situ bored pile pulling construction method according to claim 1, wherein in the fourth step, a top is grouted and sealed first in soil layers having the same permeability coefficient, then grouting is performed from bottom to top, if the permeability coefficient of a soil layer increases with depth, grouting is performed from bottom to top, and if a mutual stratum, grouting is performed first in a stratum having a large permeability or porosity.