CN113605389B - Green dismantling method for pile head embedded pipe and rope saw cutting of reinforced concrete cast-in-place pile - Google Patents

Abstract

The invention discloses a green dismantling method for a pile head pre-buried pipe and a rope saw cutting of a reinforced concrete cast-in-place pile, which adopts a mode of arranging 4 pre-buried pipes, namely a waist pipe, a rope penetrating pipe, a sleeve and a hoisting pipe, on a cast-in-place pile head and using the rope saw to cut, thereby realizing the dismantling of the green pile head without drilling, stripping, vibration, dust and noise; the invention has the advantages of less used equipment, mechanical completion of main operation, high cutting precision, flat cut, less workload of manual leveling and scabbling, low labor intensity and high safety; the operation provided by the invention has no damage to the pile body concrete and the steel bars, the construction quality is high, and compared with other construction methods, the method also has the advantages of low construction cost and short construction period.

Description

Green demolition method of reinforced concrete cast-in-place pile head embedded pipe and wire saw cutting

technical field

The invention relates to the field of dismantling of reinforced concrete structures, in particular to a green dismantling method for cutting a reinforced concrete cast-in-place pile head embedded pipe and a wire saw.

Background technique

In engineering construction, reinforced concrete cast-in-place piles are common foundations on soil foundations. In order to ensure the quality of the pile body, it is usually overfilled. After the concrete has hardened, the overfilled pile heads need to be removed. The common method of breaking pile head is manual breaking method. This method requires a lot of labor and has obvious shortcomings of high labor intensity and low production efficiency. With the gradual increase of labor costs, it will completely lose the market. In addition, the use of excavators and breakers for construction is also a relatively common construction method before, but due to the large noise and vibration of this method, which has a great impact on the quality of the concrete of the pile body, it has also been basically eliminated by the market; The hydraulic pile breaker of "International Construction Machinery Exhibition" was introduced into China. This technology has the advantages of high construction efficiency, less noise and less damage to the pile body, and has been applied in a large area. However, this technology also has some disadvantages: if it cannot handle pile heads with irregular dimensions (such as partial protruding of the pile body), the crushing efficiency of pile heads with dense longitudinal reinforcement and larger size will decrease; the strong surrounding pressure will also have a certain effect on concrete and steel bars Damage, especially the anchoring force of steel bars and concrete, has an adverse effect; in order to protect the concrete of the pile body from damage, a longer protection section should be reserved. The protection section also needs manual or mechanical chiseling or smoothing, which increases the cost and construction period and weakens the advantages of this technology. In 2018, Ma Jia and Zhang Jianguang of Shaanxi Provincial Communications Construction Group Co., Ltd. proposed a new construction method in the paper "Application of Circumcision Method for Pile Head Breaking in Pile Foundation Engineering" in the 9th issue of "Highway Transportation Science and Technology" in 2018. This construction method It is to directly insert the pre-processed release sleeve into the exposed cap of the steel cage, the main reinforcement at the outer end of the tie beam and the surface of the acoustic tube, so that the concrete at the pile head and the main reinforcement do not get caught, and then use the double-knife ring cutting method, twice. Circumcising the pile foundation, the cutting position of the pile head is drilled in the direction of the vertical pile body with a pneumatic pick, insert the separating wedge into the drill hole, and use external force to strike until the pile head and the pile body are completely separated, and then use the lifting equipment to lift the upper part. pile head. This process shortens the operation procedure and time, reduces labor costs and water costs compared with the manual crushing method, and ensures less damage to the main reinforcement, integrity of the pile foundation, and the health and environmental protection of the operators. However, this method requires an air pick to drill holes, which is noisy and still polluted by dust. The method of manually hitting the wedge to split the concrete of the pile body is labor-intensive and low-efficiency. In order to overcome this shortcoming, in 2020, Liu Keliang of China Railway Municipal Environmental Construction Co., Ltd. published the paper "New Technology of Peel-free and Circumcision-free Pile Heads for Bored Cast-in-place Pile" published in the 12th issue of the "Construction" journal in 2020. A new peel-free and ring-free construction method is characterized in that the pre-processed casing is directly inserted into the main reinforcement at the end of the reinforcement cage and the outer end surface of the acoustic tube and fixed, and the concrete at the pile head is connected with the main reinforcement. , The acoustic measuring tube is effectively isolated, and the gripping force and friction between the concrete and the steel bar and the acoustic measuring tube are separated; The crack-inducing groove is drilled, and the hydraulic splitting gun is inserted into the hole to cut off the pile head concrete; finally, the pile head is lifted out by lifting equipment. Based on the advantages of the method proposed by Ma Jia and Zhang Jianguang, the method improves the drilling method and splitting method, and achieves technological progress in reducing dust, improving splitting efficiency and reducing splitting labor intensity. However, this method also has disadvantages: three types of machinery are needed: drilling rig, hydraulic splitting machine and crane, which require high equipment. At the same time, since the cracks formed by splitting may not be flush, it is necessary to leave a long protection section (above 10cm), This section requires manual and mechanical chipping or trimming, adding to the cost. In addition, the above two construction methods are sleeved on the outer casing of the acoustic measuring tube, which also affects the acoustic measuring result. In order to overcome these shortcomings, it is necessary to improve on the basis of the above-mentioned technology, and develop a new green demolition method for pile heads that is free of stripping and drilling, and uses less equipment.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the above-mentioned deficiencies, provide a reinforced concrete cast-in-place pile head pre-embedded pipe and a wire saw cutting green dismantling method, at the beginning of the design and construction of the concrete cast-in-place pile, the problem of removing the super-cast pile head is considered, A variety of pre-embedded pipes are arranged at the head to achieve the purpose of green pile head removal with no peeling, no drilling, less mechanical equipment, wire saw cutting, low cost and low environmental impact.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is: a reinforced concrete cast-in-place pile head pre-embedded pipe, which comprises a waist pipe, a wire rope that are pre-buried in the pile head during the construction period of the reinforced concrete cast-in-place pile Pipe, casing and hoisting pipe, the waist pipe and the rope-piercing pipe are arranged in the same horizontal plane of the area above the design elevation of the pile top, this plane is the cutting plane, and the part above the cutting plane is the excised part of the pile head, the pile head The longitudinal rib of the pile head is covered with a casing above the cutting plane, and a hoisting pipe is pre-buried in the same horizontal plane of the part above the cutting plane of the pile head, and the longitudinal axis of the hoisting pipe points to the center of the horizontal plane.

Preferably, the waist tube and the rope threading tube are arranged in the same horizontal plane 3-6 cm above the design elevation of the pile top.

Preferably, the waist tube is close to the outside of the longitudinal rib to form a complete circle; the middle part of the rope-passing tube is close to the inside of the longitudinal rib, both ends extend to the inside of the waist tube, and the linear distance between the two ends is greater than 3 cm from the nearest longitudinal rib .

Preferably, a plurality of hoisting pipes are pre-buried in the upper half of the cut part of the pile head in the same horizontal plane, and the distance between the horizontal plane and the top of the cut part is greater than one quarter of the total height of the cut part, and the hoisting pipes are connected to the pile body. The surface intersection points are evenly distributed on the circumference, and the outer end of the hoisting pipe is flush with the concrete protective layer or protrudes 1-2 cm from the surface of the concrete protective layer.

Preferably, the waist pipe is formed by pre-embedding a PVC plastic pipe or a rubber pipe; the rope threading pipe and the casing are formed by pre-buying a PVC plastic pipe; the diameter of the waist pipe is equal to or greater than the thickness of the concrete protection layer of the pile body; the rope threading pipe The inner diameter is 15-25 mm; the inner diameter of the casing is 4-20 mm larger than the longitudinal rib diameter.

Preferably, the waist tube is formed by butting two ends of a PVC plastic tube or rubber tube, and the width of the wrapping tape at the joint is greater than 5cm; the two ends of the rope-passing tube are blocked with corks or gypsum; the upper and lower ends of the casing are blocked with gypsum ; Both ends of the hoisting pipe are blocked with wooden plugs.

Preferably, the waist tube and the rope-piercing tube are both bound on the longitudinal bars with binding iron wires, and all the places in contact with the longitudinal bars are bound; the upper end wall of each casing is drilled and tied to the casing after passing through the wire. Cover the upper end of the longitudinal rib.

Preferably, a plurality of acoustic pipes are arranged in the longitudinal direction of the pile head, the acoustic pipes are bent towards the pile core at the cutting plane, and a gap is left between the longitudinal bars and the acoustic pipes for the rope-passing pipes to pass through, The acoustic tube is close to the longitudinal bars or stirrups at other heights, and is bound to the longitudinal bars or stirrups.

In addition, the present invention also discloses a method for cutting the pile head with a wire saw by the pre-buried pipe at the pile head of the reinforced concrete cast-in-place pile, comprising the following steps:

1) Find the waist tube, destroy the concrete protective layer that wraps the waist tube, remove the waist tube after unwinding the tape and binding iron wire;

2) Clean the blockages at both ends of the rope threading pipe, and pass the wire saw blade through the openings at both ends of the rope threading pipe;

3) Start the wire saw to cut the concrete and the acoustic tube along the cutting plane until the boundary line; when cutting, use the water pipe to align the opening of one end of the wire pipe, and input the lubricating water to the wire saw blade on the cutting surface, and follow the cutting. As the depth increases, gradually increase the water pressure and water volume;

4) Untie the wire at the upper end of the casing to break the concrete on the outside of the rope-passing pipe on the cutting plane; cut the rope-passing pipe along the cutting plane;

5) Insert the flat head steel drill into the cutting surface of the cutting plane, and pry up the steel drill so that the reserved concrete is broken along the cutting plane;

6) Open the wooden plug at the outer end of the hoisting pipe, insert a round steel with a length greater than the depth of the hoisting pipe 10-15cm, and insert a wedge-shaped wooden bar in the gap between the round steel and the hoisting pipe to fix it, tie a steel wire rope on the round steel, and hoist it with a crane Pile head cut off part.

Preferably, the step 3) is specifically as follows: start the wire saw to cut the concrete and the acoustic tube along the cutting plane, and cut to the boundary line; use a water pipe for the lubrication water in the early stage of cutting to align the opening of one end of the wire pipe, and input it into the cutting plane. On the cutting surface; after the cutting depth is greater than 5cm, cut off the 2cm long pipe at the midpoint of the rope-passing pipe, insert the water pipe from this place, and input the lubricating water to the saw blade on the cutting surface, and gradually insert it deeply as the cutting depth increases. Water hose to get close to the wire saw blade or increase the water pressure and water volume.

The present invention has the following beneficial effects:

(1) The present invention realizes the drilling-free, peeling-free, vibration-free, less dust and low noise of the cast-in-place pile head by ingeniously arranging various types of pre-embedded pipes and introducing the wire sawing process into the demolition of the cast-in-place pile head. green demolition process;

(2) The technical solution provided by the present invention uses less equipment, the main operations are completed mechanically, the labor intensity is low, and the safety is high;

(3) In the technical solution provided by the present invention, due to the high cutting precision of the wire saw and the smooth incision, only a small amount of manual leveling and chiseling work is required, and the concrete and steel bars are not damaged, and the construction quality is high;

(4) In the technical solution provided by the present invention, since the outer casing of the acoustic measuring pipe is not required, there is no pre-embedded pipe fittings arranged in the concrete between the acoustic measuring pipes, which does not affect the detection result of the acoustic measuring pipe on the pile foundation;

(5) The present invention avoids peeling off the concrete protective layer, and avoids the longitudinal bars when the wire saw is cut, and the construction efficiency is high, which is expected to be 2-3 times the efficiency of the artificial pile head breaking process; The manual leveling work is reduced, and the efficiency has an advantage of 10-20%. Therefore, the present invention has greater advantages in cost and construction period than the prior art;

(6) In the present invention, by pre-embedding the waist tube, the cutting plane can be accurately positioned when the pile head is broken, avoiding crushing or cutting the concrete protective layer; by pre-embedding the wire tube, the wire saw can avoid the steel bars and speed up the cutting progress; Arranging the casing on the longitudinal reinforcement can avoid the concrete stripping operation in the traditional pile head breaking operation, and also avoid the damage to the longitudinal reinforcement; by pre-embedding the hoisting pipe, the hoisting operation of the cutting pile head is convenient, and the drilling operation is avoided. hole work.

Description of drawings

Fig. 1 is the A-A longitudinal section structure schematic diagram of reinforced concrete cast-in-place pile head;

Fig. 2 is the B-B cross-sectional schematic diagram when the reinforced concrete cast-in-place pile head is not removed;

Fig. 3 is the B-B cross-sectional schematic diagram when the reinforced concrete cast-in-place pile head is removed with a wire saw;

Fig. 4 is the C-C cross-sectional schematic diagram of reinforced concrete cast-in-place pile head;

In the figure, 1-pile head, 2-longitudinal reinforcement, 3-stirrup, 4-waist pipe, 5-rope pipe, 6-casing, 7-hoisting pipe, 8-binding iron wire, 9-winding tape, 10 - Wire saw blade, 11- Acoustic tube, 12- Boundary line, 13- Cutting face, 14- Retain concrete, 15- Water pipe.

Detailed ways

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

As shown in Figures 1 to 4, a reinforced concrete cast-in-place pile head pre-embedded pipe includes a waist pipe 4, a rope threading pipe 5 and a casing that are embedded in the pile head 1 during the construction period of the reinforced concrete cast-in-place pile. 6 and the hoisting pipe 7, the waist pipe 4 and the rope-piercing pipe 5 are arranged in the same horizontal plane of the area above the design elevation of the pile top, this plane is the cutting plane, and the part above the cutting plane is the excision part of the pile head 1, the pile The longitudinal rib 2 of the head 1 is covered with a casing 6 above the cutting plane, and a hoisting pipe 7 is pre-embedded in the same horizontal plane of the part above the cutting plane of the pile head 1, and the longitudinal axis of the hoisting pipe 7 points to the center of the horizontal plane.

Preferably, the waist tube 4 and the rope threading tube 5 are arranged in the same horizontal plane 3-6 cm above the design elevation of the pile top.

Preferably, the waist tube 4 is close to the outer side of the longitudinal rib 2 to form a complete circle; the middle part of the rope threading tube 5 is close to the inner side of the longitudinal rib 2, the two ends extend to the inner side of the waist tube 4, and the two ends are away from the nearest longitudinal rib. 2 The straight-line distance is greater than 3 cm.

Preferably, a plurality of hoisting pipes 7 are pre-embedded in the upper half of the cut part of the pile head 1 in the same horizontal plane, and the distance from the horizontal plane to the top of the cut part is greater than a quarter of the total height of the cut part. The hoisting pipes 7 The intersection points with the surface of the pile body are evenly distributed on the circumference, and the outer end of the hoisting pipe 7 is flush with the concrete protective layer or protrudes 1-2 cm from the surface of the concrete protective layer.

Preferably, the waist tube 4 is formed by pre-embedding a PVC plastic tube or a rubber tube; the rope threading tube 5 and the sleeve 6 are formed by pre-embedding a PVC plastic tube; the diameter of the waist tube 4 is equal to or greater than the thickness of the concrete protective layer of the pile body ; The inner diameter of the rope threading pipe 5 is 15-25 mm; the inner diameter of the casing 6 is larger than the diameter of the longitudinal rib 2 by 4-20 mm.

Preferably, the waist tube 4 is formed by butting two ends of a PVC plastic tube or rubber tube, and the width of the wrapping tape 9 at the butt joint is greater than 5 cm; the two ends of the rope-passing tube 5 are blocked with wooden plugs or plaster; the upper and lower casings 6 are up and down Both ends are blocked with gypsum; both ends of the hoisting pipe 7 are blocked with wooden plugs.

Preferably, both the waist tube 4 and the rope threading tube 5 are bound on the longitudinal bars 2 with binding iron wires 8, and all the places in contact with the longitudinal bars 2 are bound; It is bound on the upper end of the longitudinal rib 2 covered by the sleeve 6 .

Preferably, a plurality of acoustic tubes 11 are also arranged in the pile head 1 along the longitudinal direction, and the acoustic tubes 11 are bent toward the pile core at the cutting plane, leaving a gap between the longitudinal bars 2 and the acoustic tubes 11 for passing through. The rope tube 5 is passed through, and the acoustic tube 11 is close to the longitudinal bar 2 or the stirrup 3 at other heights, and is bound on the longitudinal bar 2 or the stirrup 3.

In addition, the present invention also discloses a method for cutting the pile head with a wire saw by the pre-buried pipe at the pile head of the reinforced concrete cast-in-place pile, comprising the following steps:

1) Find the waist tube 4, destroy the concrete protective layer that wraps the waist tube 4, remove the wrapping tape 9 and the binding iron wire 8, and then take out the waist tube 4;

2) Clear the blockages at both ends of the rope threading pipe 5, and pass the wire saw blade 10 from the openings at both ends of the rope threading pipe 5;

3) Start the wire saw to cut the concrete and the acoustic tube 11 along the cutting plane until the boundary line 12; when cutting, use a water pipe to align the opening of one end of the wire pipe 5, and input lubricating water to the wire saw blade 10 of the cutting surface 13 As the cutting depth increases, gradually increase the water pressure and water volume;

4) Untie the iron wire at the upper end of the casing 6 to break the concrete on the outside of the rope threading pipe 5 on the cutting plane; cut the rope threading pipe 5 along the cutting plane;

5) Insert the flat head steel drill into the cutting surface 13 of the cutting plane, and pry up the steel drill so that the reserved concrete 14 is broken along the cutting plane;

6) Open the wooden plug at the outer end of the hoisting pipe 7, insert a round steel whose length is 10-15cm greater than the depth of the hoisting pipe 7, and insert a wedge-shaped wooden strip in the gap between the round steel and the hoisting pipe 7 to fix it, and fasten the steel wire rope on the round steel. Lift the excised part of the pile head with a crane.

Preferably, the step 3) is specifically: start the wire saw to cut the concrete and the acoustic tube 11 along the cutting plane, and cut to the boundary line 12; use a water pipe for the lubricating water in the early stage of cutting to align the opening of one end of the wire pipe 5, and input it into the On the cutting surface 13 of the cutting plane; after the cutting depth is greater than 5cm, cut off a 2cm long pipe at the midpoint of the rope threading pipe 5, and insert the water pipe 15 from this place, and input the lubricating water to the saw blade 10 of the cutting surface 13. As the cutting depth increases, gradually insert the water pipe 15 deeply to approach the wire saw blade 10 or increase the water pressure and water volume.

The accompanying drawings of the present invention only show the situation of a circular section pile. When the cross section is a rectangle (including a square), all the technical features of the present invention are the same, and the above solution is also established, only one technical feature is added, that is, the 4 Arc-shaped chamfers are arranged at each corner to facilitate the perforation of the wire saw blade and the initial cutting operation.

Example 1

The diameter of the reinforced concrete cast-in-place pile is 1.2 m, with 20 longitudinal bars of diameter Ф22, the concrete strength of the pile body is C25, the thickness of the protective layer is 40 mm, and the height of the super-cast pile head is 1 m.

The waist tube and the rope threading tube are arranged in the same plane 3 cm above the design elevation of the pile top. This plane is the cutting plane, and the part above the cutting plane is the excised part of the pile head; Circle; the middle part of the rope threading tube is close to the inside of the 15 longitudinal bars, and the two ends extend to the inner side of the waist tube, and the distance from the contact point of the waist tube to the two adjacent longitudinal bars is equal; the longitudinal bars are sleeved above the cutting plane; The upper half of the excised part of the pile head is pre-buried with three hoisting pipes on the same horizontal plane. The longitudinal axis of the hoisting pipes points to the center of the circle. The intersection points of the hoisting pipes and the surface of the pile body are evenly distributed on the circumference, and the outer ends of the hoisting pipes are flush with the concrete protective layer. .

The waist tube is a rubber tube with a diameter of 45 mm; the rope threading pipe and the casing are PVC plastic pipes, the diameter of the rope threading pipe, the casing and the hoisting pipe are all 32mm, and the wall thickness is 3mm; the length of the hoisting pipe is 15cm.

The width of the wrapping tape at the joint of the waist pipe is 6 cm; the two ends of the rope-piercing pipe are blocked with gypsum; the upper and lower ends of the casing are blocked with gypsum; the two ends of the hoisting pipe are blocked with wooden plugs;

The waist tube and the rope-piercing tube are all bound on the longitudinal bars with binding iron wires, and all the places in contact with the longitudinal bars are bound; the upper end pipe wall of each casing is drilled, and after passing through the wire, it is bound on the casing to cover it. the upper end of the longitudinal ribs.

In the pile head, there are also 3 acoustic measuring tubes arranged in the longitudinal direction (the acoustic measuring tubes are evenly distributed on the same horizontal ring, and all are in contact with the waist tube), and the acoustic measuring tubes are slightly bent towards the pile center at the cutting plane, Leave a gap between the longitudinal bar and the acoustic tube for the rope-passing tube to pass through, and the acoustic tube is close to the longitudinal bar or stirrup at other heights, and is bound to the longitudinal bar or stirrup.

The hoisting pipe is a PVC plastic pipe with a diameter of 32 mm and a wall thickness of 3 mm.

The method for cutting the pile head with a wire saw using the above-mentioned reinforced concrete cast-in-place pile head embedded pipe includes the following steps:

1) Find the waist tube, destroy the concrete protective layer that wraps the waist tube, remove the waist tube after unwinding the tape and binding iron wire;

2) Clean the blockages at both ends of the rope threading pipe, and pass the wire saw blade through the openings at both ends of the rope threading pipe;

3) Start the wire saw to cut the concrete and the acoustic tube along the cutting plane, and cut to the boundary line (more than 5cm away from the longitudinal bars in the reserved concrete); when cutting, use the water pipe to align the opening of one end of the wire pipe, and input lubricating water until the cutting On the saw blade on the surface, as the cutting depth increases, the water pressure and water volume are gradually increased;

4) Untie the wire at the upper end of the casing to break the concrete on the outside of the rope-passing pipe on the cutting plane; cut the rope-passing pipe along the cutting plane;

5) Insert the flat head steel drill into the cutting surface of the cutting plane, and pry up the steel drill so that the reserved concrete is broken along the cutting plane;

6) Open the wooden plug at the outer end of the hoisting pipe, insert a round steel with a length of 25cm and a diameter of 20 mm, and insert a wedge-shaped wooden bar into the gap between the round steel and the hoisting pipe to fix it, tie a steel wire rope to the round steel, and hoist the pile head with a crane Cut off part.

Example 2

The diameter of the reinforced concrete cast-in-place pile is 2 m, equipped with 28 longitudinal bars of diameter Ф24, the concrete strength of the pile body is C25, the thickness of the protective layer is 40 mm, and the height of the super-cast pile head is 1.2 m.

The waist tube and the threading tube are arranged in the same plane 6 cm above the design elevation of the pile top. This plane is the cutting plane, and the part above the cutting plane is the excised part of the pile head; Circle; the middle part of the rope-passing tube is close to the inner side of the 22 longitudinal bars, the two ends extend to the inner side of the waist tube, and the two ends are 5 cm away from the nearest longitudinal bar; the longitudinal bars are sleeved above the cutting plane; Four hoisting pipes are pre-buried in the upper part on the same horizontal plane. The longitudinal axis of the hoisting pipes points to the center of the circle. The intersections of the hoisting pipes and the surface of the pile body are evenly distributed on the circumference. The outer ends of the hoisting pipes protrude 2 cm from the surface of the concrete protective layer.

The waist tube adopts a PVC plastic tube with a diameter of 40 mm and a wall thickness of 3.7 mm; the rope threading tube adopts a PVC plastic tube with a diameter of 25 mm and a wall thickness of 2.3 mm; the casing adopts a PVC plastic tube with a diameter of 40 mm and a wall thickness of 3.7 mm. . The hoisting pipe adopts a PVC plastic pipe with a diameter of 32mm, a wall thickness of 3 mm and a length of 20 cm.

The waist tube is formed by butting two ends of a plastic tube, and the width of the wrapping tape is 7cm at the butt joint; the two ends of the rope threading tube are blocked with wooden plugs; the upper and lower ends of the casing are blocked with gypsum; the two ends of the hoisting pipe are blocked with wooden plugs; All embedded pipes are intact and leak-free.

The waist tube and the rope-piercing tube are all bound on the longitudinal bars with binding iron wires, and all the places in contact with the longitudinal bars are bound; the upper end pipe wall of each casing is drilled, and after passing through the wire, it is bound on the casing to cover it. the upper end of the longitudinal ribs.

There are also 4 acoustic measuring tubes arranged in the longitudinal direction in the pile head (the acoustic measuring tubes are evenly distributed on the same horizontal ring, and all are in contact with the waist tube), and the acoustic measuring tubes are slightly bent towards the pile center at the cutting plane, Leave a gap between the longitudinal bar and the acoustic tube for the rope-passing tube to pass through, and the acoustic tube is close to the longitudinal bar or stirrup at other heights, and is bound to the longitudinal bar or stirrup.

The plane where the hoisting pipe is located is located in the upper half of the cut-out portion of the pile head, and the distance between the plane and the top of the cut-out portion of the pile head is 40 cm.

Utilize the above-mentioned reinforced concrete cast-in-place pile head pre-embedded pipe to wire saw cutting the pile head, comprising the following steps:

1) Find the waist tube, destroy the concrete protective layer that wraps the waist tube, remove the waist tube after unwinding the tape and binding iron wire;

2) Clean the blockages at both ends of the rope threading pipe, and pass the wire saw blade through the openings at both ends of the rope threading pipe;

3) Start the wire saw to cut the concrete and acoustic tube along the cutting plane until the boundary line (the distance between the boundary line and the nearest longitudinal bar is greater than 5cm); in the early stage of cutting, use a water pipe to align the opening of one end of the rope passing pipe and input it to the cutting plane On the cutting surface (13) of the cutting surface; after the cutting depth is greater than 5 cm, cut off the 2 cm long pipe at the midpoint of the rope-passing pipe, insert the water pipe from this place, and input the lubricating water to the saw blade on the cutting surface, as the cutting depth increases , and gradually insert the water pipe deeply to get close to the saw blade.

4) Untie the wire at the upper end of the casing to break the concrete on the outside of the rope-passing pipe on the cutting plane; cut the rope-passing pipe along the cutting plane;

5) Insert the flat head steel drill into the cutting surface of the cutting plane, and pry up the steel drill so that the reserved concrete is broken along the cutting plane;

6) Open the wooden plug at the outer end of the hoisting pipe, insert a 22mm diameter round steel with a length of more than 35 cm, and insert a wedge-shaped wooden bar into the gap between the round steel and the hoisting pipe to fix it, tie a steel wire rope to the round steel, and hoist the pile head with a crane Cut off part.

Example 3

The diameter of the reinforced concrete cast-in-place pile is 0.8 m, with 16 longitudinal bars of diameter Ф16, the concrete strength of the pile body is C25, the thickness of the protective layer is 35 mm, and the height of the super-cast pile head is 1 m.

The waist tube and the threading tube are arranged in the same plane 4 cm above the design elevation of the pile top. This plane is the cutting plane, and the part above the cutting plane is the excised part of the pile head; the waist tube is close to the outside of the 13 longitudinal bars, forming a A complete circle; the middle part of the rope-passing tube is close to the inner side of the longitudinal bar, both ends extend to the inner side of the waist tube, and the linear distance between the two ends is greater than 5 cm from the nearest longitudinal bar; the longitudinal bar is covered with a casing above the cutting plane; the pile head is removed The upper part of the part is embedded with two hoisting pipes on the same horizontal plane. The longitudinal axis of the hoisting pipes points to the center of the circle. The intersections of the hoisting pipes and the surface of the pile body are evenly distributed on the circumference, and the outer ends of the hoisting pipes protrude 1cm from the surface of the concrete protective layer.

The waist tube adopts a rubber tube with a diameter of 35 mm; the rope threading tube adopts a PVC plastic tube with a diameter of 25 mm, and the casing and the hoisting tube are both PVC plastic tubes, with a diameter of 25 mm and a rear wall of 2.3 mm; the length of the hoisting tube is 10 cm.

The waist tube is formed by butting two ends of a rubber tube, and the width of the wrapping tape is 6 cm; ; All embedded pipes are complete without leakage.

The waist tube and the rope-piercing tube are all bound on the longitudinal bars with binding iron wires, and all the places in contact with the longitudinal bars are bound; the upper end pipe wall of each casing is drilled, and after passing through the wire, it is bound on the casing to cover it. the upper end of the longitudinal ribs.

The pile head is also arranged with 2 acoustic measuring tubes along the longitudinal direction (the acoustic measuring tubes are evenly distributed on the same horizontal ring, and both are in contact with the waist tube), and the acoustic measuring tubes are slightly bent towards the pile center at the cutting plane, Leave a gap between the longitudinal bar and the acoustic tube for the rope-passing tube to pass through, and the acoustic tube is close to the longitudinal bar or stirrup at other heights, and is bound to the longitudinal bar or stirrup.

The plane where the hoisting pipe is located is located in the upper half of the cut-out portion of the pile head, and the distance between the plane and the top of the cut-out portion of the pile head is 30 cm.

The method of wire saw cutting the pile head by utilizing the above-mentioned reinforced concrete cast-in-place pile head pre-embedded pipe comprises the following steps:

1) Find the waist tube, destroy the concrete protective layer that wraps the waist tube, remove the waist tube after unwinding the tape and binding iron wire;

2) Clean the blockages at both ends of the rope threading pipe, and pass the wire saw blade through the openings at both ends of the rope threading pipe;

3) Start the wire saw to cut the concrete and the acoustic tube along the cutting plane until the boundary line; when cutting, use the water pipe to align the opening of one end of the wire pipe, and input lubricating water to the saw blade on the cutting surface. Large, gradually increase the water pressure and water volume;

4) Untie the wire at the upper end of the casing to break the concrete on the outside of the rope-passing pipe on the cutting plane; cut the rope-passing pipe along the cutting plane;

5) Insert the flat head steel drill into the cutting surface of the cutting plane, and pry up the steel drill so that the reserved concrete is broken along the cutting plane;

6) Open the wooden plug at the outer end of the hoisting pipe, insert a round steel with a length of 20 cm and a diameter of 18 mm, and insert a wedge-shaped wooden bar into the gap between the round steel and the hoisting pipe to fix it, tie a steel wire rope on the round steel, and use a crane to hoist the pile head and cut it off. part.

The above-mentioned embodiments are only the preferred technical solutions of the present invention, and should not be regarded as limitations of the present invention. The embodiments and features in the present application may be arbitrarily combined with each other without conflict. The protection scope of the present invention shall take the technical solutions described in the claims, including the equivalent alternatives of the technical features in the technical solutions described in the claims, as the protection scope. That is, equivalent replacements and improvements within this scope are also within the protection scope of the present invention.

Claims (5)

1. a method of utilizing a reinforced concrete cast-in-place pile head embedded pipe to cut a wire saw to the pile head, the reinforced concrete cast-in-place pile head embedded pipe is included in the reinforced concrete cast-in-place pile construction period and is pre-buried in its pile head (1. ), the rope threading pipe (5), the casing (6) and the hoisting pipe (7), the waist pipe (4) and the rope threading pipe (5) are arranged in the area above the design elevation of the pile top In the same horizontal plane of the pile head (1), the plane is the cutting plane, and the part above the cutting plane is the excised part of the pile head (1). , a hoisting pipe (7) is pre-buried in the same horizontal plane of the part above the cutting plane of the pile head (1), and the longitudinal axis of the hoisting pipe (7) points to the center of the horizontal plane; ) outside, forming a complete circle; the middle part of the rope threading tube (5) is close to the inside of the longitudinal rib (2), the two ends extend to the inside of the waist tube (4), and the linear distance between the two ends from the nearest longitudinal rib (2) is greater than 3 cm; the waist tube (4) is formed by butting two ends of a PVC plastic tube or rubber tube, and the width of the tape (9) around the butt joint is greater than 5 cm; the two ends of the rope-piercing tube (5) are made of wooden plugs or plaster Blocking; the upper and lower ends of the casing (6) are blocked with gypsum; the two ends of the hoisting pipe (7) are blocked with wooden plugs; the waist pipe (4) and the rope-piercing pipe (5) are tied with binding iron wires (8) in the longitudinal direction. On the rib (2), all the contact points with the longitudinal rib (2) are bound; the upper pipe wall of each casing (6) is drilled, and after passing through the wire, it is bound to the longitudinal rib ( 2) The upper end; a plurality of acoustic measuring tubes (11) are also arranged in the longitudinal direction in the pile head (1), and the acoustic measuring tubes (11) are bent towards the pile core at the cutting plane, and the longitudinal bars (2) and the acoustic measuring tubes (11) are bent towards the core of the pile at the cutting plane. Leave a gap between the pipes (11) for the rope threading pipe (5) to pass through, and the acoustic measuring pipe (11) is close to the longitudinal reinforcement (2) or stirrup (3) at other heights, and is bound to the longitudinal reinforcement (2). or stirrup (3); it is characterized in that: it comprises the following steps: 1) Find the waist tube (4), destroy the concrete protective layer that wraps the waist tube (4), remove the wrapping tape (9) and the binding iron wire (8), and then take out the waist tube (4); 2) Clear the blockages at both ends of the rope threading pipe (5), and pass the wire saw blade (10) from the openings at both ends of the rope threading pipe (5); 3) Start the wire saw to cut the concrete and the acoustic tube (11) along the cutting plane until the boundary line (12); when cutting, use a water pipe to align the opening of one end of the wire pipe (5), and input lubricating water to the cutting surface On the wire saw blade (10) of (13), as the cutting depth increases, the water pressure and water volume are gradually increased; 4) Untie the wire at the upper end of the casing (6), and break the concrete on the outside of the rope threading pipe (5) on the cutting plane; cut the rope threading pipe (5) along the cutting plane; 5) Insert the flat head steel drill into the cutting surface (13) of the cutting plane, and pry up the steel drill so that the retained concrete (14) is broken along the cutting plane; 6) Open the wooden plug at the outer end of the hoisting pipe (7), insert a round steel whose length is 10-15cm longer than the depth of the hoisting pipe (7), and insert a wedge-shaped wooden bar into the gap between the round steel and the hoisting pipe (7) to fix it. A steel wire rope is tied to the steel, and the cut off part of the pile head is hoisted by a crane. 2. The method for cutting the pile head wire saw by using the reinforced concrete cast-in-place pile head embedded pipe according to claim 1, characterized in that: the waist pipe (4) and the rope threading pipe (5) are arranged on the pile top design Within the same horizontal plane 3-6 cm above the elevation. 3 . The method for cutting the pile head with a wire saw using a reinforced concrete cast-in-place pile head embedded pipe according to claim 2 , wherein the upper half of the cut part of the pile head ( 1 ) is pre-cut in the same horizontal plane. 4 . A plurality of hoisting pipes (7) are buried, and the distance from the horizontal plane to the top of the cut part is greater than a quarter of the total height of the cut part. The intersection points of the hoisting pipes (7) and the surface of the pile body are evenly distributed on the circumference, and the hoisting pipes (7) The outer end is flush with the concrete cover or protrudes 1-2cm from the surface of the concrete cover. 4. The method for cutting the pile head with a wire saw using a reinforced concrete cast-in-place pile head embedded pipe according to claim 1, characterized in that: the waist pipe (4) is formed by pre-embedding a PVC plastic pipe or a rubber pipe; The rope pipe (5) and the casing (6) are formed by pre-embedding PVC plastic pipes; the diameter of the waist pipe (4) is equal to or greater than the thickness of the concrete protection layer of the pile body; the inner diameter of the rope pipe (5) is 15-25 mm; The inner diameter of the casing (6) is 4-20 mm larger than the diameter of the longitudinal rib (2). 5. the method that utilizes reinforced concrete cast-in-place pile head embedded pipe to cut the pile head wire saw according to claim 1, it is characterized in that: The step 3) is as follows: start the wire saw to cut the concrete and the acoustic tube (11) along the cutting plane, and cut to the boundary line (12); use a water pipe to align the opening of one end of the wire pipe (5) with water for initial lubrication , and input it to the cutting surface (13) of the cutting plane; after the cutting depth is greater than 5cm, cut off a 2cm long pipe at the midpoint of the rope threading pipe (5), and insert the water pipe (15) from there, and input the lubricating water to the cutting On the wire saw blade (10) on the surface (13), as the cutting depth increases, gradually insert the water pipe (15) deeply to approach the wire saw blade (10) or increase the water pressure and water volume.

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