CN112575784A - Construction method and construction device for removing sediment of guide pipe extrusion-injection type cast-in-place pile - Google Patents

Abstract

The invention relates to a construction method and a construction device for removing sediment of a guide pipe extrusion-injection type cast-in-place pile in the field of pile foundation engineering, wherein the construction method mainly comprises the following steps: a sealed flexible bag (2) is placed at the pile bottom position, and a sewage draining channel (5) is placed near the pile bottom position; pouring pile body concrete; after the pile body concrete is cured to a certain strength, opening the bottom of the sewage draining channel (5) for temporary plugging, and grouting into the flexible bag (2) through the fluid input channel (3); the method has the advantages that the cast-in-place pile sediment is removed from the position near the pile bottom through the sewage discharge channel (5) under the action of grouting pressure, slurry flow direction is restrained through the sealed flexible bag (2) in the construction device during grouting, the soft pile bottom sediment is extruded, the sediment is removed through the sewage discharge channel (5), the pile bottom soil layer can be squeezed, the bearing capacity of a single pile is greatly improved, the construction cost is low, and the construction quality is reliable.

Description

Construction method and construction device for removing sediment of guide pipe extrusion-injection type cast-in-place pile

Technical Field

The invention relates to a construction method and a construction device for removing sediments of a guide pipe extrusion-injection type cast-in-place pile in the field of pile foundation engineering.

Background

The cast-in-place pile is one of the most common pile types in the field of pile foundation engineering, and is widely applied due to the advantages of strong stratum adaptability, mature construction process, small construction equipment, no soil squeezing effect and the like. The cast-in-place pile can be classified into a dry-operation cast-in-place pile and a wet-operation cast-in-place pile according to a hole forming process. The dry operation cast-in-place pile, that is, the cast-in-place pile which is constructed without adopting a slurry wall protection measure in the construction process, mainly comprises a dry operation rotary digging pile, a immersed tube cast-in-place pile, a manual hole digging pile, a long spiral pressure cast-in-place pile, various forms of steel pipe wall protection cast-in-place piles and the like. The wet operation cast-in-place pile, namely the cast-in-place pile for wall protection by using slurry in the pore-forming process, comprises a cast-in-place pile for drilling, a slurry wall protection rotary digging pile and the like. The main steps of the construction of the cast-in-place pile comprise three steps of hole forming, concrete pouring and steel reinforcement cage placement. The construction sequence of the three steps is different for different piling processes. For example, the pile-forming process of cast-in-situ bored piles, manual bored piles, rotary drilled piles, immersed tube cast-in-situ piles and the like comprises the steps of forming holes, placing reinforcement cages in the holes and then pouring concrete; the long spiral pressure filling pile is characterized in that a long spiral drill is rotated to a preset depth, holes are formed while concrete is pressure filled, and a reinforcement cage is inserted into unset concrete. In dry operation or wet operation, sediment or disturbed soil exists at the bottom of the cast-in-place pile, mud or loose soil is often distributed on the side of the pile, and the existence of the mud, the disturbed soil and the sediment causes the bearing capacity potential of the cast-in-place pile to be far from being exerted. At present, the treatment of the sediment at the bottom of the cast-in-place pile, the disturbed soil and the mud at the side of the pile is generally reinforced by adopting a post-grouting mode at the bottom of the pile or at the side of the pile, and because the flow direction of the mud can not be controlled during grouting, the sediment can not be removed, the construction cost is high, the quality control is difficult, and the treatment effect is unstable.

Disclosure of Invention

The invention aims to provide a construction method for removing sediment of a guide pipe extrusion-injection type cast-in-place pile, which can remove sediment and slurry at the bottom of the cast-in-place pile, compact disturbed soil, greatly improve the bearing capacity of the cast-in-place pile, and has the advantages of safety, reliability and low manufacturing cost.

The construction method for removing the sediment of the guide pipe extrusion-injection type cast-in-place pile comprises the following steps:

a) positioning a pile, and forming a hole at the pile position;

b) placing a sealed flexible bag at the pile bottom position to enable a cavity in the flexible bag to be communicated with the operation surface through a fluid conveying channel, placing at least one hollow tubular sewage discharging channel near the pile bottom position, and temporarily blocking the bottom of the sewage discharging channel;

c) pouring pile body concrete;

d) after the pile body concrete is cured to a certain strength, opening the bottom of the sewage draining channel for temporary plugging, and grouting into the flexible bag through the fluid input channel;

e) and (4) continuously grouting, so that the deposited pile sediment is discharged from the position near the pile bottom through a sewage discharge channel under the action of grouting pressure.

In the above-mentioned construction method for removing sediment of the pipe extrusion-injection type cast-in-place pile, the bottom of the trapway may be temporarily blocked using a low-strength material or member in the above-mentioned step b), and the bottom of the hollow tubular trapway may be temporarily blocked by injecting high-pressure water or other fluid in the above-mentioned step d).

In the construction method for removing the sediment of the guide pipe extrusion-injection type cast-in-place pile, in the step e), grouting reinforcement can be performed through the drainage channel after the sediment removal of the cast-in-place pile is completed.

In the construction method for removing the sediments of the guide pipe extrusion-injection type cast-in-place pile, in the step e), the water pipe is inserted into the sewage drainage channel, and water is continuously injected into the sewage drainage channel, so that the sediments are discharged from the outlet of the sewage drainage channel along with water flow.

In the construction method for removing the sediments of the guide pipe extrusion-injection type cast-in-place pile, in the step e), the air pipe is inserted into the sewage discharge channel, and air is continuously filled into the sewage discharge channel, so that the sediments are removed from the outlet of the sewage discharge channel under the action of air flow or under the combined action of the air flow and water flow.

In the above-mentioned construction method for removing sediment from a pipe extrusion-injection type cast-in-place pile, in the step e), a drill having a crushing function is inserted into the sewage drain channel, and the sediment is crushed and discharged from the outlet of the sewage drain channel.

The second purpose of the invention is to provide a construction device for the guide pipe extrusion-injection type cast-in-place pile sediment removal construction method, which can smoothly realize the guide pipe extrusion-injection type cast-in-place pile sediment removal construction method, and has the advantages of convenient construction operation, good effect and low manufacturing cost.

The construction device used by the construction method for removing the sediment of the conduit extrusion-injection type cast-in-place pile comprises a high-pressure grouting pump, a fluid conveying channel, a flexible bag, a sewage discharge channel and a temporary plugging device, wherein the high-pressure grouting pump is a device with a high-pressure grouting function, the high-pressure grouting pump is connected with the fluid conveying channel, the fluid conveying channel is connected with the flexible bag, the flexible bag is a bag-shaped device which is sealed and has certain strength and the volume of which can change along with the volume change of substances contained in the flexible bag, the flexible bag is positioned near the bottom of the cast-in-place pile, the sewage discharge channel is of a hollow tubular structure, the bottom of the sewage discharge channel is positioned near the bottom of the cast-in-place pile, the other end of the sewage discharge channel is positioned near an operation surface, the temporary plugging device is positioned at the bottom of.

In the construction device for the method for removing sediment in the conduit extrusion-injection type cast-in-place pile, the flexible bag can be a folded elongated bag-shaped device.

In the construction device for the method for removing sediment in the conduit extrusion-jet type cast-in-place pile, the flexible bag can be an elongated bag-shaped device which is folded into a cone shape or folded into a combination of a column shape and a cone shape.

According to the construction method and the construction device for removing the sediment of the guide pipe extrusion-injection type cast-in-place pile, disclosed by the invention, the flow direction of fluid before solidification is restrained by utilizing the flexible bag, the flow direction of the sediment at the bottom of the cast-in-place pile is restrained by arranging the sewage discharge channel, and the sediment at the bottom of the cast-in-place pile is removed by pressure generated by high-pressure grouting, so that the implementation effect is good, the pile bottom soil layer can be compacted while the influence of the sediment on the bearing capacity of the cast-in-place pile is eliminated, the bearing capacity of the cast-.

Drawings

FIG. 1 is a schematic cross-sectional view of a pipe extrusion-injection type cast-in-place pile sediment removal construction apparatus used in one embodiment of the present invention;

fig. 2 is a schematic axial view of a long strip-shaped flexible bag folded into a conical cylinder shape for a guide pipe extrusion-injection type cast-in-place pile sediment removal construction device used in one embodiment of the invention.

Detailed Description

The working principle and the specific implementation steps of the method and the device for removing sediment of a conduit extrusion-injection type cast-in-place pile according to the present invention are described below with reference to fig. 1 and 2 as an embodiment of the present invention. The first step of the construction method for removing the sediment of the guide pipe extrusion-injection type cast-in-place pile is to fix the pile position and form a hole at the pile position. The bored concrete pile may be formed by using various techniques, including but not limited to slurry wall-protecting drilling, rotary drilling, long-auger drilling, manual drilling, or other methods. And finishing the first step and entering the second step. In the step, a sealed flexible bag (2) is placed at the pile bottom position, so that a cavity in the flexible bag (2) is communicated with the operation surface through a fluid conveying channel (3), at least one hollow tubular sewage drainage channel (5) is placed near the pile bottom position, and the bottom of the hollow tubular sewage drainage channel (5) is temporarily blocked. In the step, the placed flexible bag (2) is a sealed bag-shaped body with certain tensile strength, the flexible bag (2) can be empty before placement, the size is small, and the flexible bag (2) can be vacuumized to facilitate placement. The flexible bag (2) can be a bag-shaped body with larger volume and can be folded and placed when being placed, or an elastic bag can be selected, and the flexible bag (2) has the characteristic of variable volume, namely, after the flexible bag (2) is filled with a substance, the volume of the flexible bag (2) can be expanded. In the step, the flexible bag (2) can be a strip-shaped hollow bag-shaped body which can be folded in a crossed manner. In this step, the fluid transfer channel (3) is connected to the flexible bag (2) for further operation. In the step, a sewage draining channel (5) is also required to be arranged, and both the sewage draining channel (5) and the fluid conveying channel (3) can be made of tubular components such as steel pipes and the like. The bottom end of the sewage draining channel (5) can be placed in the sediment at the bottom of the pile position hole. In order to avoid the blockage of the sewage discharge channel (5), the opening at the bottom end of the sewage discharge channel (5) can be temporarily blocked by a low-strength material, such as plastic film wrapping and the like, so as to prevent sediment or concrete from entering the sewage discharge channel (5). And finishing the second step and entering the third step. In this step, pile body concrete is poured. The concrete can be poured by adopting the existing mature technology, for example, the pile body concrete can be poured by adopting a conduit method. And partial pile bottom sediment can be removed to the pile top through the impulsive force generated when the pile body concrete is poured downwards. The remaining sludge is removed in a subsequent step. And finishing the third step and entering the fourth step. In the step, after the pile body concrete (1) is cured to a certain strength, the bottom of the hollow tubular sewage draining channel (5) is opened for temporary plugging, and grouting is performed into the flexible bag (2) through the fluid input channel (3), so that the cast-in-place pile sediment is discharged from the position near the pile bottom through the sewage draining channel (5) under the action of grouting pressure. In the step, after the pile body concrete (1) is cured to a certain strength, under the working condition of grouting in the flexible bag (2), a large pressure is generated near the pile bottom, and after the sewage discharge channel (5) is communicated, the pile bottom sediment is discharged to the ground surface from the sewage discharge channel (5) under the action of compressive stress, so that the aim of removing the pile bottom sediment is fulfilled. Meanwhile, the soil body near the bottom of the cast-in-place pile can be compacted through grouting in the flexible bag (2), and the bearing capacity of the single pile is greatly improved. In this step, the temporary closure of the hollow tubular trapway (5) can be opened by injecting high pressure water or other fluid. In the step, after the sediment of the cast-in-place pile is removed, post grouting reinforcement can be performed through the sewage discharge channel (5). In this step, the grouting material may be cement paste, and after solidification, the pile bottom reinforcement (4) as shown in fig. 1 is formed. In the step, a water flushing method can be used in the sewage discharging channel (5) to reduce the sediment removal resistance, namely, in the sediment removal process of the bottom of the cast-in-place pile, a water pipe is inserted into the sewage discharging channel (5), water is continuously injected into the sewage discharging channel, and sediment is removed along with water flow from the outlet of the sewage discharging channel (5). In this step, the air tube can be inserted into the trapway (5), and the trapway is continuously filled with high-pressure air, so that the sediment is discharged from the outlet of the trapway under the action of the air flow or the combined action of the air flow and the water flow. In the step, a drill bit with a crushing function can be inserted into the sewage discharge channel, and the sediments are crushed and then discharged from an outlet of the sewage discharge channel.

Thus completing the construction method for removing the sediment of the conduit extrusion-injection type cast-in-place pile. The following part of this embodiment, with reference to fig. 1 and 2, describes the structure and operation principle of the construction apparatus used in the method for removing sediment in the conduit extrusion-injection type cast-in-place pile. The device comprises a high-pressure grouting pump (7), a fluid conveying channel (3), a flexible bag (2), a sewage draining channel (5) and a temporary plugging device, wherein the high-pressure grouting pump (7) is a device for grouting in the flexible bag (2), the high-pressure grouting pump (7) is connected with the fluid conveying channel (3), the fluid conveying channel (3) is connected with the flexible bag (2), the flexible bag (2) is a sealed bag-shaped device which has certain strength and the volume of which can change along with the volume change of materials contained in the flexible bag (2), the flexible bag (2) is positioned near the pile bottom of a cast-in-place pile (1), the sewage draining channel (5) is of a hollow tubular structure, the bottom end of the sewage draining channel (5) is positioned near the pile bottom of the cast-in-place pile (1), the other end of the sewage draining channel (5) is positioned near an operating surface, the temporary plugging device is positioned at the bottom end of the sewage, the temporary plugging device (5) is a device for temporarily plugging the inlet at the bottom end of the sewage drainage channel (5). In this embodiment, the flexible bag (2) may be a folded elongated bag-like device. The flexible bag (2) may also be an elongated bag-like device folded into a cone or a combination of a cone and a cylinder as shown in fig. 2. In this embodiment, the folded flexible pouch axis (6) of the elongated flexible pouch (2) may be a conical cylinder as shown in fig. 2. The long-strip-shaped flexible bag (2) has the advantage that the pile bottom sediment can be conveniently turned out when the cast-in-place pile is cast with concrete. In the embodiment, the flexible bag (2) can be grouted by the high-pressure grouting pump (7), the flexible bag (2) expands in volume after the cement slurry is injected, the periphery of the flexible bag (2) is plugged by the soil body and the cast-in-place pile (1), the flexible bag (2) expands in volume and then extrudes sediments near the bottom of the pile, the sediments are discharged to the ground surface along the sewage discharge channel (5), the sediment at the bottom of the pile is replaced by the bag-shaped cement slurry block after the cement slurry is solidified, and the soil body near the bottom of the pile can be compacted, so that the bearing capacity of the cast-in-place pile is greatly improved.

This patent includes, but is not limited to, other similar methods and apparatus that may be substituted by one skilled in the art.

Claims (9)

1. A construction method for removing sediments of a guide pipe extrusion-injection type cast-in-place pile comprises the following steps:

a) positioning a pile, and forming a hole at the pile position;

b) placing a sealed flexible bag (2) at the pile bottom position to enable a cavity in the flexible bag (2) to be communicated with the operation surface through a fluid conveying channel (3), placing at least one hollow tubular sewage discharging channel (5) near the pile bottom position, and temporarily blocking the bottom of the sewage discharging channel (5);

c) pouring pile body concrete;

d) after the pile body concrete is cured to a certain strength, opening the bottom of the sewage draining channel (5) for temporary plugging, and grouting into the flexible bag (2) through the fluid input channel (3);

e) and (4) continuously grouting, so that the deposited pile sediment is discharged from the position near the pile bottom through a sewage discharge channel (5) under the action of grouting pressure.

2. The method as claimed in claim 1, wherein the step b) of temporarily blocking the bottom of the sewage passage (5) with a low strength material or member, and the step d) of temporarily blocking the bottom of the hollow tubular sewage passage (5) is performed by injecting high pressure water or other fluid.

3. The method for removing sediment of a cast-in-place pile by extrusion and injection of a guide pipe as claimed in claim 1, wherein in the step e), after sediment removal of the cast-in-place pile is completed, grouting reinforcement is performed through the drainage channel (5).

4. The method as claimed in claim 1, wherein in the step e), the water pipe is inserted into the soil discharging passage (5), and water is continuously injected into the soil discharging passage (5) so that the sludge is discharged from the outlet of the soil discharging passage (5) with the water flow.

5. The method for removing sediment in a cast-in-place pile according to claim 1, wherein in the step e), the air pipe is inserted into the sewage draining passage (5), and the air is continuously filled into the sewage draining passage (5), so that the sediment is removed from the outlet of the sewage draining passage (5) under the action of the air flow or the combined action of the air flow and the water flow.

6. The method as claimed in claim 1, wherein in the step e), a drill having a crushing function is inserted into the sewage passage (5), and the crushed sediment is discharged from an outlet of the sewage passage (5).

7. A construction device used in the method of removing sediment in a conduit extrusion-injection type cast-in-place pile according to claim 1, which is characterized by comprising five parts, namely a high-pressure grouting pump (7), a fluid conveying channel (3), a flexible bag (2), a sewage draining channel (5) and a temporary plugging device, wherein the high-pressure grouting pump (7) is a device with a high-pressure grouting function, the high-pressure grouting pump (7) is connected with the fluid conveying channel (3), the fluid conveying channel (3) is connected with the flexible bag (2), the flexible bag (2) is a sealed bag-shaped device which has certain strength and the volume of which can be changed along with the volume change of substances contained in the flexible bag (2), the flexible bag (2) is positioned near the bottom of the cast-in-place pile, the sewage draining channel (5) is of a hollow tubular structure, the bottom end of the sewage draining channel (5) is positioned near the bottom of the cast-in-place pile, and the other end of the, the temporary plugging device is positioned at the bottom end of the sewage drainage channel (5), and is a device for temporarily plugging the inlet at the bottom end of the sewage drainage channel (5).

8. The apparatus for removing sediment in cast-in-place piles by squeeze-and-spray method according to claim 7, wherein said flexible bag (2) is a folded elongated bag-like apparatus.

9. The apparatus for removing sediment in cast-in-place piles according to claim 7, wherein the flexible bag (2) is a bag-shaped device folded in a cone shape or a combination of a cylindrical shape and a cone shape.

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