KR20200137907A - Partially expanding apparatus for underground pipe and composite cast in place pile method using the same - Google Patents

Abstract

The present invention relates to an underground pipe part expansion apparatus comprising a moving body (20) moved in a pipe body (10) as an outlet (21) is formed and a conveying pipe (41) connected to the outlet (21) is embedded therein, and a sealing body (30) formed at both ends of the moving body (20) to seal a partial section of the pipe body (10), and an onsite-placement composite pile construction method. The underground pipe part expansion apparatus is inserted into the pipe body (10) inserted in the ground, and then, is operated to form an expansion part (11) in the pipe body (10). Through the present invention, since an uneven portion is formed on the outer circumference surface of an onsite-placement composite pile, a substantial coupling structure between the pile and the ground can be built, thereby considerably improving the support force of the pile.

Description

An underground pipe body part expansion device and a synthetic pile construction method for cast-in-place using it {PARTIALLY EXPANDING APPARATUS FOR UNDERGROUND PIPE AND COMPOSITE CAST IN PLACE PILE METHOD USING THE SAME}

In the present invention, the ejection port 21 is formed and the pressure feed pipe 41 connected to the ejection port 21 is built-in to move the moving body 20 inside the tube body 10, and at both ends of the moving body 20 An underground pipe body part expansion device consisting of a sealing body 30 that is formed to seal a partial section of the pipe body 10, and an on-site synthetic pile construction method using the same, and expands the underground pipe body part into the pipe body 10 penetrated into the ground. After the device is put into operation, it is to form an enlarged diameter part 11 in the tube body 10.

The cast-in-place pile is a kind of pile foundation in contrast to the ready-made pile, and as shown in Fig. 1, it is constructed by pouring concrete into the pre-drilled excavation hole or the previously penetrated casing 19 and then curing. , Unlike the ready-made piles, since the process of tying the completed pile structure to the ground is unnecessary, there is an advantage of preventing noise or vibration caused in the driving process.

In general, the pile foundation resists the load of the upper structure of the pile or the negative pressure of the underground structure caused by the groundwater due to the tip bearing capacity and the main surface friction force, so that the desired bearing capacity is expressed. An excavation depth greater than or equal to the desired rock layer must be secured, or if the rock layer is too deep, a root length greater than a predetermined length must be secured.

In addition, the pile behaves not only as a structure that simply transmits the upper load to the ground, but is itself a kind of long column structure that must resist axial compression, transverse bending and buckling stress, as shown in FIG. Likewise, a reinforcing bar 99 or a steel frame is usually embedded in the concrete body as a reinforcing material.

On the other hand, as a kind of in-situ casting piles composed of such reinforcing materials, in-situ steel pipe composite concrete piles have been developed in which steel pipes are penetrated into the ground and then concrete is poured and cured while the steel pipes remain. No. 2018-9196, etc. may be mentioned.

Conventional in-situ composite piles, including Korean Patent Publication No. 2018-9196, have a structure in which steel pipes, which are reinforcing materials, cover the piles, unlike traditional on-site piles in which the main reinforcement is embedded in the piles, and steel pipes penetrated into the ground are poured. It is known to be advantageous in securing the structural rigidity of the pile structure itself, compared to the embedded reinforcement material, and serves as a formwork and a reinforcement material for concrete.

In a conventional cast-in-place pile, as shown in FIG. 1, the ground is excavated and drilled using an excavating body 91 such as an auger mounted on the excavation equipment 90, but with the excavation of the excavating body 91, When the casing 19 for maintaining the empty wall is penetrated, and the bottom of the casing 19 reaches the target depth, the excavator 91 is withdrawn and reinforcing materials such as reinforcing bars 99 are introduced into the casing 19, and the drawing Although not shown above, concrete is poured into the excavation hole.At this time, the casing 19 is drawn immediately before the concrete is placed, at the same time as the concrete is placed, or immediately after the concrete is placed.

In other words, in the construction of traditional cast-in-place piles, the casing 19 is a temporary structure used for the purpose of maintaining empty walls and is recovered and reused at the final stage, whereas in the cast-in-place steel pipe composite pile, the steel pipe is permanently retained as a reinforcing material. will be.

These traditional casing (19) recovery type cast-in-place piles and cast-in-place steel pipe composite piles cannot be called an absolutely advantageous construction method, and can be said to be a construction method applied according to various conditions in consideration of the advantages and disadvantages of each.

First of all, the traditional casing (19) recovery-type cast-in-place pile is a structure in which the concrete to be poured and the ground are in direct contact, making it easy to secure the main surface friction in the completed pile, and to recover and reuse the casing (19), which is an expensive material. While it is possible to reduce the construction cost, there is a problem in that the stiffness of the pile structure itself is relatively weak, and the construction speed is lowered during the process of drawing and reusing the casing 19.

On the other hand, as mentioned above, the cast-in-place steel pipe composite pile is advantageous in securing the structural rigidity of the pile structure itself.In the ground where the tip bearing capacity is sufficiently secured, the cross-sectional area of the pile can be reduced or the number of construction work can be reduced, but the contact surface between the pile and the ground As it is formed on the surface of this steel pipe, it is disadvantageous in securing the main surface friction.

In particular, in the construction of a synthetic pile of cast-in-place steel pipes, a casing 19 and a steel pipe for reinforcing the pile may be separately configured, and in this case, a casing 19 and a steel pipe for reinforcing the pile may be separately configured with the excavator 91 when drilling the first excavation hole After the reinforcing steel pipe is inserted, the casing 19 is pulled out and withdrawn.If the excavation casing 19 and the reinforcing steel pipe are configured separately, a cavity is formed between the steel pipe and the excavation hole or As disturbances are inevitably induced, the actual circumferential friction cannot be expected.

The present invention is invented in view of the above-described problems, as a hollow body that is introduced into the tube body 10 in a state penetrated into the ground, the lower end is closed, and the pressure delivery tube 41 and the drive tube 42 are built-in, On the side, a moving body 20 having a discharge port 21 connected to the pressure feed pipe 41 is formed, and an annular cyst installed at both ends of the moving body 20, which is connected to the drive pipe 42 and has an inner circumferential surface of the moving body 20 ) Consisting of a sealing body 30 that is in close contact with the outer circumferential surface of the body, and after the moving body 20 is inserted into the tube body 10 in a state penetrated into the ground, the sealing body 30 ) Is expanded, the inner space of the tube 10 between the sealing bodies 30 at both ends of the moving body 20 is sealed, and the tube body 10 is expanded as the pressurized fluid is supplied to the pressure delivery tube 41 It is a device for expanding the tube body.

In addition, as a tubular hollow body that is inserted into the tube body 10 in a state of being penetrated into the ground, both ends are open, and the inner support part 22 is added and the outer diameter is gradually reduced to the outside at both ends. It is formed, the pressure feed pipe 41 and the drive pipe 42 are built-in, and the movable body 20 in which the ejection port 21 connected to the pressure feed pipe 41 is formed on the side, and at both open ends of the moving body 20, respectively As a disk body to be installed, the outer diameter is gradually reduced toward the moving body 20 and a coupling pipe 24 is formed on the side of the moving body 20 so that the coupling pipe 24 is inserted into the moving body 20, and , The sealing body 30, which is a ring body installed between the inner support part 22 and the outer support part 23, is built into the moving body 20, so that the drive pipe 42 is connected and both ends of the moving body 20 It is composed of a driving body 50 that connects the outer support part 23 installed in the ground, and after the moving body 20 is inserted into the tube body 10 in a state of being penetrated into the ground, the working fluid is supplied to the drive pipe 42 to be driven. As the sieve 50 is contracted, the outer supporting portions 23 at both ends of the moving body 20 are brought close to each other, and the seal 30 between the inner supporting portion 22 and the outer supporting portion 23 expands to expand the sealing member 30 on both sides. It is an underground pipe body part expansion device characterized in that the inner space of the pipe body 10 is sealed, and the pipe body 10 is enlarged as the pressurized fluid is supplied to the pressure delivery pipe 41.

In addition, in the in-situ composite pile construction method using the underground pipe body part expansion device, the step of intruding the pipe body 10 into the ground, and when the pipe body 10 reaches a target depth, the sealing body 30 into the pipe body 10 ) Injecting an underground pipe body part expansion device in a contracted state, sealing a partial section of the pipe body 10 by expanding the sealing body 30 of the underground pipe body part expansion device, and pressurizing with a pressure delivery pipe 41 The pressurized fluid ejected through the ejection port 21 by supplying the fluid expands the tube body 10 to form an expansion part 11, and after contracting the sealing body 30, the underground tube part expansion device is connected to the tube body 10. ) It is a synthetic pile construction method that is cast in place using an underground pipe part expansion device, characterized in that it consists of a step of evacuating to the outside and a step of pouring and curing concrete in the pipe body 10.

Through the present invention, it is possible to build a solid coupling structure between the pile and the ground by forming irregularities on the outer circumferential surface of the on-site synthetic pile, thereby significantly improving the support of the pile.

In particular, since the pipe body 10 constituting the pile can be partially expanded and deformed while the pipe body 10 is penetrated into the ground, the ground structure is densified while the expansion part of the pipe body 10 compresses the surrounding ground. It can be, by combining the expansion portion of the tube body 10 to the densified ground, a further enhanced binding force can be expressed.

As a result, it is possible to significantly improve the main surface friction or cohesion while maintaining the unique structural rigidity of the cast-in-place composite pile, thereby improving the performance of the pile foundation and securing the stability of the upper structure.

1 is an explanatory diagram of a conventional cast-in-place pile construction process
Figure 2 is an explanatory diagram of the construction process of the present invention
3 is an explanatory diagram of an operation method of the apparatus of the present invention
4 is a perspective view of the device of the present invention
5 is a representative cross-sectional view of the device of the present invention
6 is an explanatory diagram of a step-by-step operation state of the inventive device
7 is a partially cut-out exploded perspective view of a modified embodiment of the device of the present invention
Figure 8 is a representative cross-sectional view of the moving state of the embodiment of Figure 7
9 is a representative cross-sectional view of the sealing state of the embodiment of FIG. 7

The detailed configuration and execution process of the present invention will be described with reference to the accompanying drawings.

First, Figure 2 shows the construction process of the present invention, as shown, expansion of the underground pipe body part of the present invention consisting of a moving body 20 and a sealing body 30, etc. into the pipe body 10 penetrated into the ground After the device is input to form the expansion part 11 in the pipe body 10, concrete is poured and cured inside the pipe body 10, thereby completing the on-site casting pile to which the present invention is applied.

That is, the present invention does not form irregularities in the piles to be cast in place by partially expanding or deformed tube 10 in the ground or by partially additionally excavating an excavation hole, but the tube body 10 In the state of being penetrated into the ground, an underground tube part expansion device is inserted into the tube body 10 to pressurize the tube body 10 from the inside to the outside to form the expansion part 11 at the corresponding part.

Therefore, in the case of penetration of the pipe body 10 processed in advance into the ground, inevitable extreme penetration resistance, disturbance of the surrounding ground, and the loss of the principal frictional force due to this are not all accompanied in the present invention, and the site in the state where the pipe body 10 remains It is possible to form a partial enlargement or unevenness in the cast pile, and in the prior art, it is possible to apply even in bad conditions such as soft ground, where partial expansion of the cast-in-place pile was impossible.

The conventional partial expansion type cast-in-place pile can be applied only to the ground where the hollow wall of the drilling hole is maintained by magnetic force without the casing (19), and a special excavator is inserted into the drilling hole in the state where the hollow wall ground is exposed. It was carried out in a way that additional excavation was carried out in the side of the empty wall, and in fact, it was applicable only to extremely stable rocky ground.

In particular, it was difficult to cover the soil and slime generated in the lateral additional excavation process on the excavation hole, so these soils and slime were forced to remain at the bottom of the excavation hole. Not only did it act as a factor that seriously damages the tip bearing capacity as well as the strength of the ball, and there was a serious problem of frequent collapse of the upper ground as a bar inevitably accompanied by considerable vibration and shock during lateral excavation of the empty wall.

On the other hand, in the present invention, as shown in Figs. 2 and 3, a partial expansion of the pipe body 10 and the drilling hole is performed while the pipe body 10 is penetrated into the ground. Not only can be applied irrespective of the problem, and no problems related to topography and collapse do not occur at all, and a plurality of expansion portions 11 can be freely formed as in the drawing.

As such, the present invention, as shown in Figure 3, in the tube body 10 in a state penetrated into the ground by inserting the underground tube portion expansion device consisting of the moving body 20 and the sealing body 30, etc. The ejected pressurized fluid pressurizes the tube 10 from the inside to the outside to form an enlarged diameter part 11 with an enlarged cross section, and the basic configuration of the underground tube part expansion device of the present invention is shown in FIGS. 4 and 5 Is shown in.

4 and 5, the underground tube part expansion apparatus of the present invention is a tubular hollow body, the lower end is closed, the pressure feed pipe 41 and the drive pipe 42 are built-in, On the side, a moving body 20 having a discharge port 21 connected to the pressure feeding pipe 41 is formed, and an annular cyst installed at both ends of the moving body 20, and the drive tube 42 and It is connected and the inner peripheral surface is composed of a sealing body 30 and the like in close contact with the outer peripheral surface of the moving body (20).

As shown in Figs. 2 and 3, the moving body 20 of the underground tube part expansion device of the present invention is a main body of the present invention expanding device that is inserted into the tube 10 in a state penetrated into the ground, and a rod 95 on the top Is connected to the ground, and when the sealing body 30 is contracted, the maximum width in the plane of the expansion device of the present invention including the sealing body 30 and the moving body 20 is set to be less than the inner diameter of the tube body 10. (10) Free movement is possible inside.

When both ends of the moving body 20, that is, when the tube body 10 is vertically penetrated into the ground, the sealing bodies 30 installed at the upper and lower ends of the moving body 20, respectively, are hollow ( As an annular cyst of 中空), when the sealing body 30 is extracted, a donut-shaped tube is formed, and an elastic material capable of contraction and expansion is applied.

4 and 5, a V-shaped concave shaft diameter portion composed of an outer support portion 23 and an inner support portion 22 is formed in the coupling portion of the sealing member 30 of the moving body 20, and is sealed. As the sieve 30 is in close contact with the outer support part 23 and the inner support part 22, the separation of the moving body 20 of the sealing body 30 is suppressed, and at the same time, airtightness between the inner circumferential surface of the sealing body 30 and the moving body 20 is secured. do.

That is, the outer support part 23 and the inner support part 22, which are V-shaped inclined surfaces, are formed at the coupling parts of the moving body 20 at both ends of the movable body 20 of the underground tube part expansion device of the present invention, and these outer support parts 23 And the sealing body 30, which is an elastic annular cyst, is tightly coupled between the inner support part 22, as shown in FIG. 5, the drive pipe 42 and the sealing body 30, which are pipes built into the moving body 20. The inside is connected.

The sealing body 30 of the underground tube part expansion device of the present invention expands or contracts as the working fluid supplied from the drive pipe 42 is supplied or sucked, as shown in FIG. 5, at both ends of the moving body 20. Each separate sealing body 30 is installed, a drive pipe 42 is directly connected to one sealing body 30, and the other sealing body 30 is connected via a connection pipe 43 to form a single drive pipe 42 ) It is possible to simultaneously drive both sealing bodies 30.

That is, in the underground tube part expansion device of the present invention, separate sealing bodies 30 are configured at the upper and lower ends, respectively, and separate driving pipes 42 are independently connected to drive these sealing bodies 30. Although it may be, as shown in FIG. 5, the sealing body 30 installed on the moving body 20 on the upper part of the drawing where the drive pipe 42 built in the rod 95 enters the moving body 20 is driven Directly connected to the pipe 42, but the lower sealing body 30 is not directly connected to the drive pipe 42, but the working fluid through the connection pipe 43 connecting the upper sealing body 30 and the lower sealing body 30 It was made to be delivered.

In the embodiment shown in FIG. 5, the working fluid pressurized and supplied through the drive pipe 42 first flows into the upper sealing body 30 and is filled, and then the working fluid discharged from the upper sealing body 30 is In a manner that is supplied to the lower sealing body 30 via the connection pipe 43, both upper and lower sealing bodies 30 can be filled with working fluid, and once the upper and lower sealing bodies 30 are As the pressurization through the working fluid continues after being filled with the working fluid, the pressure of the working fluid acts uniformly on both upper and lower sealing bodies 30, so that both upper and lower sealing bodies 30 expand.

When the pressure of the working fluid is released or the working fluid is sucked out, the sealed body 30 is contracted by its elasticity, and the working fluid is pressed or operated through the drive pipe 42 connected to the ground. The contraction and expansion of the sealing body 30 in the tube 10 can be freely controlled by simply releasing the pressurized state of the fluid.

As the working fluid for driving the sealing body 30, various fluids including mineral oil-based hydraulic oil used in a conventional hydraulic machine can be applied, and although not shown in the drawing, it is embedded in the moving body 20 to be incorporated into the sealing body 30. The connected drive pipe 42 is connected to a working fluid pressurizing means such as a hydraulic pump on the ground.

As shown in FIGS. 2 to 5, the upper end of the moving body 20 of the apparatus for expanding the underground pipe body part of the present invention is connected to the rod 95, and the rod 95 is a continuous pipe connecting the equipment and the moving body 20 on the ground. As, the total extension can be adjusted in a manner in which a plurality of unit rods 95 are connected, and as shown in Figs. 4 and 5, the pressure delivery pipe 41 and the drive pipe 42, which are internal pipes of the moving body 20, are loaded. Built in (95) and connected to the ground.

However, in addition to the continuous tube-shaped rod 95 shown in the drawings, the equipment on the ground and the moving body 20 may be connected through a wire rod such as a steel strand or a chain. In this case, the pressure pipe 41 ) And pipes such as the drive pipe 42 may be intermittently connected to the wire rod.

On the other hand, as described above, in the moving body 20 of the present invention, in addition to the drive pipe 42, a pressure feed pipe 41, which is a separate pipe, is built, and the pressure feed pipe 41 is a jet port 21 formed on the side of the moving body 20 It is connected to, and as the pressurized fluid pressurized to the pressure feeding pipe 41 is ejected through the ejection port 21, the portion of the sealed tube 10 is expanded and deformed.

That is, as shown on the left side of Fig. 6, after the moving body 20 is inserted into the tube body 10 in a state of being penetrated into the ground, the working fluid is pressurized by the drive tube 42 as shown in the center of the drawing. , As the sealing body 30 expands as it is supplied, the inner space of the tube body 10 between the sealing bodies 30 at both ends of the moving body 20 is sealed, and as shown on the right side of the drawing, the sealing body 30 expands. As the pressurized fluid is supplied, the tube body 10 is expanded and deformed.

As the pressurized fluid supplied to the pressure feed pipe 41, hydraulic oil such as mineral oil as in the above-described drive pipe 42 may be applied, but the pressurized fluid is not recovered after the expansion of the pipe body 10 is completed, but penetrates into the ground. Since the possibility is high, it is desirable to apply water as a pressurized fluid in order to prevent ground contamination and reduce construction costs.

On the other hand, Figures 7 to 9 is an embodiment in which the sealing body 30 is applied without a cavity formed therein. In the same embodiment, the sealing body 30 is by the working fluid injected into the sealing body 30 As the inner peripheral surface of the inclined sealing body 30 is not expanded, the inner circumferential surface of the sealing body 30 is expanded, and the outer diameter of the sealing body 30 is enlarged, thereby enabling a stronger sealing.

In this Fig. 7 embodiment, the moving body 20 is a tubular hollow body inserted into the tube body 10 in a state of being penetrated into the ground, and both ends of the moving body 20 are open and open. Inner support 22 is formed at both ends of which the outer diameter is gradually reduced to the outside.

In addition, the moving body 20 includes a pressure feed pipe 41 and a drive tube 42, and a blowout port 21 connected to the pressure feed pipe 41 is formed on the side of the moving body 20.

As shown in FIGS. 7 and 8, as a disk body installed at both open ends of the moving body 20, the outer diameter is gradually reduced toward the moving body 20, and a coupling pipe 24 is formed on the side of the moving body 20 to be combined. The outer support part 23 into which the tube 24 is inserted into the moving body 20 is configured, and the outer support parts 23 installed at both ends of the moving body 20 are mutually symmetric, and thus, the moving body 20 When the outer support part 23 is combined, the inner support part 22 and the outer support part 23 form a V-shaped concave shaft diameter part (縮徑部).

Between the inner support portion 22 and the outer support portion 23, a sealing body 30, which is a ring body in which a cavity for injection of the working fluid is not formed, is coupled, the inner support portion 22 and the outer support portion ( A V-shaped inclined surface corresponding to the V-shaped concave shaft diameter portion formed by 23) is also formed on the inner peripheral surface of the sealing body 30.

In addition, the driving body 50 is configured to be built into the moving body 20 to connect the drive pipe 42 and connect the outer support portions 23 installed at both ends of the moving body 20, the implementation shown in FIGS. 7 and 8 In the example, a double-acting hydraulic cylinder to which a pair of drive pipes 42 is connected is applied as the drive body 50, and as the working fluid is supplied through the drive pipe 42, the drive body 50 is expanded and contracted, and the drive body ( As 50) expands and contracts, the outer support portions 23 at both ends of the moving body 20 are spaced apart from each other and approached.

Therefore, as shown in FIG. 8, the outer support portions 23 at both ends of the moving body 20 are spaced apart from each other, and the moving body 20 is inserted into the tube body 10 penetrated into the ground while the sealing body 30 is contracted. After that, as the working fluid is supplied to the drive tube 42 as shown in FIG. 9 and the drive body 50 is contracted, the outer support parts 23 at both ends of the moving body 20 are brought close to each other, and the inner support part 22 and the outer support part (23) The sealing body 30 is expanded so that the inner space of the tube body 10 between the sealing bodies 30 on both sides may be sealed.

As shown in FIG. 8, the sealing bodies 30 at both ends of the moving body 20 are expanded and compressed to the inner circumferential surface of the tube body 10, and then, although not shown in the drawing, as the pressurized fluid is supplied to the pressure delivery tube 41, the tube body ( 10) is enlarged so that the enlarged part 11 is formed in the tube body 10 of the corresponding part.

By using the underground pipe body part expansion device of the present invention as described above, an expansion part 11 protruding outward can be formed in the pipe body 10 in a state penetrated into the ground, whereby the pipe body 10 is covered with a reinforcing material. In the cast-in-place composite pile applied to, it is possible to dramatically improve the bearing capacity including the main surface friction, and the execution process of the cast-in-place composite pile construction method of the present invention will be described as follows.

First, as shown in the left end of Fig. 2, the step of penetrating the tube 10 into the ground is performed.

The ground penetration of the pipe body 10 can be performed in various ways, and as shown in FIG. 1, the method of using the excavation body 91 and the casing 19, which is penetrated together, remains on the ground and utilized as the pipe body 10 Of course, after inserting a separate tube 10 into the casing 19, a method of pulling out the casing 19 with only the tube 10 remaining is also possible, and the temporary or long term of the empty wall immediately after the drawing of the casing 19 In the ground that can be maintained, it is also possible to apply a method of first drawing the casing 19 and then inserting the pipe body 10 into the excavation hole.

In addition, as the material of the pipe body 10 applied in the present invention, as well as steel as in a general casing 19 or an underground press-fit pipe, various metals rich in malleability or ductility can be applied. In addition, a variety of materials such as synthetic resin, which facilitates the formation of the expansion portion 11 and maintains the empty wall, may be applied.

When the tube body 10 reaches the target depth, the step of introducing the underground tube part expansion device in the state where the sealing body 30 is contracted into the tube body 10 is performed, and when the sealing body 30 is contracted, Invention Since the maximum width on the plane of the underground tube part expansion device is set to be less than the inner diameter of the tube body 10, it is possible to smoothly insert the underground tube part part expansion device into the tube body 10.

When the underground pipe body part expansion device inserted into the pipe body 10 reaches the point where the expansion part 11 is planned to be formed, a step of sealing some sections of the pipe body 10 by expanding the sealing body 30 of the underground pipe body part expansion device is performed. do.

That is, by simultaneously expanding the sealing body 30 at the upper end of the moving body 20 and the sealing body 30 at the lower end of the moving body 20, the inner space of the tube 10 between the sealing bodies 30 on both sides is sealed.

Thereafter, the step of forming the diameter expansion portion 11 by supplying the pressurized fluid to the pressure feed pipe 41 and the pressurized fluid ejected through the ejection port 21 is performed. 11) After the formation is completed, the sealing body 30 is contracted and the underground tube part expansion device is moved, and then expansion of the sealing body 30 and pressure-feeding injection of the pressurized fluid are performed again. Likewise, it is possible to repeatedly form a plurality of enlarged portions 11.

When the formation of the entire expansion part 11 is completed, the step of withdrawing the underground tube part expansion device to the outside of the tube body 10 after contracting the sealing body 30 is performed, and then pouring and curing concrete in the tube body 10 By performing the step of, the synthetic pile construction method of cast-in-place using the underground pipe part expansion apparatus of the present invention is completed.

10: tube body
11: enlarged neck
19: casing
20: moving object
21: spout
22: inner support
23: outer support
24: coupling pipe
30: sealing body
41: pressure pipe
42: drive tube
43: connector
50: driving body
90: excavation equipment
91: excavator
95: load
99: rebar

Claims (2)

As a hollow body that is introduced into the tube body 10 in a state of being penetrated into the ground, the lower end is closed, the pressure delivery pipe 41 and the drive pipe 42 are built-in, and the ejection port 21 connected to the pressure delivery pipe 41 at the side A moving body 20 is formed;
As an annular cyst installed at both ends of the moving body 20, it is connected to the drive pipe 42 and composed of a sealing body 30 having an inner peripheral surface in close contact with the outer peripheral surface of the moving body 20;
After the moving body 20 is inserted into the tube body 10 in a state of being penetrated into the ground, the sealing body 30 expands as the working fluid is supplied to the drive pipe 42, and the sealing body at both ends of the moving body 20 An underground tube part expansion device, characterized in that the inner space of the tube body 10 is sealed, and the tube body 10 is expanded as the pressurized fluid is supplied to the pressure delivery tube 41.
In the synthetic pile construction method for cast-in-place using the underground pipe part expansion device of claim 1,
Intruding the tube body 10 into the ground;
When the tube body 10 reaches the target depth, injecting an underground tube portion expansion device in a state in which the sealing body 30 is contracted into the tube body 10;
Sealing a partial section of the tube body 10 by expanding the sealing body 30 of the underground tube part expansion device;
Supplying the pressurized fluid to the pressure feed pipe (41), and the pressurized fluid ejected through the ejection port (21) expands the tube body (10) to form an enlarged diameter portion (11);
After contracting the sealing body 30, the step of withdrawing the underground tube part expansion device to the outside of the tube body 10;
In-situ casting synthetic pile construction method using an underground pipe part expansion device, characterized in that it consists of a step of pouring and curing concrete in the pipe body (10).

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