KR102581402B1 - Rapid pile head treatment method using flat jack - Google Patents

Abstract

In the present invention, when arranging the head of a cast-in-place concrete pile, an arc-shaped flat jack is inserted into a groove formed by cutting the outer peripheral surface of the pile, and then hydraulic pressure is applied to expand the inside of the flat jack to induce cracking, quickly and without concrete crushing work. This is about a rapid pile head removal method using a flat jack that can remove pile heads with precision.
The present invention is to prepare the head of a cast-in-place concrete pile that is formed with a circular cross-section with a plurality of reinforcing bars arranged in a circular shape inside and protrudes above the ground. (a) Cutting the outer peripheral surface of the pile at the height of the head clearance to form a groove. steps; (b) inserting a plurality of arc-shaped flat jacks along the circumference of the groove; (c) inducing cracks in the pile by applying hydraulic pressure to the inside of the flat jack to expand it; and (d) lifting and removing the head of the pile; Consists of a guide hose that surrounds the core of the pile inside the reinforcing bar and has both ends protruding outside the pile, is installed inside the pile at the height of the head clearance, and in any one of steps (a) to (c) above, the inside of the guide hose It is characterized by inserting a wire saw into and cutting part or all of the core of the pile by reciprocating driving of the wire saw.

Description

Rapid pile head treatment method using flat jack}

In the present invention, when arranging the head of a cast-in-place concrete pile, an arc-shaped flat jack is inserted into a groove formed by cutting the outer peripheral surface of the pile, and then hydraulic pressure is applied to expand the inside of the flat jack to induce cracking, quickly and without concrete crushing work. This is about a rapid pile head removal method using a flat jack that can remove pile heads with precision.

Cast-in-place concrete piles are constructed by excavating the ground, inserting a reinforcing bar network into the excavation hole, and then pouring concrete. At this time, before pouring concrete, a tremie pipe is inserted into the excavation hole in advance to prevent material separation due to falling concrete, and the concrete is poured while the lower end of the tremie pipe is buried to a certain depth in the concrete being poured.

However, unlike upper construction, pile construction requires a very high concrete pour height, and some soil exists inside the excavation hole. Therefore, mixed soil and sand exist in the upper concrete layer, and laitance occurs in the early stages of curing, resulting in poor quality of concrete at the top of the pile.

For this reason, head preparation work is carried out by pouring concrete about 1m higher than the planned design height and then cutting the head.

Previously, when clearing tofu, hydraulic breakers or small backhoes were used to crush piles.

However, because this method relies on manpower, it not only takes a lot of time, but also has limitations in working precision. In addition, there are cases where reinforcing bars or piles are damaged, deteriorating quality, and requiring separate repair and reinforcement work.

In addition, workers are exposed to a poor working environment due to noise and dust when crushing tofu, and additional manpower and time are required to clean the crushing debris and dispose of waste.

KR 10-0597069 B1

In order to solve the above problems, the present invention seeks to provide a rapid pile head preparation method using a flat jack that can easily separate the head concrete without manual concrete crushing work when preparing the head of a cast-in-place concrete pile.

The present invention according to a preferred embodiment is to prepare the head of a cast-in-place concrete pile that is formed with a circular cross-section with a plurality of reinforcing bars arranged in a circular shape inside and protrudes above the ground, (a) the outer peripheral surface of the pile at the head clearance height Cutting to form a groove; (b) inserting a plurality of arc-shaped flat jacks along the circumference of the groove; (c) inducing cracks in the pile by applying hydraulic pressure to the inside of the flat jack to expand it; and (d) lifting and removing the head of the pile; Consists of a guide hose that surrounds the core of the pile inside the reinforcing bar and has both ends protruding outside the pile, is installed inside the pile at the height of the head clearance, and in any one of steps (a) to (c) above, the inside of the guide hose The aim is to provide a rapid pile head preparation method using a flat jack, which is characterized by inserting a wire saw into and cutting part or all of the core of the pile by reciprocating driving of the wire saw.

According to another preferred embodiment of the present invention, the flat jack has an upper plate and a lower plate each formed of an arc-shaped steel band and spaced apart upward and downward, and a space provided on the outer side between the upper and lower plates and closed between the upper and lower plates. To provide a rapid pile head arrangement method using a flat jack, characterized in that it consists of a sealing bar forming a connecting pipe, one end of which communicates with the space and the other end protruding toward the front side of the upper and lower plates to supply fluid to the space. do.

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According to the present invention, when arranging the head of a cast-in-place concrete pile, an arc-shaped flat jack is inserted into a groove formed by cutting the outer peripheral surface of the pile, and then hydraulic pressure is applied to expand the inside of the flat jack to induce cracking, without crushing the concrete. It is possible to provide a rapid pile head preparation method using a flat jack that can quickly and precisely lift and remove the pile head.

In particular, since the head is separated without applying impact to the pile, damage to the pile or rebar can be prevented. In addition, as there is no noise or dust generated, the field work environment can be kept clean and waste disposal work can be simplified.

Figure 1 is a perspective view showing a cast-in-place concrete pile.
Figures 2 to 5 are diagrams showing the step-by-step process of the rapid pile head preparation method using a flat jack of the present invention.
Figure 6 is a perspective view showing a flat jack.
Figure 7 is a cross-sectional view showing the operational relationship of a flat jack.
Figure 8 is a perspective view showing a crack inducing auxiliary plate.
Figure 9 is a perspective view showing a crack inducing auxiliary plate formed in two layers.
Figure 10 is a perspective view showing the combined state of the reinforcing bar and the crack inducing auxiliary plate.
Figure 11 is a perspective view showing the coupling relationship between a crack inducing auxiliary plate and a flat jack.
Figure 12 is a cross-sectional view showing the connection relationship between the crack inducing auxiliary plate and the flat jack.
Figure 13 is a perspective view showing the exposed state of the guide tip.
14 to 16 are cross-sectional views showing the installation state of the wire saw.
Figure 17 is a cross-sectional view showing the perforation state of the crack inducing hole.

Hereinafter, the present invention will be described in detail according to the accompanying drawings and preferred embodiments.

Figure 1 is a perspective view showing a cast-in-place concrete pile, and Figures 2 to 5 are diagrams showing the step-by-step process of the rapid pile head preparation method using a flat jack of the present invention.

The present invention's rapid pile head preparation method using a flat jack is for organizing the head of the cast-in-place concrete pile (1), which is formed with a circular cross-section with a plurality of reinforcing bars (11) arranged in a circular shape inside and protrudes above the ground. (a) forming a groove 12 by cutting the outer peripheral surface of the pile 1 at a head clearance height; (b) inserting a plurality of arc-shaped flat jacks (3) into the groove portion (12) along the circumference; (c) inducing a crack in the pile (1) by applying hydraulic pressure to the inside of the flat jack (3) to expand it; and (d) lifting and removing the head (1') of the pile (1); It is characterized by being composed of.

The present invention is intended to provide a rapid pile head preparation method using a flat jack that can easily separate the head concrete without manual concrete crushing work when preparing the head of a cast-in-place concrete pile (1).

The present invention makes it easy to separate the head concrete by generating a crack at the height of the head when preparing the head of the cast-in-place concrete pile (1).

The cast-in-place concrete pile (1) is formed with a circular cross-section in which a plurality of reinforcing bars (11) are arranged in a circular manner (FIG. 1).

The cast-in-place concrete pile (1) can be formed into a circular cross-section by inserting a sacrificial steel pipe into the ground, excavating the ground, inserting a reinforcing bar network, and pouring concrete.

The head of the cast-in-place concrete pile (1) protrudes a certain length above the ground.

Before arranging the pile (1) head, remove the sacrificial steel pipe.

In the present invention, first, (a) the outer circumferential surface of the pile (1) at the height of the head is cut to form a groove (12) (FIG. 2).

In step (a), the outer peripheral surface of the pile (1) is cut at the height of the head of the pile (1), that is, at the position where the head is to be cut, to form a groove (12) of a predetermined depth.

The groove 12 may be formed in the concrete covering portion outside the reinforcing bar 11.

A concrete cutting jig (2) can be used to precisely cut the head of the pile (1).

The concrete cutting jig (2) can be composed of a fixing part (21) fixed to the top of the pile (1) and a rotary arm (22) whose one end is rotatably coupled to the center of the fixing part (21). . A rotary shaft 23 may be coupled to the lower end of the rotary arm 22, and a cutting disk 24 may be coupled to the lower end of the rotary shaft 23.

As the rotary arm 22 rotates, the cutting disk 24 cuts the outer peripheral surface of the pile 1 to form the groove 12.

Next, (b) a plurality of arc-shaped flat jacks (3) are inserted into the groove portion (12) along the circumference (FIG. 3).

That is, a plurality of flat jacks (3) are inserted into the groove portion (12) formed in the covering portion of the head of the pile (1).

The flat jack 3 can be formed in the shape of a flat, arc-shaped plate.

The thickness of the flat jack 3 can be increased by hydraulic pressure.

The plurality of flat jacks 3 may form an overall plate-shaped ring shape to fill the groove portion 12.

And (c) hydraulic pressure is applied to the inside of the flat jack (3) to expand it, thereby inducing a crack in the pile (1) (FIG. 4).

In step (c), hydraulic pressure is applied to the flat jack (3) to expand the flat jack (3) up and down. Accordingly, the head of the pile (1) is pushed upward, causing cracks to occur in the concrete of the pile (1) at the height of the groove (12).

Finally, (d) the head (1') of the pile (1) is lifted and removed (FIG. 5).

The pile head (1') can be removed by lifting it with a lifting device such as a crane.

For this purpose, a lifting ring (13) can be embedded in advance at the top of the pile (1).

To reduce the adhesion between the reinforcing bar (11) inside the pile (1) and the head concrete so that the head (1') can be easily separated, a separate protective agent is applied to the surface of the reinforcing bar (11) of the head (1') or the reinforcing bar (11) is ) A tube can be placed on the outside.

The protective agent or tube may serve to protect the reinforcing bar 11 when forming the groove 12.

That is, if the protective agent is exposed when cutting the pile 1, the cutting operation can be stopped and the formation of the groove 12 can be completed.

As described above, in the present invention, the head of the pile (1) can be organized quickly and precisely without the process of crushing concrete.

In other words, since the head 1' can be separated without applying impact to the pile 1, damage to the pile 1 or the reinforcing bar 11 can be prevented. In addition, the field work environment can be kept clean and waste disposal work can be simplified.

Figure 6 is a perspective view showing a flat jack, and Figure 7 is a cross-sectional view showing the operational relationship of the flat jack.

As shown in FIGS. 6, 7, etc., the flat jack 3 is formed of an arc-shaped steel band and has an upper and lower plate 31 and a lower plate 32 spaced apart vertically, and the upper and lower plates 31 and 32. ) is provided on the outer side between the upper and lower plates (31, 32) and forms a closed space (S) between the upper and lower plates (31, 32); It may be composed of a connection pipe 34 that protrudes toward the front side of 31, 32) and supplies fluid F to the space S.

The flat jack 3 has an upper plate 31 and a lower plate 32, which are arc-shaped steel plates, spaced apart at a certain distance up and down, so that a space S filled with hydraulic pressure can be formed therebetween.

A sealing bar 33 is provided on the outer side between the upper and lower plates 31 and 32 to close the space S between the upper plate 31 and the lower plate 32.

The sealing bar 33 can be made of a steel bar and can be fixed to the upper and lower plates 31 and 32 by welding.

The sealing bar 33 can be connected to a connector 34 that communicates with the internal space S by cutting a portion of the front side of the flat jack 3 (FIG. 7(a)).

When the fluid (F) is supplied into the space (S) through the connection pipe (34), the gap between the central portions of the upper plate (31) and the lower plate (32) widens due to the hydraulic pressure of the fluid (F) (Fig. 7 (b)). Accordingly, the head of the pile (1) is pushed upward, and a crack occurs in the concrete at the height of the groove (12).

Here, the fluid (F) can be oil or water.

The end of the connection pipe 34 may be provided with a nipple 35 for connection to the hydraulic hose 36 through which the fluid F is supplied.

In this way, if the flat jack 3 is composed of the upper and lower plates 31 and 32, which are steel strips, and the sealing bar 33, which is a steel bar, the flat jack 3 can be manufactured simply and economically.

The flat jack (3) expanded by fluid (F) supply can be restored to its original state by pressurizing it with equipment such as a vise if necessary and then reused.

Figure 8 is a perspective view showing a crack inducing auxiliary plate.

As shown in FIGS. 8 and 12, a crack inducing auxiliary plate (4) may be embedded and installed inside the reinforcing bar (11) inside the pile (1) at the height of the head clearance.

If the pile (1) has a large diameter compared to the cover, the crack depth induced by the flat jack (3) may not be deep enough or the crack induction itself may be difficult, making it difficult to remove the concrete from the head of the pile (1).

In this case, a disk-shaped crack inducing auxiliary plate (4) can be pre-embedded in the head of the pile (1) so that the crack can be easily induced with a small amount of force.

The crack inducing auxiliary plate (4) can be manufactured from various materials such as steel plate and plastic.

The crack inducing auxiliary plate (4) can be installed in advance when placing the reinforcing bar (11) and embedded in the head of the pile (1) by pouring concrete.

The crack inducing auxiliary plate (4) may be installed after arranging the reinforcing bars (11), or may be pre-assembled into a reinforcing bar network and constructed together.

A flow hole 41 may be formed through the center of the crack inducing auxiliary plate 4 for insertion of a tremie pipe for concrete pouring or for concrete flow.

The upper surface of the crack inducing auxiliary plate (4) may be provided with a guide rod (42) whose upper end is exposed to the top of the pile (1) so that the embedding height of the crack inducing auxiliary plate (4) can be checked.

Figure 9 is a perspective view showing a crack inducing auxiliary plate formed in two layers.

As shown in Figure 9, the crack inducing auxiliary plates (4a, 4b) are provided as an upper and lower pair and can be in close contact with each other.

Since the crack inducing auxiliary plate 4 is embedded in concrete, it may be difficult to remove the head 1' due to the adhesion between the crack inducing auxiliary plate 4 and the concrete.

Therefore, the crack inducing auxiliary plates (4a, 4b) can be stacked vertically in two layers so that the head (1') can be separated regardless of the adhesive force between the crack inducing auxiliary plate (4) and the concrete.

Accordingly, when hydraulic pressure is applied to the flat jack (3) to spread the concrete covering part of the pile (1), the upper and lower concrete parts of the crack inducing auxiliary plates (4a, 4b) are already separated, so the upper and lower crack inducing auxiliary plates (4a, 4b) ) are easily separated from each other.

In addition, the concrete core on the flow hole 41 side can be easily and completely separated by inducing cracks by the crack inducing auxiliary plates 4a and 4b that open up and down.

Figure 10 is a perspective view showing the combined state of the reinforcing bar and the crack inducing auxiliary plate.

As shown in FIGS. 8 and 10, a reinforcing bar groove 43 into which the reinforcing bar 11 is inserted may be formed on the outer peripheral surface of the crack inducing auxiliary plate 4.

In order to prevent the crack inducing auxiliary plate (4) from leaving its position during concrete placement, the crack inducing auxiliary plate (4) must be firmly fixed to the reinforcing bar (11).

For this purpose, a reinforcing bar groove 43 into which the reinforcing bar 11 is inserted and fixed can be formed on the outer peripheral surface of the crack inducing auxiliary plate 4.

The reinforcing bar grooves 43 may be formed in plural numbers to be spaced apart from each other along the outer peripheral surface of the crack inducing auxiliary plate 4.

Figure 11 is a perspective view showing the coupling relationship between the crack inducing auxiliary plate and the flat jack, and Figure 12 is a cross-sectional view showing the coupling relationship between the crack inducing auxiliary plate and the flat jack.

As shown in FIGS. 11 and 12, the crack inducing auxiliary plate (4) has a portion between the reinforcing bar grooves (43) protruding to the outside of the reinforcing bar (11), and the flat jack (3) is located at the outer shear of the protruding portion. A mounting groove 44 into which a portion of can be inserted may be formed.

In order to induce a crack at the exact location of the head of the pile (1), it is desirable that the flat jack (3) is installed precisely at the height of the crack inducing auxiliary plate (4).

In addition, in order to easily insert the flat jack 3 into the groove 12, the height of the groove 12 must be formed higher than the thickness of the flat jack 3. In this case, the flat jack 3 and the groove 12 It is difficult to accurately fix the flat jack (3) to the height of the crack induction auxiliary plate (4) due to the gap between them.

Therefore, the outer peripheral surface of the crack induction auxiliary plate (4) is protruded to the outside of the reinforcing bar (11), a mounting groove (44) is formed at the front end of the protruding portion, and one end of the flat jack (3) is inserted into the mounting groove (44). It can be configured to be mounted.

Accordingly, the head 1' of the pile 1 can be accurately separated based on the crack inducing auxiliary plate 4.

Figure 12 (a) shows the state before the crack inducing auxiliary plate 4 and the flat jack 3 are combined, and Figure 12 (b) shows the flat jack in the mounting groove 44 of the crack inducing auxiliary plate 4. The jack 3 is shown in a mounted state.

Figure 13 is a perspective view showing the exposed state of the guide tip.

As shown in FIGS. 8 and 13, a guide tip 45 whose shear is exposed to the outer circumferential surface of the pile 1 may be formed to protrude on the outer peripheral surface of the crack inducing auxiliary plate 4.

The groove portion 12 must be formed at an accurate position by cutting the pile 1 at the height where the crack inducing auxiliary plate 4 is installed. However, since the crack inducing auxiliary plate (4) is embedded inside the concrete, it may be difficult to find the exact location of the crack inducing auxiliary plate (4).

Therefore, a guide tip 45 can be formed on the outer peripheral surface of the crack inducing auxiliary plate 4 and exposed to the outer peripheral surface of the pile 1.

Accordingly, by determining the position of the guide tip 45, the height of the crack inducing auxiliary plate 4 can be accurately known.

A plurality of guide tips 45 may be provided on the outer peripheral surface of the crack inducing auxiliary plate 4.

If the guide tip 45 is in close contact with the inner surface of the sacrificial steel pipe, it can serve as a spacer to keep the covering thickness of the reinforcing bar 11 constant.

Figures 14 to 16 are cross-sectional views showing the installation state of the wire saw.

As shown in Figures 14 to 16, inside the pile (1) at the height of the head clearance, there is a guide hose (5) that surrounds the core of the pile (1) inside the reinforcing bar (11) and both ends protrude outside the pile (1). It is installed buried, and in any one of steps (a) to (c), a wire saw (6) is inserted into the guide hose (5) and a portion of the core of the pile (1) is removed by reciprocating driving of the wire saw (6). Or you can cut the whole thing.

In another embodiment to assist in inducing cracking of the pile (1), the core portion of the pile (1) may be cut using a wire saw (6).

In order to install the wire saw (6), the guide hose (5) can be installed and buried at the head cutting position of the pile (1) before pouring concrete for the pile.

The guide hose (5) surrounds the core of the pile (1), but both ends are pulled out to the outside of the pile (1).

Therefore, after completing the construction of the pile (1), insert the wire saw (6) into the inside of the guide hose (5) so that both ends are pulled out of the pile (1), and then use the wire saw's driving equipment (not shown) to insert the wire saw (6) into the guide hose (5). By reciprocating (6), the deep concrete of the pile (1) can be cut.

It is preferable that the process of cutting the deep concrete of the pile (1) by the wire saw (6) is performed before driving the flat jack (3) to facilitate crack induction when driving the flat jack (3).

The wire saw 6 can be installed in various shapes such as U-shaped (FIG. 14), circular (FIG. 15), and cross-shaped (FIG. 16), and it is desirable to prevent the reinforcing bar 11 from being cut when cutting concrete.

The position of the wire saw (6) can be guided by a wire guide (7) provided outside the pile (1).

Figure 17 is a cross-sectional view showing the perforation state of the crack inducing hole.

As shown in FIG. 17, in step (a), after cutting the groove 12, a plurality of crack inducing holes 14 can be drilled through the groove 12 toward the core of the pile 1.

In another embodiment to assist in inducing cracks in the pile (1), after forming the groove portion (12), a plurality of crack inducing holes (14) may be drilled through the groove portion (12) toward the deep portion of the pile (1).

The crack inducing holes 14 can be drilled using drill equipment, and can be formed in plural numbers radially.

After cutting the covering of the pile (1) to form the groove (12), the reinforcing bar protector can be visually confirmed. Therefore, it is possible to avoid interference with the reinforcing bar 11 and drill the crack inducing hole 14 without damaging the reinforcing bar 11.

1: Pile 1': Tofu
11: rebar 12: groove
13: Lifting ring 14: Crack induction ball
2: Cutting jig 21: Fixing part
22: Rotating arm 23: Rotating shaft
24: cutting disc 3: flat jack
31: upper plate 32: lower plate
33: sealing bar 34: connector
35: Nipple 36: Hydraulic hose
4, 4a, 4b: Crack induction auxiliary plate 41: Flow hole
42: Guide rod 43: Reinforcing bar groove
44: Mounting groove 45: Guide tip
5: Guide hose 6: Wire saw
7: Wire guide F: Fluid
S: space

Claims (9)

This is to organize the head of the cast-in-place concrete pile (1), which is formed in a circular cross-section with a plurality of reinforcing bars (11) arranged in a circular shape inside, and protrudes above the ground.
(a) forming a groove 12 by cutting the outer peripheral surface of the pile 1 at a head clearance height;
(b) inserting a plurality of arc-shaped flat jacks (3) into the groove portion (12) along the circumference;
(c) inducing a crack in the pile (1) by applying hydraulic pressure to the inside of the flat jack (3) to expand it; and
(d) lifting and removing the head (1') of the pile (1); It consists of,
Inside the pile (1) at the height of the head clearance, a guide hose (5) is embedded and installed to surround the core of the pile (1) inside the reinforcing bar (11) and both ends protrude to the outside of the pile (1).
In any one of the steps (a) to (c), the wire saw (6) is inserted into the guide hose (5) to cut part or all of the core portion of the pile (1) by reciprocating the wire saw (6). A rapid pile head preparation method using a flat jack, characterized in that.
In paragraph 1:
The flat jack (3) is formed of an arc-shaped iron plate and is provided on the outer side between the upper and lower plates (31 and 32), which are spaced apart vertically, and includes upper and lower plates ( A sealing bar 33 forming a closed space S between 31 and 32, one end of which is in communication with the space S and the other end protruding toward the front side of the upper and lower plates 31 and 32 to form a space A rapid pile head preparation method using a flat jack, characterized in that it consists of a connector (34) that supplies fluid (F) to (S).
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