TWI622692B - Pile head treatment method - Google Patents

Abstract

The present invention provides a pile head treatment method which can appropriately dismantle and remove excess concrete of a pile head and has high work efficiency. A steel cage in which a CD tube is arranged in a spiral shape near the main rib is attached to the hole, and concrete is cast to cause a field cast pile. Then, on the boundary surface of the excess concrete exposed to the pile head on the ground and the structural concrete below the pile, a charge hole is bored in the horizontal direction from the side to the inner side, and the non-powder breaker is charged. Further, in the excess concrete, the linear explosive is charged as a breaking agent in the CD tube, and the charging hole is perforated in a portion on the inner side of the main rib, and the linear explosive is charged as a breaking agent. After winding the sheet and the metal wire around the excess concrete, the non-gunpowder crushing agent and the crushing agent are blasted in sequence, and the excess concrete and the structural concrete are separated up and down on the boundary surface, and the excess concrete after the breaking is broken.

Description

Pile head treatment method Field of invention

The invention relates to a pile head processing method for a field cast pile.

Background of the invention

Underground piles such as foundation piles are constructed by field casting. An example of the field casting of the pile is shown in Figure 11. In this example, as shown in Fig. 11(a), after the excavation of the ground plate 100 is performed to form the hole 101, the reinforcing cage 102 is attached to the hole 101 as shown in Fig. 11(b), and as shown in Fig. 11(c) It is shown that the concrete 103 is started to be laid using a special pipe or the like.

As shown in Fig. 11(d), as the concrete 103 is placed, the first concrete is raised to become the excess concrete 103a of the pile head. Although the pile is formed by the hardening of the concrete 103, the excess concrete 103a contains impurities such as soil which have been located at the bottom of the hole 101 and cannot be a structure, so it must be disassembled and removed. In this example, as shown in Fig. 11(e), after the ground 100 around the pile head is excavated, the excess concrete 103a is disassembled and removed on the ground as shown in Fig. 11(f).

Here, the method of disassembling the excess concrete is generally a method of manually disassembling using a hand-carrying crusher or the like.

Further, Patent Document 1 describes the use of gunpowder, explosives, etc. The method by which the drug is disintegrated. In this method, the charging holes in the vertical direction and the charging holes in the lateral direction of the non-crushing portion under the excess concrete are perforated on the excess concrete, and the breaking charges are filled in the charging holes. Then, the pulverization of the pulverizing agent is simultaneously performed in the order of the charging hole in the vertical direction and the charging hole in the lateral direction, or in the charging direction in the vertical direction and the charging hole in the lateral direction, whereby the excess concrete is broken.

Others, there are also known methods for disintegration using a static breaker. In this method, for example, a steel cage in which a static breaker (a sizing agent having hydration swelling property) is installed in advance is installed, and concrete is placed. When the concrete hardens, the comminuted heat is slowly used to swell the crushing agent, thereby splitting the concrete. The split concrete is picked up and removed.

[First technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 50-120103

Summary of invention

When the excess concrete is dismantled by hand using a hand-crusher or the like, it is possible to remove excess concrete, but there is a problem that noise, vibration, and work efficiency are poor. In order to suppress the occurrence of noise or the like, temporary covering may be provided by using a single tube or a soundproof sheet. However, since a plurality of piles are usually constructed, it is inefficient to perform the work in accordance with the progress of the work.

Further, the method of Patent Document 1 is also crushed by explosives or the like in the vertical direction and the lateral direction, so that large noise and vibration are caused. Further, cracks and breakages may be caused to the non-crushed portion due to the explosives, etc., and the main rib at the upper end of the reinforcing bar may be bent when used in the pile head treatment, and the function of the reinforcing bar may be deteriorated. When the main rib at the upper end of the reinforcing bar is inserted into a structure such as a concrete foundation provided above the pile, the main rib is less preferred.

The method of using a static breaker is developed to suppress noise and improve work efficiency. However, before the concrete is laid, the static breaker is placed in the cage, and concrete is generated inside the hole when the concrete is laid. Hardening and cracking, so it is difficult to control the crack. Since the construction of the pile is often uneven, it is difficult to make the static breaker work properly. When the pile head treatment is used, as in Patent Document 1, the main rib at the upper end of the steel cage is bent, and in this case, the picking up of the concrete after the division becomes difficult. Furthermore, since it is necessary to arrange the static breaker in the steel cage without interfering with the special pipe or the like when the concrete is laid, it is difficult to arrange the concrete in a fine manner, and the crushed material is broken. The weight of the block becomes large, and there are many cases where a large crane is required. At this time, there is a problem that the crane cannot be disposed due to the scene, or the temporary gantry for arranging the crane becomes a problem of excess performance.

The present invention has been made in view of the above problems, and it is an object of the invention to provide a pile head processing method which can appropriately disassemble excess concrete of a pile head and has high work efficiency.

The present invention for achieving the foregoing object is a pile head treatment method comprising the steps of: (a) loading a non-powder breaker into a line from the concrete side of the pile head exposed to the ground at the time of the pile field casting; And charging the crushing agent on the concrete above the non-gunpowder breaker; and (b) separating the concrete by the blasting of the non-gunpowder breaker, and then dividing the concrete by the blasting of the crushing agent The crushing of the concrete above the broken.

According to the present invention, the excess concrete of the pile head can be separated from the concrete below by the non-gunpowder breaker, and the broken excess concrete is crushed by a breaker such as an explosive. Non-gunpowder breakers have low noise and vibration. When non-gunpowder breakers and breakers are used to disintegrate excess concrete, noise and vibration can be suppressed instantaneously and in a small amount. These occurrence times can also be set freely in accordance with the surrounding environment. Further, the non-powder breaker which does not accompany the shock wave is used to break the excess concrete from the concrete below, and then the excess concrete is broken after the breaking, so that the excess concrete is not affected by the breaking and breaking of the concrete.

Further, since the charging and the crushing are carried out after the use of the ground work, the charging position and the like are adjusted to an appropriate position by the completion pattern of the pile, and the excess concrete can be surely broken into the size of the adult head. Therefore, the broken pieces can be removed only by human or small heavy tools. Moreover, after the charging operation is completed, it can be broken in a moment, so the work efficiency is also high.

It is desirable to embed the main rib in the vertical direction outside the concrete, and in the above step (a), the explosive is charged into a linear shape as the first crushing agent in the vicinity of the main rib, and is vertically oriented on the inner side than the first crushing agent. Direction will The explosive charge is linearized as a second breaker.

In the above step (b), it is desirable that the first crushing agent and the second crushing agent are blasted sequentially from the outer periphery of the concrete.

In this way, each of the crushing agents is disposed, and the controlled blasting is sequentially performed, whereby the excess concrete is crushed in such a manner that the outer side is sequentially pressed out, and a small amount of the crushing agent can be efficiently disassembled. As a result, the noise and vibration are also reduced, and the amount of dust is also reduced.

It is desirable to provide a restraint material for restraining the deformation of the main rib before the step (b).

Thereby, the deformation of the main rib can be restrained when the excess concrete is broken.

Further, it is desirable to provide a protective material having elasticity in advance around the main rib.

Thereby, in addition to protecting the main ribs, it is possible to ensure the extent of movement of the excess concrete at the time of crushing, and it is possible to cause the cracks to occur in the excess concrete, and the crushing can be appropriately performed.

In the above step (a), it is desirable that the first crushing agent is charged in the vicinity of the main rib in the circumferential direction of the concrete in a spiral shape.

Alternatively, it is desirable to preliminarily arrange the first crushing agent in the vicinity of the main rib in the vertical direction of the pipe.

In this way, the pipe for charging the crushing agent is provided in advance at a position that does not interfere with the special pipe for laying the concrete, etc., thereby eliminating the work time for piercing the charging hole after the concrete is laid. in front In the case of the case, the number of tubes and the number of times of charging are small, and the latter case has the advantage of simply completing the charge.

Further, it is desirable to cover the periphery of the concrete of the pile head with a sheet before the step (b).

Thereby, the excess concrete after the breakage can be prevented from scattering.

According to the present invention, it is possible to provide a pile head treatment method which can appropriately disassemble and remove excess concrete of a pile head and has high work efficiency.

1‧‧‧ field cast pile

2‧‧‧ holes

3‧‧‧Excess concrete

5‧‧‧Boundary

7‧‧‧ main tendons

8‧‧‧ stirrups

9‧‧‧ Charge hole

15‧‧‧ Non-gunpowder breaker

15a‧‧‧Ignition Department

17‧‧‧ sand

22‧‧‧Hose

23‧‧‧Foot line

24‧‧‧ vinyl tape

25‧‧‧Steel cage

27‧‧‧Structural concrete

29‧‧‧Protective materials

31‧‧‧CD tube

31a‧‧‧End

36‧‧‧Fracturing agent

37‧‧‧ Charge hole

37a‧‧‧ Charge hole

37b‧‧‧ Charge hole

37c‧‧‧ Charge hole

37d‧‧‧ Charge hole

38‧‧‧Crusher

39‧‧‧ sand

40‧‧‧Sheet

41‧‧‧Metal wire

43‧‧‧CD tube

44‧‧‧Setting fixture

100‧‧‧ Site

101‧‧‧ hole

102‧‧‧Steel cage

103‧‧‧Concrete

103a‧‧‧Excess concrete

A‧‧‧ arrow

B‧‧‧ arrow

C‧‧‧ arrow

FIG. 1 is a view showing a field cast pile 1.

2(a) to (b) are diagrams showing the reinforcing cage 25.

3(a) to (c) are diagrams showing the charging holes 9, 37 and the CD tube 31.

4(a) to (c) are diagrams showing the charge for the breaker.

FIG. 5 is a diagram showing a non-gunpowder breaker 15.

Figure 6 is a diagram illustrating a method of processing a pile head.

7(a) to (b) are diagrams for explaining a method of processing a pile head.

8(a) to (b) are diagrams for explaining a method of processing a pile head.

9(a) to (b) are diagrams showing the reinforcing cage 25.

Fig. 10 is a view showing the charging hole 37 and the CD tube 43.

11(a) to (f) are diagrams for explaining the sequence of field casting of the pile.

Detailed description of the preferred embodiment

[Formation for implementing the invention]

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[First Embodiment]

(Field cast pile 1)

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a field cast pile 1 in which excess pile concrete is disassembled by a pile head treatment method according to an embodiment of the present invention. This field cast pile 1 is formed in the same manner as in Fig. 11, and the reinforcing cage 25 is attached to the hole 2 formed in the ground, and concrete is formed. Fig. 1 shows the same stage as the above-mentioned Fig. 11(e), in which the concrete is hardened, and the surrounding ground is dug down, and the pile head is exposed to the ground.

As shown in Fig. 1, the concrete of the field cast pile 1 is composed of excess concrete 3 exposed to the pile head portion on the ground, and structural concrete 27 used as a pile below the excess concrete 3, and a steel cage 25 is embedded in the outer peripheral portion. The main ribs 7. The cast pile 1 is a cylinder having a diameter of about 2.0 m, and the height of the excess concrete 3 is about 800 mm. However, the size and shape of the cast pile 1 are not limited thereto.

2 is a view showing a reinforcing cage 25 used for construction of the field cast pile 1. Fig. 2(a) is a view showing a side surface of an upper portion of the reinforcing cage 25, and Fig. 2(b) is a view of the reinforcing cage 25 as seen from above. The reinforcing cage 25 is provided around the plurality of main ribs 7 in the vertical direction which is circumferentially spaced apart from each other, and a plurality of stirrups 8 are disposed in the vertical direction with a gap therebetween.

A protective member 29 is provided around the end of each of the main ribs 7 of the reinforcing cage 25. The protective material 29 is a member having elasticity such as a sponge. Further, no stirrups 8 are provided at the upper end of the main rib 7.

At the upper end portion of the reinforcing cage 25, near the inner side of the main rib 7, the CD tube 31 is provided in a spiral shape. The CD tube 31 is, for example, a flexible material made of polyvinyl chloride and having a diameter of about 15 mm. The excess concrete 3 in Fig. 1 is embedded in the circumferential direction of the excess concrete 3 near the inner side of the main rib 7. The CD tube 31 is used as a charge hole for charging a linear explosive to be described later. The end portion 31a is provided to protrude from the excess concrete 3 to the outside (refer to Fig. 1). The CD tube 31 may also be divided into a plurality of root settings.

(pile head processing method)

Next, a method of processing the pile head for disassembling the excess concrete 3 of the field cast pile 1 described above will be described.

(1. Formation of charge hole)

In the present embodiment, from the state shown in Fig. 1, the excess concrete 3 is first perforated to form a small-diameter charging hole. Figure 3 is a view showing the charging holes 9, 37 and the CD tube 31, Figure 3 (a) is a view showing the upper surface of the excess concrete 3, and Figure 3 (b) is along the Figure 3 (a) A cross-sectional view of the line AA in the vertical direction. Further, Fig. 3(c) is a view showing the boundary surface 5 (see Fig. 1) of the excess concrete 3 and the structural concrete 27 below it.

Here, as shown in FIGS. 3(a) and 3(b), the portion of the CD tube 31 located in the vicinity of the main rib 7 is pierced downward from the upper surface of the excess concrete 3, and a charge is formed above the boundary surface 5. Hole 37.

In the present embodiment, the charge holes 37d are formed in the center of the excess concrete 3, and the charge holes 37a, 37b, and 37c are formed as the charges on the triple concentric circles having different diameters around the charge hole 37d. Hole 37. Each of the charging holes 37a, 37b, 37c is, for example, between 200 mm and 300 mm. The plurality of partitions are arranged in a circumferential shape. The charge holes 37a are disposed on the outermost side, and the charge holes 37b and 37c are disposed in the order of the inner side.

The diameter and depth of the charge holes 37 (37a to 37d) are, for example, about 22 mm and about 600 mm, respectively. Further, at least a part of the positions of the charge holes 37a, 37b, and 37c in the circumferential direction are not aligned (see a, b, and c in Fig. 3(a)), and are arranged in a bird shape.

On the other hand, as shown in Fig. 3(c), the boundary surface 5 of the excess concrete 3 and the structural concrete 27 below it is perforated in the horizontal direction from the side surface toward the inside toward the center of the concrete, thereby forming a plurality of charging holes. 9. In the present embodiment, the position in the circumferential direction is shifted at 45° every 45°. The depth of the charging hole 9 is about 7 to 80% of the radius of the field cast pile 1, and is, for example, about 700 mm to 800 mm. The diameter of the charging hole 9 is, for example, about 22 mm.

(2. Charge of the breaker)

After the charge hole is formed as described above, the charge of the breaker is performed. Here, the breaker is a high-energy substance such as an explosive, a gunpowder, or a non-gunpowder breaker, and an explosion shock wave or a gas pressure is generated by ignition (initiation), whereby the object is broken. In the case of explosives, an explosion shock wave occurs, and in the case of using a gunpowder or a non-gunpowder breaker, gas pressure occurs.

Figure 4 is a diagram showing the charge of the breaker, which is the same as Figure 3, Figure 4(a) is an illustration of the top of the excess concrete 3, and Figure 4(b) is along the line AA of Figure 4(a). A cross-sectional view in the vertical direction, and FIG. 4(c) is a diagram showing the boundary surface 5.

In the present embodiment, as shown in FIGS. 4(a) and 4(b), as shown in FIGS. 4(a) and 4(b), the spiral rib is arranged in the vicinity of the main rib 7. The CD tube 31 serves as a charge hole for charging the breaker 36 (first breaker). Further, the charge 38 (37a to 37d) which has just been formed is charged with the breaker 38 (second breaker).

The breaker 36 is used to crush the portion located outside the main rib 7 of the excess concrete 3. The breaker 38 is disposed on the inner side of the breaker 36 to break the inner portion of the main rib 7. In the present embodiment, linear explosives are used as the breakers 36, 38. Linear explosives are those that process explosives into wire of appropriate length and that are fitted with electrical detonators and foot lines. A time delay detonator can be used as an electrical detonator.

In the present embodiment, the crushing agent 36 is inserted from the end portion 31a of the CD tube 31 to the inside of the CD tube 31 to the depth of the tube substantially across the entire length, and sand (not shown) is inserted near the end portion 31a. Further, as shown in Fig. 4 (b), the breaker 38 is inserted until the hole of the charging hole 37 is deep, and the sand 39 is inserted near the opening. The breaker 38 is processed, for example, to a length of about 400 mm.

On the other hand, in the charging hole 9 in the horizontal direction of the boundary surface 5, as shown in Fig. 4(c), the linear non-powder breaker 15 is inserted up to the depth of the hole, and the sand 17 is inserted near the opening. The length of the non-powder breaking agent 15 is about 70% of the length of the charging hole 9, and is, for example, about 500 mm. Further, in the present embodiment, the sand is inserted as a stuffing material in the vicinity of the end portion 31a of the CD tube 31 or in the vicinity of the opening of the charging holes 9, 37. However, the packing may be other than sand.

FIG. 5 is a diagram showing a non-gunpowder breaker 15. As shown in Fig. 5, the non-powder breaker 15 is, for example, a hose 22 made of polyvinyl chloride having an outer diameter of about 18 mm, and the leg wire 23 is connected to the ignition portion 15a at the end. The slit of the hose 22 is closed with a vinyl tape 24 or the like. Non-gunpowder breaker 15 is by point A high-energy substance that causes a gas pressure to generate a gas and thereby breaks the object, and refers to a crushing agent other than the gunpowder. Further, the leg wires of the breakers 36, 38 and the leg wires 23 of the non-powder breaker 15 are first extended outside the CD tube 31 or the charging holes 37, 9 for wire bonding. The illustration of the foot lines is omitted in FIG.

(3. Maintenance of excess concrete 3)

After the charge is carried out as described above, as shown in Fig. 6, the periphery of the excess concrete 3 is covered with a high-strength sheet 40 such as a sheet made of a polyamide fiber. Then, the metal wire 41 is wound around the sheet 40 and the excess concrete 3 is cured. Further, as the sheet 40, if sufficient strength can be secured, a melamine fiber can be used, and the method of fixing the sheet 40 is not limited to the use of the metal wire 41, for example, if it is firmly When the ends of the sheet 40 itself are connected to each other and are fixed more than the outer circumference of the concrete 3, the metal wires 41 may be omitted.

(4. Breaking of excess concrete 3)

Next, the crushing of the excess concrete 3 is performed. In the present embodiment, the non-gunpowder breaker 15 and the breakers 36 and 38 are connected, and as will be described later, the controlled blasting of the non-powder breaker 15 and the breakers 36 and 38 is performed with a predetermined time difference.

In the present embodiment, first, blasting of the non-powder breaker 15 in the horizontal direction is performed. The tensile stress is continuously applied to the concrete by the gas expansion pressure generated during the blasting of the non-gunpowder breaker 15, whereby the field cast pile 1 is formed on the boundary surface 5 as indicated by the arrow A in Fig. 7(a). The excess concrete 3 and the structural concrete 27 are vertically divided. Unlike explosives, non-gunpowder crusher 15 does not generate shock waves when blasting, so the structural concrete below 27 No damage, no noise or vibration. Moreover, the illustration of the sheet 40 and the like is omitted in FIG.

After the non-gunpowder breaker 15 in the horizontal direction is blasted, the breaker 36 of the CD tube 31 is blasted at intervals of, for example, about 30 milliseconds. By the blasting of the crushing agent 36, as shown by an arrow B in Fig. 8(a), the outer peripheral surface of the excess concrete 3 which is located outside the inner side of the main rib 7 toward the free surface is pushed outward and moved outward. Cracks are generated and broken.

After the crushing agent 36 is blasted, the crushing agent 38 disposed in the circumferential charging port 37a inside the crushing agent 36 is blasted at intervals of about 50 milliseconds. As shown by the arrow C in FIG. 8(b), the excess concrete 3 on the outer side of the charging hole 37a is pushed outward by the crack surface formed as described above, whereby the new crack is generated inside the main rib 7. The excess concrete 3 is broken.

Similarly, in the same manner, the crushing agent 38 disposed in the circumferential charging holes 37b and 37c and the center charging hole 37d is sequentially blasted from the outside toward the inside at intervals of about 50 msec. In this way, the excess concrete 3 on the outer side of each of the charging holes 37b, 37c, and 37d is sequentially pushed outward and moved in the same manner as described above, and is broken.

The protective material 29 provided on the main rib 7 secures the space in which the excess concrete 3 moves while being broken while protecting the main rib 7. The sheet 40 and the wire 41 wound around the outer periphery of the excess concrete 3 suppress the excessive movement of the broken excess concrete 3, and realize the task of restraining the restraint of the main rib 7 with the deformation of the concrete movement. Moreover, the sheet 40 also prevents the broken excess The concrete 3 is scattered. Thus, an example in which the excess concrete 3 is broken is shown in Fig. 7(b).

As shown in Fig. 7(b), by the blasting of the breakers 36, 38, the excess concrete 3 is broken by the size of the adult head. The blasting of the breaking agents 36, 38 is accompanied by a shock wave, but the structural concrete 27 is not damaged due to the cutting of the excess concrete 3 above and the edge of the structural concrete 27 below. Since a series of blasting operations are completed in about 1 second, noise and vibration occur only momentarily.

(5. Removal of excess concrete 3)

After the crushing of the excess concrete 3 is completed, the broken pieces, the sheet 40, the metal wire 41, and the like are removed, and the pile head treatment is completed. The recycling and transportation of scraps and the like can be carried out in small heavy equipment. Or you can use manpower.

As described above, in the present embodiment, the excess concrete 3 of the pile head and the structural concrete 27 below are separated by the non-powder breaker 15 and can be separated by the breaking agents 36 and 38 such as explosives. The excess concrete 3 is broken. The non-gunpowder breaker 15 has a small noise and vibration. When the non-powder breaker 15 and the breakers 36 and 38 are used to disassemble the excess concrete 3, the occurrence of noise and vibration can be suppressed to an instant and small. The occurrence time of these can also be set freely in accordance with the surrounding environment. In addition, since the non-powder breaker 15 which does not accompany the shock wave is used, the excess concrete 3 is cut off from the structural concrete 27 below, and then the excess concrete 3 is broken after being cut, so that the excess concrete 3 is broken and broken. Does not affect the structural concrete 27.

Furthermore, since the charge and the crushing are used after the ground operation The work is carried out, so that the position of the pile can be adjusted to a suitable position by the completion pattern of the pile, so as to reliably crush the excess concrete 3 into the large pieces of the adult head. Therefore, the broken pieces can be removed only by human or small heavy tools. Moreover, since the crushing can be performed immediately after the completion of the charging operation, the work efficiency is also high. According to the method of the present embodiment, the construction period can be shortened at the same cost as compared with the pile head treatment using the hand-carrying crusher. When the trial results were based on the results of experiments with a pile of 2.0 m in diameter (5 workers), the cost was equal and the work efficiency was about 1.6 times.

Further, in the present embodiment, the linear explosive is charged as the crushing agent 36 in the vicinity of the main rib 7 in the outer peripheral portion of the excess concrete 3, and the linear explosive is charged in the vertical direction from the inside of the crushing agent 36. The crushing agent 38, and the crushing agents are sequentially controlled to blast from the crushing agent near the outer periphery of the excess concrete 3 toward the inner side. Thereby, the portion of the main rib 7 which is located outside the main rib 7 of the excess concrete 3 can be crushed outward by the crushing agent 36 so as to be pressed outward by the crushing agent 38, and A small amount of the breaker can be effectively disintegrated. As a result, the noise and vibration are also reduced, and the amount of dust is also reduced.

Further, when the excess concrete 3 is broken, the deformation of the main rib 7 is restrained by the sheet 40 and the wire 41, so that the main rib 7 can be prevented from being bent. Moreover, the task of preventing the broken excess concrete 3 from scattering by the sheet 40 is also achieved.

Further, since the elastic material 29 is provided around the main rib 7, the main rib 7 can be protected, and the movement width of the excess concrete 3 at the time of crushing can be ensured so that the crack does occur and the crushing can be appropriately performed.

Further, in the first embodiment, the spiral CD tube 31 is provided in advance in the vicinity of the main rib 7 of the reinforcing cage 25, and is used for charging the crushing agent 36, thereby eliminating the need for perforating the charging hole. time. The CD tube 31 also does not interfere with a special tube or the like for laying concrete. Further, since the CD tube 31 is arranged in a spiral shape, even if the concrete in the vicinity of the main rib 7 which requires a large amount of energy at the time of crushing is provided, it is only necessary to arrange 1 to several CD tubes 31, and the charge is completed once.

Further, in the present embodiment, the charging holes 37a, 37b, and 37c are arranged in a thousand bird shape so that at least a part thereof does not coincide with the position in the circumferential direction. However, all the charging holes 37a, 37b, 37c and the circumferential direction may be used. The location is configured to be consistent. Further, as in the case of the present embodiment, when the charging holes 37a, 37b, and 37c are arranged in a thousand bird shape that does not coincide with the position in the circumferential direction, the charging holes 37a, 37b, and 37c may be arranged in a smaller position than the circumferential position. The number of holes in the hole makes the broken pieces smaller.

In the present embodiment, the charging holes 37 (37a, 37b, 37c, and 37d) are formed by perforating the charging holes 37 (37a, 37b, 37c, and 37d). However, when a pipe such as a CD tube is provided in the vertical direction inside the main rib 7 of the reinforcing cage 25, These charging holes 37 also save the working time of the perforation. However, when the CD tube is provided inside the main rib 7, it is necessary to consider interference with a special tube or the like for the concrete.

Further, in the present embodiment, the sheet 40 and the wire 41 are wound around the excess concrete 3 to restrict the deformation of the main rib 7 when the excess concrete 3 is broken. However, the method of restraining the deformation of the main rib 7 is not limited thereto. For example, in the steel cage 25, it is also possible to provide a cutting or the like around the main rib 7 in advance for easy disassembly. Binding materials such as stirrups. At this time, as long as the excess concrete 3 is broken, the restraint material is cut and removed.

Further, the arrangement, the size, and the number of the charge holes are not limited to those described in the embodiment. It can be set freely according to the style or construction plan of the cast-in-situ pile 1. For example, in the first embodiment, as shown in Fig. 3(c), eight horizontal charging holes 9 are formed at intervals of 45 degrees, but the number of charging holes 9 in the horizontal direction is effective for the boundary surface. The breaking of 5 may vary depending on the diameter of the pile, and when the diameter of the cast-in-situ pile 1 is small (for example, 1.3 m or less), four of them may be formed at intervals of 90 degrees.

Further, in the present embodiment, linear explosives are used as the breaking agents 36 and 38. However, it is also possible to perform the same controlled blasting using a crushing agent such as a gunpowder or a non-gunpowder breaker instead of the linear explosive. Since the non-gunpowder breaker has a slightly lower energy at the time of blasting, it must be charged at a greater extent, but there is an advantage in that the pile head treatment does not require a predetermined prior permission. Further, even if the field cast pile is constructed by the unreinforced concrete, the above-described pile head treatment method can be applied.

[Second Embodiment]

Next, a second embodiment of the present invention will be described. In the second embodiment, a CD tube in the vertical direction is provided in the vicinity of the main rib of the steel cage instead of the spiral CD tube, and an example of the charge hole is used. The other points are substantially the same as those in the first embodiment, and the same reference numerals are used in the drawings and the like, and the description thereof is omitted.

Fig. 9 is a view showing the reinforcing cage 25 of the second embodiment, Fig. 9(a) is a view showing the side surface of the upper portion of the reinforcing cage 25, and Fig. 9(b) is from the top View the view of the steel cage 25.

As shown in Fig. 9, in the present embodiment, the CD tube 43 is provided in the upper end portion of the reinforcing cage 25 at a position in the vicinity of the inner side of each of the main ribs 7 in the vertical direction parallel to the main rib 7. The CD tube 43 is made of, for example, a pipe made of polyvinyl chloride having a diameter of 15 mm and a length of about 600 mm. When the pile tube is cast, the upper end of the CD tube 43 is exposed from the upper surface of the excess concrete, and the jig 44 or the like is used.

In the present embodiment, the field cast pile 1 is formed in the same manner as described above using the reinforcing cage 25, and then the excess concrete 3 of the pile head is cut, broken, and removed using a non-gunpowder breaker and a breaker.

Fig. 10 is a view showing the charging hole 37 and the CD tube 43, which is an illustration of the upper surface of the excess concrete 3. In the present embodiment, the charging hole 9 of the boundary surface 5 (see Fig. 1) and the charging holes 37a to 37d forming the inner side of the main rib 7 are formed in the same manner as in the first embodiment, and the same is described above. The drug hole is charged with the non-gunpowder breaker 15 and the breaker 38. Further, in the vicinity of the main rib 7, the linear explosive similar to the above-mentioned crushing agent 38 is charged until the hole of the CD tube 43 of the charging hole is deep, and the portion which is located outside the main rib 7 is broken. 1 crushing agent, and stuffing sand and the like near the opening. The length of the linear explosive is, for example, about 300 mm shorter than the buried length of the CD tube 43.

Thereafter, the sheet and the metal wire are used to cure the excess concrete 3 in the same manner as in the first embodiment, and the non-gunpowder breaker 15 and the breaker are connected and controlled blasting. At this time, the blasting of the non-gunpowder breaker 15 is first performed, and the excess concrete 3 is broken from the structural concrete 27 below. Thereafter, the breaker of the CD tube 43 is blasted at intervals of about 30 microseconds, and the excess concrete 3 located outside the inner side of the main rib 7 is blasted so as to be pushed outward. In the same manner as in the first embodiment, the pulverization of the pulverizing agent 38 of the charging holes 37a to 37d is sequentially performed at intervals of about 50 microseconds, whereby the excess concrete 3 is broken into the adult head in the same manner as the example of Fig. 7(b). The size is around.

Also in the second embodiment, the same results as in the first embodiment can be obtained. Further, by providing the CD tube 43 in the vicinity of the main rib 7, the punching operation of the charge hole can be reduced, and the charge can be easily completed by using the CD tube 43 in the lead direction. However, instead of using the CD tube 43, the excess concrete 3 may be perforated in the vertical direction near the inner side of each of the main ribs 7, and a charge such as a linear explosive may be charged.

Although the embodiments of the present invention have been described above with reference to the drawings, the technical scope of the present invention is not affected by the above embodiments. It is to be understood that various modifications and changes can be made without departing from the scope of the invention as described in the appended claims.

Claims (7)

A pile head processing method comprising the following steps: (a) when the pile field is cast, the non-powder breaker is charged from the concrete side of the pile head with the main ribs in the vertical direction from the exposed ground. Forming a line, and charging the crushing agent on the concrete above the non-powder breaker; and (b) breaking the concrete up and down by the blasting of the non-gunpowder breaker, by blasting the crushing agent The crushing of the concrete above the divided portion is performed, and before the step (b), the restraining material for restraining the deformation of the main rib is provided. The pile head processing method according to claim 1, wherein in the step (a), the explosive is charged in a line shape as a first breaker in the vicinity of the main rib, and is vertically oriented on the inner side than the first breaker. The explosive charge is linearized as a second breaker. The pile head processing method according to claim 2, wherein in the step (b), the first crushing agent and the second crushing agent are sequentially blasted from the outer periphery of the concrete. The pile head processing method according to any one of claims 1 to 3, wherein a protective material having elasticity is provided in advance around the aforementioned main rib. The pile head processing method according to claim 2 or claim 3, wherein in the step (a), the first crushing agent is subjected to pre-arrangement in a spiral shape of the inside of the concrete in the vicinity of the main rib. Charge. The pile head processing method according to claim 2 or claim 3, wherein in the step (a), the first crushing agent is charged in the vicinity of the main rib in advance in a pipe in a vertical direction. The pile head processing method of claim 1, wherein the periphery of the concrete of the pile head is covered with a sheet before the step (b).