JP2018016940A - Demolition method of columnar structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demolition method of a concrete columnar structure 11 that enables a bottom part 13 of a gate columnar structure 11 to be blasted into small pieces without removing fragments from blasting of the gate columnar structure.SOLUTION: A demolition method of the present invention for a columnar structure 11 is for demolishing the concrete columnar structure 11 that has been erected by toppling the same, and includes the following steps for: installing a cushioning material 20 for receiving the columnar structure 11 on a ground surface 51 on a side toward which the columnar structure 11 is to be toppled, leaving a prescribed distance C from the columnar structure 11; forming by blasting a groove that opens to the side toward which the columnar structure 11 is to be toppled, at a portion of the columnar structure 11 close to a height of the cushioning material 20; and toppling onto the cushioning material 20 a concrete column 12 located above a bottom part 13, when the groove is seen as a boundary, thereby demolishing the columnar structure 11.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for dismantling a concrete columnar structure, for example, a method for dismantling a gate column structure of a dam by blasting.

  Conventionally, a method described in Non-Patent Document 1 is known as a method of dismantling a dam gate pillar structure which is a kind of concrete columnar structure. This method of dismantling the gatepost structure is to install a work scaffold around the gatepost structure, cut the reinforcing bars in the gatepost structure with a concrete cutter, and fill the charge hole from the upper end to the lower end of the gatepost structure. The gate pillar structure is divided into multiple times and blasted sequentially.

  However, the dismantling method of the above-mentioned portal post structure requires that the worker install the work scaffold at a high place and drill the charge hole when dismantling the gate post structure having a long overall length. The burden is heavy.

  Moreover, in the dismantling method of the above-mentioned gate pillar structure, if the work scaffold is not removed at the time of blasting the gate pillar structure, the work scaffold is involved in the blast of the gate pillar structure. Therefore, the work scaffold must be removed every time the gate pillar structure is blasted, and the work scaffold must be installed for the next blast work, which may prolong the entire construction period.

  On the other hand, the applicant of the present application lays a cushioning material for receiving the gate pillar structure on the ground surface on the side where the gate pillar structure is to be overturned, and applies the explosive to the charge hole drilled near the base of the gate pillar structure. We have proposed a method of dismantling the gate pillar structure that loads the gate pillar with its own weight by one blasting, and then dismantles the gate pillar structure by simply blasting the gate pillar and the base.

  According to the dismantling method of the gate pillar structure, it is not necessary for the worker to install the work scaffold at a high place and drill the charge hole, and it is not necessary to install and remove the work scaffold several times. . Therefore, the period required for the dismantling work of the gate pillar structure can be shortened, and the number of blasts of the gate pillar structure can be reduced. Thereby, it is possible to avoid blasting noise and vibration for a long period of time, and to reduce the influence on the surrounding residents and surrounding traffic.

Arase Dam removal plan (draft) Kumamoto Prefectural Enterprise Bureau September 2011 p58

  However, there is room for further improvement in the following points regarding the dismantling method of the gate pillar structure.

  That is, since fragments etc. generated when blasting the gate pillar structure are scattered on the cushioning material and cover the periphery of the base, it is difficult to provide a space for loading the explosive when the base is blasted.

  In addition, if the above cushioning material is present in the vicinity of the root and attempts to blast the root, the energy of the cushioning material when blasting the root is attenuated, resulting in poor blasting efficiency and blasting the root. Due to the energy at the time, there is a risk of a gun phenomenon in which debris and the like, which are generated when the gate pillar structure is blasted, and the cushion material jump out vigorously.

  Therefore, in order to blast the root, it is necessary to blast the gate pillar once and remove the fragments and the like generated by the blasting.

  The present invention has been made in view of the above points, and its technical problem is to break the root part of the base without removing the fragments generated when the gate pillar structure is blasted. An object of the present invention is to provide a method for dismantling a concrete columnar structure that can be used.

  In order to solve the above-described technical problem, the columnar structure dismantling method of the present invention is a columnar structure dismantling method in which a standing columnar structure made of concrete is overturned and disassembled. A cushioning material for receiving the columnar structure is laid on the ground surface on the side to be overturned at a predetermined distance from the columnar structure, and is located near the height of the cushioning material in the columnar structure. And by blasting a groove that opens toward the side on which the columnar structure is to be overturned, a concrete column located above the base with the groove as a boundary is overturned on the cushion material, and the columnar structure is formed. It is characterized by dismantling.

  In addition, after the concrete pillar falls on the cushion material, the fallen concrete pillar and the root may be broken apart.

  Further, the cushion material may be formed with a protruding portion that protrudes upward.

  The cushion material may be made of concrete.

  Further, the groove is formed by exploding an explosive loaded in a charge hole drilled in the columnar structure, and the charge hole is formed of a plurality of slants inclined upward from the explosive insertion port. An upward charging hole, and a plurality of downward charging holes that are above the upward charging hole and are inclined downward from the explosive insertion hole, and the number of the downward charging holes is The number may be larger than the number of upward charging holes.

  According to the concrete columnar structure dismantling method of the present invention, the cushion material is laid at a predetermined distance from the columnar structure, so that fragments generated when blasting the columnar structure are rooted. As a result, it is not possible to cover the periphery of the structure, and the gun phenomenon due to the energy when the base is broken and broken is not generated. Therefore, the root can be broken and broken without removing the fragments of the columnar structure.

It is a side view which shows the gate pillar structure of the dam which is the object of dismantling of embodiment of the dismantling method of the columnar structure which concerns on this invention. It is the figure which looked at the gate pillar structure of the dam which is the object of disassembly of embodiment of the disassembly method of the columnar structure which concerns on this invention from the E side (upstream side) in FIG. It is a principal part enlarged view of FIG. 2 which shows the state which loaded the explosive to the charge hole drilled in the gate pillar structure of the dam which is the object of dismantling of embodiment of the disassembly method of the columnar structure which concerns on this invention. It is a figure which shows embodiment of the disassembly method of the columnar structure which concerns on this invention, (a) shows the state which blasted the gate pillar structure, (b) shows the state which the gate pillar fell on the cushioning material.

  Hereinafter, an embodiment of a columnar structure according to the present invention will be described with reference to the drawings. An object to be dismantled by the dismantling method of the columnar structure according to the present invention is the gate pillar structure 11 that supports a gate that opens and closes in order to adjust the amount of water of the dam 10 that is built across a river or the like.

  The dam 10 includes a reinforced concrete gate pillar structure 11 placed in a plurality along the width direction of the river, and a gate (not shown) that is disposed between adjacent gate pillar structures 11 and that opens and closes in the vertical direction. The gate pillar structure 11 is provided with a lower portion embedded in the ground 50 and provided with a steel rail 14 that guides opening and closing of the gate. In the present embodiment, the gate has already been removed. Further, the left side in FIG. 1 is the upstream E of the river, and the right side in FIG. 1 is the downstream F of the river.

  Next, a method for dismantling the gate pillar structure 11 will be described.

  The dismantling of the gate pillar structure 11 can be broadly divided into a preparatory process before the gate pillar structure 11 is blasted with the explosive 34, a blasting process of blasting the gate pillar 12 and tumbling, and the gate pillar 12 that has fallen due to this blasting is finely crushed. A small blasting process.

  In the preparation process, a cushion material 20 for receiving the gate pillar 12 is laid on the ground surface 51 in a direction in which the gate pillar 12 is to be overturned, a part of the gate pillar structure 11 is removed by a breaker or the like, and a charge hole is formed in the gate pillar structure 11. 30 is drilled, and the explosive 34 is loaded into the charge hole 30.

  The cushion material 20 is made of concrete such as crushed concrete, and is laid at a required distance C between the gate pillar structure 11 and is evenly laid on the entire surface 51 in the direction in which the gate pillar 12 should be overturned. Is. In addition, a raised portion 21 is formed on the cushion material 20. In addition, the concrete waste can use the concrete crushed material etc. which generate | occur | produced on the spot.

  As shown in FIGS. 1 and 2, the raised portion 21 is raised on the cushion material 20, extends from the upstream side E toward the downstream side F, and in a direction in which the gate pillar 12 should fall. A plurality of them are formed at a required interval.

  The vicinity of the end portion on the upstream side E (A1 in FIG. 1) and the vicinity of the end portion on the downstream side F (A2 in FIG. 1) in the gate pillar structure 11 are different in shape, or in the vicinity of the rail 14 of the gate pillar structure 11 Since (A3 in FIG. 1) is made of steel, there is a possibility that A1, A2, A3 may inhibit the blasting effect when blasting the gate pillar structure 11. Therefore, A1, A2, and A3 are previously removed by a breaker.

  As shown in FIG. 1, the charge holes 30 are formed at a plurality of locations at a predetermined interval from the upstream side E to the downstream side F (B in FIG. 1) of the gate pole structure 11. As shown in FIGS. 2 and 3, 30 is formed on the upper side of the two upward charging holes 32 inclined upward from the explosive insertion port 33 and the upward charging hole 32, and the explosive insertion port 33. 3 downward charging holes 31 that incline toward the lower side. Then, the explosive 34 is loaded from the explosive insertion port 33 toward the deepest portions of the upward charging hole 32 and the downward charging hole 31.

  In the blasting process, the gate pillar structure 11 is blasted with the explosive 34 to form a groove 40 at the position indicated by the symbol B in FIG. 1 in the gate pillar structure 11, and the gate pillar 12 positioned above the root 13 is placed on the cushion material 20. Tilt up.

  When blasting the gate pillar structure 11, the explosive 34 loaded in the downward charge hole 31a and the upward charge hole 32a in the charge hole 30 was blown up and loaded in the downward charge hole 31b and the upward charge hole 32b. The gate pillar structure 11 is blasted in a chain by blasting the explosive 34 and finally blasting the explosive 34 loaded in the downward charging hole 31c. Thereby, the fragments etc. of the gate pillar structure 11 produced by the blasting are scattered so as to be paid out from the upper side to the lower side.

  Due to this blasting, as shown in FIG. 4 (a), a groove 40 having a substantially V-shaped cross section opening toward the fall direction D of the gate pillar 12 is formed in the gate pillar structure 11, and the groove 40 is defined as a boundary. The gate pillar structure 11 includes a root 13 and a gate pillar 12 positioned above the root 13.

  As shown in FIG. 4A, the gate pole 12 positioned above the root 13 is in a cantilever state, and as shown in FIG. 4B, the gate pole 12 positioned above the root 13 falls. It falls by losing the support of D and falls on the cushion material 20.

  When the fallen gate pillar 12 is received by the cushion material 20, a part of the fallen gate pillar 12 comes into contact with the raised portion 21, and stress concentrates on this contact portion, thereby causing the gate pillar 12 to crack. .

  In the split blasting step, the gate pillar 12 and the root 13 are finely crushed by loading the explosive 34 into the fallen gate pillar 12 and the root 13 embedded in the underground 50 and simultaneously breaking them apart.

  As described above, according to the dismantling method of the gate pillar structure 11 according to the present embodiment, the gate pillar 12 positioned above the root 13 loses support by the groove 40 formed by blasting the gate pillar structure 11. In order to fall, the fall direction D of the gate pillar 12 located above the root 13 can be controlled in accordance with the position and direction in which the groove 40 is formed.

  Further, according to the method for disassembling the gate pillar structure 11 according to the present embodiment, the cushion material 20 is laid at a required distance C between the gate pillar structure 11 and the gate pillar structure 11 is blasted. Since the generated fragments do not cover the periphery of the base 13 and the gun phenomenon due to the blasting energy that occurs when the base 13 is broken apart, the gate pillar 12 and The root 13 can be blasted at the same time. Therefore, the number of times of blasting when removing the gate pillar structure 11 can be reduced. In particular, when there are inhabitants and traffic networks in the vicinity, when blasting the gate pillar structure 11, there may be a predetermined time for performing the blasting work, so the number of blasting can be reduced. This embodiment is particularly useful.

  In addition, since the cushion material 20 according to the present embodiment is made of concrete, the cushion material 20 receives the load of the fallen gate pillar 12 and has an effect of absorbing the impact of the concrete pillars when the gate pillar 12 falls. . Thereby, the noise and vibration when the gate pole 12 is overturned can be reduced.

  In addition, the cushion material 20 according to the present embodiment first collides with a part of the fallen gate pillar 12, and stress concentrates on a part of the gate pillar 12, so that the gate pillar 12 is cracked. Therefore, the gate pillar 12 can be broken down more efficiently.

DESCRIPTION OF SYMBOLS 10 Dam 11 Gate pillar structure 12 Gate pillar 13 Base 14 Rail 20 Cushion material 21 Raised part 30 Charge hole 31,31a, 31b, 31c Down charge hole 32, 32a, 32b Up charge hole 33 Explosive insertion port 34 Explosive 40 Groove 50 Underground 51 Ground surface A Removal range B Blasting range C Distance D Falling direction E Upstream side F Downstream side

Claims (5)

In the dismantling method of the columnar structure that falls down and dismantles the standing concrete columnar structure,
A cushioning material for receiving the columnar structure is laid on the ground surface on the side where the columnar structure is to be overturned with a required distance between the columnar structure,
While being located in the vicinity of the height of the cushion material among the columnar structures, a groove is formed by blasting that opens toward the side where the columnar structures are to be overturned,
A method for disassembling a columnar structure, comprising: tumbling a concrete column located above the base with the groove as a boundary onto the cushion material to disassemble the columnar structure. In the dismantling method of the columnar structure according to claim 1,
A method for disassembling a columnar structure comprising disassembling the columnar structure by breaking the concrete column and the base at the same time after breaking the concrete column over the cushion material. . In the dismantling method of the columnar structure according to claim 1 or 2,
A method of disassembling a columnar structure, wherein the cushion material is formed with a raised portion protruding upward.   4. The method for disassembling a columnar structure according to any one of claims 1 to 3, wherein the cushion material is made of concrete. In the disassembly method of the columnar structure according to any one of claims 1 to 4,
The groove is formed by detonating an explosive loaded in a charge hole drilled in the columnar structure,
The charging holes are a plurality of upward charging holes inclined upward from the explosive insertion port, and a plurality of upward charging holes that are inclined upward from the explosive insertion port. A downwardly charged charge hole,
The method for disassembling a columnar structure, wherein the number of downward charging holes is greater than the number of upward charging holes.

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