JPS63176569A - Partial disassembling construction method of concrete structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a construction method for dismantling and removing a portion of the surface of a concrete structure using high-pressure fluid. [Conventional technology]

Conventionally, when demolishing a specific range of 2 degrees on the surface of a reinforced concrete structure 1'' as shown in Figure 6, the concrete part was crushed and demolished using a pneumatic or hydraulic breaker 4' as shown in Figure 7. In addition, when it is desired to remove the reinforcing bars 3' in the concrete, the exposed reinforcing bars are cut off using a fusing machine 6', etc., and the concrete is dismantled and removed. Surface layer peeling method for reinforced concrete structures (Japanese Patent Laid-Open No. 58-17
No. 3259), and surface peeling demolition method for reinforced concrete structures (Unexamined Japanese Patent Publication No. 3259), which destroys a certain thickness by injecting an expansive filler into cut grooves or driving wedges to destroy the roots between each groove. No. 146665/1982) etc. are also known.

[Problems to be solved by the invention]

However, the conventional method using a pneumatic or hydraulic breaker 4 has the following drawbacks. i) When the breaker 4 is activated, in addition to the sound generated from the main body, the impact sound generated when the chisel 5 at the tip collides with concrete or reinforcing steel is mixed, creating a large noise, and the dust and debris caused by the crushing. etc. occur in large quantities. ii) Since a breaker is used, there is a risk that cracks will propagate to healthy adjacent concrete parts that do not need to be removed, causing strength deterioration, and that if the concrete part is removed but the reinforcing bars are to be left, the reinforcing bars may deteriorate and be damaged. There is. 111) If you want to remove concrete to the location or depth where reinforcing bars are buried, the chisel 5" will be obstructed by the reinforcing bars and will have to penetrate deeper than that, significantly reducing the construction speed. Also, without using a breaker. When a crack is generated at the root and destroyed by injecting an expandable filler into the cut groove or driving a wedge into the cut groove, a force in the width direction is simply applied to the cut groove, so the direction of crack generation and propagation tends to be uncertain ( In addition, since the length is short, it is necessary to drill a large number of cut grooves with narrow intervals, and then inject an expandable filler or drive a rod into each of the cut grooves at a predetermined interval, resulting in a complicated work. There is.

[Problems to be solved by the invention] This invention was created as a result of intensive research to solve the above-mentioned drawbacks, and its main problems are to suppress the vibration and noise generated without using impact force to remove crushed concrete, and to identify the direction of crack generation. To provide a partial demolition method for a concrete structure, which can efficiently remove concrete by separating the concrete in the area scheduled for demolition at the interface with the non-demolition part. [Means to solve the problem]

In order to solve the above problems, the present invention provides a construction method for demolishing a predetermined area on the surface of a concrete structure, which includes: (b) an introduction hole formation step of drilling an introduction hole with a depth scheduled for disassembly in the middle of the area scheduled for disassembly; (C) Next, an ultra-high-pressure fluid injection nozzle whose spray angle is set in a direction substantially perpendicular to the rotation axis is inserted into the introduction hole, and the ultra-high-pressure fluid is injected at the bottom of the introduction hole, gradually expanding the area at the bottom. (d) Then, a separation process is performed in which high-pressure fluid is introduced into the enlarged bottom through the introduction hole to generate cracks and separate the concrete in the area scheduled for demolition. We are taking technical measures.

[For use]

In the outer circumferential groove forming step, a slit portion is formed around the area to be dismantled, in other words, on the boundary surface in the width direction with the non-dismantled portion, and in the introduction hole forming step, an introduction hole is formed in the middle portion. This introduction hole is enlarged in the direction of gradually expanding the bottom area in the bottom expansion step. By applying high-pressure fluid to the expanded bottom, the direction of crack generation and propagation is formed at the bottom of the slit along the boundary surface in the thickness direction between the area to be demolished and the non-demolition area. The planned area can be accurately separated and removed from the non-demolition part without damaging the adjacent non-demolition part. Furthermore, since only the concrete is demolished using high-pressure fluid, even if there are buried reinforcing bars, the reinforcing bars will not be damaged.

【Example】

Preferred embodiments of the method for partially dismantling a concrete structure according to the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which an outer circumferential groove forming process and an introduction hole forming process have been performed in an area 2 to be demolished of a concrete structure 1. That is, a series of frame-shaped slits 4 are bored along the outer periphery of a predetermined demolition area 2 of the concrete structure 1 at the demolition planned depth. As a result, the planned disassembly area 2 and the non-dismantled portion are separated at the boundary surface in the width direction. Further, an introduction hole 6 is bored in the center of the planned disassembly area 2 at the planned disassembly depth. This order may be in any order, and there may be a plurality of introduction holes 6. The slit portion 4 and the introduction hole 6 may be formed by a known cutting or crushing means, but in this embodiment, the cutting is performed using ultra-high pressure jet water. It should be noted that the ultra-high pressure here is sufficient as long as it is a water pressure that can cut concrete. For this, as shown in FIG. 3, the injection angle of the injection nozzle N1 is at an acute angle θ<90 with respect to the rotation axis of the injection nozzle N1.
An injection nozzle with an inclined configuration is used. Therefore, by injecting ultra-high pressure jet water from this injection nozzle N1, the wide slit portion 4 and the introduction hole 6 can be formed, respectively. At this time, if the concrete structure 1 has built-in reinforcing bars 3, the reinforcing bars 3 will be exposed and remain as they are, so if necessary depending on the purpose of demolition, the reinforcing bars 3 can be melted (or cut) using an acetylene gas flame, etc. ) to form the reinforcing bar fusion section 5. Next, as shown in FIG. 4, a bottom widening process is performed using the injection nozzle N2 configured such that the injection angle of the injection nozzle N2 is perpendicular to the rotation axis of the injection nozzle N2 at 90 degrees. That is, the ultra-high-pressure jet water injection nozzle N2 is inserted into the introduction hole 6, and the ultra-high-pressure jet water is injected at the bottom of the introduction hole 6 to expand the bottom in a substantially horizontal direction into a substantially disc-shaped bottom part. form 7. It is preferable that the optimal shape of the enlarged bottom portion 7 is experimentally determined in advance in accordance with the size of the area 2 to be dismantled. Next, the inside of the enlarged bottom part 7 of the introduction hole 6 is made airtight and filled with a large amount of high-pressure water, and a separation step is performed in which a crack 8 is generated toward the bottom of the slit part 4 to separate the concrete in the area 2 scheduled for demolition. That is, the high-pressure water introduction pipe 9 is inserted into the introduction hole 6, the gap between the high-pressure water introduction pipe 9 and the introduction hole 6 is airtightly sealed with a known high-pressure water sealing member 10, and the expanded bottom portion 7 is sealed with high-pressure water. The introduction pipe 9 is sealed so as to be the only inlet, and high pressure water 11 is introduced into the expanded bottom portion 7 via the high pressure water introduction pipe 9. The amount and pressure of this high-pressure water 11 may be such that it can be introduced into the expanded bottom portion 7 and cause a crack 8 to reach the bottom of the slit portion 4, and the bottom can be expanded at once in as short a time as possible. It is preferable to fill the inside of the portion 7. In this way, cracks 8 can be generated from the side tips of the expanded bottom part 7 to the bottom of the surrounding slit part 4 by the hydraulic action of the high-pressure water filled in the expanded bottom part 7, and the concrete in the area 2 scheduled for demolition is can be separated from the non-disassembly portion at the boundary line position in the thickness direction, and together with the slit portion 4, the disassembly scheduled range 2 can be removed from the non-disassembly portion. For this removal, an appropriate impact force may be applied depending on the degree of occurrence of cracks, but it is sufficient that the impact force is small compared to the crushing of the conventional structure. In this embodiment, one introduction hole 6 is provided at the center of the planned demolition area 2, but a plurality of introduction holes 6 may be provided at approximately equal intervals. Further, in this embodiment, high pressure water and ultra-high pressure jet water were used as the high-pressure fluid and the ultra-high pressure fluid, but in the present invention, fluids outside the waterside may be used.

【Effect of the invention】

Since this invention has the above-mentioned configuration, (1) When demolishing and removing concrete, it does not use impact force unlike conventional pneumatic or hydraulic breakers, so it is possible to suppress the vibration and noise generated during demolition work. The environment can be improved. ■ Instead of crushing all parts of the concrete to be removed, concrete is crushed only during the process of forming the slit and introduction hole, and the process of expanding the bottom of the introduction hole, and filling the expanded bottom with high-pressure fluid. Cracks are generated and propagated in a predetermined direction, and the area to be dismantled and the area to be dismantled can be separated and removed at the interface in the thickness direction, which simplifies the demolition work and significantly shortens the work time. can.

[Brief explanation of the drawing]

Fig. 1 is an external view of a concrete structure 1 of the present invention in which the construction method is implemented by a partial demolition method, Fig. 2 is a cross-sectional view thereof, and Fig. 3 is a concrete structure 1 used in the outer circumferential groove forming process and the introduction hole forming process. Fig. 4 is an external view of the ultra-high pressure jet water injection nozzle used in the bottom expansion process, and Fig. 5 is a cross section showing how high pressure water is introduced into the bottom expansion part during the destruction process. Fig. 6 is an external view showing the concrete removal situation of a specific part, and Fig. 7 is a sectional view showing the concrete structure removal work situation by the conventional construction method. 1... Concrete structure 2... Area to be demolished 3... Reinforced bars 4... Slit section 5... Reinforcement melted section 6... Water guide hole 7... Expanded bottom section 8... Cracks 9 ... High pressure water introduction pipe 10 ... High pressure water seal 11 ... Introducing high pressure water

Claims (7)

[Claims] (1) In a construction method for demolishing a predetermined area on the surface of a concrete structure, forming a peripheral groove in which a slit section is bored from the surface of the concrete structure at the planned demolition depth and along the outer periphery of the planned demolition area. An introduction hole forming step of drilling an introduction hole to the depth scheduled for demolition in the middle of the area scheduled for demolition, and an ultra-high pressure injecting angle set in the introduction hole in a direction substantially perpendicular to the axis of rotation. A bottom expanding step in which a fluid injection nozzle is inserted and ultra-high pressure fluid is jetted at the bottom of the introduction hole to gradually expand the area of the bottom, and high pressure is applied to the enlarged bottom through the introduction hole. A partial demolition method for a concrete structure comprising a separation step of introducing a fluid and generating cracks to separate concrete in an area scheduled for demolition. (2) The method for partially dismantling a concrete structure according to claim 1, wherein the introduction hole drilled in the introduction hole forming step is drilled in the center of the area to be demolished. (3) The method for partially dismantling a concrete structure according to claim 1, wherein the ultra-high pressure fluid and the high-pressure fluid consist of ultra-high pressure water and high-pressure water. (4) The drilling of the slit portion in the outer circumferential groove forming step, the drilling of the water guide hole in the water guide hole forming step, and the drilling of the bottom expanding portion in the bottom expanding step are performed by jetting ultra-high pressure jet water. A method for partially dismantling a concrete structure according to claim 3. (5) The injection angle of the ultra-high pressure jet water injection nozzle used for drilling the slit part in the outer circumferential groove forming process and the water guide hole in the water guide hole forming process is at an acute angle with respect to the rotation axis of the injection nozzle. 5. A method for partially dismantling a concrete structure according to claim 4, wherein the structure is inclined at a slant. (6) A patent claim characterized in that the injection angle of the ultra-high pressure jet water injection nozzle used for drilling the bottom expansion part in the bottom expansion process is arranged approximately at right angles to the rotation axis of the injection nozzle. Partial demolition method of concrete structure described in item 4. (7) The concrete structure is made of reinforced concrete, and in the process of forming the outer circumferential groove, the penetrating reinforcing bars are cut or fused at the slit portions. A method for partially dismantling concrete structures.