JP2001182337A - Circular-opening forming method for concrete body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently bore a circular through-hole in a concrete body such as an existing dam, and to efficiently remove a concrete columnar body in excellent work environment. SOLUTION: The cores 12 of the concrete columnar bodies bored by a hole saw boring device 30 are extracted from the concrete body, and cut in a sectional shape by a wire saw cable 21 and lifted and removed by a crane. Extraction and cutting in the sectional shape are repeated, and the cores 12 are all removed efficiently. An operator can operate at a place separated from the place of cutting during cutting works, and can operate in excellent environment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing a thick concrete body with a circular opening, such as a case where an existing concrete dam is provided with a circular opening for providing a spillway or the like.

[0002]

2. Description of the Related Art As a method of installing an opening in an existing concrete body, there is a method using a wire saw disclosed in Japanese Patent No. 2554584. In this method, a scaffold is constructed on the downstream side of the concrete body, a wire saw driving device is installed, a hole is made through the dam concrete body at the corner of the opening to be installed, and a wire saw cable is inserted between these holes. The concrete column is cut off from the concrete body by bridging and cutting between the holes, and after the cutting is completed, the concrete column is crushed and removed to provide an opening.

[0003]

According to this method, it is necessary to construct a scaffold for installing a wire saw driving device on the downstream side of the dam, and in the case of horizontal cutting, the wire saw cable is inserted in the guide hole. Because it was very difficult to make the cutting line straight by dancing or sagging, the cut concrete column could not be pulled out to the side of the concrete body, and the cut column was crushed and removed . Therefore, the efficiency of the removal operation is low, and the work environment is not good. The only way to make the opening circular was to provide a guide hole in a polygonal shape and resemble a circle, increasing the number of guide holes to be installed, resulting in poor efficiency and impractical. Steel pipes were installed in the square openings, concrete was filled around the steel pipes, and round openings were used. However, extra steps such as reinforcement of the surroundings were required. An object of the present invention is to enable removal of a cut cylindrical body efficiently and in a favorable working environment, and to provide a circular opening directly.

[0004]

Means for Solving the Problems A concrete cylinder which has been circularly perforated by a hole saw perforator is extracted from the concrete body, and the extracted portion is cut into a circle by a wire saw, cut, and lifted and removed by a crane or the like. Efficiency was improved. In addition, the operator can operate at a place away from the cutting place during the cutting work, can perform the circular opening installation work in a favorable environment, and furthermore, by using a hole saw, a large diameter circular opening can be directly To be provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to an embodiment in which a circular opening is provided in a concrete dam.

[Embodiment 1] As shown in a side view of a state where holes are being drilled by a hole saw drilling device 30 in FIG.
The workbench 25 is attached to the wall surface 11 of, and the hole saw punching device 30 is fixed to the wall surface 11 with an anchor. The hole saw drilling device 30 includes a hole saw having a cutting edge made of diamond or the like at its tip and an open rear end, a driving device for rotating the hole saw, and a moving device for moving the hole saw back and forth.

After the concrete body of the dam 10 is cut and penetrated by rotating and driving the hole saw, the driving device and the like are removed with the hole saw remaining in the concrete body, and as shown in FIG. Inserting the extraction rod 41 into the extraction hole provided in the core 12 in advance, the core 12
The pull-out bar 41 is connected and fixed to the back side of the device by a fixing member.
The other end of the extraction rod 41 is fixed to the pressing member 42 on the extraction side. A screw rebar is used as the pull-out bar 41, and a screw rebar is inserted into a hole provided in the pressing member 42 and fixed with a nut, thereby facilitating attachment and detachment.

A jack 4 is provided between the wall 11 and the pressing member 42.
3 is installed, and the pressing member 42 is pressed by applying a reaction force to the wall surface. The force applied to the pressing member 42 is transmitted to the back side of the core 12 via the pull-out bar 41, and the core 12 is extruded from the concrete body. Core 12 is about 1m wall surface 11
When the jack 43 has been pulled out, the jack 43 is stopped, and the pulling rod 41 is once removed from the core 12.

As shown in FIG. 3, a pulley 22 for guiding the wire saw cable 21 is fixed at an appropriate position, and the wire saw cable 21 is hung on the extracted core 12.
It is looped over a wire saw drive device 20 installed at the top of the dam 10. The wire saw driving device 20 is driven to travel while applying an appropriate tension to the wire saw cable 21, and the core 12 pulled out from the wall surface is cut into a ring by a wire saw and lifted by a crane. The traveling speed and tension of the wire saw cable 21 are appropriately determined according to the size of the core 12 and the like. Usually the speed is 20-30m
/ Sec, tension is 50 to 150 kg, and the cutting operation is performed while supplying water to the wire saw.

The extraction rod 41 is set on the core 12 again, and the jack 43 is operated to pull out the core 12 from the concrete body. Similarly, the core 12 is cut by a wire saw. By repeating this operation, the entire core 12 is removed from the concrete body, and a circular opening is provided. A steel pipe is installed in a circular opening, and reinforcing materials such as reinforcing bars are arranged around the steel pipe and filled with concrete to be used as a spillway for a dam.

[0010]

[Embodiment 2] A hole-saw punching device 30 incorporating a core pull-out device as shown in Japanese Patent No. 2852911 shown in FIG. 4 is used to improve the efficiency of the drilling operation and the core extracting operation. The core 12 is pulled out by piercing with the hole saw piercing device 30, burying and fixing an eyebolt on the surface of the core 12, and operating the winch 50 provided on the frame of the hole saw piercing device. As in the case of the first embodiment, the wire is cut into pieces by a wire saw. By repeating this operation, all the cores 12 are removed from the concrete body to provide a circular opening.

[0011]

Embodiment 3 Using a hole saw punching device 30 in which a core pushing device 60 as shown in Japanese Patent No. 2960879 shown in FIG. 5 is incorporated, the core 12 is pushed out to the side opposite to the installation side of the hole saw punching device 30, This allows the core 12 to be cut quickly without moving the hole saw drilling device.

After the core 12 has been pierced through the hole saw punching device 30, the driving device of the hole saw punching device 30 is removed from the frame, and the pushing device 60 is attached to the base frame 61. The extruding device 60 is provided with a hydraulic cylinder 63 having an extruding seat body 62 fixed to the end at the end of the extruding member. The hydraulic cylinder 63 is actuated, the reaction force is applied to the base frame 61 fixed to the concrete body wall surface, and the core 12 is pushed out to the back side of the concrete body. A wire saw cable 21 is looped around the extruded core 12 in a loop, and the wire saw driving device 20
Circulates the wire saw cable to make a round slice.

By repeating this operation, all the cores 12 are removed from the concrete body, and a circular opening is provided in the concrete body. The cutting of the core 12 is performed by the hole saw drilling device 3.
The work is performed on the opposite side to the installation location of No. 0, so that the work space can be widened, and the work can be performed quickly without the need to move the hole saw drilling device at the time of round cutting.

[0014]

Embodiment 4 As shown in FIG. 6, a concrete body is passed through a hole saw 3 having a diameter of about 10 cm along a circular cutting line. Since it is a small hole saw, it can be easily transported even in a mountainous area, and the drilling device can be installed and moved and removed quickly. The columnar body 2 cut off by the hole saw is extracted from the side surface of the concrete body by any of the methods described in the above-mentioned embodiments, and is cut off by a wire saw and removed, and a circular opening is provided in the concrete body. Since there is unevenness on the inner peripheral surface of the opening, it is shaped and smoothed as necessary. When a small-diameter hole saw is used as in this embodiment, the shape of the cutting line can be set arbitrarily, and an opening having a shape other than a circle can be easily provided in the concrete body.

[0015]

According to the present invention, a circular opening is directly provided in a concrete body by a hole saw drilling device, so that it is not necessary to cut and remove excess concrete as compared with a wire saw, and the opening portion is not required. By making the shape circular, the stress can be dispersed, and the cost required for reinforcement can be saved, which is economical. In addition, after cutting, the core is extracted from the concrete body, the extracted part is cut into a suitable size with a wire saw, lifted with a crane etc. and removed, so the removal efficiency is good, and the worker can cut during the cutting work. Since the operation is performed in a place away from the place, it is possible to work in a favorable environment as compared with crushing.

[Brief description of the drawings]

FIG. 1 is a side view of a state in which a hole saw punching device is fixed.

FIG. 2 is a side view of a state where a core is extracted.

FIG. 3 is a side view of a state in which the extracted core is cut into slices.

FIG. 4 is a side view of a second embodiment using a core drawing device.

FIG. 5 is a side view of a third embodiment using a core pushing device.

FIG. 6 is a front view of a fourth embodiment using a small-diameter hole saw.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Wall 12 Core 25 Work table 20 Wire-saw drive device 21 Wire-saw cable 30 Hole-saw drilling device 41 Pull-out rod 42 Pressing member 43 Jack 50 Winch 60 Extruder 61 Base frame 62 Seat body 63 Hydraulic cylinder

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2E176 AA01 DD22 3C069 AA01 AA04 BA06 BA09 BB04 CA07 EA01

Claims (1)

[Claims] 1. A method of installing a circular opening in a concrete body in which a concrete body is pierced circularly with a hole saw piercing device, a core is extracted from the side of the concrete body, and the core is cut into a circle with a wire saw and removed.