JPS6150006A - Position measuring method of radiation absorbing body, which is embedded in structure - Google Patents

Abstract

PURPOSE:To measure the position of an embedded material without the effect of the thickness of a body, by providing a hole, which matches the size of a radiation source, in the body such as a wall body, and inserting the radiation source in the hole. CONSTITUTION:An embedded material 2 such as an reinforcing bar is provided in the inside of a body 1, which is a body, a beam, a pillar and the like of concrete and the like. A radiation source inserting hole 3 is provided in the body 1. A film 4 is fixed to the surface of the body 1 so that the center of the film is aligned with a mark 6. Then, a radiation source 5 is inserted in the radiation source inserting hole 3, and X rays are projected on the film 4. As a result, the projected image (d) of the embedded material 2 and the projected image of the mark 6 are formed on the film 4 by the X rays. The projected images are analyzed, and the position of the embedded material 2 is measured.

Description

[Detailed Description of the Invention] The present invention allows radiation such as X-rays to pass through structures, such as walls, in which radiation absorbing materials such as pipes and reinforcing bars (hereinafter referred to as "buried objects") buried deep inside are buried. The present invention relates to a method for measuring the position of buried objects within a wall by analysis based on a projection map created by the method.

[B] Prior art Accurately ascertaining the positions of reinforcing bars, piping, etc. installed inside concrete walls and columns, etc., in advance, during safety inspections of the seismic strength of existing concrete buildings and during building remodeling. is an important element in construction.

For example, when expanding or renovating a concrete apartment complex, ceilings and walls may be removed, or openings may be installed to install a ventilation fan in the wall, or new through-holes may be installed for connection pipes for air conditioning equipment. In some cases, existing water, gas, electrical conduit pipes, etc. buried within the pillars may be further branched, or new pipes may be installed next to them.

Knowing the exact location of the existing underground pipes and reinforcing bars is essential for improving work efficiency.

Originally, pipes and reinforcing bars should be buried in accurate locations based on the construction drawings, but in reality, the positions on all four sides of the construction may be inconsistent or the drawings may be missing.

Due to this discrepancy, unexpected piping or reinforcing bars may be discovered during chisel work at the location where the opening will be provided, and the opening location may have to be changed to another location.

Furthermore, in order to discover the target piping, etc., a wall must be destroyed on a large scale, and then the hole must be repaired, which is an inefficient and wasteful situation that requires a great deal of effort.

Therefore, electromagnetic induction exploration methods and the like have been devised as a so-called non-destructive method of detecting the position of buried objects buried inside concrete walls, columns, etc. of buildings.

In this electromagnetic induction exploration method, a measuring instrument containing an electromagnetic coil is moved while touching the surface of the wall to be inspected, and the instrument detects and displays the reaction of the electromagnetic coil to the buried object.
This method measures the location of buried objects.

[Explanation] Problems to be Solved by the Invention The measurement method using the electromagnetic induction survey method described above has the following problems.

(1) Even if you can confirm the location of the buried item, you cannot measure the depth of the buried item.

In particular, if the burial depth is deep, it becomes impossible to confirm the buried position, and measurements are subject to certain limitations.

(2) Large measurement error.

(3) When buried objects are buried in a wall in a complicated manner, it is almost impossible to judge the measured values.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and provide a method for measuring the position of a radiation absorbing body buried in a structure, which is configured to quickly and easily measure a more accurate position.

[Means for solving the box problem] The present invention provides a hole that matches the size of the radiation source in a frame such as a wallff1l.
Then, a radiation source is inserted into this hole, and buried objects such as reinforcing bars are imaged on a radiation film that has been set on the surface of the structure in advance.

This is a method of determining the location of buried objects, such as reinforcing bars, buried within a wall by analyzing the images of the buried objects captured on film.

Next, one embodiment of the present invention will be described based on the drawings.

(1) Opening of the radiation source insertion hole In FIG. 1, a frame 1 is a frame made of concrete or the like, or a beam, a column, etc., and a buried object 2 such as a reinforcing bar is buried therein.

A radiation source insertion hole 3 is provided in this frame 1.

The radiation source insertion hole 3 is a hole whose purpose is to emit radiation (for example, α rays, β rays, γ rays, neutron rays, X-rays, etc.) from within the body 1, so the radiation source can be inserted depending on the hole diameter. Form to the appropriate dimensions.

Furthermore, a sign 6 is provided on the surface of the frame 1 by pasting lead or the like.

Furthermore, a film 4 is fixed on the surface of the frame 1 with its center aligned with the mark 6.

(2) Insertion of radiation source Next, the radiation source 5 is inserted into the radiation source insertion hole 3.

This radiation source 5 has a known structure capable of irradiating radiation in a direction perpendicular to the opening direction of the radiation source insertion hole 3.

(3) Radiation irradiation For example, X-rays are irradiated from a radiation source 5 toward the film 4 .

As a result, a projected image d of the buried object 2 and a projected image of the marker 6 are projected onto the film 4 by the X-rays transmitted through the frame 1.

(4) Actual Measurement and Instrumentation In FIG. 2, d indicates the diameter of the buried object 2 projected onto the film 4.

FFD is the distance from the radiation source 5 to the surface of the film 4.

y is the distance from the projection point of the marker 6 on the film 4 to the center of the projected image of the buried object 2.

Here, as shown in Fig. 2, if the distance from the surface of the building frame 1 to the center of the buried object 2 is X, and the distance from the line connecting the radiation source 5 and the marker 6 to the center of the buried object 2 is Y, then X and Y
The position of the buried object 2 within the body 1 can be determined by determining the distance.

First, the following formula holds true for X, and the value can be found.

Further, regarding Y, the following formula holds true, and the value of Y is obtained.

Therefore, by substituting the respective numerical values into the formulas (1) and (2), the accurate j! of the buried object 2 can be determined. ll! It is possible to grasp the installation location.

Since the present invention is as explained above, the following effects can be expected.

(b) Even if buried objects such as reinforcing bars are buried deep in the building structure, it is possible to open a hole in the middle of the building structure and irradiate radiation from inside this hole to photograph the buried object.

Therefore, the position of the buried object can be measured without being affected by the thickness of the building structure.

It is also much more accurate than electromagnetic induction exploration methods, and can locate buried objects without requiring any skill.

(b) Since the present invention allows the positions of reinforcing bars and the like within a building frame to be measured eight minutes in advance, there is no need to waste effort, time, and expense when, for example, extending or renovating a concrete house.

(c) Since the pipes, etc. inside the building frame are displayed numerically, the reinforcing condition of the insert can be clearly seen, making it possible to improve the efficiency of safety inspections to confirm seismic performance.

[Brief explanation of the drawing]

Fig. 1 2 An explanatory diagram of an embodiment of the present invention Fig. 2: An explanatory diagram of measured values 1: Body 2: Buried object 3: Intruder on the reading side 4: Film 5: Ray source

Claims (1)

[Claims] A radiation source insertion hole is opened in a structure in which a radiation absorber with a known cross-sectional diameter is embedded, and a marker and a film sensitive to radiation transmission are placed on the surface of this structure. , a structure characterized in that radiation is irradiated from inside the radiation source insertion hole toward the film surface, and the position of the buried radiation absorber is measured by analyzing based on the projected image projected on the film. A method for measuring the position of radiation absorbers embedded in objects.