JPH0242408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention irradiates radiation such as X-rays to a structure in which objects such as pipes and reinforcing bars are present, for example, a wall, and actually measures the dimensions of a projected view caused by the transmitted X-rays. This invention relates to a method of measuring the position of a buried object within a wall using mathematical formulas or drawings.

When conducting safety inspections of the seismic strength of existing concrete buildings or remodeling buildings, it is important to accurately determine the locations of reinforcing bars and piping placed inside concrete walls and columns in advance. It is.

For example, when extending or renovating a concrete house, ceilings and walls may be removed, and new penetrations such as installation ports for ventilation fans and connecting pipes for air conditioning equipment may be installed in the walls. In some cases, existing underground pipes for various services such as water, gas, and electrical conduits may be further branched, or new pipes may be added in parallel to them.

Knowing the exact location of the existing underground pipes and reinforcing bars is an essential requirement in order to improve work efficiency.

Originally, whether it is piping or reinforcing steel, it should be constructed in the location based on the drawings, but in reality, the location often differs from the location shown in the construction drawings.

Due to this discrepancy, unexpected piping or reinforcing bars may be discovered during chisel work to provide an opening, and the opening location may have to be changed to multiple locations.

Furthermore, in many cases, a large-scale wall is destroyed in order to excavate the desired piping, and then a large amount of labor is required to repair the hole, which is inefficient and uneconomical.

Therefore, electromagnetic 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 method, a measuring instrument containing a magnet is moved while touching the surface of the wall to be inspected, and the instrument detects and displays the reaction of the magnet to the buried object.
This method measures the position of buried objects, but this conventional method has the disadvantage that the depth of the buried object is not known, and the measurement error is large.Also, when the buried object is buried in a complex manner within the wall, had the disadvantage that highly skilled techniques were required to judge the measured values.

An object of the present invention is to solve the above-mentioned drawbacks and provide a method for measuring the position of a radiation-reactive object buried in a structure, which is configured to quickly and easily measure a more accurate position. However, a marker line with known dimensions is pasted on the wall surface in advance, a radiation film is attached to the back of the wall, and then radiation such as X-rays is irradiated from a position perpendicular to the wall surface at the center of the marker line. The purpose of this method is to measure the position of a radiation-reactive object, such as a cylindrical structure, buried within a wall from the dimensions and relative positional relationship of the projected image produced by the transmitted X-rays.

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

(b) Positional relationship of each device used in the present invention In FIG.
is buried.

Further, reference numeral 3 denotes a marking line 3 made of wire such as lead or tungsten, and is pasted horizontally on the surface of the wall 1.

Further, reference numeral 4 denotes an X-ray film 4 attached to the back surface of the wall 1, that is, the back surface of the surface on which the marker line 3 is pasted.

Reference numeral 5 denotes an X-ray irradiation source 5, and its position is at an arbitrary distance on a line extending perpendicularly from a point bisecting the marker line 3 of the wall 1.

(b) Irradiation of X-rays Next, X-rays are irradiated toward the wall 1 from the X-ray irradiation source 5.

A projected view of the cylindrical structure 2 and the marker line 3 is captured on the film 4 on the back surface of the wall by the X-rays transmitted through the wall 1.

(c) Actual measurements and calculations By substituting the values actually measured for these two projections into the following formula, along with the distances between the front and back surfaces of the wall 1 and the X-ray irradiation source 5, the dimensions of the marker lines, etc. The position of the cylindrical structure 2 can be known.

In FIG. 2, D indicates the diameter of the cylindrical structure 2 having a diameter of d projected onto the film 4, and L indicates the length of the marker line 3 having a length of 1 projected onto the film 4.

Further, FWD is the distance from the X-ray irradiation source 5 to the surface of the wall 1, and FFD is the distance from the X-ray irradiation source 5 to the film 4.

Further, X is the distance between the respective centers of the cylindrical structure 2 and the marker line 3 projected on the film 4.

All of the above dimensions can be actually measured, except for knowing the diameter d of the cylindrical structure 2, which is a standard product, from drawings or the like.

Here, as shown in Fig. 2, the distance from the surface of the wall 1 to the center of the cylindrical structure 2 is y, and the marker line 3
Let x be the horizontal distance from the bisector of the wall 1 to the center of the cylindrical structure 2 on the surface of the wall 1.
The position of the cylindrical structure 2 inside is known.

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

L/l=FFD/FWD...(1) D/d=FFD/FWD+y...(2) When FFD is deleted from (1) and (2), y=(Ld/lD-1)×FWD... (3) By substituting the respective numerical values into the formula (3), y, that is, the distance from the surface of the wall 1 to the center of the cylindrical structure 2, can be determined.

Next, the formula for x is as follows.

x=X×d/D (4) Therefore, the distance from the point that bisects the marker line 3 to the center of the cylindrical structure 2 on the surface of the wall 1 is found.

Furthermore, since the following equation is derived from the above equation, when the thickness of the wall 1 is T, that T can also be determined by the following equation (5).

T=FFD-FWD=(L/l-1)×FWD...(5) (d) Position confirmation by drawing (Figure 3) The X-ray irradiation source 5 set on the drawing is s, and s
Extend a straight line with the measured distance FWD to the surface of the wall 1 and define one end as s', and on the line that intersects the straight line ss' at right angles, find a point half the distance of half the marker line 3 on the left and right from the intersection. Let p, p′.

Next, draw a line connecting the X-ray irradiation source 5 and points p and p'.

A straight line connecting point rr' on the extension line of straight lines sp and sp', which is parallel to straight line pp' and whose length is the length L projected on film 4 of marker line 3.
rr′ becomes the projected marker line portion.

Next, a straight line connecting the point tt' on the straight line connecting the irradiation source s and both ends qq' of the projected view of the cylindrical structure 2 appearing in the marked line part obtained above,
The embedding position of the cylindrical structure 2 is a circle whose diameter is a straight line tt' which is parallel to the straight line pp' and has a diameter distance d of the cylindrical structure.

(E) Other examples In this example, the marker lines were pasted horizontally, but they can also be pasted vertically to check for buried objects extending horizontally, or marker lines arranged in a cross pattern can be used. For example, it is possible to easily check buried objects extending in both the vertical and horizontal directions, and further, by using this principle, it is possible to check not only buried objects in the vertical and horizontal directions but also various forms of buried objects.

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

(b) Since the position of an object within a wall is displayed as a clear numerical value, it is much more accurate and quick than electromagnetic methods, and the position of buried objects can be determined without requiring much skill.

(b) According to the present invention, the positions of reinforcing bars, etc. within a wall can be measured in advance, so there is no need to waste effort, time, and expense when, for example, extending or renovating a concrete house.

(c) Since the piping inside the wall is displayed numerically, the reinforcing condition of the structure can be clearly seen, making it possible to improve the efficiency of safety inspections to confirm seismic performance.

<D> One of the conventionally known methods is to use two X-ray sources.
There is a way to use it in more than one place.

Such a method is not only different in principle from the analysis principle of the present invention, but also in practical terms.

This is because such known methods are particularly unsuitable for working in busy hospitals or office buildings.

This is because bringing two or more X-ray sources to a predetermined location requires a large space, which has a large impact on the surroundings, such as setting up scaffolding and moving equipment.

In contrast, the method of the present invention uses a single X-ray source, so it not only has a different principle compared to known methods, but also allows imaging even in a narrow space and is extremely fast. It is quick and practical.

[Brief explanation of the drawing]

Figure 1: An explanatory diagram of an embodiment of the present invention, Figure 2:
Explanatory diagram of measured values, Figure 3: Explanatory diagram of position confirmation by drawing 1: Wall, 2: Cylindrical structure, 3: Sign line, 4:
Film, 5: X-ray irradiation source.

Claims (1)

[Claims] 1. A marker line with known dimensions is affixed to one side of a structure in which a radioactive reactant is buried, and a film sensitive to the transmitted intensity of radiation is attached to the other side, and the marker line is Radiation is irradiated from a single point source placed at a fixed position on an axis perpendicular to one surface of the structure at the center, and the relative positional relationship between the marker line projected on the film and the projection of the radiation-reactive object is calculated. A method for measuring the position of a radiation-reactive object buried in a structure, comprising: actually measuring dimensions and measuring the position of the buried radiation-reactive object.