JP6796824B2 - Radiation shielding wall - Google Patents

Description

The present invention relates to a radiation shielding wall.

Conventionally, as a radiation shielding wall, there is one in which a plurality of precast concrete panels (hereinafter referred to as PCa panels) are continuously formed (see, for example, Patent Document 1). In this radiation shielding wall, a seam is formed between the PCa panel and the PCa panel. The joint material filled in the seam has lower radiation shielding performance than the PCa panel portion. Therefore, in this type of radiation shielding wall, the plate thickness of the PCa panel is set to a size that can shield radiation only with the joint material.

Japanese Unexamined Patent Publication No. 2004-333345

However, since the size that can shield radiation only with the joint material is larger than the size that can shield radiation only with concrete, there is a problem that the radiation shielding wall becomes unnecessarily thick and the manufacturing cost increases.

The present invention has been made in view of the above, and an object of the present invention is to provide a radiation shielding wall capable of suppressing a manufacturing cost and satisfying a radiation shielding performance.

In order to solve the above-mentioned problems and achieve the object, the radiation shielding wall according to the present invention is a radiation shielding wall formed by arranging a plurality of rectangular plate-shaped precast concrete panels with their end faces facing each other. The precast concrete panel is formed between a main body portion having a constant plate thickness and both ends of the main body portion having a plate thickness larger than that of the main body portion and adjacent to each other. It has a joint portion on which a joint material is arranged, and the plate thickness of the joint portion is inside in a reference plane orthogonal to the surface of the main body portion along the parallel arrangement direction of the precast concrete panel. For all straight lines from the surface to the outer surface, the total length of passage through the precast concrete panel portion is configured to be greater than or equal to the minimum shielding dimension that meets the required radiation shielding performance of concrete. The plate thickness of the main body portion is not more than the minimum shielding dimension and is set to a value smaller than the plate thickness of the joint portion.

Further, in the radiation shielding wall according to the present invention, it is preferable that the joint portion of the precast concrete panel protrudes from the surface inside the main body portion.

According to these configurations, the precast concrete panel is provided for all straight lines from the inner surface to the outer surface along the parallel direction of the precast concrete panels and on the reference plane orthogonal to the surface of the main body. Since the joint portion is formed so that the total passing length of the passage is equal to or larger than the minimum shielding dimension, the plate thickness of the joint portion can be easily calculated by geometric calculation. Moreover, since the main body of the precast concrete panel is set to a size that is equal to or greater than the minimum shielding size and smaller than the plate thickness of the joint, the amount of concrete in the entire precast concrete panel can be reduced, and the manufacturing cost can be suppressed. Can be done.

FIG. 1 is a rear view showing a radiation shielding wall according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of the radiation shielding wall shown in FIG. FIG. 3 is a perspective view showing a precast concrete panel constituting the radiation shielding wall shown in FIG. FIG. 4 is an enlarged cross-sectional view of a main part showing a main part of the radiation shielding wall shown in FIG.

A preferred embodiment of the radiation shielding wall according to the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the radiation shielding wall 1 is configured by arranging the end faces of a plurality of precast concrete panels (hereinafter referred to as PCa panels) 2 so as to abut each other.

The PCa panel 2 is a precast concrete product produced in a factory using concrete, and is configured to have a rectangular outer shape. As shown in FIG. 3, the PCa panel 2 has a main body portion 11 and joint portions 12a and 12b. The main body portion 11 is formed in a flat plate shape having a constant plate thickness w1. The plate thickness w1 of the main body 11 is set to the minimum shielding dimension S that satisfies the required shielding performance of radiation by the concrete that is the raw material of the PCa panel 2. The plate thickness w1 does not necessarily have to match the minimum shielding dimension S, and if the value is smaller than the plate thickness w2 of the joint portions 12a and 12b described later, even if the value exceeds the minimum shielding dimension S. good.

The joint portions 12a and 12b are thick plate portions provided at both ends of the main body portion 11, and each is formed so as to protrude from one surface 22 of the main body portion 11. The joint portions 12a and 12b are formed so that the surface 31 on one side thereof exists on the same plane as the other surface 23 of the main body portion 11. The joint portion 12a provided at one end of the main body 11 has a first end surface 13, a stepped surface 14, and a second end surface 15. The first end surface 13 is a plane formed so as to be orthogonal to the extending direction of the main body portion 11 from the surface 31 on one side of the joint portion 12a toward the surface 32 on the other side. The stepped surface 14 is a plane extending upward from one end in the extending direction of the first end surface 13 so as to be orthogonal to the first end surface 13. The second end surface 15 is a plane extending parallel to the first end surface 13 from one end of the stepped surface 14 in the extending direction toward the surface 32 side of the joint portion 12a.

The joint portion 12b provided at the other end portion has a first end surface 16, a stepped surface 17, and a second end surface 18. The first end surface 16 is a plane formed so as to be orthogonal to the extending direction of the main body portion 11 from the surface 31 on one side of the joint portion 12b toward the surface 32 on the other side. The stepped surface 17 is a plane extending upward in FIG. 3 from one end in the extending direction of the first end surface 16 in a direction orthogonal to the first end surface 16. The second end surface 18 is a plane extending parallel to the first end surface 16 from one end of the stepped surface 17 in the extending direction toward the surface 32 side.

The joint portions 12a and 12b have the same plate thickness w2, and when the joint portions 12a and the joint portions 12b of the two PCa panels 2 face each other, the first end surface 13 and the first end surface 16 become The stepped surface 14 and the stepped surface 17 face each other, and the second end surface 15 and the second end surface 18 face each other. The dimensions of each end face are set so that they can be arranged with equal spacing from each other.

In the PCa panel 2 configured as described above, one joint portion 12a and the other joint portion 12b face each other, and the protruding portions 21a, 21b of the joint portions 12a, 12b face the radiation source B. The radiation shielding wall 1 is formed by filling the joint material 3 between the joint portions 12a and 12b.

Here, the plate thickness w2 of the joint portions 12a and 12b is in the state where the radiation shielding wall 1 is configured, that is, in the state where the joint portions 12a and 12b of the adjacent panels are opposed to each other, in the parallel direction of the PCa panels 2. A virtual reference plane H is set along the reference plane and orthogonal to the surfaces 22 and 23 of the main body 11, and the concrete portion of the PCa panel 2 is formed on the reference plane H for all straight lines from the surface 32 to the surface 31. The total length of passage is configured to be equal to or greater than the minimum shielding dimension S.

For example, in FIG. 4, the straight line X1 that passes through the joint material 3 exposed inside and is orthogonal to the radiation shielding wall 1 has a total length that passes through the concrete portion of the PCa panel 2 on the reference plane H. .. Therefore, in the PCa panel 2, the plate thickness a from the surface 31 to the stepped surface 17 at the joint portion 12b is set so that S = <a. Similarly, the straight line X2 that passes through the joint material 3 exposed to the outside and is orthogonal to the radiation shielding wall 1 has a total length b that passes through the concrete portion on the reference plane H. Therefore, in the PCa panel 2, the plate thickness b from the stepped surface 14 to the surface 32 at the joint portion 12a is set so that S = <b. Further, in the straight line X3 that is oblique to the radiation shielding wall 1 so as to alternately pass through the concrete portion and the joint material 3, the total length g of the length passing through the concrete portion on the reference plane H is c + d + e + f. Therefore, in the PCa panel 2, the plate thicknesses w2 of the joint portions 12a and 12b are set so that the length g satisfies S = <g (= c + d + e + f). Hereinafter, the plate thickness w2 of the joint portions 12a and 12b can be determined by geometrically calculating in the same manner. In this way, if the total length of the straight lines X1, X2, and X3 on the reference plane H passing through the concrete portion of the PCa panel 2 is set to the minimum shielding dimension S or more, the radiation shielding performance of the joint material 3 can be obtained. Regardless, the radiation shielding performance as the radiation shielding wall 1 can be satisfied.

On the outer surface (surfaces 23 and 31) of the PCa panel 2, the first fastener 41 is embedded in two places on the lower side in FIG. 4 at predetermined intervals in the extending direction of the PCa panel 2. ing. The first fastener 41 is formed so that the plate-shaped portion 41a protrudes from the outer surface of the PCa panel 2. The plate-shaped portion 41a is arranged so that its plate surface is perpendicular to the outer surface of the PCa panel 2 and parallel to the extending direction of the PCa panel 2.

In FIG. 4, the second fastener 42 is embedded in the PCa panel 2 at two places on the upper side at a predetermined interval in the extending direction of the PCa panel 2. The second fastener 42 is a metal fitting that forms a hole into which a bolt is fitted.

The PCa panel 2 formed in this way is arranged so that the first fastener 41 is placed on the steel frame 52 arranged on the girder 51. A pin 53 protrudes from the upper part of the steel frame 52, and the pin 53 is inserted into a hole formed in the plate-shaped portion 41a of the first fastener 41. Further, the upper part of the PCa panel 2 connects the second fastener 42 and the girder on the upper floor via an angle. The steel frame 52 is arranged at a position (inside) off the center line L along the length direction of the girder 51, but the PCa panel 2 has a center of gravity of the main body 11 by being recessed from the girder 51. Is formed so as to be closer to the girder 51, so that the twist of the girder 51 can be reduced.

In the present embodiment, a virtual reference plane H is set along the parallel direction of the PCa panels 2 and orthogonal to the surfaces 22 and 23 of the main body 11, and all the planes from the surface 32 to the surface 31 are set. The dimensions of the joint portions 12a and 12b in the thickness direction are determined so that the total length of passage through the PCa panel 2 with respect to the straight line is equal to or greater than the minimum shielding dimension S. Therefore, the radiation shielding performance of the joint portions 12a and 12b can be satisfied without obtaining the radiation shielding rate of the joint material 3 by experiments or advanced calculations, and the manufacturing cost can be suppressed. Further, since the plate thickness w1 of the main body portion 11 of the PCa panel 2 is formed so as to be equal to or larger than the minimum shielding dimension S by concrete and smaller than the plate thickness w2 of the joint portions 12a and 12b, the entire PCa panel 2 is formed. The amount of concrete required is small, and the manufacturing cost can be reduced.

Although a panel having a rectangular outer shape is illustrated, it is possible to form a joint portion in the same manner even if it is a parallelogram or a trapezoid.

1 Radiation shielding wall 2 Precast concrete panel 3 Joint material 11 Main body 12a, 12b Joint 13 First end surface 14 Step surface 15 Second end surface 16 First end surface 17 Step surface 18 Second end surface 22, 23 Surface 31 , 32 Surface

Claims (2)

It is a radiation shielding wall composed of a plurality of rectangular plate-shaped precast concrete panels with their end faces facing each other and arranged side by side.
The precast concrete panel is formed between a main body having a constant plate thickness and both ends of the main body having a plate thickness larger than that of the main body, and is a joint material between adjacent precast concrete panels. Has, and has a joint
The thickness of the joint portion is the thickness of the joint portion with respect to all straight lines from the inner surface to the outer surface on the reference plane orthogonal to the surface of the main body portion and along the parallel direction of the precast concrete panels. the sum of the passage length passing through a portion of the precast concrete panels, the body portion of the thickness or become so constructed have radiation shield wall, characterized in Rukoto. The precast concrete panel, a radiation shield wall according to claim 1, wherein the joint portion from a surface facing inward with respect to the body portion and wherein the protruding.

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