JP7833342B2 - Structural slits - Google Patents

Description

This invention relates to structural slits installed in the walls of buildings and the like.

Conventionally, structural slits are sometimes provided to prevent stress concentration in structural members caused by the installation of seismic walls (see, for example, Patent Document 1). Rooms used for treatment with powerful radiation (such as linear accelerator rooms) need to be surrounded on all sides by thick concrete walls (for example, walls with a thickness of t = 1400 mm) for radiation shielding, but stress concentration naturally occurs in these walls as well.

Japanese Unexamined Patent Publication No. 167853/1983

To mitigate the stress concentration mentioned above, measures such as installing seismic walls on the outer perimeter of the linac room on the same floor, increasing the load-bearing capacity of the members surrounding the linac room, or isolating the linac room from the surrounding frame are sometimes implemented. However, this has the problem of increasing construction time compared to pure steel structures.

The problem of stress concentration can be solved by incorporating structural slits into the walls of the linac chamber. However, conventional slit materials, such as polyethylene, have low radiation shielding capabilities, making them unsuitable for use. Therefore, structural slits with radiation shielding capabilities were needed.

This invention has been made in view of the above, and aims to provide a structural slit with radiation shielding functionality.

To solve the above-mentioned problems and achieve the objective, the structural slit according to the present invention is a structural slit consisting of a slit provided at the end of a wall, comprising a plate-shaped radiation shielding material that is movable within the slit and exhibits a radiation shielding function, characterized in that the arrangement angle of the radiation shielding material within the slit changes in accordance with the change in the width of the slit.

Furthermore, another structural slit according to the present invention is characterized in that, in the above-described invention, it comprises a shaft portion that rotatably fixes the radiation shielding material to the inside of the slit, and a torsion spring that biases the radiation shielding material in a direction that closes the slit.

Furthermore, another structural slit according to the present invention is characterized in that, in the above-described invention, the slit is a vertical slit extending in the vertical direction.

Furthermore, another structural slit according to the present invention is a structural slit consisting of a horizontal slit provided in the upper or lower part of a wall, comprising a plate-shaped radiation shielding material that is movable within the horizontal slit and exhibits a radiation shielding function, characterized in that the radiation shielding material is composed of a plurality of iron plates stacked and arranged so as to be slidable from one another within the horizontal slit.

The structural slit according to the present invention is a structural slit provided at the end of a wall, comprising a plate-shaped radiation shielding material that is movable within the slit and exhibits a radiation shielding function. The radiation shielding material is configured such that its arrangement angle within the slit changes in accordance with changes in the width of the slit. Therefore, the present invention provides a structural slit with a radiation shielding function.

Furthermore, according to another structural slit of the present invention, since it has a shaft portion that rotatably fixes the radiation shielding material inside the slit and a torsion spring that biases the radiation shielding material in a direction that closes the slit, it has the effect of being able to exert its radiation shielding function even when the radiation shielding material rotates around the shaft portion in accordance with changes in the width of the slit.

Furthermore, according to another structural slit of the present invention, since the slit is a vertical slit extending in the vertical direction, it has the effect of providing a vertical slit with radiation shielding functionality.

Furthermore, according to another structural slit of the present invention, a structural slit consisting of a horizontal slit provided in the upper or lower part of a wall is provided with a plate-shaped radiation shielding material that is movable inside the horizontal slit and exhibits a radiation shielding function. Since the radiation shielding material is composed of multiple iron plates stacked and arranged to slide relative to each other inside the horizontal slit, it is possible to provide a horizontal structural slit with a radiation shielding function.

Figure 1 is a front view showing an embodiment of the structural slit according to the present invention. Figure 2 is a perspective view of the main part of section A in Figure 1. Figure 3 is a plan view of section A in Figure 1, where (1) is under normal conditions and (2) is during an earthquake. Figure 4(1) is a cross-sectional view of section B in Figure 1, and (2) is a cross-sectional perspective view.

The following describes in detail an embodiment of the structural slit according to the present invention, based on the drawings. However, this embodiment does not limit the invention.

As shown in Figure 1, a wall 16 of a radiation utilization facility (e.g., a linac room) is provided in the area enclosed by the column 10 and the upper and lower beams 12 and 14. The column 10, upper beam 12, lower beam 14, and wall 16 are all made of reinforced concrete. The wall 16 is a seismic-resistant wall, with only its upper edge directly fixed to the upper beam 12. The sides and bottom of the wall 16 are structurally insulated from the column 10 and lower beam 14 by slits 18 and 20, respectively. A structural slit 100 consisting of a vertically extending vertical slit 18 is provided between the wall 16 and the column 10, and a structural slit 200 consisting of a horizontally extending horizontal slit 20 is provided between the wall 16 and the lower beam 14. The structural slit 100 between the wall 16 and the column 10 corresponds to the structural slit according to the embodiment of the present invention.

As shown in Figures 2 and 3(1), the structural slit 100 is movably installed inside the vertical slit 18 and comprises multiple rectangular steel plates 22 (radiation shielding material) that provide radiation shielding functionality. The steel plates 22 consist of a steel plate 24 installed along the side end surface 10A of the column 10, a steel plate 26 installed along the side end surface 16A of the wall 16, a steel plate 28 installed along the front and rear opening surfaces 18A of the vertical slit 18, and a steel plate 30 installed inside the area surrounded by these plates.

The iron plate 30 is configured such that its positioning angle θ within the vertical slit 18 changes in accordance with the change in the width W of the vertical slit 18. Specifically, the iron plate 30 is positioned with its longitudinal direction vertical, and when viewed from above, its short side is positioned diagonally to the wall thickness direction D. The dimensions of the iron plate 30 are such that it can provide radiation shielding in the vertical slit 18. Preferably, its longitudinal length is approximately the same as the vertical height of the vertical slit 18, and its short side length is longer than the width W of the vertical slit 18. Multiple iron plates 30 are arranged parallel to each other with spacing in the wall thickness direction D (four in the example shown in the figure). The more iron plates 30 there are, the better the radiation shielding performance can be.

A steel rod 32 (shaft portion) extending vertically is welded to the side edge of one side of the steel plate 30. The upper end of the steel rod 32 is rotatably inserted into a recess on the lower surface of the upper beam 12, and the lower end of the steel rod 32 is rotatably inserted into a recess provided in the steel plate 36 of the horizontal slit 20. Therefore, the steel plate 30 is fixed so as to be rotatable around the steel rod 32 inside the vertical slit 18. It is preferable that the recess into which the upper and lower ends of the steel rod 32 are inserted be formed as a long groove extending in the wall thickness direction D. In this way, the steel rod 32 is movable in the wall thickness direction D. Furthermore, on the other side of the steel plate 30, multiple torsion springs 34 are arranged vertically at intervals (three in the example of Figure 2) on the side edge corresponding to the position of the steel rod 32. The torsion springs 34 have the effect of biasing the steel plate 30 in a direction that closes the opening surface 18A of the vertical slit 18. Furthermore, the present invention is not limited to torsion springs; other biasing means may be used. In this way, even when the steel plate 30 rotates around the steel rod 32 in response to changes in the width W of the vertical slit 18, the radiation shielding function can still be achieved.

In this embodiment, four steel plates 30A, with the steel rod 32 positioned closer to the column 10, and four steel plates 30B, with the steel rod 32 positioned closer to the wall 16, are arranged alternately in the wall thickness direction D. For the steel plate 30A with the steel rod 32 closer to the column 10, one end of the torsion spring 34 is fixed to the steel plate 30A, and the other end abuts against the steel plate 24 on the column 10 side. For the steel plate 30B with the steel rod 32 closer to the wall 16, one end of the torsion spring 34 is fixed to the steel plate 30B, and the other end abuts against the steel plate 26 on the wall 16 side.

The steel plates 28 provided on the front and rear opening surfaces 18A of the vertical slit 18 are arranged in a manner that connects the column surface and the wall surface almost flush. These steel plates 28 are positioned to straddle the notches 10B formed at the corners of the columns 10 on either side of the vertical slit 18 and the notches 16B formed at the corners of the wall 16, and are configured to slide horizontally (left-right) between these notches in accordance with changes in the width W of the vertical slit 18.

As shown in Figure 4, the structural slit 200 consists of multiple (two or more) rectangular steel plates 36 stacked vertically within the horizontal slit 20, and fixing members 38 that pivotably secure these steel plates 36 to the lower surface of the wall 16 and the upper surface of the lower beam 14. The fixing members 38 are composed of cylindrical foamed resin material 38A and anchor bars 38B, and are arranged in multiples at intervals in the longitudinal and transverse directions of the lower beam 14. The foamed resin material 38A is embedded in a recess 16C provided in the lower surface of the wall 16. The anchor bars 38B penetrate holes 36A provided in the steel plates 36, connecting the foamed resin material 38A and the lower beam 14 vertically. With this configuration, the multiple steel plates 36 stacked within the horizontal slit 20 are slidable relative to each other. By sliding these steel plates 36 between the lower surface of the wall 16 and the upper surface of the lower beam 14, the horizontal slit can be made to function.

The operation and function of the above configuration will be explained.
As shown in Figure 3(2), when the columns 10 and walls 16 deform due to inter-story deformation during an earthquake, the width W of the vertical slit 18 changes. As a result of this change, the steel plate 24 on the column 10 side and the steel plate 26 on the wall 16 side move closer together as shown in Figure 3(2) from (b) to (a), causing the internal steel plate 30 to rotate around the steel rod 32 via the torsion spring 34. This changes the arrangement angle θ of the steel plates 30 inside the vertical slit 18. Note that even if a gap occurs between the steel plates 30, a gap of about 1 mm will not affect the radiation shielding capacity. In the example of Figure 3(2)(a), the steel rod 32 and torsion spring 34 are omitted from the illustration for explanatory purposes.

According to this embodiment, by using steel plates as the material for the structural slits, radiation shielding capability can be ensured while separating the wall 16 from the columns and beams. Furthermore, by laying rotatable steel plates 30 between the columns 10 and the wall 16, the structure can follow inter-story deformation. In this way, it can function as a vertical slit with radiation shielding capabilities.

Furthermore, design rationalization becomes possible through stress concentration mitigation. By eliminating the conventional perimeter seismic walls used as a stress concentration countermeasure and replacing reinforced concrete (RC) columns and beams with steel (S) structures, construction time can be shortened.

Furthermore, in the above embodiment, the example described was one in which only the upper edge of the wall 16 is directly fixed to the upper beam 12, thereby providing a horizontal slit 20 between the wall 16 and the lower beam 14. However, the present invention is not limited to this, and may also be applied to a configuration in which only the lower edge of the wall 16 is directly fixed to the lower beam 14, thereby providing a horizontal slit between the wall 16 and the upper beam 12. The same effects and advantages as described above can be achieved in this configuration as well.

As described above, the structural slit according to the present invention is a structural slit consisting of a slit provided at the end of a wall, comprising a plate-shaped radiation shielding material that is movable inside the slit and exhibits a radiation shielding function, wherein the arrangement angle of the radiation shielding material inside the slit changes in accordance with the change in the width of the slit, thus providing a structural slit with a radiation shielding function.

Furthermore, according to another structural slit of the present invention, since it has a shaft portion that rotatably fixes the radiation shielding material inside the slit and a torsion spring that biases the radiation shielding material in a direction that closes the slit, the radiation shielding function can be maintained even when the radiation shielding material rotates around the shaft portion in accordance with changes in the width of the slit.

Furthermore, according to another structural slit of the present invention, since the slit is a vertical slit extending in the vertical direction, it is possible to provide a vertical slit with radiation shielding functionality.

Furthermore, according to another structural slit of the present invention, a structural slit consisting of a horizontal slit provided in the upper or lower part of a wall is provided, comprising a plate-shaped radiation shielding material that is movable within the horizontal slit and exhibits a radiation shielding function. Since the radiation shielding material is composed of multiple iron plates stacked and arranged to slide relative to each other within the horizontal slit, a horizontal structural slit with a radiation shielding function can be provided.

As described above, the structural slit according to the present invention is useful for building walls and the like, and is particularly suitable for structural slits installed in the walls of radiation utilization facilities.

10 Columns 12 Upper beams 14 Lower beams 16 Walls 18 Vertical slits 20 Horizontal slits 22, 24, 26, 28, 30, 36 Steel plates (radiation shielding material)
32 Steel rod (shaft)
34 Torsion spring 38 Fixing member 38A Foamed resin material 38B Anchor reinforcement 100 Structural slit D Wall thickness direction W Width θ Angle

Claims (3)

A structural slit consisting of a slit provided at the end of a wall,
The slit is provided with a plate-shaped radiation shielding material that is movable and provides radiation shielding functionality,
The radiation shielding material is configured such that its positioning angle within the slit changes in accordance with the change in the width of the slit.
A structural slit characterized by having a shaft portion for fixing the radiation shielding material rotatably inside the slit, and a torsion spring for biasing the radiation shielding material in a direction that closes the slit . The structural slit according to claim 1 , characterized in that the slit is a vertical slit extending in the vertical direction. A structural slit consisting of a horizontal slit extending horizontally, provided between a wall and a lower beam, or between a wall and an upper beam ,
The horizontal slit is movably provided and includes a plate-shaped radiation shielding material that exhibits a radiation shielding function,
The structural slit is characterized in that the radiation shielding material is composed of a plurality of iron plates stacked vertically and arranged so as to be slidable from one another within the horizontal slit.