Steel frame staircase with fireproof coating means, staircase room structure

Abstract

Since the steel staircase with fireproof coating means can be manufactured in a factory and transported to the site without damage, the work of providing fireproof coating at the site can be reduced. [Solution] An upper landing 8 and a lower landing 11 are arranged on a staircase part 6 including a step 4, and are sandwiched between steel stringers 16 to form a steel frame staircase 1. A fireproof covering frame 24 formed along the underside of the steel frame staircase 1 is filled with fireproof rock wool 27, and the fireproof covering frame 24 is fixed to the underside of the steel frame staircase 1. A fireproof ceiling board 23 is formed along the underside of the fireproof covering frame 24, and the upper surface of the fireproof ceiling board 23 is fixed to the underside of the fireproof covering frame 24. Next, a flame-retardant gasket 30 is arranged on the outer periphery of the steel frame staircase 1 (especially the outer surface 17a of the stringers 16) above the fireproof covering frame 24 to form a steel frame staircase 32 with a fireproof covering means). If the steel frame staircase 32 with a fireproof covering means is installed in a staircase 40, the flame-retardant gasket 30 will be in close contact with the inner surface 43a of the staircase wall 43, preventing any gaps from being generated.

Description

[Technical field]

[0001] The present invention relates to a steel staircase with fire-resistant covering means and a staircase structure using the steel staircase. [Background technology]

[0002] In buildings, especially high-rise buildings, stairs installed in stairwells surrounded by fire-resistant walls are used as evacuation stairs in the event of a fire. The Building Standards Act stipulates that the walls, columns, beams, and floors of stairwells must be fire-resistant for one hour as fire compartments, but there are no specific regulations for the stairs themselves. (Article 112 of the Building Standards Act Enforcement Order: Fire Compartments). Generally, there are also reinforced concrete stairs that are formed at the construction site by assembling forms and rebars and pouring concrete, but more often, steel frame stairs, which are formed by sandwiching the steps between plate-shaped steel stringers, are manufactured in a factory and attached to the structure (beams, etc.) at the construction site. This is because steel frame stairs are more effective because they require less work on site, are highly accurate, and are lightweight. However, compared to reinforced concrete stairs, the fire resistance of steel frame stairs is not sufficient. For this reason, when steel staircases are used for fire compartments, the general method is to attach ALC boards (lightweight aerated concrete building materials) or fireproof boards (gypsum boards) to the back side of the steel staircase as if it were a wall or floor, and make it suitable for the compartment. However, with this method, after the steel staircase is attached to the structure, the work of attaching these materials to the back side of the steel staircase is required on site, which increases the amount of on-site work, and since the work is done while facing upwards, it is very difficult to work, and there are safety issues such as the materials falling during installation. In addition, when the steel staircase installed in the staircase room is used as a work staircase, the stairs must be closed while the materials are being installed, and the work route to the upper and lower floors is blocked, which has a negative impact on ensuring safe passage and work efficiency. There have also been attempts to fix ALC panels or fireproof boards to steel staircases in advance at a factory and transport them from the factory to the construction site in that state, but this was not practical because the steel staircase would twist and break during the production of the steel staircase at the factory, during transportation to the site, and during installation and lifting at the site. This was particularly problematic when installing two series of stairs with opposite directions, called X-stairs, in parallel inside a staircase room to double the amount of people moving around (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-93742 [Patent Document 2] Japanese Patent Application Publication No. 4-309650 [Patent Document 3] JP 2023-97570 A Summary of the Invention [Problem to be solved by the invention]

[0004] There has been a proposal to make the landing and staircase (treads) fireproof by pouring concrete on-site (Patent Document 2), but this has not been possible to achieve a fireproof structure for the entire steel staircase. In particular, it was difficult to fireproof the underside of the steel stringers. Also, in wooden buildings, there have been many proposals to fireproof the underside of wooden stairs installed in staircase rooms by forming a fireproof covering means on-site (for example, Patent Document 3), but there has been no proposal to fireproof stairs in advance at a factory. [Means for solving the problem]

[0005] The present invention solves the above-mentioned problems by arranging the fire-resistant covering means comprising a fire-resistant ceiling plate that covers the underside of the steel staircase and protruding the outer surface of the fire-resistant covering means outward from the outer surface of the stringers in a plan view to form a steel staircase with fire-resistant covering means, or by using this steel staircase with fire-resistant covering means and applying an elastic flame-retardant gasket to form a staircase structure.

[0006] That is, among the inventions regarding the steel staircase with fire-resistant coating means, the invention described in claim 1 is a steel staircase consisting of a "step-like step" or a "step-like step and landing" sandwiched between the inner surface of a steel stringer. In advance The steel staircase with fire-resistant covering means is formed and characterized in that it is configured as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer.

[0007] The invention described in claim 2 is as follows: This steel staircase with fire-resistant covering means is constructed as follows, by forming a fire-resistant covering means on a steel staircase that is constructed by sandwiching "step-like treads" or "step-like treads and a landing portion" with the inside surface of a steel stringer. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer. (3) The fire-resistant covering means is configured by fixing a fire-resistant ceiling panel shaped to follow the outer surface of the fire-resistant covering material frame in a planar view to the underside of a fire-resistant covering material frame that covers the underside of the steel staircase and follows the undersides of both stringers in a planar view, and filling the fire-resistant covering material frame with fire-resistant rock wool. (4) The fireproof covering material frame of the fireproof covering means is fixed to the underside of the stringer. Ta.

[0008] In addition, Claim 3 The invention described in A steel staircase with fire-resistant covering means is formed on a steel staircase that is constructed by sandwiching a "step-like tread" or a "step-like tread and a landing portion" with the inside surface of a steel stringer, and is characterized in that the steel staircase with fire-resistant covering means is formed on the steel staircase and is constructed as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer. (3) A resilient, fire-retardant gasket was secured to the upper side of the fire-resistant covering means and to the outer surface of each stringer. (4) The outer peripheral surface of the flame-retardant gasket protrudes outward from the outer surface of the fire-resistant covering means in a plan view. Ta.

[0009] In addition, among the inventions related to staircase structures, Claim 4 The invention described in is a staircase structure in which a steel frame staircase with fire-resistant covering means is erected between the staircase floor located above on one side in the staircase walking direction and the staircase floor located below on the other side, in a staircase space spanning upper and lower floors that is partitioned by staircase walls of a specified fire-resistant construction and has a staircase floor also of a specified fire-resistant construction, and the staircase structure is configured as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means is Steel staircase The fire-resistant covering means protrudes outward in a plan view from the outer surface of the stringer, and the outer surface of the fire-resistant covering means is abutted against the wall surface of the staircase wall or is disposed in a position adjacent to the wall surface of the staircase wall. (3) An elastic flame-retardant gasket is attached to the upper side of the fire-resistant covering means between the outer surfaces of the two stringers and the wall surface of the staircase wall, and the flame-retardant gasket is disposed on the outer surfaces of the two stringers over the entire length of the staircase in the direction of walking.

[0010] moreover, Claim 5 The invention described in Claim 4 The present invention provides a staircase structure characterized by the following configuration. (1) A central staircase wall is placed approximately in the center of the staircase wall in the direction of stairway walking, and the central staircase wall is used as a dividing line to divide the building vertically into two sections, a first section and a second section. A steel frame staircase with a first fire-resistant covering means is erected in the first section, and a steel frame staircase with a second fire-resistant covering means is erected in the second section. The first steel frame staircase with fire-resistant covering means and the second steel frame staircase with fire-resistant covering means are arranged in a cross pattern on the same floor. (2) In the steel staircase with the first fire-resistant covering means and the steel staircase with the second fire-resistant covering means, the outer surface of the fire-resistant covering means protrudes outward in a plan view from the outer surface of each of the stringers, and the outer surface of each of the fire-resistant covering means abuts against the wall surface of the staircase wall and the wall surface of the central staircase wall, or is positioned in the vicinity of the wall surface of the staircase wall. (3) In the steel staircase with the first fire-resistant covering means and the steel staircase with the second fire-resistant covering means, in the first section and the second section, elastic flame-retardant gaskets are in close contact with the upper surface of each fire-resistant covering means, between the outer surface of the stringers and the wall surface of the central staircase wall, and between the outer surface of the stringers and the wall surface of the staircase wall, and the flame-retardant gaskets are disposed on the outer surface of each stringer over the entire length of the staircase in the direction of walking.

[0011] When the steel staircase with fire-resistant coating is applied to a staircase, a small gap often remains between the wall of the staircase and the outer surface of the stringer of the steel staircase. From the viewpoint of fire resistance, there is a risk that flames and smoke may move up and down through the gap in the event of a fire, sandwiching the steel staircase, and it is necessary to take measures to prevent this. From this viewpoint, the invention related to the steel staircase with fire-resistant coating addresses the problem with the following measures. In the steel staircase with fire-resistant covering means described in claim 1, the outer surface of the fire-resistant covering means (any of the members constituting the fire-resistant covering means, i.e., the fire-resistant ceiling board and / or the fire-resistant covering material) is configured to protrude outward in a plan view (horizontally) from the outer surface of the stringers. This allows the outer surface of the fire-resistant covering means to abut against the wall surface of the staircase chamber, thereby closing the "gap". In addition, in the invention of a steel staircase with fire-resistant covering means described in claim 2, among the components constituting the fire-resistant covering means, the outer surfaces of the fire-resistant covering material frame and / or the fire-resistant ceiling board and / or the fire-resistant covering material can be abutted against the wall surface of the staircase wall, thereby similarly sealing the ``gap.'' Also, Claim 3In the invention of the steel staircase with fire-resistant covering means described above, the outer peripheral surface of the flame-retardant gasket protrudes outward from the outer surface of the fire-resistant covering means in a plan view (horizontal direction), so that the outer peripheral surface of the flame-retardant gasket can be abutted against the wall surface of the staircase wall at least on the stringer side of the steel staircase with fire-resistant covering means, and the "gap" can be more effectively closed. Even if the flame-retardant gasket is not provided on the surface of the steel staircase with fire-resistant covering means other than the stringer side, the outer peripheral surface of any of the members of the fire-resistant covering means can be abutted against the wall surface of the staircase wall, and the "gap" can be closed, as in claim 1. Ma Iron An elastic flame-retardant gasket is fixed around the entire circumference of the bone staircase in a plan view (approximately horizontal direction), and the outer peripheral surface of the flame-retardant gasket protrudes outward from the outer surface of the fire-resistant covering means. By doing so, The outer surface of the flame-retardant gasket can be abutted against the wall surface of the staircase hall around the entire circumference of the steel staircase with fire-resistant coating means, making it possible to more effectively seal the "gap."

[0012] In addition, the staircase floor in the above-mentioned case refers to a structural member that can support both the upper and lower ends of a normal steel frame staircase, and also includes steel beams that support the floor. Effect of the Invention

[0013] According to the invention of the steel staircase with fire-resistant covering means, the fire-resistant covering means can be fixed to the steel staircase in advance, so the steel staircase with fire-resistant covering means can be manufactured in a factory and transported to the site. This significantly reduces the work of applying fire-resistant covering after the steel staircase is installed in the staircase room at the site. In addition, since a fire-resistant ceiling plate is provided as the fire-resistant covering means, damage to the fire-resistant covering means can be reduced when the steel staircase with fire-resistant covering means is transported from the factory to the site. Furthermore, if the fire-resistant covering means is formed from a fire-resistant covering material frame, damage to the fire-resistant covering means and the fire-resistant covering work at the site can be further reduced. In addition, a fireproof ceiling plate that can cover the underside of the steel staircase is provided to form the fireproof covering means, and the outer surface of the fireproof covering means is configured to protrude outward from the outer surface of the stringers in a plan view, so that when the steel staircase with fireproof covering means is applied to a staircase, the outer surface of the fireproof covering means can be abutted against the wall surface of the staircase when the steel staircase is placed inside the staircase. This makes it possible to block or greatly reduce the flames and smoke of a fire on both sides of the steel staircase with fireproof covering means inside the staircase.

[0014] In the invention of the staircase structure, a steel staircase with fire-resistant covering means is erected in the staircase, and the fire-resistant covering means comprises a fire-resistant ceiling plate and a fire-resistant covering material capable of sealing the underside of the steel staircase, and the outer surface of the fire-resistant covering means protrudes outward from the outer surface of the stringers in a plan view, and a resilient flame-retardant gasket is attached between the outer surfaces of both stringers and the wall surface of the staircase wall, so that the gap between the wall surface of the staircase wall and the steel staircase with fire-resistant covering means can be made extremely small, and in the event of a fire, the movement of flames and smoke up and down across the steel staircase with fire-resistant covering means can be significantly reduced. Furthermore, a resilient flame-retardant gasket is fixed to the outer surface of the stringers and / or the upper surface of the fire-resistant covering means, and the outer surface of the resilient flame-retardant gasket protrudes outward from the outer periphery of the fire-resistant covering means, so that the movement of flames and smoke vertically across the steel staircase with fire-resistant covering means can also be prevented. [Brief description of the drawings]

[0015] [Figure 1] 1A is a front view of the steel staircase with fire-resistant covering means of the present invention, FIG. 1B is a bottom view of the steel staircase with fire-resistant covering means, and FIG. 1C is an AA cross-sectional view of a steel staircase with fire-resistant covering means installed in the staircase wall. [Diagram 2] 1(b), (b) is a plan view of the fire-resistant covering means used, and (c) is a CC cross-sectional view. [Diagram 3] FIG. 1 is an enlarged vertical cross-sectional view showing the relationship between the steel staircase with fire-resistant coating means of this invention and the staircase wall, where (a) shows the structure before the steel staircase with fire-resistant coating means is attached to the staircase wall, and (b) shows the structure after the steel staircase with fire-resistant coating means has been attached to the staircase wall. [Figure 4] 1 shows a horizontal cross-sectional view of the steel staircase and stairwell with fire-resistant covering means of the present invention applied to an X-shaped staircase. [Diagram 5] is a cross-sectional view taken along line D-D of Fig. 4, showing the central staircase wall in a transparent state. [Figure 6] 4 and 5. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the present invention will be described with reference to the drawings.

[0017] 1. Configuration of steel staircase 1

[0018] (1) The steel frame staircase 1 used in the embodiment of the present invention is the same as a normal steel frame staircase. The staircase section 6 is composed of a plate-shaped steel riser 3 formed with a predetermined stair width and a bottomed frame-shaped tread 4 (FIG. 2(a)). A plate-shaped steel upper landing 8 is connected to the upper end of the staircase section 6 with a predetermined number of steps, and a plate-shaped steel lower landing 11 is connected to the lower end of the staircase section 6 with a predetermined number of steps. The upper landing 8 and the lower landing 11 form the landing section 13. The staircase section 6 and the landing section 13 constructed as above are fixed to the stringers 16, 16 so that they are sandwiched between the inner surfaces 17, 17 of the steel stringers 16, 16 from the left and right. The stringers 16 are fixed to the staircase section 6 or the landing section 13 by any conventional method such as welding or bolts and nuts. The steel staircase 1 is constructed by filling the bottomed frame-shaped tread 4, the bottomed frame-shaped upper landing 8, and the lower landing 11 with mortar 21 (cement-based material). The mortar 21 (cement-based material) can also be filled at the construction site after the steel staircase 1 (steel staircase with fireproof coating means 32) is installed. Here, the other side of the stringer 16 from the inner surface 17 (the side where the staircase section 6 and the landing section 13 are arranged) is defined as the outer surface (staircase wall side) 17a. Here, the direction connecting both stringers 16, 16 is defined as the staircase width direction.

[0019] (2) A steel fireproof coating material frame 24 is formed so as to match the shape of the underside of the steel staircase 1, i.e., to be able to cover and cover both the undersides 18 (lower edges) of both stringers 16. The fireproof coating material frame 24 is arranged in a size and position that will cover the undersides (lower edges) 18 of the stringers 16 and the entire undersides of the staircase section 6 and the landing section 13. If the fireproof coating material frame 24 is shaped so as to be able to cover and cover both the undersides 18 (lower edges) of both stringers 16, then it will necessarily cover the undersides of the staircase section 6 and the landing section 13 as well. The fireproof covering material frame 24 is formed of two first members 25a, 25a shaped along the lower surface (lower edge) 18 of the stringer 16, and second members 25b, 25b (in the staircase width direction) connecting the first members 25a, 25a at both ends. If necessary, a third member 25c (in the staircase width direction) connecting the first members 25a, 25a can be added at any position and in any number for reinforcement at the middle of the first member 25a (FIG. 2(b)). In addition, the upper surface 23a of a fireproof ceiling board 23 having a predetermined fire resistance is placed on the lower surface of the fireproof covering material frame 24, and the upper surface 23a of the fireproof ceiling board 23 is fixed to the first member 25a and the second member 25b by welding. Therefore, the outer peripheral shape of the fireproof ceiling board 23 in the horizontal direction in a plan view is also the same as that of the first member 25a. Therefore, the outer periphery of the fireproof ceiling board 23 in the horizontal direction in a plan view is formed to be substantially the same as the outer periphery of the first member 25a and the second member 25b in the fixed state. The fireproof ceiling board 23 may be, for example, a steel plate material with a thickness of about 2 mm, but the material and thickness are arbitrary as long as it has the fire resistance required for the installation location. Here, the above-mentioned steel material is used because of its fire resistance, ease of processing, and ease of welding and fixing to the fireproof covering material frame 24. Here, the first member 25a and the second member 25b are made of lipped channel steel (channel steel with a C-shaped cross-sectional shape) with the groove facing toward the inside of the fire-resistant coating material frame 24 to be formed, and the third member 25c is made of angle iron (angle iron with an L-shaped cross-sectional shape). However, as long as the fire-resistant coating material frame 24 can be formed and the fire-resistant performance required at the installation location is satisfied, the material and thickness of the member can be freely selected, and the shape of the member can also be freely selected. It is preferable that the fire-resistant covering material frame 24 be made of steel, and the reason for using steel rather than aluminum or other materials is that it is easy to fix to the steel stringers 16, easy to process, and has fire and heat resistance. Also, the reason for using lipped channel iron and angle iron to achieve the above shape is that it is easy to assemble into a frame, and as will be described later, it is easy to install (stuff) the fire-resistant rock wool 27 after assembling it into the frame.

[0020] (3) There are several variations in the method of manufacturing the steel staircase 32 with fire-resistant covering means, but here, a manufacturing method (combined type) will be described in which the fire-resistant covering means 29 is first constructed and then fixed to the steel staircase 1 and combined. The first members 25a, 25a and the second members 25b, 25b form a fire-resistant covering material frame 24, and the fire-resistant ceiling board 23 is fixed to its underside. After that, fire-resistant rock wool (fire-resistant covering material) 27 is spread over the upper surface 23a of the fire-resistant ceiling board 23. As the fire-resistant rock wool 27, "Makibee (registered trademark)" (density 60 to 120 kg / m) manufactured by Nichias Corporation is used. 3 ) was arranged to a thickness of 65 mm, but this is not particularly limited. However, a fireproof covering material formed in advance in a roll shape is preferable because it is easy to spread. The first member 25a and the second member 25b are channel steels arranged with the grooves (openings) facing inward, so that the four peripheral edges of the fireproof rock wool 27 are accommodated in the first member 25a and the second member 25b, and the fireproof rock wool 27 is arranged in an orderly manner without coming apart. A welding pin or the like is driven from the upper surface side of the fireproof rock wool 27 to fix the fireproof rock wool 27 to the fireproof ceiling board 23 on the lower surface. Here, since the fireproof ceiling board 23 and the fireproof covering material frame 24 are fixed, the fireproof rock wool 27 spread and filled in the fireproof covering material frame 24 is held in the fireproof covering material frame 24. At this time, it is preferable to fix the fireproof rock wool 27 to the fireproof ceiling board 23 so as to maintain the original shape of the fireproof rock wool so that compression is not generated as much as possible at the pressed part. In this manner, the fireproof rock wool 27 is stuffed into the fireproof covering material frame 24 to which the fireproof ceiling board 23 is fixed, thereby forming a fireproof covering means 29 (FIGS. 2(b) and 2(c), FIG. 1(c)).

[0021] (4) The fireproof covering material is not limited to fireproof rock wool, and fireproof sheets, fireproof paints, etc. can be used as long as the material can exhibit a predetermined fireproof performance (not shown). For example, when using a fireproof sheet or fireproof paint, the fireproof sheet is attached to the upper surface 23a of the fireproof ceiling board 23 (and also the lower surface 23b as necessary), or the fireproof paint is applied thereto. Considering the fireproof and heatproof performance, it is preferable to apply the fireproof sheet or the fireproof paint to the upper surface 23a of the fireproof ceiling board 23. In this case, it is necessary that the fireproof sheet or the fireproof paint reaches the range where the entire lower surface (lower edge) 18 of the stringer 16 is in contact with the upper surface 23a of the fireproof ceiling board 23. In addition, when a fire-resistant sheet or fire-resistant paint is used, the fire-resistant covering material frame 24 can be omitted. In this case, the ends of the fire-resistant ceiling board 23 are bent upward and fixed to the outer surface of the stringer 16 by welding (not shown).

[0022] (5) The upper surface 29b of the prefabricated fire-resistant covering means 29 (i.e., the upper surface of the fire-resistant covering material frame 24, opposite the side on which the fire-resistant ceiling board 23 is placed) is fixed to the lower surfaces (lower edges) 18 of the stringers 16, 16.

[0023] (6) Additionally, a resilient, annular (hollow) fire-retardant gasket 30 is disposed on the outer surface 17a of the stringer 16, directly above the fire-resistant covering means 29. The fire-retardant gasket 30 is secured to the outer surface 17a of the stringer 16, or secured to the upper surface 29b of the fire-resistant covering means 29, or secured to both. When the steel staircase 32 with fire-resistant covering means is installed in the staircase 40, if the flame-retardant gasket 30 is positioned so as not to move relative to the stringers 16 or the fire-resistant covering means 29 while in contact with the inner surface 43a of the staircase wall 43, the outer surface 17a of the stringers 16, and the fire-resistant covering means 29 (FIGS. 2(b)(c)), the flame-retardant gasket 30 may not be fixed to the outer surface 17a of the stringers 16. Also, the flame-retardant gasket 30 is a gasket for construction, and may be made of any material or cross-sectional shape as long as it is made of an elastic fire-resistant material.

[0024] (7) In the above manner, a steel staircase 32 with fire-resistant covering means is constructed (Figs. 1(a)(b), 2(a)). Here, the outer surface 29a (side surface of the first member 25a) of the fire-resistant covering means 29 protrudes outward from the outer surface 17a of the stringer 16 in plan view (Figs. 1(a)(b)(c), 3(a)). Also, the outer peripheral surface (outermost end) 30a of the flame-retardant gasket 30 protrudes outward from the outer surface 29a of the fire-resistant covering means 29 in plan view (Figs. 1(a)(b), 3(a)).

[0025] (8) Although the above description has been given of an integrated type method for manufacturing the steel staircase 32 with fire-resistant covering means, there is also a manufacturing method (assembly type) in which the fire-resistant covering means 29 is constructed by fixing each component of the fire-resistant covering means 29 (each component of the fire-resistant covering material frame 24, the fire-resistant rock wool 27, the fire-resistant ceiling panel 23, etc.) in order to the underside of the steel staircase 1. In this method, the assembly procedure is arbitrary, but for example, the first member 25a, the second member 25b, and the third member 25c of the fireproof coating material frame 24 are fixed to the underside of the steel frame staircase 1, i.e., the underside (lower edge) 18 of the stringer 16, while the members 25a, 25b, and 25c are also fixed to each other to form the fireproof coating material frame 24. Then, fireproof rock wool 27 is packed into the fireproof coating material frame 24 fixed to the underside of the steel frame staircase 1 (stringer 16), and the rock wool 27 is held within the fireproof coating material frame 24. Next, the upper surface 23a of the fireproof ceiling board 23 is fixed to the members 25a, 25b, and 25c of the fireproof coating material frame 24.

[0026] (9) The differences between the two production methods result in the following advantages and disadvantages: In the combined type, the steel staircase 1 and the fire-resistant covering means 29 can be assembled separately and stored in advance, simplifying the assembly work. In addition, the assembly work of the fire-resistant covering means 29, particularly the fire-resistant covering material frame 24 (first member 25a, second member 25b, third member 25c), is easy, and the manufacturing time of the steel staircase 32 with fire-resistant covering means can be shortened overall. However, since the steel staircase 1 and the fire-resistant covering means 29 each have some manufacturing errors, depending on the occurrence of the manufacturing errors of the steel staircase 1 and the fire-resistant covering means 29, when the two are combined, the manufacturing errors of each may be magnified, and it may take a long time to correct them. In addition, in the assembly type, each component 25a, 25b, 25c of the fireproof coating material frame 24 cut to size is attached individually to the steel frame staircase 1, so even if there is some manufacturing error, the fireproof coating material frame 24 can be constructed while fine-tuning each time using the steel frame staircase 1 as a ruler. This makes it possible to increase the manufacturing accuracy of the finished steel frame staircase 32 with fireproof coating means. However, in the assembly type, the steel frame staircase 32 with fireproof coating means is manufactured while fine-tuning and attaching each component, so it takes more time to manufacture than the combined type. Both manufacturing methods have their pros and cons, but it is expected that a lot of work will be required to correct manufacturing errors, and under the current circumstances, the assembly type may be more appropriate.

[0027] 2. Staircase structure

[0028] (1) In a building having a stairwell 40, a steel staircase 32 with fire-resistant covering means is erected and fixed between a reference floor (stairwell floor) 46 and the floor below (stairwell floor) 48 (Fig. 1(a) and Fig. 2(a)). Note that the reference floor 46 here represents any general floor, and may be the ground floor, second floor, basement floor, etc. At this time, the outer surface 29a of the fire-resistant covering means 29 protrudes outward from the outer surface 17a of the stringer 16, so that the outer surface 29a of the fire-resistant covering means 29 abuts or is arranged very close to (sometimes leaving a very small gap) the inner surface 43a of the staircase wall 43. Also, at this time, the outer peripheral surface (outermost end) 30a of the flame-retardant gasket 30 protrudes outward from the outer surface 29a of the fire-resistant covering means 29, and since the flame-retardant gasket 30 employs an elastic material, the flame-retardant gasket 30 is sandwiched between the outer surface 17a of the stringer 17 and the wall inner surface 43a of the staircase wall 43, and is crushed and deformed, so that the gap between the outer surface 17a of the stringer 17 and the wall inner surface 43a of the staircase wall 43 can be sealed (FIGS. 1(c) and 3(b)). Therefore, even if a gap occurs between the outer surface of the fire-resistant coating means 29 (fire-resistant coating material frame 24) of a steel staircase 32 with fire-resistant coating means and the wall inner surface 43a of the staircase wall 43, the flame-retardant gasket 30 can absorb this gap and adhere to the wall inner surface 43a of the staircase wall 43.

[0029] (2) Similarly, on the side of the reference floor 46 and the lower floor 48, the tip 29d of the fire-resistant covering means 29 in the stair walking direction 38 protrudes outward from the tip (so-called baseboard part, outer surface) 1a of the steel staircase 1 of the steel staircase with fire-resistant covering means 32, so that the tip 29d of the fire-resistant covering means 29 is disposed in contact with or very close proximity to the reference floor 46 (or the lower floor 48) (in some cases, a very small gap may occur). In addition, at this time, the outer peripheral surface (outermost end) 30a of the flame-retardant gasket 30 protrudes outward from the outer surface 29a of the fire-resistant covering means 29, and since the flame-retardant gasket 30 adopts an elastic material, the flame-retardant gasket 30 is sandwiched between the reference floor 46 (or the lower floor 48) and is crushed and deformed, so that the gap between the tip 1a of the steel staircase 1 and the reference floor 46 (or the lower floor 48) can be sealed (not shown).

[0030] (3) In this way, within the staircase 40, the outer surface of the flame-retardant gasket is arranged around the entire circumference of the steel staircase 32 with fire-resistant coating means in such a manner that the outer surface of the flame-retardant gasket is in close contact with the wall surface of the staircase, or in close contact with the reference floor 46 or the floor 48 below it.

[0031] (4) In addition, when walking up the steel staircase with fire-resistant covering means 32, the underside of the steel staircase with fire-resistant covering means 32 located above is visible, but since the fire-resistant ceiling plate 23 is arranged on the underside of the steel staircase with fire-resistant covering means 32, i.e., on the underside 29c of the fire-resistant covering means 29, only the underside 23b of the fire-resistant ceiling plate 23 is exposed, and the fire-resistant rock wool 27 and the like are not visible, so the appearance is not impaired. Furthermore, since the underside 23b of the fire-resistant ceiling plate 23 is flat, this flat surface can be used to display various guide signs (for example, displaying the floor numbers of upper floors) according to the location of the steel staircase with fire-resistant covering means 32, or a display for display can be installed (not shown).

[0032] (5) Furthermore, according to experiments, with such a configuration, even when the area directly below the steel staircase 32 with fire-resistant covering means (directly below the fire-resistant ceiling board 23) is burned for one hour (60 minutes) with a gas burner or the like to rapidly raise the temperature and heat it to a final temperature of about 940°C, flames and smoke do not reach the top of the steel staircase 32 with fire-resistant covering means, and it has been confirmed that the steel staircase 32 with fire-resistant covering means can be fully used as a one-hour fire-resistant staircase. Therefore, by adjusting the thickness of the fire-resistant ceiling board 23, the configuration (especially the number of third members 25c) and thickness of each member 25a, 25b, 25c of the fire-resistant covering material frame 24, and the thickness and amount of the rock wool 27, it is possible to achieve not only 1-hour fire resistance but also 90-minute and 120-minute fire resistance.

[0033] 3. Configuration of stairwell for X-staircase

[0034] (1) As with the normal staircase 40, the staircase 40 for the X staircase is surrounded by staircase walls 43 (staircase walls 43A, 43B). Here, a central staircase wall 45 is provided within the staircase 40 between the staircase walls 43A, 43B and parallel to the staircase walls 43A, 43B (parallel to the stair walking direction 38). The staircase 40 is vertically divided into two series of sections, a first section A and a second section B, with the central staircase wall 45 as the boundary (Figure 4). In addition, the wall surface of the central staircase wall 45 facing the first section A side is referred to as the inner wall 45a, and the wall surface facing the second section B side is referred to as the inner wall 45b.

[0035] (2) On one side 46a of the reference floor (staircase floor) 46, a steel staircase 32A with a first fire-resistant covering means is erected in the first section A, which is directed upward toward the other side 49b of the upper floor (staircase floor) 49, and a steel staircase 32B with a second fire-resistant covering means is erected in the second section B, which is directed downward toward the other side 48b of the lower floor (staircase floor) 48 (Figs. 5 and 6). Similarly, on the other side 46b of the reference floor 46, a steel staircase 32A with a first fire-resistant covering means is erected in the first section A, which is directed downward toward the other side 48a of the lower floor 48, and a steel staircase 32B with a second fire-resistant covering means is erected in the second section B, which is directed upward toward the other side 49a of the upper floor 49 (Figs. 5 and 6). Therefore, in this embodiment, the first steel staircase with fire-resistant covering means 32A and the second steel staircase with fire-resistant covering means 32B are arranged in a cross shape on the same floor.

[0036] (3) In this case, in the first section A, the outer surface 29a of the fire-resistant covering means 29 of each steel staircase with first fire-resistant covering means 32A protrudes outward from the outer surface 17a of the stringer 16, so that in the step chamber wall 43A, the outer surface 25a of the fire-resistant covering material frame 24 of the fire-resistant covering means 29 of the steel staircase with first fire-resistant covering means 32A abuts or is close to the wall inner surface 43Aa of the step wall 43A, and the flame-retardant gasket 30 is in close contact with the wall inner surface 43Aa of the step wall 43A. Also, in the central staircase wall 45, the outer surface 25a of the fire-resistant covering material frame 24 of the fire-resistant covering means 29 of the steel staircase with first fire-resistant covering means 32A abuts or is close to the wall inner surface 45a of the step wall 45, and the flame-retardant gasket 30 is in close contact with the wall inner surface 45a of the step wall 45. Similarly, in the second section B, in each steel staircase with second fire-resistant covering means 32B, the outer surface 29a of the fire-resistant covering means 29 protrudes outward beyond the outer surface 17a of the stringer 16, so that in the step chamber wall 43B, the outer surface 25a of the fire-resistant covering material frame 24 of the fire-resistant covering means 29 of the steel staircase with second fire-resistant covering means 32B abuts or is close to the wall inner surface 43Ba of the step chamber wall 43B, and the flame-retardant gasket 30 is in close contact with the wall inner surface 43Ba of the step chamber wall 43B. Also, in the central staircase wall 45, the outer surface 25a of the fire-resistant covering material frame 24 of the fire-resistant covering means 29 of the steel staircase with second fire-resistant covering means 32B abuts or is close to the wall inner surface 45b of the step wall 45, and the flame-retardant gasket 30 is in close contact with the wall inner surface 45b of the step wall 45. Also, on the floor side such as the reference floor 46 (46a, 46b), similar to the above-mentioned normal staircase 40, the steel staircases 32A, 32B with fire-resistant coating means are adhered closely to the reference floor 46 (46a, 46b) etc. by the tip 25d of the fire-resistant coating material frame 24 and further by the flame-retardant gasket 30 (not shown).

[0037] (4) Therefore, even in the case of the X staircase, it is considered that the steel staircase 32 with fire-resistant covering means (steel staircase 32A with first fire-resistant covering means, steel staircase 32B with second fire-resistant covering means) can be sufficiently used as a one-hour fire-resistant staircase. Therefore, in the event of a fire, even if either the first compartment A or the second compartment B on either floor of the stairwell is filled with smoke, it is possible to safely evacuate using the stairs in the other compartment.

[0038] (5) Furthermore, in the case of the X staircase, the vertical distance between the tread 4 (stair section 6) of the steel staircase with first fire-resistant covering means 32A (steel staircase with second fire-resistant covering means 32B) located above and the underside (i.e., the underside 29c of the fire-resistant covering means 29 and the underside of the fire-resistant ceiling board 23) of the steel staircase with first fire-resistant covering means 32A (steel staircase with second fire-resistant covering means 32B) is shorter than in the case of a steel staircase arranged in a normal staircase (Figure 5), so that a person walking on the tread 4 (stair section 6) recognizes that the underside of the steel staircase with first fire-resistant covering means 32A (steel staircase with second fire-resistant covering means 32B) is close to overhead. In this case, too, in a normal X-shaped staircase, the underside of the staircase portion 6 of the steel staircase is visible up close, but in this embodiment, the underside of the steel staircase with first fire-resistant covering means 32A (steel staircase with second fire-resistant covering means 32B) located above is located to the underside of the fire-resistant ceiling board 23, so only the flat surface of the fire-resistant ceiling board 23 is visible, and the effect of the fire-resistant ceiling board 23 in not impairing the appearance is demonstrated more than in the case of the normal staircase 40.

[0039] 4. Other embodiments

[0040] (1) In the above embodiment, the fireproof covering material frame 24 is composed of the first member 25a, the second member 25b, and the third member 25c, but other configurations are also possible (not shown) as long as the frame shape can be formed. Furthermore, if the fireproof ceiling board 23 and the fireproof rock wool 27 can be fixed to the underside of the steel frame staircase 1 (the underside of the stringer 16), the fireproof covering material frame 24 can be omitted and the fireproof covering means 29 can be formed (not shown).

[0041] (2) In the above embodiment, if both ends 1a, 1a (so-called baseboard parts, outer surfaces, Fig. 1(a) and Fig. 2(a)) of the steel staircase 1 used for each steel staircase with fire-resistant covering means 32, 32A, 32B in the staircase walking direction 38 can be fixed closely to each floor (reference floor 46, lower floor 48, lower floor 49), the edge 29d (i.e., the outer surface of the second member 25b, Fig. 1(a)(b)) of the fire-resistant covering means 29 can be prevented from protruding from the end 1a in the staircase walking direction 38. Furthermore, in this case, the flame-retardant gasket 30 can be omitted on the surfaces of both ends 1a, 1a of the steel staircase 1 in the staircase walking direction 38 (so-called baseboard parts, i.e., the surfaces on the edge 29d side of the fire-resistant covering means 29 and the outer surface side of the second member 25b). That is, in this case, the tip 29a of the fire-resistant covering means 29 protrudes from the outer surface 17a of the stringer 1 only on the stringer 16 side, or the outer surface 30a of the flame-retardant gasket 30 protrudes from the outer surface of the stringer 1 only on the stringer 16 side.

[0042] (3) In the above embodiment, the flame-retardant gasket is annular (hollow) to ensure better elasticity, but it may be a solid rod (not shown). Similarly, the cross-sectional outer shell shape is assumed to be circular, but it may be other shapes such as a square (not shown). [Explanation of symbols]

[0043] 1 Steel Stairs 1a End of steel staircase (baseboard part, outside surface) 3. Riser board (riser part) 4 Step board (step board part) 6 Stairs section 8 Upper landing (landing part) 11 Lower landing (landing part) 13 Landing area 16 Stringer 17 Inside of stringer 17a Outer surface of stringer 18 Underside of stringer (lower edge) 21 Mortar (cement-based materials) 23 Fireproof ceiling board 23a Upper surface of fireproof ceiling plate 23b Underside of fireproof ceiling plate 24 Fireproof coating material frame 25a First member (fireproof coating material frame) 25b Second member (fireproof coating material frame) 25c Third member (fireproof coating material frame) 25d End of fireproof coating material frame 27 Fireproof rock wool (fireproof coating material) 29 Fireproof coating means 29a Outer surface of fire-resistant covering means 29b Upper surface of fire-resistant covering means 29c Underside of fire-resistant covering means 29d Tip of fire-resistant covering means 30 Flame retardant gasket 30a Outer surface of flame-retardant gasket 32 Steel staircase with fire-resistant covering 32A Steel staircase with first fire-resistant covering means 32B Steel staircase with first fire-resistant covering means 38 Staircase walking direction 40 Staircase 43, 43A, 43B Staircase wall 43a, 43Aa, 43Ba Inner surface of staircase walls 45 Central staircase wall 45a, 45b Central staircase wall 46 Standard floor (staircase floor) 46a One side of the reference floor 46b Other side of the reference floor 48 Lower floor (staircase floor) 48a One side of the lower floor 48b Other side of lower floor 49 Upper floor (staircase floor) 49a One side of the upper floor 49b Other side of upper floor A First Section B Second Section

Claims

1. A steel staircase with fire-resistant covering means is formed in advance on a steel staircase constructed by sandwiching "step-like treads" or "step-like treads and a landing portion" with the inside surface of a steel stringer, and is characterized in that the steel staircase with fire-resistant covering means is constructed as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer.

2. A steel staircase with fire-resistant covering means is formed on a steel staircase that is constructed by sandwiching a "step-like tread" or a "step-like tread and a landing portion" with the inside surface of a steel stringer, and is characterized in that the steel staircase with fire-resistant covering means is formed on the steel staircase and is constructed as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer. (3) The fire-resistant covering means is configured by fixing a fire-resistant ceiling panel having a shape that follows the outer surface of the fire-resistant covering material frame in a planar view to the underside of a fire-resistant covering material frame that covers the underside of the steel staircase and follows the undersides of both stringers in a planar view, and by filling the fire-resistant covering material frame with fire-resistant rock wool. (4) The fire-resistant coating material frame of the fire-resistant coating means was fixed to the underside of the stringer.

3. A steel staircase with fire-resistant covering means is formed on a steel staircase that is constructed by sandwiching a "step-like tread" or a "step-like tread and a landing portion" with the inside surface of a steel stringer, and is characterized in that the steel staircase with fire-resistant covering means is formed on the steel staircase and is constructed as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means facing the stringer protrudes outward in a plan view from the outer surface of the stringer. (3) A resilient, fire-retardant gasket is secured to the upper surface of the fire-resistant covering means and to the outer surface of each stringer. (4) The outer peripheral surface of the flame-retardant gasket protrudes outward in plan view from the outer surface of the fire-resistant covering means.

4. A staircase structure spanning upper and lower floors, partitioned by staircase walls of a specified fire-resistant construction and equipped with a staircase floor of a specified fire-resistant construction, in which a steel frame staircase with fire-resistant covering means is erected between the staircase floor located above on one side in the direction of stair walking and the staircase floor located below on the other side, and which is configured as follows. (1) The fire-resistant covering means is configured by disposing a fire-resistant covering material between the upper surface of a fire-resistant ceiling plate capable of covering the underside of the steel staircase and the underside of the steel staircase. (2) The outer surface of the fire-resistant covering means protrudes outward in a plan view from the outer surface of the stringer of the steel staircase, and the outer surface of the fire-resistant covering means abuts against the wall surface of the staircase wall or is positioned in the vicinity of the wall surface of the staircase wall. (3) An elastic flame-retardant gasket is attached to the upper side of the fire-resistant covering means between the outer surfaces of the two stringers and the wall surface of the staircase wall, and the flame-retardant gasket is disposed on the outer surfaces of the two stringers over the entire length of the staircase in the direction of walking.

5. 5. The staircase structure according to claim 4, characterized in that it is configured as follows: (1) A central staircase wall is placed approximately in the center of the staircase wall in the direction of stairway walking, and the central staircase wall is used as a dividing line to divide the building vertically into two sections, a first section and a second section. A steel frame staircase with a first fire-resistant covering means is erected in the first section, and a steel frame staircase with a second fire-resistant covering means is erected in the second section. The first steel frame staircase with fire-resistant covering means and the second steel frame staircase with fire-resistant covering means are arranged in a cross pattern on the same floor. (2) In the steel staircase with the first fire-resistant covering means and the steel staircase with the second fire-resistant covering means, the outer surface of the fire-resistant covering means protrudes outward in a plan view from the outer surface of each of the stringers, and the outer surface of each of the fire-resistant covering means abuts against the wall surface of the staircase wall and the wall surface of the central staircase wall, or is positioned in the vicinity of the wall surface of the staircase wall. (3) In the steel staircase with the first fire-resistant covering means and the steel staircase with the second fire-resistant covering means, in the first section and the second section, elastic flame-retardant gaskets are in close contact with the upper surface of each fire-resistant covering means, between the outer surface of the stringers and the wall surface of the central staircase wall, and between the outer surface of the stringers and the wall surface of the staircase wall, and the flame-retardant gaskets are disposed on the outer surface of each stringer over the entire length of the staircase in the direction of walking.

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