JP2024068545A - Structure and design method of structure - Google Patents

Abstract

To provide a structure and the like of which rationality in a structural plan and an architectural plan is enhanced without using expansion joints.SOLUTION: A structure comprises a first space, a second space adjacent to the first space, and a structural body partitioning the first space and second space and structurally standing by itself and having fire resistance performance, wherein the first space is connected to the structural body using means other than expansion joints, and the structural body is designed not to collapse when the first space receives fire.SELECTED DRAWING: Figure 8

Description

The present invention relates to a structure and a method for designing a structure.

Currently, when planning a large-scale wooden building with a total floor area of more than 3,000 m2, it is necessary to make it a fireproof building or satisfy the technical standards for "walls, etc." stipulated in Article 21, Paragraph 2, Item 2 of the Building Standards Act. Article 109-7 of the Building Standards Act Enforcement Order stipulates the technical standards for the above-mentioned "walls, etc.", and Item 4 of the same requires that "walls, etc." not collapse when stress caused by the collapse of parts of the building other than the wall, etc. due to a normal fire is transmitted to the wall, etc." As a specific structural method that meets the technical standards, Item 4 of the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250 of 2015 in Non-Patent Document 1 clearly states that "walls, etc., are connected to parts of the building other than the wall, etc. only by expansion joints or other structural methods that do not transmit stress to each other." In other words, "expansion joints" are listed as an example of a specification that meets the above technical standards.

Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250, No. 4 of 2015

In order to establish an expansion joint, a structural member that can support the load is required in addition to the wall, etc., and the expansion part reduces the effective rate of space, so there were issues with irrational aspects in terms of structural and architectural planning.

The present invention was made in consideration of these circumstances, and aims to provide a structure that improves the rationality of structural and architectural planning without using expansion joints, and a design method for this structure.

In order to achieve this object, the structure of the present invention comprises:
The first space,
A second space adjacent to the first space;
A structure that partitions the first space and the second space, is structurally independent, and has fire resistance,
The first space is connected to the structure by means other than an expansion joint,
The structural body is a structure that is characterized in that it is designed not to collapse when the first space is hit by a fire.
Other features of the present invention will become apparent from the following detailed description of the present invention and the accompanying drawings.

The present invention provides a structure and a design method for this structure that improves the rationality of structural and architectural planning without using expansion joints.

1 is a front view showing a structure according to the present embodiment. FIG. FIG. 3(a) is a diagram showing the joint between the upper chord member and the beam member, and FIG. 3(b) is a view taken along the arrow C in FIG. 3(a). FIG. 4(a) is a diagram showing the joint between the lower chord, beam and diagonal member, and FIG. 4(b) is a view taken along the arrow D in FIG. 4(a). FIG. 1 is a perspective view showing a joint between a fire wall and a wooden beam. FIG. 13 is a perspective view showing a side fixing bracket fixed to a firewall. This is a top view of the steel beam installed in the central space. FIG. 2 is a flow diagram showing a method for designing a structure according to the present embodiment. This is a conceptual diagram of wooden beams and steel beams of "buildings other than fire walls (walls, etc.)" that are connected to fire walls (walls, etc.). FIG. 1 shows a joint of a wooden beam that connects to a fire barrier (wall, etc.). FIG. 1 shows the joint of a steel beam connected to a fire wall (wall, etc.). This figure shows the type of destruction that occurs when the part of a wooden beam farthest from a wall or the like burns down. This figure shows the external force acting on a fire wall when the part of a wooden beam farthest from a wall or the like burns down. FIG. 1 is a cross-sectional plan view showing an example of a fire wall structure. This figure shows the types of failure that occur when steel plates at beam joints yield in bending, fail in shear, and when bolts yield in bending. This is a diagram showing the type of failure that occurs when one side of a beam burns down and the remaining side becomes a cantilever beam. FIG. 1 is a diagram showing the type of failure that occurs when a concrete part of a wall or the like is subjected to cone-shaped failure due to the pulling out of an anchor bolt at the outermost end. FIG. 1 is a diagram showing the type of failure when an anchor bolt yields in shear. This figure shows the type of failure that occurs when bolts, gusset plates, etc., undergo shear or bending yielding. FIG. 1 is a diagram showing the type of failure that occurs when a concrete part such as a wall is punched and destroyed by compression of a beam material. This is a diagram showing the type of failure that occurs when a steel beam undergoes thermal expansion deformation. FIG. 1 is a diagram illustrating the type of failure that occurs when the end joint of a steel beam is damaged. This figure shows the types of failure that occur when a high-strength bolt experiences shear failure or sliding failure. FIG. 13 is a diagram showing the type of failure when a gusset plate or an anchor bolt yields in shear. 1A and 1B are diagrams showing the type of destruction that occurs when a beam collides with a wall or the like due to thermal expansion and deformation (punching destruction).

At least the following points will become apparent from the following specification and drawings.
Aspect 1: a first space,
A second space adjacent to the first space;
A structure that partitions the first space and the second space, is structurally independent, and has fire resistance,
The first space is connected to the structure by means other than an expansion joint,
The structural body is a structure that is characterized in that it is designed not to collapse when the first space is hit by a fire.

According to the structure of aspect 1, the structure that separates the first space from the second space is structurally independent and has fire resistance, and is designed not to collapse if the first space connected to the structure by something other than an expansion joint catches fire. Therefore, even if the first space connected to the structure by something other than an expansion joint catches fire, the structure will not collapse and it will be possible to prevent the fire from spreading to the first space that has caught fire and to the adjacent second space through the structure.

Aspect 2: The structure of aspect 1,
The first space has a first cross member supported by the structure,
The structure is characterized in that it is configured not to collapse when the first cross member expands due to the fire.

According to the structure of aspect 2, even if the cross members supported by the structure in the first space affected by the fire are expanded by the fire, the structure will not collapse, so it is possible to prevent the fire from spreading to the adjacent second space via the first space and the structure.

Aspect 3: The structure of aspect 1,
The first space has a first cross member supported by the structure,
The structure is characterized in that it is designed not to collapse if the first cross member is damaged by the fire.

According to the structure of aspect 3, even if the cross members supported by the structure in the first space affected by the fire are damaged by the fire, the structure will not collapse, making it possible to prevent the fire from spreading to the adjacent second space via the first space and the structure.

Aspect 4: The structure of aspect 3,
The first space has a first connecting member that connects the structure and the first cross member,
The first connecting material is designed so that even if the first connecting material is damaged, the structure will not collapse.

The structure of embodiment 4 is designed so that the structure will not collapse even if the connecting material between the cross member supported by the structure and the structure in the first space affected by the fire is damaged. Therefore, even if the connecting material is damaged by fire, the structure will not collapse and it is possible to prevent the fire from spreading to the adjacent second space via the first space and the structure.

Aspect 5: a first space,
A second space adjacent to the first space;
A structural body that partitions the first space and the second space and is structurally independent and has fire resistance, comprising:
The first space is connected to the structure by means other than an expansion joint,
The present invention provides a method for designing a structure, characterized in that the structure is designed so as not to collapse when the first space is hit by a fire.

According to the design method of the structure of aspect 5, the structure that separates the first space from the second space is structurally independent and has fire resistance, and is designed so that the structure will not collapse if the first space connected to the structure by something other than an expansion joint catches fire. Therefore, even if the first space connected to the structure by something other than an expansion joint catches fire, it is possible to design a structure that will not collapse and can prevent the fire from spreading to the first space that has caught fire and the adjacent second space through the structure.

Aspect 6: A method for designing a structure according to aspect 5, comprising:
A construction plan setting step for setting a construction plan for the structure;
a fire behavior calculation step of calculating a fire behavior to which the structure is subjected;
having
If the equivalent fire duration based on the fire characteristics calculated in the fire characteristics calculation step is longer than a predetermined time, the method returns to the architectural plan setting step, and the architectural plan for the structure is reset.

According to the structure design method of aspect 6, the construction plan of the structure is set, the fire characteristics to which the structure will be subjected are calculated, and if the equivalent fire duration is longer than a predetermined time under the calculated fire characteristics, the construction plan of the structure is reset, so that it is possible to reliably design a structure whose equivalent fire duration is equal to or shorter than the predetermined time.

Aspect 7: A method for designing a structure according to aspect 6, comprising:
A structural plan setting step of setting a structural plan for the structure;
a strength degradation characteristic setting step for setting a deterioration characteristic of a material/component strength of the structure at the predetermined time;
A failure type setting step of setting a failure type of a portion of the structure other than the structure;
a load calculation step for calculating a stress acting on the structure from a portion of the structure other than the structure and an allowable strength of the structure at the predetermined time,
If the calculated allowable strength of the structure is smaller than the stress acting on the structure from parts of the structure other than the structure, and if the temperature of the non-heated surface of the structure is higher than the combustion temperature of combustible material, the method returns to the structural plan setting step and resets the structural plan of the structure.

According to the method for designing a structure of aspect 7, the structural plan of the structure, the deterioration characteristics of the material/component strength of the structure at a specified time, and the failure type at the part of the structure excluding the structure are set, and the stress acting on the structure from the part of the structure excluding the structure and the allowable strength of the structure at a specified time are calculated. If the calculated allowable strength of the structure is smaller than the stress acting on the structure from the first space or the second space, and if the temperature of the unheated surface of the structure is higher than the combustible combustion temperature, the structural plan of the structure is reset, so that it is possible to reliably design a structure whose allowable strength is equal to or greater than the stress acting on the structure from the first space or the second space, and whose unheated surface temperature is equal to or lower than the combustible combustion temperature.

About the Present Invention
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A structure and a method for designing a structure according to an embodiment of the present invention will be described below with reference to the drawings.
First, an outline of the structure according to the present invention and a method for designing this structure will be described.

As mentioned above, under the current Building Standards Act, when planning a large-scale wooden building with a total floor area of more than 3,000 m2, it is necessary to make it a fireproof building or satisfy the technical standards for "walls, etc." stipulated in Article 21, Paragraph 2, Item 2 of the Building Standards Act. In addition, the technical standards for "walls, etc." are stipulated in Article 109-7 of the Building Standards Act Enforcement Order, and Item 4 requires that "walls, etc." not collapse when stress caused by the collapse of parts of the building other than the wall, etc. due to a normal fire is transmitted to the wall, etc." As an example of a specification that meets the specific technical standards, Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250, 2015, Item 4 lists expansion joints, and clearly states that "walls, etc. are connected to parts of the building other than the wall, etc. only by expansion joints or other structural methods that do not transmit stress to each other."

However, in order to establish an expansion joint, a structural member that can support the load is required in addition to the wall, etc., and the expansion portion reduces the effective rate of the space, which is unreasonable in terms of structural and architectural planning. For this reason, the present invention provides a structure that meets the above technical standards without using an expansion joint, and that is more rational in terms of structural and architectural planning, as well as a design method for this structure. Note that, although the current Building Standards Act defines a large-scale wooden building as one with a total floor area of more than 3,000 m2, if the total floor area is changed due to legal amendments, etc., it will not be limited to 3,000 m2.

As shown in FIG. 1, the structure of this embodiment is a structure 1 having three spaces R1, R2, and R3, and has a left-side fire wall 2 that separates a first space R1 located on the left side from a second space R2 located in the center, and a right-side fire wall 2 that separates the second space R2 located in the center from a third space R3 located on the right side. Both the left-side and right-side fire walls 2 are constructed integrally with the foundation 3 and are structurally self-supporting reinforced concrete walls.

The first space R1 has a left-side fire wall 2, a first exterior wall 4 made of reinforced concrete arranged to face the left side of the left-side fire wall 2 with a gap between them, and a wooden beam 5 having a truss structure made of multiple wooden members as a first cross member arranged between the left-side fire wall 2 and the first exterior wall 4, and a roof material 6 is provided on top of the wooden beam 5.
The third space R3 has a right-side fire wall 2, a third exterior wall 4 made of reinforced concrete arranged to face the right-side fire wall 2 with a gap between them, and a wooden beam 5 serving as a third cross member arranged between the right-side fire wall 2 and the third exterior wall 4, and a roof material 6 is provided on top of the wooden beam 5.

The second space R2 has a steel beam 7 as a second cross member that is spanned between the left fire wall 2 and the right fire wall 2. In the second space R2, a plurality of steel beams 7 are spanned at appropriate intervals in the width direction of the two fire walls 2 between the left fire wall 2 that separates the first space R1 from the second space R2 and the right fire wall 3 that separates the second space R2 from the third space R3, and a roof material 8 is provided on top of the steel beams 7.

The third space R3 is a space similar to the first space R1, but with the left and right reversed, provided on the right side of the right-side firewall 2 that separates the second space R2 and the third space R3.

In the following explanation, we will use an example of a first space R1 and a second space R2 that are adjacent to each other, and assume that a fire originates in the first space R1.

The first space R1 has a wooden beam 5 that spans between the left fire wall 2 and the first exterior wall 4. The wooden beam 5 corresponds to the first cross member that is supported by the fire wall 2 as a structural member and is connected (joined) to the fire wall 2 by means other than an expansion joint.

As shown in FIG. 2, the wooden beam 5 is a wooden member in which the upper chord 51, lower chord 52, beam 53, and diagonal member 54 all have a substantially rectangular cross section cut in a direction perpendicular to the longitudinal direction, and is, for example, made up of three plank-shaped wooden boards stacked horizontally and glued together to form an integrated structure.

As shown in Figures 3 and 4, for example, the upper chord 51 and the lower chord 52 and the bundle 53 are joined by a binding material (not shown) that is inserted in the stacking direction by inserting the protruding portion 53a of the bundle 53 into the through holes 51a and 52a of the upper chord 51 and the lower chord 52. At the upper and lower ends of the bundle 53, the ends of the two wooden boards exposed to the outside of the three wooden boards are cut off by the width of the upper chord 51 or the lower chord 52 in the vertical direction, and the central wooden board of the three wooden boards has a protruding portion 53a that protrudes upward and downward. At the position where the bundle 53 is provided, the upper chord 51 and the lower chord 52 are cut off by the width of the protruding portion 53a of the bundle 53 so that it penetrates in the vertical direction.

The diagonal member 54 is cut so that both ends face the lower surface 51b of the upper chord member 51 or the upper surface 52b of the lower chord member 52, and the central wooden board among the three wooden boards is cut out at the parts where the upper chord member 51 and the diagonal member 54, and the lower chord member 52 and the diagonal member 54 face each other vertically. Joining boards 9 made of wood such as spruce processed to the thickness of the wooden boards are inserted between the upper chord member 51 and the diagonal member 54, or between the lower chord member 52 and the diagonal member 54, and are joined by a fastening member (not shown) or the like inserted in the stacking direction. In other words, no metal members are used in the wooden beam 5 to connect the upper chord member 51, the lower chord member 52, and the diagonal member 54, except for the fastening member.

As shown in FIG. 2, the upper chord 51 of the wooden beam 5 protrudes beyond the beam 53 attached to the end of the wooden beam 5 in the longitudinal direction, and the protruding end 51d of the upper chord 51 is placed on the fire wall 2 and fixed via an upper fixing bracket 15. The end of the lower chord 52 has a joint 5a with the beam 53 and diagonal member 54 fixed to the left side 2a of the fire wall 2 via a side fixing bracket 16. In the following explanation, the direction in which the three wooden boards are stacked in the wooden beam 5 is the width direction.

The upper fixing bracket 15 has a flat base plate portion 15a that is placed on the fire wall 2, and two gusset plate portions 15b that are arranged vertically on the upper surface of the base plate portion 15a and welded. The gusset plate portions 15b are arranged facing each other with a gap in between in the width direction of the upper chord member 51. The base plate portion 15a has an anchor insertion hole (not shown) through which an anchor bolt 17 that is provided on the fire wall 2 and protrudes upward is inserted. Each gusset plate portion 15b also has multiple through holes (not shown) through which fastening materials such as drift pins and high-strength bolts are inserted.

The protruding end 51d of the upper chord 51 has the outer surface in the width direction of the middle wooden board of the three stacked wooden boards cut away by the thickness of the gusset plate portion 15b, and when the three wooden boards are stacked, a slit (not shown) is formed on the inside of each of the wooden boards on both sides in the width direction.

The upper fixing bracket 15 has two gusset plate sections 15b inserted into the slits, a fastening material inserted in the width direction is inserted into the through hole, and it is fixed to the end 51d of the upper chord member 51 by a high-strength bolt 19 and nut inserted into the through hole.

The upper chord 51 to which the upper fixing bracket 15 is fixed has its base plate portion 15a placed on the fire wall 2, and the anchor bolt 17 protruding upward from the fire wall 2 is inserted into the anchor insertion hole of the base plate portion 15a and fixed by screwing the nut 17a.

As shown in Figures 2, 5, and 6, the side fixing bracket 16 has a flat base plate portion 16a that abuts against the side surface 2a of the fire wall 2, a flat bottom surface portion 16b that is placed under the lower chord member 52, and two plate-shaped gusset plate portions 16c that are perpendicular to the base plate portion 16a and bottom surface portion 16b and are inserted into the ends of the lower chord member 52, the beam member 53, and the diagonal member 54.

The gusset plate sections 16c are arranged facing each other with a gap in the width direction of the lower chord member 52, the beam member 53, and the diagonal member 54. The base plate section 16a is provided with an anchor insertion hole (not shown) through which an anchor bolt 18 provided in the fire wall 2 and protruding in the horizontal direction is inserted. Each gusset plate section 16c is also provided with a plurality of through holes (not shown) through which fastening materials such as drift pins and high-strength bolts 19 are inserted.

At the ends where the lower chord 52, the baffle 53, and the diagonal member 54 are joined, the outer surface in the width direction of the middle wooden board of the three stacked wooden boards is cut away by the thickness of the gusset plate portion 16c, and when the three wooden boards are stacked, slits (not shown) connected to the lower chord 52, the baffle 53, and the diagonal member 54 are formed on the inside of the wooden boards on both sides in the width direction.

The side fixing bracket 16 has two gusset plate portions inserted into slits connected to the lower chord 52, the beam 53, and the diagonal member 54, and the fastening material inserted in the width direction is inserted into the through hole. It is also fixed to the ends of the lower chord 52, the beam 53, and the diagonal member 54 by using high-strength bolts 19 and nuts inserted into the through holes.

The end where the lower chord 52, the beam 53, and the diagonal member 54 to which the side fixing bracket 16 is fixed are abutted with the base plate portion 16a facing the side surface 2a of the fire wall 2, and the anchor bolt 18 protruding horizontally from the side surface 2a of the fire wall 2 is inserted into the anchor insertion hole of the base plate portion 16a and fixed by screwing the nut 18a. Here, the upper fixing bracket 15, the side fixing bracket 16, and the anchor bolts 17 and 18 correspond to the first connecting member that connects (joins) the structure (fire wall 2) and the first cross member (wooden beam 5).

On the side surface 2b of the left fire wall 2 facing the second space R2, multiple steel beams 7 are provided at appropriate intervals in the width direction between the left fire wall 2 and the right fire wall 2, and adjacent steel beams 7 in the width direction are joined to each other with multiple stiffeners 70 as shown in FIG. 7. Each steel beam 7 is an H-shaped steel, and both ends are connected (joined) to the fire wall 2 via steel beam connectors 20 that form second connectors that connect to the fire wall 2 in the second space R2.

As shown in FIG. 2, the steel beam connector 20 has a flat base plate portion 20a that contacts the right side surface 2b of the fire wall 2, and a gusset plate portion 20b that is perpendicular to and welded to the base plate portion 20a, and has an L-shaped cross section.

The base plate portion 20a is provided with anchor insertion holes (not shown) through which anchor bolts 21 that are provided in the fire wall 2 and protrude horizontally are inserted. The gusset plate portion 20b is provided with a number of through holes (not shown) through which high-strength bolts are inserted.

The steel beam 7 is arranged so that the gusset plate portions 20b of the two steel beam connectors 20, which are arranged on either side of the vertically arranged web 7a, sandwich the web 7a from both sides, and the steel beam connectors 20 are fixed to the steel beam 7 by fastening nuts to high-strength bolts that pass through the two gusset plate portions 20b and the web 7a.

The steel beam 7 to which the steel beam connection fitting 20 is fixed is abutted with the base plate portion 20a facing the side surface 2b of the fire wall 2, and the anchor bolt 21 protruding horizontally from the side surface 2b of the fire wall 2 is inserted into the anchor insertion hole of the base plate portion 20a and fixed by screwing the nut 21a.

The structure 1 described above is designed by the design method described below so that the fire wall 2 will not collapse when the first space R1 catches fire. More specifically, the fire wall 2 is designed not to collapse even if the wooden beams 5 supported by the fire wall 2 are stretched by fire or damaged by fire, and further, the fire wall 2 is designed not to collapse even if the first connectors 15, 16, 17, 18 connecting (joining) the fire wall 2 and the wooden beams 5 and the second connectors 20, 21 connecting (joining) the fire wall 2 and the steel beams 7 are damaged by fire.

The design method for this structure is explained below.
The design method for structures of the present invention is targeted at semi-fireproof wooden buildings (in whole or in part) with a total floor area exceeding 3,000 m2, and with regard to "walls, etc." as defined in Article 21 Paragraph 2 of the Building Standards Act, Article 109-7 Item 4 of the Enforcement Order of the Building Standards Act states that "when stress caused by the collapse of parts of the building other than said wall, etc. due to an ordinary fire is transmitted to said wall, etc., said wall, etc. shall not collapse." This is defined as a case where an external force is applied to a wall, etc., when stress caused by the collapse of parts of the building other than said wall, etc. due to an ordinary fire is transmitted to said wall, etc., and the required performance is that "the wall, etc. shall not collapse" against this external force. Furthermore, the method provides a structure design method that considers the thermal deformation and thermal stress that occur transiently in the process by which "parts of a building other than walls, etc." collapse due to a fire as external forces, and verifies that the "walls, etc." will not collapse even in response to these external forces, thereby enabling the walls, etc., i.e., the fire walls in the structure 1, to be designed to specifications that are applicable to "walls, etc." as stipulated in Article 21, paragraph 2 of the Building Standards Act. In the following explanation, the "walls, etc." corresponds to the fire walls 2 in the structure 1.

<<Design policy for the design method of this structure>>
(1) Scope of application of this structure This structure and design method apply to semi-fireproof wooden buildings (in whole or in part) with a total floor area exceeding 3,000 m2 and to buildings that are divided into sections of no more than 3,000 m2 of floor space by "walls, etc." as defined in Article 21, Paragraph 2 of the Building Standards Act.

The scope of application of this law to structures equipped with "walls, etc." covers "wall type" types of walls, etc. of structures that meet the technical standards of Article 109-7 "Walls, etc." of the Enforcement Order of the Building Standards Act, and covers "cases where separation is achieved by load-bearing partition walls and fire prevention equipment" as specified in Item 2, Paragraph 1, (i) of Notification No. 250, 2015, Ministry of Land, Infrastructure, Transport and Tourism.

The scope of application of the structural method (structural type) of "partition walls that are load-bearing walls" among the building parts that constitute "walls, etc." is to apply to reinforced concrete construction among the structural types listed in 2-i (1) of Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250 of 2015 (*Reinforced concrete construction (limited to those that do not impede fire prevention in cases where the concrete covering the reinforcing bars is based on the standards of 2-2-2 of Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1372 of 2001) with a thickness of 85 mm or more). In addition, the scope of application of structural members (structural types) connecting "building parts other than walls, etc." to "walls, etc." is to apply to wooden beams (laminated timber, LVL) and steel beams, and the scope of application of the connection method is to apply to exposed type connections using base plates, anchor bolts, and high-strength bolt connections using gusset plates. The scope of application of the structural materials and standard strengths used in each of these structural methods shall conform to the scope of application of the Fire Resistance Performance Verification Act stipulated in Ministry of Construction Notification No. 1433 of 2000.

The "fire prevention equipment" installed in openings in walls, etc. must be constructed in a manner that satisfies the specifications of the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250 of 2015, No. 2, Entrance No. 1, and is not covered in this design.

<<Required performance in the design method of this structure>>
In this design, based on Article 109-7, Clause 4 of the Enforcement Order of the Building Standards Act, "when stress caused by the collapse of parts of the building other than the wall in question due to a normal fire is transmitted to the wall, etc." is defined as the case where an external force acts, and the required performance is that "the wall, etc." will not collapse against this external force. Furthermore, in the process in which "parts of the building other than the wall, etc." collapse due to a fire, the thermal deformation and thermal stress that occur transiently are also considered as external forces, and it is verified that the "wall, etc." will not collapse against this external force.

Here, "walls, etc." are required to have structural fire resistance (non-damage) so that they do not collapse in the event of a fire, and performance (heat insulation and flame insulation) to prevent the spread of fire from adjacent fire compartments to non-fire compartments through "walls, etc." Therefore, the required performance of "not collapsing" can be summarized as follows from the perspective of "non-damage" and "heat insulation" against fires assumed in the design.
- Non-damage (structural fire resistance)
Required performance 1: The entire structure of the "wall, etc." must not collapse. Required performance 2: There must be no localized destruction or damage that would impede the independence of the "wall, etc." - Heat insulation (fire spread prevention performance)
Required performance 3: No localized destruction or damage that would impair the fire spread prevention performance of "walls, etc." In other words, the design method for a structure of the present invention makes it possible to design a structure that satisfies the above required performances 1 to 3.

<<Basic design policy>>
The basic design policy for the above-mentioned performance requirements 1 to 3 is shown below. Regarding the external forces in each design event, the thermal deformation and thermal stress that occur transiently in the process leading to the collapse of "parts of the building other than walls, etc." due to fire are also assumed as external forces and verified.

(1) Design Policy 1
Required performance 1 (that the entire structure of the "wall, etc." does not collapse) will be verified in accordance with the following design guidelines.
A. When an external force caused by the collapse of a part of a building other than a wall acts on a wall,
The stress (overturning moment) generated in the legs and foundations of the walls, etc. is
(Fall resistance strength) or less.
Or, an external force acting from a part of the building other than the wall may cause the wall to collapse.
The joints of the structural members connecting to the wall, etc. break before the overturning moment reaches the limit.
The loss of stress transmission capability due to breakage.

(2) Design Policy 2
Required performance 2 (no localized destruction or damage that would impede the stability of the "wall, etc.") shall be verified in accordance with the following design guidelines.
B. When an external force caused by the collapse of a part of a building other than a wall acts on a wall, etc.
Stresses (bending moment, shear force, axial force) occurring in the cross sections of walls, etc. and foundations
, the allowable strength of the wall, etc. (sectional strength = bending strength, shear strength, axial strength) is less than this.
thing.
C. At the joint where external force acts from the structural member (beam, etc.) on the fire compartment side,
Punching destruction of concrete, pulling out of anchor bolts (cone-shaped fracture of concrete)
There will be no destruction or damage that would impair the independence of walls, etc. due to construction work, etc.

(3) Design Policy 3
Required performance 3 (no localized destruction or damage that would impair the fire spread prevention performance of "walls, etc.") shall be verified in accordance with the following design guidelines.
D. Provisions of 2015 Ministry of Land, Infrastructure, Transport and Tourism Notification No. 250, Article 2, Item 1, (1) (Reinforced Concrete
Based on the above, the specifications have a certain level of heat insulation.
In addition, localized destruction and damage to structural members connected to walls and their joints
No cross-sectional defects occur in walls, etc. due to damage that would prevent the walls from maintaining the required thermal insulation properties.
thing.

<<Design Criteria>>
The pass/fail criteria for the verification of each of the required performances described above are shown below.
(1) Non-damage (structural fire resistance) 1) Collapse inspection of walls, etc. (foundations):
Overturning resistance strength of "walls, etc."> Overturning moment Here, the overturning resistance strength of "walls, etc." is calculated based on the short-term bearing capacity of the supporting ground. Note that since the foundation (underground part) is not directly exposed to fire heat, the calculation is based on the material strength at room temperature.

2) Sectional inspection of walls, etc.:
Sectional strength of "walls, etc."> Stress acting from "parts of the building other than walls, etc." Here, the section strength of "walls, etc." (bending, shear, axial force) is evaluated based on short-term allowable stress. The material strength of concrete and reinforcing steel is based on the Ministry of Construction Notification No. 1433 of 2000, taking into account the decrease in strength at high temperatures.

3) Consideration of joints:
Strength of joints between "walls, etc." and "parts of the building other than walls, etc."> stress acting from "parts of the building other than walls, etc." Here, the strength of the joints is calculated based on the short-term allowable stress, but the strength of the joints of "parts of the building other than walls, etc." is calculated by taking the ultimate strength so that the stress acting on the "walls, etc." is the greatest, as a safe evaluation.

(2) Heat insulation (fire spread prevention performance)
Surface temperature of the unheated side of "walls, etc." ≦ Combustible combustion temperature Here, the surface temperature of the unheated side of "walls, etc." is calculated in accordance with Ministry of Construction Notification No. 1433 of 2000. In addition, the combustible combustion temperature is set to an average temperature of 160°C and a maximum temperature of 200°C, based on Ministry of Construction Notification No. 1432 of 2000 (*Temperature increments when normal temperature is 20°C are an average of 140°C and a maximum of 180°C).
In addition, if cross-sectional defects occur in joints, etc. provided in "walls, etc.", the thermal insulation performance shall be verified based on the remaining effective cross-section.

<<Terminology>>
The following explains the definitions of the terms used in explaining the design method of this structure.
- Fire duration: The duration of combustion within a fire compartment, calculated using the fire resistance verification method stipulated in Article 108-3, Paragraph 2 of the Enforcement Order of the Building Standards Act and Ministry of Construction Notification No. 1433 of 2000.
・Fire temperature rise coefficient: A coefficient that specifies the temperature rise characteristics within a fire compartment, calculated using the method of Ministry of Construction Notification No. 1433 of 2000. The standard heating temperature curve of ISO 834 has a fire temperature rise coefficient of 460.
・Equivalent fire time: Fire duration calculated based on the fire duration and fire temperature rise coefficient calculated by Ministry of Construction Notification No. 1433 of 2000, converted to the fire temperature rise coefficient (=460) in the standard heating temperature curve of ISO834. ・Design fire time: Equivalent fire time set as thermal external force for each fire compartment. In the design of this structure, the applicable range is within 90 minutes. For "walls, etc.", the maximum equivalent fire time is set to 108 minutes (=90 x 1.2) as the safest setting, regardless of the calculation results for each fire compartment, as a consideration for safety during the cooling process after the fire has ended. The maximum design fire time is currently set to 90 minutes based on the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 249 of 2015, but it will be set appropriately in response to amendments to the notification, etc.
・Walls, etc.: According to Article 21, Paragraph 2, Item 2 of the Building Standards Act, this refers to components that separate large wooden buildings into fireproof sections every 3,000 m2. Walls, etc. are required to have fire prevention performance against normal fires (non-damage, heat insulation, fire insulation, collapse prevention, and prevention of fire spread through outdoors). At present, the area of a large wooden building divided by walls, etc. is set to every 3,000 m2 according to the current Article 21, Paragraph 2, Item 2 of the Building Standards Act, but this will be set appropriately in response to amendments to the Building Standards Act, etc.
- Non-damageability: This is the performance required for walls, etc., that when the heat of a normal fire is applied for the design fire time, the walls, etc. must not deform, melt, break or suffer any other damage that would impair their independence or structural strength against the constant load acting on the walls, etc., and the external forces acting through the deformation and destruction of the surrounding parts that join to the walls, etc.
- Heat insulation: This is the performance required to prevent the spread of fire, and when heat from a normal fire is applied to a wall, etc. for the design fire time, the temperature of the surfaces other than the heated surface does not rise above the combustion temperature of combustibles. In addition, the heat insulation performance must not be impaired by local destruction or damage to the structure of the wall, etc. and its joints, etc.
・Overturning resistance strength: Allowable strength against the overturning moment acting on "walls, etc." In this design, it is calculated based on the short-term bearing capacity of the ground.
- Sectional strength: Allowable section strength against bending, shear and axial force of "walls, etc." In this design, it is calculated based on the short-term allowable stress of concrete and reinforcing bars.
- Joint strength: The allowable strength of a joint between a "wall, etc." and a "part of the building other than the wall, etc." (beam, etc.).

<<Design flow for this structure design method>>
As shown in FIG. 8, the flow of the design method for a structure according to this embodiment includes a step of setting/confirming an architectural plan (a step of setting an architectural plan) S1, a step of calculating fire properties S2, a step of judging whether the equivalent fire time is appropriate or not S3, a step of confirming the completion of the judgment of the equivalent fire time in all fire compartments S4, a step of setting/confirming a structural plan (a step of setting a structural plan) S5, a step of setting the deterioration property of the material/component strength of "walls, etc." (a step of setting the strength deterioration property) S6, a step of setting the destruction type in the event of a fire of "parts of the building other than walls, etc." (a step of setting the destruction type) S7, a step of calculating the stress acting on "walls, etc." from "parts of the building other than walls, etc." and calculating the allowable strength of "walls, etc." in the design fire time (a step of calculating the load on the structure) S8, a step of judging whether the allowable strength of "walls, etc." is acceptable or not S9, a step of judging whether the non-heated surface temperature of "walls, etc." is acceptable or not S10, and a step of confirming the completion of the judgment for all destruction types S11.

<<Calculating fire duration>>
In step S1 of setting/confirming the architectural plan, the architectural plan is confirmed. Specifically, based on the design documents (floor plans, elevations, sections, finish schedules, fittings schedules, etc.), information required for calculating the fire duration, i.e., setting conditions related to the spatial configuration such as floor area and ceiling height of each room in the building, windows and doors (opening area), etc., as well as information required for calculating the amount of combustible materials such as room use and finishing materials, is confirmed.

In the fire characteristics calculation step S2, the fire duration is calculated for each room of the building facing the "wall, etc." At this time, fire compartments (simultaneous combustion ranges) are set assuming that the fire spread prevention performance of the "wall, etc." is ensured, and the fire duration in each adjacent fire compartment separated by the "wall, etc." is calculated.

The method for calculating fire duration shall conform to Article 108-3, Paragraph 2 of the Building Standards Act Enforcement Order and the Fire Resistance Verification Method stipulated in Ministry of Construction Notification No. 1433 of 2000. The amount of stored combustible materials based on room use shall be set in accordance with Ministry of Construction Notification No. 1433 of 2000 and the "2001 Edition Explanation of Fire Resistance Verification Method and Calculation Examples and Explanations," but for room uses not exemplified in these, the amount of combustible materials shall be set according to the actual situation (assumed conditions) after the building is placed in service.

Furthermore, for structures that make up "walls, etc.", following the "follow-up" approach to fire-resistant structures, and taking into consideration safety during the cooling process after a fire has ended, the design fire time will be set to 1.2 times the equivalent fire time calculated above (for structural members other than "walls, etc.", verification will be based on the equivalent fire time calculated above).

The criteria for the judgment in step S3 of judging the suitability of the equivalent fire time are that currently, for fire protection equipment installed in openings in "walls, etc.", the upper limit is the "90 minutes" fire resistance specification set forth in Notification No. 249 of the Ministry of Land, Infrastructure, Transport and Tourism of 2015, and there are no specifications or certified products with fire resistance performance that exceeds this. Therefore, the upper limit for the fire duration (equivalent fire time) for this structure is set at "90 minutes." If the calculation results in an equivalent fire time exceeding 90 minutes, the architectural plan will be reviewed and changed so that it is 90 minutes or less.

The design fire time (magnitude of external thermal force) for this structure is defined as follows:
Structure constituting the "wall, etc." (fire wall 2 in this embodiment):
Regardless of the calculation results of the fire duration in each fire compartment, the safest assumption is set at 108 minutes (= 90 minutes x 1.2) based on the upper limit of the equivalent fire duration.
・Structural members and joints other than those mentioned above:
The equivalent fire time in each fire compartment is the design fire time.

The process from step S1 of setting/confirming the building plan to step S3 of determining whether the equivalent fire time is appropriate must be performed for all fire compartments of the target structure, so in step S4 of confirming the completion of the determination of the equivalent fire time for all fire compartments, it is confirmed whether the process has been completed for all fire compartments.

<<Calculation of stress acting from "parts of a building other than walls, etc." and allowable strength of "walls, etc.">>
When it is confirmed in step S4 that the construction plans for all fire compartments have been completed, the process proceeds to step S5 of setting/confirming the structural plan.

In the structural plan setting/confirmation step S5, based on the design documents (structural drawings, structural calculations, etc.), as shown in Figures 9 to 11, the structural type of the "walls, etc." consisting of the fire walls 2 is reinforced concrete (hereinafter referred to as RC), the structural types of the members connected to the "walls, etc." are wooden beams 5 and steel beams 7, and the connection methods are exposed type connections using base plate sections 15a, 16a and anchor bolts 17, 18, and high strength bolt connections via gusset plate sections 15b, 16c, as well as the standard strengths of various materials and loading conditions, etc. are confirmed.

In step S6, which sets the deterioration characteristics of the material and component strength of "walls, etc.", the material strength of concrete and reinforcing bars, taking into account the deterioration in strength due to temperature rise during a fire, is calculated based on the "Explanation and Calculation Examples of the 2001 Edition of the Fire Resistance Verification Method and Their Explanations" (hereinafter referred to as the "Explanation Manual").

Regarding concrete strength, the commentary states that "the compressive strength of parts where the temperature is below 500°C is 2/3 of the design strength, and parts where the temperature exceeds 500°C are set to zero to calculate the strength of the components," and the position (depth from the surface) where the internal temperature is 500°C or higher for a design fire duration of 108 minutes is determined, and the compressive strength of the concrete in that range is set to zero, and the compressive strength of the concrete outside that range is set to 2/3 of the design strength.

The strength of the rebar is set by quoting from the manual, "The yield strength of rebar starts to decrease gradually from about 300°C. At 500°C, the yield strength is about half that at room temperature." First, the temperature of the rebar is assumed to be the same as the temperature of the concrete at the depth corresponding to the rebar position. The strength of the rebar is assumed to retain its strength at room temperature up to 300°C, and in the temperature range above 300°C, it is calculated by interpolating with a linear gradient that is half the strength at room temperature at 500°C (strength is zero at 700°C). Note that in this design, only rebar that bears tensile stress is taken into consideration, and the cross-sectional strength is calculated under conditions where rebar on the compression side is safely ignored.

In step S7, the destruction type in the event of a fire for the "parts of the building other than walls, etc." is set for the cases where the "parts of the building other than walls, etc." are wooden beams and where the "parts of the building other than walls, etc." are steel beams. Below, the destruction type set in step S7 for the "parts of the building other than walls, etc." in the event of a fire in the structure of this embodiment described above, the stress acting on the "walls, etc." from the "parts of the building other than walls, etc." calculated in step S8 for calculating the stress acting on the "walls, etc." from the "parts of the building other than walls, etc." and the allowable strength of the "walls, etc." in the design fire time, and the allowable strength of the "walls, etc." in the design fire time are explained.

(1) Flow of examination in the failure type setting step S7 and the load calculation step S8 for the structure (1-1) In the case of wooden beams (1-1a) Setting of external force (finding the largest external force among possible events)
When the part of the base material farthest from the wall is broken (part E in FIG. 12)
(The event in which the greatest external force (moment) is applied to a wall, etc. occurs when the part of the base material farthest from the wall, etc., breaks.)
The external force is determined by the weakest part of the following A or B. (The reason that the external force is determined by the weakest part is that if the weakest part breaks first, no subsequent events can occur.)
A. When the base material is in a cantilevered state, the fracture occurs at the part with the smallest cross section (part F1 in Figure 12) or at the base end position (part F2 in Figure 12) (Figure 13) (Figure 15) (Figure 16)
A. Joint fracture (part G in Figure 12)
・When an anchor bolt breaks in shear (Figure 18)
- When bolts, gusset plates, etc., are shear- or bending-yielded (Figure 19)
After a weakest point event occurs, the beam is in a state where it will drop.

(1-1b) When an external force caused by the inspection of walls, etc. or the collapse of parts of a building other than walls, etc. acts on a wall, etc. due to the external force determined above, confirm that the stress (overturning moment) generated in the legs and foundations of the wall, etc. is equal to or less than the allowable strength (overturning resistance strength) of the wall, etc.
- Verify that the stresses (bending moment, shear force, axial force) occurring in the cross sections of walls, etc. and foundations are below the allowable strength of the walls, etc. (cross-sectional strength = bending strength, shear strength, axial strength).
・Confirm that no localized damage occurs at the joints (body side) of walls, etc. (・Confirm that the compression of the beam material does not cause punching damage to the concrete part of the wall, etc. (Figure 20), ・Confirm that the pulling out of the anchor bolts at the outermost ends does not cause cone-shaped damage to the concrete part of the wall, etc. (Figure 17))
・The strength of walls, etc. is confirmed based on the strength reduced by the design fire duration. The strength of the tensile reinforcement is not reduced because the tensile direction of the bending moment is the non-fire compartment side. Only the strength and effective cross section of the concrete are reduced. (Figure 14)

(1-1c) Others Based on the concept of destruction type fire resistance design where the entire wooden beam is damaged, the evaluation is performed based on the limit time when the entire wooden beam is uniformly damaged in cross section and is no longer able to support a long-term load. The strength of the wall, etc., whose strength has decreased due to the limit time, is used to verify that the wall, etc. will not collapse.

(1-2) In the case of steel beams, the effect of transient thermal stress caused by thermal expansion and deformation due to temperature rise of steel beams is considered (Figure 21 (a)).
(1-2a) Setting the external force The external force is determined by the lowest temperature event among the following events A to C.
A. Calculate the stress and temperature of the base material (beam) when the wall's collapse resistance or cross-sectional strength reaches its limit (calculated under conditions that ignore buckling, etc.).
A. Calculate the lateral buckling strength (bending moment and temperature) of the main beam. (Assuming that lateral stiffening by the sub-beam cannot be expected.)
Furthermore, if the temperature of A is greater than the temperature of B, event A will not occur.
For the temperature in (a) above, the bending buckling of the beams is examined, followed by bending buckling of the lateral stiffeners, etc. If all are found to be in a bending buckling state, the assumption in (a) above that lateral stiffening by the beams cannot be expected is valid.
In examining the bending buckling of beams, etc. (Fig. 21(b)), we consider the case where a beam undergoes thermal expansion deformation due to a fire. Specifically, we calculate the amount of thermal expansion deformation that occurs when the temperature of the steel material rises from room temperature, and calculate the reaction force applied to the beam when this thermal expansion deformation is restrained. We perform inspections of the beam (bending, shear, compression, tension) based on the condition that the compressive axial force caused by this reaction force is applied to the beam in a long-term stress state. We also consider shear fracture of the connecting bolts at the end of the beam and end-pull fracture of the connecting plate.
C. At the temperature mentioned in (a) above, an inspection is conducted to see if the joint of the base material (beam) (part H in Figure 22) will break.
(When high strength bolts break due to shear or sliding (Figure 23), when gusset plates or anchor bolts break or break in shear at the gap (Figure 24))
If a joint breaks, the girder will fall at the temperature at the time of joint breakage (C), which is lower than the temperature (I), and event (I) will not occur.

(1-2b) Inspect walls etc. using the external forces determined above.
- When an external force caused by the collapse of a part of a building other than the walls acts on the walls, etc., confirm that the stress (overturning moment) generated in the legs and foundations of the walls, etc. is below the allowable strength (overturning resistance strength) of the walls, etc.
- Verify that the stresses (bending moment, shear force, axial force) occurring in the cross sections of walls, etc. and foundations are below the allowable strength of the walls, etc. (cross-sectional strength = bending strength, shear strength, axial strength).
- Confirm that there is no localized damage to the joints (on the frame side) of walls, etc. (Confirm that there is no collision (punching damage) with walls, etc. due to thermal expansion deformation of beams (Figure 25))
・The strength of walls, etc. is verified with the strength reduced by the design fire time. Since the tensile direction of the bending moment is on the fire compartment side, the strength of the tensile reinforcement is reduced, and the number of reinforcement bars is reduced to an equivalent number. In addition, the effective cross section and strength of the concrete are reduced. (Figure 21 (c))

(1-2c) Inspection of steel frame at ultimate state (a. After lateral buckling of the girder, when the temperature of the steel beam rises)
We will consider what happens after the girder buckles laterally due to thermal expansion and deformation as a result of the event in (a) above, and no longer pushes against the wall, etc. Although the steel beam buckles laterally, it continues to bear the bending moment and shear force due to the long-term load. After that, as the temperature of the steel beam rises, it yields, becomes a three-hinge structure, begins to sag, and pulls against the wall, etc. We will consider what happens when this happens.

a. Calculation of steel beam yield temperature Based on the fire resistance performance verification method, the upper limit temperature determined by the high temperature strength of the steel beam is calculated.
(=When the beam has 3 hinges)

b. Calculation of the fracture temperature of steel beam end joints
Determine the temperature at which the steel beam end joint breaks under long-term load (taking into account the reduction in strength at high temperatures).
If the temperature of a. is greater than the temperature of b., the steel beam will fall before event a. occurs.

c. Testing the fracture of steel beam end joints at high temperatures as described in a. above (when b. does not hold)
a. Determine the breaking strength (tensile and shear) of the steel beam joint at high temperatures (when the beam has three hinges). (Consider the decrease in strength at high temperatures: Estimate the breaking strength of the steel at high temperatures from the graph of the stress-strain relationship of steel at high temperatures in the "2001 Edition: Calculation Examples and Explanations of the Fire Resistance Verification Method" and take into account the decrease in strength at high temperatures.)

In addition, assuming an event in which the steel beams yield and pull on the walls, etc., a fracture test will be performed to determine the tensile fracture strength when tension and shear forces are simultaneously applied to the steel beam joints.

d. Inspect walls, etc. when they are subjected to a long-term load and a tensile force equivalent to the tensile breaking strength specified in c. above.
If the test shows that the wall or other structure does not collapse, then event c has been established and the steel beam will form a triple hinge and begin to pull the wall or other structure, but the wall or other structure will not collapse; instead, the steel beam joint will suffer tensile failure and the wall or other structure will fall.

(2) Strength increase rate of ultimate strength When setting an external force, set the largest external force acting on the wall, etc. Since the design ultimate strength of the member does not use the upper limit of the experimental value, the design ultimate strength is multiplied by the strength increase rate to be on the safe side.
(2-1) Strength increase rate of wooden structures (laminated timber and LVL lumber) The strength increase rate of laminated timber and LVL is 1.5 times.
(2-2) Strength increase rate of steel material for steel frame and anchor bolts The strength increase rate of steel material for steel frame and anchor bolts shall be 1.3 times.

(2-3) Strength increase rate of high-strength bolts The strength increase rate of high-strength bolts shall be 1.2 times.
(2-4) Strength increase rate of buckling strength of steel material A. The strength increase rate of bending buckling strength shall be 1.5 times.
a. The strength increase rate of the lateral buckling strength of the beam shall be 1.0 times.
Walls, etc. designed and constructed in accordance with the above-mentioned design guidelines can be said to have the same performance as other parts of the building that do not transmit stress between them and expansion joints or other structural methods.

As described above, the various failure modes set for the structure of this embodiment, the stress acting on the "walls, etc." for each failure mode, and the allowable strength of the "walls, etc." are calculated, and in step S9 for determining whether the allowable strength of the "walls, etc." is acceptable or not, a test is performed to determine whether the allowable strength of the "walls, etc." is greater than the stress acting on the "walls, etc." for each calculated failure mode.

In addition, when "parts of a building other than walls, etc." are wooden beams, and when "parts of a building other than walls, etc." are steel beams, it will be confirmed that punching destruction or other events will not cause local destruction or damage to the structural members connected to the walls, etc. and their joints, resulting in cross-sectional defects in the walls, etc. that would prevent them from maintaining the specified heat insulation properties.

In step S10, which determines whether or not the non-heated surface temperature of "walls, etc." is acceptable, it is confirmed that the wall, etc. has heat insulation properties that keep the surface temperature of the non-fire compartment side below the combustible combustion temperature. In step S10, which determines whether or not the non-heated surface temperature of "walls, etc." is acceptable, the time it takes for the surface temperature of the wall, etc. on the non-fire compartment side to reach the combustible combustion temperature in the event of a predicted fire is calculated according to Article 3, Paragraph 1, (i) of Ministry of Construction Notification No. 1433 of 2000 (Fire Resistance Performance Verification Method). Heat insulation properties are confirmed when the obtained result is converted into an equivalent fire time of 90 minutes or more.

For this reason, in "walls, etc." (fire walls) whose heat insulation performance is determined to meet the standard in step S10 for determining whether the non-heated surface temperature of the "walls, etc." meets the provisions of Notification No. 250, Article 2, it can be said that the wall, etc. has heat insulation performance for the design fire duration, assuming that there is no localized destruction or damage.

For reference, the time it takes for the surface temperature of walls, etc. on the non-fire compartment side to reach the combustion temperature of combustible materials is calculated in accordance with Article 3, Paragraph 1 (a) of the Ministry of Construction Notification No. 1433 of 2000 (Fire Resistance Verification Method). The heat insulation performance is confirmed when the obtained result is converted into the equivalent fire time and is equal to or exceeds the design fire time.

The process from step S5 of setting/confirming the structural plan to step S10 of judging whether the non-heated surface temperature of "walls, etc." is acceptable or not must be performed for all fire compartments of the target structure, so in step S11 of confirming the completion of judgment for all destruction types, it is confirmed whether the process has been completed for all fire compartments.

In this manner, in the structure 1 of this embodiment designed by executing all steps of the design method of this structure, the fire wall 2 separating the adjacent first space R1 and second space R2 is structurally independent and has fire resistance, and the fire wall 2 will not collapse even if the wooden beams 5 connected to the fire wall 2 by the upper fixing brackets 15 and side fixing brackets 16 in the first space R1 and second space R2 catch fire. Therefore, even if the first space R1 catches fire in the structure 1 in which the fire wall 2 and the wooden beams 5 are not connected by expansion joints, the fire wall 2 that does not collapse can prevent the fire from spreading to the adjacent second space R2. In addition, since the structure 1 does not have a structure that establishes an expansion joint, no structural member that supports the load is required in addition to the fire wall 2, and the first space R1 can be used effectively.

In addition, even if the second space R2 in the structure 1 catches fire, the fire wall 2 is designed not to collapse if the steel beam 7 serving as the second cross member connected by a means other than an expansion joint is stretched by fire, so even if the steel beam 7 stretches due to fire, the fire wall 2 will not collapse and it is possible to prevent the fire from spreading to the adjacent first space R1.

In addition, the wooden beams 5, which are connected by means other than expansion joints and supported by the fire wall 2, are designed not to collapse if damaged by fire. Therefore, even if the wooden beams 5 are damaged by fire, the fire wall 2 will not collapse and it is possible to prevent the fire from spreading to the adjacent second space R2.

In addition, the fire wall 2 is designed not to collapse even if the upper fixing bracket 15, side fixing bracket 16, and anchor bolts 17, 18, which are connecting materials between the wooden beam 5 supported by the fire wall 2 and the fire wall 2 and are connected by means other than expansion joints, are damaged. Therefore, even if the upper fixing bracket 15, side fixing bracket 16, and anchor bolts 17, 18 are damaged by a fire, the fire wall 2 will not collapse and it is possible to prevent the fire from spreading to the adjacent second space R2.

In addition, according to the design method for the structure 1 of this embodiment, the fire wall 2 that separates the adjacent first space R1 and second space R2 is designed to be structurally independent and have fire resistance, and to not collapse in the event of a fire in the first space R1 and second space R2, where the wooden beams 5 connected to the fire wall 2 by means other than expansion joints are affected by the fire. Therefore, it is possible to design a structure 1 that can prevent the spread of fire to the adjacent second space S2 by the fire wall 2 that will not collapse, even if the wooden beams 5 connected to the fire wall 2 by means other than expansion joints are affected by a fire.

In addition, the construction plan for structure 1 is set, the fire characteristics to which structure 1 will be exposed are calculated, and if the equivalent fire duration based on the calculated fire characteristics is longer than a predetermined time, the construction plan for structure 1 is reset, making it possible to more reliably design structure 1 so that the equivalent fire duration is equal to or shorter than the predetermined time.

In addition, the structural plan of the structure 1, the deterioration characteristics of the material and component strength of the fire wall 2 at a specified time, and the failure type at parts of the structure 1 excluding the fire wall 2 are set, and the stress acting on the fire wall 2 from parts of the structure 1 excluding the fire wall 2 and the allowable strength of the fire wall 2 at a specified time are calculated. If the calculated allowable strength of the fire wall 2 is smaller than the stress acting on the fire wall 2 from the first space R1 and if the temperature of the unheated surface of the fire wall 2 is higher than the combustible combustion temperature, the structural plan of the structure 1 is reset, so that it is possible to reliably design a structure 1 whose allowable strength is equal to or greater than the stress acting on the fire wall 2 from the first space R1 and whose unheated surface temperature is equal to or lower than the combustible combustion temperature.

In the above embodiment, the parts connected to the structure by means other than expansion joints have been explained using wooden beams 5 that form a wooden truss structure as an example, but the beams that form the cross members do not have to have a truss structure, and may be wooden beams or steel beams.
In the above embodiment, the first space R1 is the source of the fire, but the second space R2 may be the source of the fire. The structure may be a structure in which both adjacent spaces have cross members connected to the structure by means other than an expansion joint, for example, a structure in which the first space R1 and the third space R3 are adjacent to each other.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit of the invention, and it goes without saying that the present invention includes equivalents.

1 Structure 2 Fire wall (structural element)
2a Left side 2b Right side 3 Foundation 4 Exterior wall (first exterior wall, third exterior wall)
5. Wooden beams (first cross member, third cross member)
5a Joint 6 Roof material 7 Steel beam (second cross member)
7a Web 8 Roof material 9 Joint plate material 15 Upper fixing metal fitting (first connecting material)
15a Base plate portion 15b Gusset plate portion 16 Side fixing metal fitting (first connecting member)
16a Base plate portion 16b Bottom surface portion 16c Gusset plate portion 17 Anchor bolt (first connecting member)
17a Nut 18 Anchor bolt (first connecting material)
18a Nut 19 High strength bolt 20 Steel beam connection fitting (second connection material)
20a Base plate portion 20b Gusset plate portion 21 Anchor bolt (second connecting member)
21a Nut 51 Upper chord member 51a Through hole 51b Lower surface 51c Cut-out portion 51d End portion 52 Lower chord member 52a Through hole 52b Upper surface 52c Cut-out portion 53 Strap member 53a Protruding portion 54 Diagonal member 70 Stiffener R1 First space R2 Second space R3 Third space

Claims (7)

The first space,
A second space adjacent to the first space;
A structure that partitions the first space and the second space, is structurally independent, and has fire resistance,
The first space is connected to the structure by means other than an expansion joint,
The structure is characterized in that the structural body is configured not to collapse when the first space is hit by a fire. 2. The structure of claim 1,
The first space has a first cross member supported by the structure,
The structure is characterized in that the structural body is configured not to collapse when the first cross member expands due to the fire. 2. The structure of claim 1,
The first space has a first cross member supported by the structure,
The structure is characterized in that the structural body is configured not to collapse when the first cross member is damaged by the fire. 4. The structure of claim 3,
The first space has a first connecting member that connects the structure and the first cross member,
A structure characterized in that the first connecting material is designed so that the structural body will not collapse even if the first connecting material is damaged. The first space,
A second space adjacent to the first space;
A structural body that partitions the first space and the second space and is structurally independent and has fire resistance, comprising:
The first space is connected to the structure by means other than an expansion joint,
A method for designing a structure, comprising the steps of: designing the structure so that it will not collapse if the first space is hit by a fire. A method for designing a structure according to claim 5, comprising the steps of:
A construction plan setting step for setting a construction plan for the structure;
a fire behavior calculation step of calculating a fire behavior to which the structure is subjected;
having
When the equivalent fire duration is longer than a predetermined time for the fire properties calculated in the fire property calculation step, the method for designing a structure is characterized in that the method returns to the architectural plan setting step and resets the architectural plan for the structure. A method for designing a structure according to claim 6, comprising the steps of:
A structural plan setting step of setting a structural plan for the structure;
a strength degradation characteristic setting step for setting a deterioration characteristic of a material/component strength of the structure at the predetermined time;
A failure type setting step of setting a failure type of a portion of the structure other than the structure;
a load calculation step for calculating a stress acting on the structure from a portion of the structure other than the structure and an allowable strength of the structure at the predetermined time,
A method for designing a structure, characterized in that if the calculated allowable strength of the structure is smaller than the stress acting on the structure from parts of the structure other than the structure, and if the non-heated surface temperature of the structure is higher than the combustion temperature of combustible material, the method returns to the structural plan setting step and resets the structural plan of the structure.

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