JP2001083059A - Method for evaluating fireproof performance of high- strength bolt junction part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically increase the fireproof performance of a junction part by obtaining the shear resistance of a high-strength bolt at a high temperature such as a fire temperature by multiplying the shear strength of the high-strength bolt by the number of used bolts, and a sectional area. SOLUTION: Shear resistance of a junction part at a high temperature of a high- strength bolt junction part obtained by multiplying shear strength at a fire temperature by the number of high-strength bolts used for the high-strength bolt junction part, the axial sectional area of the high-strength bolt, and the number of shear surfaces of the high-strength bolt becomes larger than the long-term load shear resistance operating on the S10T high-strength bolt. More specifically, when performing the fireproof design of a steel frame structure used for the junction part of the high- strength bolt with S10T based on the current building standard law execution method, it may be evaluated that the fireproof property exists if the assumed fire temperature is 550 deg.C or less. Even if an experiment at a high temperature being assumed in fireproof design is not performed each time, the shear strength of the high-strength bolt can be obtained by calculation, thus easily discussing the fireproof design at a high temperature being assumed under various conditions including the case of fire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for evaluating the fire resistance of a high-strength bolted joint of a steel structure.

[0002]

2. Description of the Related Art Conventionally, the fire resistance performance of a steel structure has been evaluated based on the allowable temperature of the member and the fire resistance time. Therefore, as long as the conventional evaluation method is adopted, for example,
In the fire resistance design of steel structures, it is only possible to design fire resistance below the allowable temperature of steel materials (average temperature 350 ° C) specified by the Building Standards Law. could not.

However, as a practical requirement, the above 350
In many cases, a fire-resistant design above ℃ is required. Therefore,
For example, in recent years, a method for evaluating the fire resistance performance of the entire frame has been proposed as a method capable of designing a fire resistance exceeding 350 ° C.

[0004] Such a method is a method of analytically obtaining stress and deformation applied to a frame at the time of a fire and evaluating fire resistance performance. (57-1986) ”(FIG. 3).

[0005] In accordance with the flow shown in FIG. 3, a fire-resistant design of a steel structure is performed as follows. First, a target level of fire resistance is set. The target level of fire resistance is set based on the fire resistance design standards and the plan for fire prevention compartments. An evaluation criterion is determined in accordance with the target level of fire resistance performance set in this way, and whether or not the fire resistance design is appropriate is determined based on whether the evaluation criterion is met.

[0006] Next, with respect to the design plan drafted in this manner, a property prediction calculation at the time of fire is performed to predict the fire resistance performance of the steel structure. In the property prediction calculation, as shown in the flow of FIG. 3, the calculation is performed using the external force and the design constant set after appropriately setting the safety coefficient from the fire resistance design standard.

When setting the external force and the design constant, a database is prepared in advance of the fire resistance performance data obtained by experiments, and this database is used. When data is insufficient, data collection is performed by experiments as appropriate.

Further, the fire property prediction calculation is performed based on the property prediction calculation method, the simple calculation program, and the design calculation chart using the above design constants.

The property prediction calculation includes a step of calculating the relationship between fire temperature and time by substituting actual test results and calculation data into a theoretical formula, a step of calculating a relationship between member temperature and time, Through a series of steps including a step of calculating the relationship between deformation, proof stress, and time, the property prediction is precisely settled.

In addition to the above settlement, the property prediction calculation includes a step of calculating the maximum fire time by multiplying the safety factor based on the equivalent design, and a step of calculating the maximum temperature of the member by multiplying the safety factor. There is a rough calculation for estimating the properties in anticipation of the safety factor through a series of processes consisting of multiplying the safety factor and calculating the deformation and the proof stress of the member.

However, conventionally, the database used for calculating the property prediction calculation is insufficient, or there is no clear evaluation criterion, and the calculation result cannot be evaluated substantially. For this reason, there have been few examples in which a fireproof design for evaluating the fireproof performance of the entire frame is performed.

Therefore, the present inventor has proposed a method for evaluating the fire resistance performance of a steel frame member based on the experimental data (experimental data exceeding 350 ° C.) of the steel frame member (Japanese Patent Application No. Hei 10 (1999)).
0-136707), but this does not include the method of evaluating the joint.

[0013]

Conventionally, no specific evaluation criteria for the fire resistance performance of the joint have been proposed, and the fire resistance of the joint is evaluated in the architectural design in which the fire resistance design evaluation is performed on the entire frame. And could not be applied to real architectural designs.

The inventor of the present invention has collected temperature data based on a fire test of a high-strength bolt used for a joint of a steel structure, and has urgently implemented a concrete evaluation method for enabling the above fire-resistant design based on the data. Thought it needed to be established.

[0015] In particular, the present inventors have, from a more practical point of view,
It was urgently needed to establish a method for evaluating the fire resistance performance of joints using high-strength bolts of F10T specified by Japanese Industrial Standards (JIS) and S10T specified by Japan Steel Structure Association Standards (JSS).

An object of the present invention is to provide Japanese Industrial Standards (JIS).
F10T and the Japan Steel Structure Association Standard (J
The present invention proposes specific fire resistance evaluation criteria for high strength bolted joints using S10T high strength bolts specified in SS).

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0018]

SUMMARY OF THE INVENTION The present invention relates to a steel structure using a high-strength bolt of F10T defined by the Japanese Industrial Standard (JIS) or S10T defined by the Japan Steel Structure Association (JSS). The high-temperature shear strength of the high-strength bolt at a high temperature such as a fire temperature at the joint portion of the high-strength bolt joint is based on the shear strength of the high-strength bolt at the high temperature.
When the number of the high-strength bolts used is multiplied by the cross-sectional area of the high-strength bolt, and the high-temperature shear strength is larger than the long-term load shear force acting on the high-strength bolt joint due to a long-term load. In the high strength bolt joint,
A method for evaluating the fire resistance of a high-strength bolt joint which is evaluated to have fire resistance to high temperatures, wherein the shear strength of the high-strength bolt is τ = σ / 3 ^1/2 = ｛F × κ ( in T)} / 3 ^1/2 consisting formula, tau: shear strength of the high strength bolt of F10T or S10T at high temperatures sigma: tensile strength of high strength bolt of F10T or S10T at high temperatures F: at the normal temperature F10T or Tensile strength of high-strength bolt of S10T T: Temperature (° C) of F10T or high-strength bolt of S10T assumed at high temperature κ (T): As a function of temperature T, κ (T) when T ≦ 300 ° C T) = 1, when 300 ° C. <T ≦ 700 ° C., κ (T) = 1− (T−
300) / 400.

[0019] The present invention also relates to F10T defined by Japanese Industrial Standards (JIS) or Japan Steel Structure Association Standard (J
SS), the high-temperature joint strength of the high-strength bolt joint at high temperature such as fire temperature at the joint of the high-strength bolt joint of the steel structure using the high-strength bolt of S10T is determined by the long-term load. When the shear strength is greater than the long-term load joint acting on the high-strength bolted joint, the high-strength bolted joint is evaluated to have fire resistance at high temperatures. The method
When the high temperature is 500 ° C., 550 ° C., and 600 ° C., the high-temperature joint shear strength at each high temperature is 500 ° C.
3.16 tf / cm ² at 2.50 tf / c at 550 ° C.
shear strength in m ^2, 600 each temperature of 1.48tf / cm ² and the high-strength bolts at ° C., and use the number of the high-strength bolts, the cross-sectional area of the high-strength bolts, shear of the high-strength bolts It is obtained by multiplying by the number of surfaces.

The allowable shear stress for the long-term stress of the F10T or S10T high-strength bolt is 1.5 tf / c.
The steel structure designed based on the structural design defining and m ^2, the temperature of the high temperature of the high-strength bolts in the high-strength bolted connection is, if 550 ° C. or less is evaluated as having a fire resistance It is characterized by the following.

The present invention also relates to F10T defined in Japanese Industrial Standards (JIS) or Japan Steel Structure Association (JS).
A method for evaluating the fire resistance performance of a high-strength bolt joint of a steel frame structure using a high-strength bolt of S10T defined in S), the shear strength of the high-strength bolt at high temperature, the number of the high-strength bolts used, The shear strength of the high-strength bolt joint obtained by multiplying the cross-sectional area of the high-strength bolt by the number of shear planes of the high-strength bolt is determined by the tensile strength of the base material at the high temperature. If the strength of the side wall of the high-strength bolt insertion base material hole obtained by multiplying the bolt shaft diameter by the base material thickness is larger, the high-strength bolt is more refractory than the base material hole side wall at that temperature. It is characterized by having the property.

According to the invention having the above-described structure, the F defined by the Japanese Industrial Standard (JIS), which is frequently used in actual construction sites, is used.
There is no objective standard because the fire resistance of the joint using 10T or S10T high-strength bolts defined by the Japan Steel Structure Association Standard (JSS) can be evaluated in light of numerical standards obtained by experiments. Therefore, it is possible to design fire resistance of the steel structure at a high temperature exceeding the allowable temperature of 350 ° C. or more, which has not been conventionally performed.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples.

(Example) FIG. 1 (a) shows a joint specimen used for an experiment of the fire resistance performance of a high-strength bolt joint using a high-strength bolt of S10T specified by the Japan Steel Structure Association Standard (JSS). FIG. 2B is a plan view, and FIG. FIG. 2 is a front view of a force applying device used for a fire resistance performance test.

In the experiment, the shear strength of a high-strength bolt at a high temperature such as a fire temperature assumed at the time of a fire, for example, was measured using a test body having the configuration shown in FIG. As shown in FIG. 1, the test body was formed by joining both base materials 10 and 10 ′ in a two-plane shearing friction joining manner.

In the case shown in FIG. 1, a rectangular auxiliary plate 11 is provided on the front and back surfaces of one end of a steel plate having a thickness of 25 mm.
Are joined by welding, and the steel plate of the other base material 10 ′ to be joined can be inserted between the auxiliary plates 11.
As the high-strength bolt, S10 of JSSII09 standard is used.
A torsia-type high-strength bolt for T structure was used.

The base material 10 has 630 × 125 × 25 mm
Is 760 x 100 x 25 mm
Steel plates are used. Two base plates 11 formed of a 330 × 100 × 12 mm steel plate are used as base materials 1 of base material 10.
The end portion 11a of the base plate 11 is welded to the front surface and the back surface side of the base material 10 so as to protrude in the longitudinal direction at a position 200 mm before the butt end to be joined to 0 '.

The base material 10 ′ is inserted between the two attachment plates 11 so that the butted end faces are separated from each other by 10 mm from the butted end faces of the base material 10. Attachment plate 11
The base material 10 ′ is provided with a high-strength bolt insertion hole for joining, respectively, and the base material 10 ′ is inserted between the two base plates 11, and the base material 10 ′ and the base material 10 ′ are respectively inserted. The high-strength bolt insertion holes are aligned with each other.

In this state, the high-strength bolt of S10T-M22 is passed through these high-strength bolt insertion holes in this state, and the joint is subjected to high-strength bolt joining, and the two-surface shearing by SM490A is performed. The joint test body 12 of the frictional joint type is constructed.

As described above, in the joint specimen 12, S1
A high-strength bolt of 0T-M22 is used to join the high-strength bolts using two steel plates so that the longitudinal distance after joining of the base materials 10, 10 'is 1400 mm. FIG. 1 shows the dimensions of each part of the joint specimen 12 so that the above configuration can be clearly understood.

A test is performed by attaching the joint test body 12 having such a configuration to the force applying device shown in FIG. As the force test device, a hydraulic 200tf universal testing machine was used. An upper chuck 1 for mounting a test piece is provided in the force test device.
3 and a lower chuck 14 are provided.

An electric furnace 15 is provided between the upper chuck 13 and the lower chuck 14 so as to cover the joint specimen 12. The lower crosshead 16 provided with the lower chuck 14 is fixed, and the upper crosshead 17 provided with the upper chuck 13 can move upward.

A displacement measuring jig 18 is provided between a frame portion 17a that follows the movement of the upper crosshead 17 and a lower frame 16a that follows the lower crosshead.

One end 10a side of the base material 10 constituting the joint test body 12 is chucked and fixed to the upper chuck 13 so as to hang down. In this state, as shown in FIG.
An electric furnace 15 is set so as to cover the heating section with the range of m as a heating section.

In the electric furnace 15, the heating section of the high-strength bolted joint is heated to a high temperature expected at the time of a fire, and when the temperature reaches a predetermined temperature, the temperature is maintained for one hour, for example.
Then, the lower end side 10 ′ of the joint specimen 12 is attached to the lower chuck.
a is chucked and fixed.

While the lower crosshead 16 side is fixed, the upper crosshead 17 side is gradually moved upward, and the high-strength bolt S10T-M22 joining the base materials 10, 10 'of the joint test body 12 is formed. Is given a shearing force and the load is measured.

At the time of the test, the high-strength bolt may be appropriately covered with a stainless net or the like so as not to cause damage to the surroundings due to the scattering of broken pieces at the time of shear fracture of the high-strength bolt.

[0038]

[Table 1]

Twenty-one joint specimens 12 having the above configuration were prepared, and these joint specimens 12 were subjected to a test under the conditions shown in Table 1. That is, room temperature, 200 ° C, 300 ° C,
At 400 ° C, 500 ° C, 550 ° C, and 600 ° C,
The joint specimen 12 was heated and maintained in the electric furnace 15, and the shearing force of the high-strength bolt at that time was measured.

Table 2 shows the average value of the shearing force at each temperature obtained by the shearing force test performed as described above. In addition,
The values in Table 2 are the shear strength (tf / cm ² ) of the S10T high strength bolt at each temperature.

[0041]

[Table 2]

When designing a fire-resistant steel frame structure based on the current Building Standard Law, the Japanese Industrial Standards (JIS)
F10T specified in Japan or the Japan Steel Structure Association Standard (JS
When using S10T high strength bolts specified in S),
Specified reference tension T _{0 of} high-strength bolt (5 tf / c
m ² ), 0.3T ₀ (1.5tf
/ Cm ² ).

When the allowable shear stress is compared with the shear strength obtained by the experiment in Table 2, if the temperature assumed as the fire temperature of the high strength bolt joint is 550 ° C. or less,
It can be seen that, at any temperature, the shear strength exceeds the allowable shear stress shown in the above-mentioned example of the current Building Standard Law.

Accordingly, the shear strength at the fire temperature, the number of high-strength bolts used for the high-strength bolt joint, the axial cross-sectional area (unit: cm ² ) of the high-strength bolt used, and the shear strength of the high-strength bolt The high-temperature joint strength of the high-strength bolted joint obtained by multiplying the number of
It is larger than the long-term load shear strength acting on the 0T high-strength bolt.

That is, in the case of performing a fire-resistant design of a steel frame structure using S10T high-strength bolts for joints based on the current Building Standard Law enforcement order, the assumed fire temperature is 55
If the temperature is 0 ° C. or less, it may be evaluated that it has fire resistance.

Further, by comparing the following equation conventionally proposed as an equation indicating the shear strength of a high-strength bolt with the shear strength at each high temperature obtained in the above experiment, τ = σ / 3 ^1/2 = {F × κ (T)} / 3 ^1/2 τ: Shear strength of S10T high strength bolt at high temperature σ: Tensile strength of S10T high strength bolt at high temperature F: Normal temperature Tensile strength of high-strength bolt of S10T T: Temperature (° C) of high-strength bolt of S10T assumed at high temperature κ (T): Function of temperature T With good accuracy, κ (T): Temperature T When T ≦ 300 ° C., κ (T) = 1, and when 300 ° C. <T ≦ 700 ° C., κ (T) = 1− (T−
300) / 400.

In the empirical formula, a value slightly lower than the experimental value at the same temperature is calculated in consideration of the safety factor when calculating the formula.

In the case where a high-strength bolt of S10T is used, it is possible to calculate the shear strength at an arbitrary temperature up to 700 ° C. from the tensile strength of the high-strength bolt of S10T at room temperature. it can.

This time, the present inventor has found such an empirical formula. As a result, in the high-strength bolt of S10T,
The shear strength of high-strength bolts can be calculated by calculation without having to perform experiments at high temperatures assumed each time when designing fire resistance, and the fire resistance at high temperatures expected in various situations including fires can be calculated. The design can be easily studied.

In the above description, only the case where a high-strength bolt of S10T is used has been described. However, a high-strength bolt of F10T defined by Japanese Industrial Standards (JIS) having substantially the same configuration as S10T is also described. And can be similarly applied.

[0051]

[Table 3]

Further, from the results shown in Table 2, when a base material having a thickness smaller than the thickness of the base material used in the high-strength bolt joint at each temperature shown in Table 3 is used, the high-strength bolt joint at each temperature is used. The shear strength is larger than the strength of the side wall of the high-strength bolt insertion base material hole, so that the high-strength bolt does not break before the base material, and the fire resistance of the high-strength bolt joint can be secured.

Table 3 shows the upper limit of the thickness of the base material that can be used in the high-strength bolted joint at each temperature. In an actual design, the base material, the nominal diameter, and each temperature are used. The upper limit of the usable base material thickness may be read from Table 3.

In the above embodiment, the high temperature condition is described as a high temperature assumed at the time of a fire. However, the high temperature may be a high temperature derived from a situation other than a fire.

[0055]

According to the present invention, it is possible to evaluate the fire resistance performance of a high strength bolt joint.

For this reason, the Ministry of Construction's Comprehensive Technology Development Project “Development of Fire Protection Design Method for Buildings (1972 to 1982)
By performing the fire resistance evaluation of the high-strength bolted joint according to the flow of “1st year)”, the fire resistance design according to the above flow can be specifically performed, unlike the related art.

According to the present invention, in a steel structure having a temperature exceeding 350 ° C., it is possible to design such that the fire resistance of the joint is raised to about 600 ° C.

[Brief description of the drawings]

FIG. 1A is a plan view showing a configuration of a joint specimen, and FIG. 1B is a side view thereof.

FIG. 2 is a front view showing a configuration of a force applying device.

FIG. 3 is a flowchart of “development of a fire protection design method for buildings” proposed in the Ministry of Construction's Comprehensive Technology Development Project.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Base material 10a One end 10 'Base material 10a' one end 11 Attached plate 12 Joint test piece 13 Upper chuck 14 Lower chuck 15 Electric furnace 16 Lower crosshead 16a frame 17 Upper crosshead 17a Frame 18 Displacement measuring jig

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 000195971 Nishimatsu Construction Co., Ltd. 1-20-10 Toranomon, Minato-ku, Tokyo (71) Applicant 000140982 Ma-gumi Co., Ltd. 2-5-2-8 Kitaaoyama, Minato-ku, Tokyo Applicant 000201478 Maeda Construction Industry Co., Ltd. 2-10-26 Fujimi, Chiyoda-ku, Tokyo (71) Applicant 000112668 Fujita Co., Ltd. 4-6-115 Sendagaya, Shibuya-ku, Tokyo (72) Inventor Hikaru Saito Narashino, Chiba Prefecture 1-2-1 Ichizumi-cho, Nihon University Research Institute for Science and Technology (72) Inventor Hideki Uesugi 1-33 Yayoimachi, Inage-ku, Chiba-shi, Chiba Graduate School of Science and Technology, Chiba Univ. Ichihara 2 Better Living Foundation (72) Inventor Yasuyuki Yamauchi 1 Tsukuba Ibaraki Ibaraki Pref. Masatomo Yoshida 5-8-1, Fujishirodai, Suita-shi, Osaka (72) Inside the Building Research Institute, Japan (72) Inventor Hiroyuki Nagana 47-3 Mita, Atsugi-shi, Kanagawa Prefecture Sato Industrial Co., Ltd. (72) Inventor Toshiyasu Orimo 47-3 Mita, Atsugi-shi, Kanagawa Prefecture Inside Sato Kogyo Co., Ltd. (72) Inventor Osamu Chiba 4-6-1 Hatchobori, Chuo-ku, Tokyo Inside Hatchobori Center Building Toda Construction Co., Ltd. 315 Toda Construction Co., Ltd. (72) Inventor Hiroshi Asaga 4054 Nishimatsu Sakuradai, Aikawa-cho, Aika-gun, Kanagawa Prefecture Nishimatsu Construction Co., Ltd. Within Construction Co., Ltd. (72) Inventor Shuichi Takakura 2-58-8 Kita-Aoyama, Minato-ku, Tokyo Intra-company group (72) Inventor Akio Hori 2-58-8 Kita-Aoyama, Minato-ku, Tokyo Intra-company group (72) Inventor Takeho Ikeda Maeda Construction, 2-10-26 Fujimi, Chiyoda-ku, Tokyo (72) Inventor Akira Nakagome 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. (72) Inventor Masashi Matsudo 4-6-115 Sendagaya, Shibuya-ku, Tokyo Stock Company Inside Fujita (72) Inventor Takeo Hirashima 4-6-15 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd.

Claims (4)

[Claims] 1. F defined by Japanese Industrial Standards (JIS)
High-temperature shearing of high-strength bolts at high temperatures such as fire temperatures at joints of high-strength bolt joints of steel structures using 10T or S10T high-strength bolts defined by the Japan Steel Structure Association Standard (JSS) The proof stress is obtained by multiplying the shear strength of the high-strength bolt at the high temperature by the number of the high-strength bolts used and the cross-sectional area of the high-strength bolt. If greater than the long-term load shear force acting on the high strength bolt joint,
A method for evaluating the fire resistance performance of a high-strength bolt joint that evaluates the high-strength bolt joint to have fire resistance to the high temperature, wherein the shear strength of the high-strength bolt is: τ = σ / 3 in ^{1/2 = {F × κ (T} )} / 3 1/2 consisting formula, tau: high strength bolts F10T or S10T at high temperature shear strength sigma: the F10T or S10T at high temperature high-strength bolts for Tensile strength F: Tensile strength of F10T or S10T high-strength bolt at normal temperature T: Temperature (° C) of F10T or S10T high-strength bolt assumed at high temperature κ (T): Function of temperature T, T When ≦ 300 ° C., κ (T) = 1, and when 300 ° C. <T ≦ 700 ° C., κ (T) = 1− (T−
(300) / 400. 2. F defined by Japanese Industrial Standards (JIS)
High temperature of high-strength bolt joints at high temperature such as fire temperature at joints of high-strength bolt joints of steel structures using 10T or S10T high-strength bolts specified by the Japan Steel Structure Association Standard (JSS) When the shear strength at the time of joining is larger than the long-term load shearing force acting on the high-strength bolt joint due to the long-term load, the high-strength bolt joint has fire resistance to the high temperature. A method for evaluating the fire resistance performance of a high-strength bolted joint to be evaluated, wherein when the high temperature is 500 ° C., 550 ° C., and 600 ° C., the high-temperature joint strength at each temperature is 500 ° C.
3.16 tf / cm ² at 2.50 tf / c at 550 ° C.
shear strength in m ^2, 600 each temperature of 1.48tf / cm ² and the high-strength bolts at ° C., and use the number of the high-strength bolts, the cross-sectional area of the high-strength bolts, shear of the high-strength bolts A method for evaluating the fire resistance performance of a high-strength bolted joint obtained by multiplying by the number of surfaces. 3. The method for evaluating the fire resistance performance of a high-strength bolted joint according to claim 2, wherein the allowable shear stress for long-term stress of the F10T or S10T high-strength bolt is set to 1.5 tf / cm ^2. In the steel frame structure designed based on the high-temperature bolt at the high-strength bolt joint at a high temperature,
A method for evaluating the fire resistance performance of a high-strength bolted joint, wherein the method is evaluated as having fire resistance if the temperature is 550 ° C. or lower. 4. F10 specified in Japanese Industrial Standards (JIS)
T or S defined in the Japan Steel Structure Association Standard (JSS)
A method for evaluating fire resistance of a high-strength bolt joint of a steel structure using a 10T high-strength bolt, comprising: a shear strength of the high-strength bolt at a high temperature; And the shear strength of the high-strength bolt joint obtained by multiplying the cross-sectional area of the high-strength bolt by the number of shearing sections of the high-strength bolt, the tensile strength of the base material at the high temperature, the shaft diameter of the high-strength bolt When the strength of the side wall of the high-strength bolt insertion base material hole obtained by multiplying by the thickness of the base material is larger than that of the base material hole side wall at that temperature, the high-strength bolt has more fire resistance. A method for evaluating the fire resistance performance of a high-strength bolted joint, characterized in that it is evaluated that the joint has high resistance.