JP4637415B2 - Floor magnification test method for building structural elements - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a floor magnification test method for building structural elements, and more particularly to a floor magnification test method for evaluating the structural strength of a horizontal building surface such as a floor, a roof, and a hut.
[0002]
[Prior art]
According to the Act on Promotion of Housing Quality Assurance (Act No. 81 of 1999, hereinafter referred to as the Quality Assurance Act), there is a system for displaying the performance of a house using a house performance evaluation report. In response to this method of accuracy, the Ministry of Construction Notification No. 1654-144 stipulates the details of the standard for evaluating the performance of houses.
[0003]
There are a wide variety of inspection items and test items for evaluating the performance of a house. Among them, there are a wall magnification and a floor magnification for evaluating the strength of a structural element such as a house wall, a floor, and a roof. These are the main criteria for assessing the strength performance of a house.
[0004]
Wall magnification is an index that indicates the level of structural strength of a wall that is a vertical surface, and floor magnification is an index that indicates the level of structural strength of a horizontal surface such as a floor assembly, a roof hut assembly, or a roof surface. It is. The higher these indices are, the higher the evaluation grade of the structure of the house is, and it means that the building is strong against external forces such as earthquakes and wind pressure. The Ministry of Construction Notification No. 1654-154 only shows the minimum standard values for wall magnification and floor magnification, and does not stipulate specific test methods uniformly. Etc. have proposed test methods and evaluation methods.
[0005]
Therefore, FIG. 6 shows a standard wall magnification and floor magnification test method adopted by a public performance evaluation organization.
Both the wall magnification and floor magnification are measured while applying a force from a specific direction determined by the test method to the specimen 2 in a fixed state, and it is necessary to obtain a certain amount of deformation. The wall magnification and the floor magnification are obtained based on the magnitude of the applied force.
[0006]
[Problems to be solved by the invention]
FIG. 7 shows the effect of seismic force and wind pressure on the building walls, flooring and roof. The basic concept of the standard wall magnification and test method described above is that, in the case of a wall that constitutes a vertical plane, if the wall 4 is parallel to the X direction, the seismic force and wind pressure from the X direction If the wall 5 has a certain level of structural strength and is parallel to the Y direction, the wall 5 may have a certain level of structural strength against the seismic force from the Y direction.
[0007]
However, the same concept as the wall magnification test is applied to the floor magnification for the floor, roof, and hut assembly that make up the horizontal construction surface in that a force is applied from one direction. That is, in the case of the floor 6, the seismic force and the wind pressure can act from the X direction or the Y direction, while the floor magnification is calculated by applying the force from the X direction to the test body of the floor 6. Strictly speaking, this floor magnification is the structural strength in the X direction and not the structural strength in the Y direction. There is no problem as long as the specimen itself is a member that is isotropic with respect to force. However, a structural member used for an actual floor or the like generally has anisotropy in terms of structural strength and has a specific direction. Many have the property of being strong against force and weak against force in a certain direction.
[0008]
However, in the case of members such as floor panels used for floors, etc., the rigidity varies depending on the direction depending on the direction of the panel and the direction of joining, but it is important to determine which direction is strong and which direction is weak. Have difficulty.
[0009]
Therefore, conventionally, for example, even if the specimen of the floor 6 has anisotropy that is strong in the X direction and weak in the Y direction, the floor magnification is calculated based on the force applied from the strong X direction in strength. In this case, an evaluation grade higher than the substantial structural strength performance may be represented.
[0010]
Therefore, an object of the present invention is to perform a test with a test body incorporating factors considered to be disadvantageous in strength by solving the problems of the prior art and introducing the concept of a strong axis and a weak axis for the test body. Another object of the present invention is to provide a method for testing the floor magnification of a building structural element that can correctly evaluate the substantial structural strength of the horizontal surface of the building.
[0011]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention relates to a building performance evaluation standard in accordance with laws and ordinances, etc., for a floor set or a roof shed set and a structural element used for a roof surface constituting a horizontal plane of a building. A floor magnification test method for obtaining a floor magnification designated as: a first axis and a second axis that are orthogonal to each other and serve as a reference for a weak axis and a strong axis for the structural element; A first test body for testing the floor magnification of the structural element with the first axial direction as the force direction, and a floor test of the structural element with the second axial direction as the force direction A second test body is prepared, and each of the first test body and the second test body is applied with force to measure the standard strength data, and the measured standard strength data is used for the first test body and the second test body. The direction of force applied to the specimen with weaker strength It is determined that the structural element is in the direction of the weak axis, and the base proof stress is measured for a plurality of test bodies having the weak axis direction of the structural element as the force direction, and the floor magnification is determined based on these standard proof strengths. It is characterized by calculating.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a floor magnification test method for building structural elements according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a specimen used for the floor magnification test method according to the present embodiment. Here, a test body for obtaining the floor magnification of a floor panel used as a floor set will be described as an example.
[0013]
Reference numeral 10 indicates the entire floor panel. As shown in FIG. 1, the floor panel 10 is set with an X axis and a Y axis, which are used as criteria for determining a weak axis and a strong axis. Here, the weak axis is the axis that is weaker in structural strength, and the strong axis is the axis that is stronger in structural strength.
[0014]
As the test body, an X-axis test body 12 and a Y-axis test body 14 are produced using the floor panel 10 as a material. In this case, the X-axis test body 12 is a test body for testing the floor magnification when a force P from the X-axis direction is applied to the floor panel 10, and the Y-axis test body 14 is Y on the floor panel 10. It is a test body for testing the floor magnification when the applied force P from the axial direction is applied. Such a relationship between the X-axis test body 12 and the Y-axis test body 14 is produced by changing the direction by 90 degrees.
[0015]
The specification of such a test body is standardized in JIS A 1414 as an in-plane shear test method for a panel as a building component. Here, each of the X-axis test body 12 and the Y-axis test body 14 is formed by joining a wooden box and a floor panel material with wood screws.
[0016]
The width of the test specimen is about 1.82 m and the height is about 2.73 m.
[0017]
Next, FIG. 2 shows a test apparatus used for the test. FIG. 2 is a plan view, and the X-axis test body 12 and the Y-axis test body are fixed to the test apparatus in a horizontal posture by using two tie rods 17a and 17b, and are attached to JIS A 1414 by a hydraulic jack 15. The force is applied to the position specified by the test method of the tie rod type wooden frame bearing wall. Reference numeral 16 denotes a load cell that measures the magnitude of the applied force. H1 and H2 are displacement meters that measure the amount of deformation in the direction parallel to the applied force, and V3 and V4 are displacement meters that measure the amount of deformation in the direction perpendicular to the applied force. In this case, after the applied force reaches the maximum load, the applied force is applied until the load is reduced to 80% of the maximized net or until the displacement angle of the specimen reaches 1/15 rad or more. Measure. Then, from the measured data, yield ratio Py, ultimate yield strength Pu multiplied by 0.2Ds (Ds is the structural characteristic coefficient), 2/3 of maximum load Pmax, and the floor magnification calculation such as the yield strength at specific deformation The standard proof stress data required for Details of these measurements are explained in “Structural Design of Wooden Houses (Amended Standards Act and Quality Assurance Act)” (Architectural Technology, March 2001 issue, separate volume 6 published by Building Technology Co., Ltd.).
[0018]
The details of the floor magnification test method will be described below with reference to the flowchart of FIG.
First, in the first step S10, regarding the X-axis specimen 12 and the Y-axis specimen 14, it is determined on the desk which of the X-axis and the Y-axis is the strong axis and which is the weak axis. This is determined by intensity calculation or the like. If it cannot be determined, the process proceeds to step S11 and subsequent steps.
[0019]
In step S11, each of the X-axis specimen 12 and the Y-axis specimen 14 is obtained by multiplying the yield strength Py and the ultimate strength Pu by 0.2 Ds by the method shown in FIG. 2 (Ds is a structural characteristic coefficient). The standard proof stress data necessary for calculating the floor magnification, such as the value of the maximum load Pmax2 / 3 and the proof strength at the time of specific deformation, is obtained, and the data is compared between the X-axis test body 12 and the Y-axis test body 14.
[0020]
FIG. 4 shows an example of measurement data. In this case, when both are compared, the Y-axis specimen 14 has a higher strength than any other data, so the weak axis and the strong axis can be determined (yes in step S12). Therefore, in the subsequent step S13, it is determined that the Y axis is a strong axis and the X axis is a weak axis.
[0021]
Next, in step S14, with respect to the X-axis specimen 12 determined to be a weak axis, the yield strength Py and the ultimate strength Pu obtained by multiplying 0.2 Ds by the method of FIG. Characteristic coefficient), maximum load Pmax2 / 3 value, yield strength at the time of specific deformation, take the standard proof stress data necessary for floor magnification calculation, and combine it with the data of the first X-axis test mate 12 Collect data. An example of this data is shown in FIG.
[0022]
Finally, in step S15, the floor magnification is calculated from these data. Here, the floor magnification is a floor magnification such as a value obtained by multiplying the above yield strength Py and ultimate strength Pu by 0.2 Ds (Ds is a structural characteristic coefficient), a value of maximum load Pmax2 / 3, and a yield strength at a specific deformation. Among the values calculated by multiplying the average value of the proof stress obtained from the standard proof stress data necessary for the calculation by the variation coefficient, the shortest reference shear strength P0 is set.
The floor magnification is calculated by the following formula.
Floor magnification = short-term reference shear strength P0 / (effective length of test specimen × 1.96 kN)
As described above, the floor magnification obtained by applying force from the weak axis direction, which is weak in strength, can be obtained. Therefore, when evaluating the strength performance of a building, it is calculated by incorporating factors considered to be disadvantageous in strength. The floor magnification can be used to make a legitimate assessment of safety.
[0023]
Next, step S16 is a test method in the case where it is possible to determine the weak axis and the strong axis on the desk in step S10. In this case, a three-body test is performed on the test body that is determined as the weak axis, The floor magnification may be calculated in the same manner as described above.
[0024]
Step S17 is a process performed when the weak axis and the strong axis cannot be determined in step S12. Here, when the weak axis and the strong axis cannot be discriminated, the values are different or similar even when the proof stress data of the X-axis test body 12 and the Y-axis test body 14 are compared. This is the case when it is difficult to judge.
[0025]
In that case, further, each of the X-axis test body 12 and the Y-axis test body 14 is tested two by two, yield strength data is collected, and the data of the previous step S11 are combined to obtain three X-axis tests for convenience. The floor magnification is calculated from the data of the body 12 and the Y-axis specimen 14, respectively, and the lower one is the weak axis.
[0026]
Thus, even when it is difficult to determine the weak axis and the strong axis, the floor magnification obtained by the force applied from the weak axis can be surely obtained. In addition, by using the initial data, the number of test bodies is three, and an efficient test can be performed.
[0027]
【The invention's effect】
As is apparent from the above description, according to the present invention, by introducing the concept of a strong axis and a weak axis for the test body, the test is performed with the test body incorporating factors considered to be disadvantageous in strength, and the building It is possible to correctly evaluate the substantial structural strength of the horizontal surface.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory diagram showing a test specimen used for a floor magnification test method according to the present invention.
FIG. 2 is a plan view showing a test apparatus used in the floor magnification test method according to the present invention.
FIG. 3 is a flowchart showing the procedure of a floor magnification test method according to the present invention.
FIG. 4 is a diagram showing an example of yield strength data for an X-axis specimen and a Y-axis specimen.
FIG. 5 is a diagram showing an example of yield strength data for a test specimen determined as a weak axis.
FIG. 6 is a diagram showing the concept of a floor magnification test method.
FIG. 7 is a diagram showing the direction of external force acting on a building.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Floor panel 12 X-axis test body 14 Y-axis test body 15 Hydraulic jack 16 Load cell 17a, 17b Tie rod

Claims (1)

With the floor magnification test method to obtain the floor magnification specified as the performance evaluation standard of the building by law, etc., for the floor set or the roof shed set and the structural elements used for the roof surface that make up the horizontal surface of the building There,
A first axis and a second axis that are orthogonal to each other and serve as a reference for the weak axis and the strong axis for the structural element,
A first test body for testing the floor magnification of the structural element with the first axial direction as the force direction, and a floor test of the structural element with the second axial direction as the force direction Prepare a second specimen and
The standard strength data is measured by applying force to each of the first test body and the second test body, and the measured standard strength data is compared between the first test body and the second test body. It is determined that the direction of body force is the direction of the weak axis of the structural element,
Further, for a plurality of test bodies having a direction of weak axis of the structural element as a force direction, the standard proof stress is measured, and the floor magnification is calculated based on the standard proof stress. Floor magnification test method.

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