Vibration prediction method of dry jointed floor and design change method based on vibration prediction result of dry jointed floor

Abstract

To provide a vibration prediction method for a dry jointed floor, which can predict vibration with high accuracy by a relatively simple method, and a design change method based on a vibration prediction result of the dry jointed floor.SOLUTION: The vibration prediction method is provided for a dry-jointed floor in which end portions of a floor panel are jointed to a plurality of beams provided side by side at intervals by jointing hardware. The vibration prediction is a prediction using a physical index corresponding to human evaluation, and is set by the following equation (X).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for predicting vibrations of a dry-jointed floor and a method for modifying the design based on the results of vibration predictions of the dry-jointed floor. [Background technology]

[0002] In recent years, with the diversification of building uses, there has been a desire to realize large spaces using long-span beams in industrialized housing, and in order to realize this, it is necessary to properly evaluate the risk of vibration disorders caused by environmental vibrations (especially walking vibrations). In particular, buildings used for residential purposes are spaces where residents can relax, and considering that people are spending more time at home due to recent social conditions, even greater attention is needed to vibration disorders.

[0003] In industrialized housing, dry joining is sometimes used to join beams and floor panels in order to improve construction efficiency, but this dry joining secures the beams and floor panels less firmly than wet joining, and currently there is no established method for analytically evaluating floor vibration.For example, there is a method for evaluating floor vibration of a dry-jointed floor in which a pair of opposing end sides (e.g., short sides) of a rectangular floor panel in plan view is placed on two beams placed next to each other, and the ends of the beam and floor panel are joined with joint metal fittings, while the other pair of end sides (e.g., long sides) are free and not fixed to the beams.

[0004] The magnitude of floor vibration caused by people walking in a house cannot be easily predicted, and in order to make such predictions, the floor in question is typically modeled in a computer and vibration analysis is performed, but simple analytical models cannot take into account the influence of interior and exterior walls, such as partition walls, that support the floor panels in addition to the beams that support the floor panels, and therefore cannot predict floor vibration with high accuracy.On the other hand, vibration analysis based on detailed modeling that takes into account these interior walls, etc., requires a great deal of time and effort for the series of analyses, including modeling, and raises new issues such as high analysis costs.

[0005] In light of the above, there is a need for a method for predicting the vibration of dry-jointed floors that can predict vibration with high accuracy in a relatively simple manner, without having to perform highly accurate vibration analysis, which requires time and effort.

[0006] Here, a floor vibration analysis system is proposed in Patent Document 1. This floor vibration analysis system is a floor vibration analysis system that analyzes vibrations at vibration evaluation points present in an evaluation area that is rectangular in plan view and includes a beam structure in which minor beams are arranged in a space surrounded by major beams of a steel-framed building, and a rectangular floor slab supported by the beam structure. This floor vibration analysis system calculates the vertical acceleration of a time-varying vibration evaluation point when a time-varying excitation force acts as an external force at the vibration evaluation point in an evaluation area where a partition wall is located, and is equipped with a mass calculation unit that calculates the mass at the vibration of the vibration evaluation point from the weight of the floor slab of the evaluation area acting on the beam structure, a spring constant calculation unit that calculates the natural frequency of the floor in the evaluation area based on information about the beam structure and information about the floor slab and calculates the spring constant at the vibration of the vibration evaluation point based on the natural frequency, a damping constant calculation unit that calculates the damping constant at the vibration of the vibration evaluation point from at least information about the partition wall, and an acceleration calculation unit that calculates the acceleration of the time-varying vibration evaluation point as the vibration of a one-degree-of-freedom system of the floor slab and beam structure based on the time-varying excitation force, spring constant, mass, and damping constant. [Prior art documents] [Non-patent literature]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-158338 Summary of the Invention [Problem to be solved by the invention]

[0008] The floor vibration analysis system described in Patent Document 1 is said to be able to analyze floor vibrations of a building while taking into account the effects of partition walls. However, it is necessary to build a new system to analyze floor vibrations, and it is difficult to say that vibration prediction can be performed with high accuracy using a relatively simple method.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a method for predicting the vibration of dry-jointed floors that can perform highly accurate vibration predictions in a relatively simple manner without performing highly accurate vibration analysis that requires time and effort, and a method for making design changes based on the results of the vibration prediction of dry-jointed floors. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the vibration prediction method for a dry-jointed floor according to the present invention is to: A vibration prediction method for a dry-jointed floor in which the ends of floor panels are joined to a plurality of beams arranged side by side at intervals by metal joints, comprising: The vibration prediction is a prediction using a physical index corresponding to a human evaluation, and is characterized by being set by the following formula (X):

[0011]

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[0012] According to this embodiment, vibration prediction is performed using equation (X) as a prediction using physical indicators corresponding to human evaluation, and vibration prediction of dry-bonded beds can be performed with high accuracy in a relatively simple manner without performing highly accurate vibration analysis, which requires time and effort.

[0013] Here, VLTp is a vibration evaluation index that quantifies human evaluation by applying a sensory testing method, and more specifically, it is a value calculated using a mathematical formula derived from an acceleration-time curve based on the relationship between human evaluation and walking vibration input by the inspector during the inspection. In this prediction method, this physical index has been replaced with a formula that uses distance from the floor panel, the beams that support the floor panel, the interior walls, etc. as elements.

[0014] Formula (X) takes into account the distance between the floor panel and interior walls such as partition walls or pillars as one of its elements, and is a formula that more closely reflects the actual phenomenon in which, when the floor panel is close to an interior wall, etc., it is less likely to vibrate due to the restraining effect.

[0015] Here, floor panels that form the dry-jointed floors that are the subject of vibration prediction can be deck plates, plywood (including structural plywood), cross-laminated timber (CLT), laminated veneer lumber (LVL), autoclaved lightweight concrete (ALC), etc. Floor panels include joist floor panels that have steel joists (for example, steel joist floor panels), as well as floor panels that do not have joists, such as ALC panels. Furthermore, steel beams formed from shaped steel materials such as H-shaped steel can be used for the beams that are the subject of the beam model.

[0016] Additionally, the beams that support the floor panels include main girders that span between columns and sub-girders that span between main girders, but "multiple beams arranged side by side at intervals" means main girders and sub-girders that are arranged side by side, or sub-girders and sub-girders that are arranged side by side.Multiple floor panels are placed on multiple beams (main girders and sub-girders) made of H-shaped steel or the like that are arranged side by side, and the ends of each floor panel are dry-joined to the beams via metal joints.

[0017] Furthermore, since the second moment of area of ​​the beam supporting the floor panel corresponding to "I" in the formula is greatly affected by beams with low rigidity when it comes to floor panel vibration, if the floor panel is supported by multiple beams with different second moments of area, the second moment of area of ​​the beam with the smallest second moment of area is applied.

[0018] Another aspect of the vibration prediction method for a dry-jointed floor according to the present invention is to A feature of the method is that a, b, c, d, and e are set by performing multiple regression analysis using a plurality of measured values ​​related to floor vibration.

[0019] According to this embodiment, by performing multiple regression analysis using multiple past measurements of floor vibration (measurements of floor vibration in various building properties) and setting the coefficients a, b, c, d, and e in formula (X), it is possible to define formula (X) with high accuracy for predicting the vibration of dry-bonded floors.

[0020] In addition, one aspect of the design modification method based on the vibration prediction results of a dry-jointed floor according to the present invention is as follows: Identifying the VLTp using the dry-bonded floor vibration prediction method; If the specified VLTp exceeds the standard value for VLTp, design changes are made to shorten the length of the floor panel in the beam-to-beam direction and / or increase the second moment of area of ​​the beams supporting the floor panel so that the standard value is met.

[0021] According to this aspect, if the specified VLTp exceeds the reference value, floor vibration can be effectively suppressed by a relatively easy design change by making either or both of the following design changes so that the reference value is met: shortening the length of the floor panel in the beam-to-beam direction, or increasing the moment of inertia of the beams supporting the floor panel. For example, although VLTp can be reduced by shortening the length of the beams, shortening the length of the beams is not an easy design change, and changing the distance from interior walls or columns is also not an easy design change because it directly leads to a plan change. [Effects of the Invention]

[0022] As can be understood from the above explanation, the dry-bonded floor vibration prediction method of the present invention allows for highly accurate vibration prediction of dry-bonded floors using a relatively simple method, without the need for highly accurate vibration analysis, which requires time and effort.Furthermore, the design change method based on the dry-bonded floor vibration prediction result of the present invention allows for relatively simple design changes to be made based on the dry-bonded floor vibration prediction result, and floor vibration can be effectively suppressed when the vibration prediction result exceeds the reference value. [Brief explanation of the drawings]

[0023] [Figure 1] This is a plan view of an example of a planar frame on which floor panels are installed, to which a vibration prediction method for dry-jointed floors is applied, and shows walking lines and vibration prediction points. [Figure 2] 2 is a diagram showing an example of an inner wall supporting the plane frame and a floor panel placed on the plane frame, in comparison with the plan view of the plane frame shown in FIG. 1. FIG. [Figure 3] FIG. 1 is a diagram showing coefficients a, b, c, d, and e in formula (X) and the coefficient of determination, which are set by multiple regression analysis based on a plurality of actual measurements of floor vibration. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an example of a method for predicting vibrations of a dry-bonded floor according to an embodiment and a method for modifying a design based on the results of vibration predictions of a dry-bonded floor will be described with reference to the accompanying drawings. Note that in this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant explanations.

[0025] [Method for predicting vibration of dry-jointed floors according to the embodiment and method for modifying design based on the results of vibration prediction of dry-jointed floors] First, an example of a vibration prediction method for a dry-jointed floor according to an embodiment will be described with reference to Figures 1 and 2. Here, Figure 1 is a plan view of an example of a plane frame on which floor panels are installed, to which the vibration prediction method for a dry-jointed floor is applied, and is a diagram showing walking lines and vibration prediction points. Furthermore, Figure 2 is a diagram showing an example of an inner wall supporting the plane frame and floor panels placed on the plane frame, in relation to the plan view of the plane frame shown in Figure 1.

[0026] The planar frame shown in the example of Figures 1 and 2 is formed by connecting both ends of sub-beams, such as A beam, B beam, and C beam, which are also made of H-shaped steel and are arranged side by side, to four main beams made of H-shaped steel and connected to four columns.

[0027] In addition, at the center position of the short side of the rectangular planar frame when viewed from above, the left and right main beams and adjacent sub-beams (beam A), and adjacent sub-beams and sub-beams (beam A and beam B, beam B and beam C, etc.) are each connected by steel connecting materials along the beam-to-beam direction (longitudinal direction), which is the direction between each sub-beam.

[0028] The length of one side of the grid indicated by the dotted lines is 1P, which is quantitatively a length of, for example, 910 mm.

[0029] The floor panels that are spanned across adjacent beams and have their ends dry-joined to each sub-beam with metal joints are ALC panels, steel joist floor panels, etc. Anti-vibration rubber, etc. may be placed between the beams and the floor panels.

[0030] As shown by the diagonal lines in Figure 2, the planar dimensions of rectangular floor panels in plan view vary, such as 2P x 1P, 2P x 2P, and 1P x 1P, and floor panels of various planar dimensions can be installed together on a single planar frame.

[0031] As vibration prediction points for predicting floor vibration, vibration prediction point 1 is set at the midpoint of the connecting material connecting beam A and beam B, and vibration prediction point 2 is set at the center position of beam C.

[0032] As can be seen from Figure 2, the partition wall, an inner wall, is installed in a key-shaped line at the center of the planar frame, and vibration prediction point 2 is set directly above the inner wall. In other words, vibration at vibration prediction point 2 is largely restrained by the inner wall. In contrast, vibration prediction point 1 is located midway between the inner wall on the left and the central inner wall, and is farther away from another inner wall that is positioned perpendicular to these inner walls. Therefore, although floor vibration at vibration prediction point 1 is not restrained by the inner wall as much as at vibration prediction point 2, it is inferred that there is a certain degree of restraint effect.

[0033] As shown in Figures 1 and 2, the source of floor vibration is generally considered to be foot vibration caused by walking along the walking line on beam B (an example of a beam) and on the floor panel between beam B and beam C (an example of a floor panel, not on a beam), as shown in the example.

[0034] The vibration prediction method for a dry-type jointed floor according to the embodiment is a prediction method that uses physical indicators corresponding to human evaluations, and is set by the following equation (Q).

[0035]

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[0036] At vibration prediction points 1 and 2 of the model shown in Figures 1 and 2, 2P (because in this example, the maximum value of the floor panel's length in the beam-to-beam direction is 2P) or 0P (when it is on a beam, as at vibration prediction point 2, the element of the floor panel's length is set to 0) is selected for Lp. Also, for I, beam B or beam C is selected, and more specifically, the smallest moment of inertia of either is selected. Also, since the length of each sub-beam is 4P, 4P is selected for l. Furthermore, for Lw, 1.5P (the distance from the left and right main beams to the interior wall at vibration prediction point 1 and in the direction perpendicular to it) or 0P (because vibration prediction point 2 is directly above the interior wall) is selected as the distance from each vibration prediction point 1 and 2 to the nearest interior wall in the beam-to-beam direction and in the direction perpendicular to it) is selected.

[0037] The coefficients a, b, c, d, and e mentioned above were determined by performing a multiple regression analysis using actual measurements of floor vibrations in multiple real properties in the past. More specifically, multiple regression analysis was performed for different types of data to be used, and the coefficients a, b, c, d, and e for each case were identified, formula (Q) was set, and the coefficient of determination for each formula (Q) was determined.

[0038] Figure 3 shows the prediction accuracy of floor vibration for each data set by each equation (Q), which is a diagram showing the coefficients a, b, c, d, and e in each equation (Q) and the coefficient of determination, which are set by multiple regression analysis based on multiple measured values ​​of floor vibration.

[0039] Here, there are 104 pieces of measured data, of which 29 pieces of data are considered to be little affected by interior walls (including partition walls).

[0040] In Figure 3, four verification results are shown, and the verification result on the far left is the result of setting equation (Q) using multiple regression analysis, taking into account all of the measured data and the influence of Lw, which is an element such as the inner wall.

[0041] Coefficient of determination (r 2 ) is 0.41, and the correlation coefficient (r) is the square root of the coefficient of determination, so the value is 0.64, which is a value with relatively high prediction accuracy.

[0042] In contrast, the second verification result from the left is the result of setting equation (Q) using multiple regression analysis, which covers all the measured data but does not take into account the influence of Lw, which is an element such as the inner wall.

[0043] Coefficient of determination (r 2 ) is 0.17, which is significantly lower than the leftmost result.

[0044] These two verification results demonstrate that, with regard to floor vibration of dry floor panels, when the planar frame including the beams that support the floor panels is supported by an interior wall such as a partition wall, taking into account the influence of the interior wall will improve the accuracy of predicting the vibration of the floor panel, and it is clear that there is great significance in including the Lw element in equation (Q).

[0045] On the other hand, the third and fourth verification results from the left were both based on 29 data points where the distance to the interior wall was 1.5P or more and the influence of the interior wall on the floor vibration of the floor panel was considered to be relatively low. The third verification result from the left was the result of formula (Q) being set using multiple regression analysis when the influence of Lw, an element of the interior wall, etc. was also taken into account, while the fourth verification result from the left (far right) was the result of formula (Q) being set using multiple regression analysis when the influence of Lw, an element of the interior wall, etc. was ignored.

[0046] Both coefficients of determination (r 2 ) are similar values ​​of 0.38 and 0.41, which shows that when there is a distance to the inner wall and its influence is relatively low, the influence of Lw, which is a factor of the inner wall, etc., does not have a significant effect on accuracy.

[0047] Taking all the above results into consideration, it can be said that although the impact on vibration prediction is low when the distance to the interior wall, etc. is long, the vibration prediction accuracy of the dry floor panel floor vibration using formula (Q), which includes the element Lw, which is an element of the interior wall, etc., is relatively high.

[0048] By using the above formula (Q) to predict the floor vibration of a dry floor panel, it is possible to predict vibration with high accuracy in a relatively simple manner, without having to perform highly accurate vibration analysis, which requires time and effort.

[0049] Next, a design change method using the vibration prediction results obtained using the above formula (Q) (a design change method based on the vibration prediction results of a dry-jointed floor according to an embodiment) will be outlined.

[0050] First, a level of vibration that is bothersome to the occupants is set as a reference value for VLTp. For example, 75 to 85 dB can be set as the reference value for VLTp.

[0051] Next, vibration prediction of the dry-bonded floor is performed using equation (Q), and if the identified VLTp exceeds the standard value, design changes are made to satisfy the standard value.

[0052] Specifically, the design changes will be made to either shorten the length of the floor panel in the beam-to-beam direction or to increase the second moment of area of ​​the beams supporting the floor panel.

[0053] All of these design changes are relatively easy to implement, so by implementing these design changes at the building design stage, floor vibration can be effectively suppressed.

[0054] Regarding these design changes, for example, VLTp can be reduced by shortening the length of the beams, but shortening the length of the beams is not an easy design change to make. Also, VLTp can be reduced by changing the distance from the interior walls or columns (increasing the distance), but this is not an easy design change to make because it directly leads to a change in the plan, and is not a desirable design change.

[0055] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form.

Claims

1. A vibration prediction method for a dry-jointed floor in which the ends of floor panels are joined to a plurality of beams arranged side by side at intervals by metal joints, comprising: A method for predicting vibrations of a dry-bonded floor, characterized in that the vibration prediction is a prediction using physical indicators corresponding to human evaluations and is set by the following formula (X). [Equation 1]

2. 2. A method for predicting vibration of a dry-bonded floor as described in claim 1, characterized in that a, b, c, d, and e are set by performing multiple regression analysis using multiple measured values ​​of floor vibration.

3. The VLTp is determined by the vibration prediction method for a dry-bonded bed according to claim 1 or 2, A design modification method based on vibration prediction results for a dry-jointed floor, characterized in that if the specified VLTp exceeds a reference value for the VLTp, design modifications are made to shorten the length of the floor panel in the beam-to-beam direction and / or increase the second moment of area of ​​the beams supporting the floor panel so that the reference value is satisfied.

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