JP6820514B2 - Vibration test method - Google Patents

Description

The present invention relates to a vibration test device, and more particularly to a vibration test device and a vibration test method capable of reproducing seismic motion including fault displacement.

The Kumamoto earthquake that occurred in April 2016 caused enormous damage to structures near the fault that appeared on the surface of the earth. Some of the seismic waveforms observed at this time include components due to fault displacement in addition to vibrations due to seismic motion. Seismic motion including fault displacement is called Fling Step, and it has a great influence on long-period structures with relatively long natural periods, and especially in the case of seismic isolation structures, it may cause retaining wall collisions. , Has become an important research topic.

The fault displacement observed in the Kumamoto earthquake is as large as about 2 m at the maximum, and it is difficult to carry out a reproduction experiment on a normal shaking table. Due to the structure of the shaking table, its movable displacement is about 1 m at the maximum, and in some cases, it is not realistic to design a shaking table that can reproduce the seismic motion near the fault reaching several meters. Furthermore, fault motion is an irreversible one in which permanent displacement remains after an earthquake, but it is difficult to control because the shaking table is designed on the assumption that it will return to the origin position after the experiment.

On the other hand, as conventional shaking tables, for example, a shaking table in which two stages are stacked to increase displacement and a shaking table that amplifies vibration by using inertial mass are known (see, for example, Patent Documents 1 to 5). ). However, these shaking tables have problems that they are relatively expensive and require complicated control.

Japanese Unexamined Patent Publication No. 7-55630 Japanese Unexamined Patent Publication No. 2000-171374 Japanese Unexamined Patent Publication No. 2001-30008 Japanese Unexamined Patent Publication No. 2003-287475 Japanese Unexamined Patent Publication No. 2004-612261

For this reason, there has been a demand for the development of a vibration test device that can reliably reproduce seismic motion including fault displacement at low cost.

The present invention has been made in view of the above, and an object of the present invention is to provide a vibration test apparatus and a vibration test method capable of reliably and inexpensively reproducing seismic motion including fault displacement.

In order to solve the above-mentioned problems and achieve the object, the vibration test apparatus according to the present invention is a vibration test apparatus including a shaking table and a vibrating means for vibrating the shaking table. The operation of the loading table, which is fixed on the table table so as to be movable in the horizontal direction and on which the test piece is placed, the displacement applying means for horizontally shifting the loading table relative to the shaking table, and the displacement applying means It is characterized by further providing an operation interlocking means for interlocking the operation of the vibration means and the operation of the vibration means.

Further, another vibration test apparatus according to the present invention is characterized in that, in the above-described invention, the displacement applying means is a hydraulic cylinder fixed on a shaking table and relatively displaces the loading table in the horizontal direction. ..

Further, in the above-described invention, another vibration test apparatus according to the present invention is further provided with a pressure accumulating means for accumulating hydraulic oil on the shaking table, and the hydraulic cylinder is operated by the hydraulic oil supplied from the accumulating means. It is characterized by doing.

Further, another vibration test apparatus according to the present invention is further provided with a hydraulic control means for controlling the hydraulic pressure of the hydraulic oil supplied from the accumulator means to the hydraulic cylinder in the above-described invention.

Further, the vibration test method according to the present invention is a method of performing a vibration test using the above-mentioned vibration test apparatus, and before the vibration test, the accumulator means and an external hydraulic source are connected to apply hydraulic oil to the accumulator means. It is characterized in that it accumulates, and then the vibration test is performed after disconnecting the accumulator means and the external hydraulic source.

Further, another vibration test method according to the present invention is a method of performing a vibration test using the above-mentioned vibration test apparatus, and the hydraulic control means is configured to include a proportional control solenoid valve before the vibration test. After conducting a preliminary test to determine the opening / closing pattern of the proportional control solenoid valve, the desired relative displacement is given to the loading table by controlling the opening / closing of the proportional control solenoid valve with the determined opening / closing pattern during the vibration test. It is characterized by that.

According to the vibration test device according to the present invention, the vibration test device includes a shaking table and a vibrating means for vibrating the shaking table, and is fixed on the shaking table so as to be movable in the horizontal direction. The operation interlocking of the loading table on which the test piece is placed, the displacement applying means for horizontally displaced the loading table with respect to the shaking table table, and the operation of the displacement applying means and the operation of the vibrating means. Since the means are further provided, it is possible to reliably apply the displacement simulating the fault displacement to the loading table by the displacement applying means during the operation of the vibrating means. Moreover, according to this configuration, it is possible to reproduce seismic motion including fault displacement by utilizing the existing shaking table. Therefore, according to the present invention, there is an effect that seismic motion including fault displacement can be reproduced inexpensively and reliably.

Further, according to another vibration test apparatus according to the present invention, the displacement applying means is composed of a hydraulic cylinder fixed on the shaking table and relatively displaces the loading table in the horizontal direction. Therefore, the operation of the hydraulic cylinder causes a fault. It has the effect of being able to give a displacement that simulates the displacement to the loading table.

Further, according to another vibration test apparatus according to the present invention, a pressure accumulating means provided on the shaking table and accumulating hydraulic oil is further provided, and the hydraulic cylinder is operated by the hydraulic oil supplied from the accumulating means. It is no longer necessary to connect the hydraulic cylinder to an external hydraulic source such as a hydraulic pump during the vibration test. Therefore, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table, and it is possible to easily carry out the vibration test.

Further, according to another vibration test apparatus according to the present invention, since the hydraulic control means for controlling the hydraulic pressure of the hydraulic oil supplied from the accumulator means to the hydraulic cylinder is further provided, the load is loaded by controlling the hydraulic pressure with the hydraulic control means. It has the effect of giving the table a simulated fault displacement of interest.

Further, according to the vibration test method according to the present invention, the vibration test is performed using the vibration test apparatus described above, and the pressure accumulating means and the external hydraulic source are connected to operate the pressure accumulating means before the vibration test. Since the vibration test is performed after the oil is accumulated and then the connection between the pressure accumulating means and the external hydraulic source is disconnected, it is necessary to connect the hydraulic cylinder to the external hydraulic pump or other hydraulic source during the vibration test. Absent. Therefore, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table, and it is possible to easily carry out the vibration test.

Further, according to another vibration test method according to the present invention, it is a method of performing a vibration test using the above-mentioned vibration test apparatus, and the hydraulic control means is configured to include a proportional control solenoid valve and vibrates. After conducting a preliminary test to determine the opening / closing pattern of the proportional control solenoid valve before the test, the desired relative displacement is applied to the loading table by controlling the opening / closing of the proportional control solenoid valve with the determined opening / closing pattern during the vibration test. Since it is given, it has the effect of being able to give a target simulated fault displacement to the loading table.

FIG. 1 is a side sectional view showing an embodiment of a vibration test apparatus and a vibration test method according to the present invention. FIG. 2 is a diagram showing the time waveform of the input wave, (1) is the observed seismic wave (δ = δ1 + δ2), (2) is the component wave of the shaking table table displacement (δ1), and (3) is a simulated fault. It is a component wave of displacement (δ2).

Hereinafter, embodiments of the vibration test apparatus and the vibration test method according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

(Vibration test device)
First, an embodiment of the vibration test apparatus according to the present invention will be described.

As shown in FIG. 1, the vibration test device 10 according to the present invention includes a concave support pedestal 12, vibration machines 14A to 14D (vibration means) having one end fixed to the support pedestal 12, and vibration thereof. It includes a shaking table 18 connected to the machines 14A to 14D via bearings 16A to 16D, and a control device 20.

The exciters 14A to 14D are operated by the vibration control signal from the control device 20, and the shaking table table 18 can be vibrated in the horizontal axis direction and the vertical axis direction. In addition to the exciters 14A to 14D installed on the left, right, and below the vibrating table 18, similar vibrators are provided before and after the vibrating table 18, so that the vibrating table 18 is placed in the horizontal biaxial direction. It may be configured so that it can be vibrated in three dimensions (horizontal direction, front-back direction) and vertical axis direction.

The shaking table 18 is a quadrangular table when viewed from above. A loading table 22 on which the test body C is placed, a hydraulic cylinder 24, and a pressure accumulator cylinder 26 are installed on the shaking table table 18.

The loading table 22 is fixed on a linear guide 28 fixed to the upper surface on the right side of the shaking table table 18 so as to be linearly movable in the left-right direction (horizontal direction) via a slider.

The hydraulic cylinder 24 is a displacement applying means that causes the loading table 22 to be displaced relative to the shaking table table 18 in the left-right direction (horizontal direction). The hydraulic cylinder 24 is fixed to the upper surface on the left side of the shaking table table 18, and has a piston (not shown) slidably inserted into the hydraulic cylinder 24 and a piston that is slidably inserted into the hydraulic cylinder 24 and has one end. Is provided with a rod 30 connected to this piston. The rod 30 projects to the right from the right end of the hydraulic cylinder 24, and the right end thereof is connected to the left end of the loading table 22. The rod 30 expands and contracts in the left-right direction according to the movement of a piston (not shown) inside the hydraulic cylinder 24 to give the loading table 22 a relative displacement in the left-right direction. By the expansion and contraction operation of the rod 30, a displacement simulating a fault displacement can be given to the loading table 22. The displacement applying means of the present invention is not limited to the hydraulic cylinder 24, and may be a pneumatic cylinder using a gas as long as it can apply a linear displacement in the left-right direction to the loading table 22. , It may be a linear motor or a linear actuator.

Here, a hydraulic pump is usually required for the hydraulic source that moves the hydraulic cylinder 24, but it is difficult to install this on the shaking table table 18. When installing a hydraulic pump outside the shaking table table 18, it is necessary to pipe to the hydraulic cylinder 24 on the shaking table 18 to send hydraulic oil, but a flexible pressure-resistant hose that does not interfere with the displacement of the shaking table 18 is designed. It's difficult to do. Therefore, in the present embodiment, only the accumulator cylinder 26 is installed on the shaking table table 18, and before the vibration test, the hydraulic oil is connected to the hydraulic pump outside the mobile or shaking table 18 with a pressure resistant hose. And remove the pressure resistant hose before conducting the vibration test.

The pressure accumulating cylinder 26 is a pressure accumulating means for accumulating the hydraulic oil supplied to the hydraulic cylinder 24, and is fixed at a position on the upper surface of the shaking table table 18 so as not to hinder the movement of the loading table 22 and the rod 30. The accumulator cylinder 26 and the hydraulic cylinder 24 are connected by a pipeline 32, and the hydraulic cylinder 24 is operated by the hydraulic oil supplied from the accumulator cylinder 26. The hydraulic pressure of the hydraulic oil supplied from the accumulator cylinder 26 to the hydraulic cylinder 24 is controlled by opening and closing a proportional control solenoid valve 34 (hydraulic control means) provided in the middle of the pipeline 32. The opening and closing of the proportional control solenoid valve 34 is controlled by a valve opening degree control signal from the control device 20. By providing the accumulator cylinder 26, it is not necessary to connect the hydraulic cylinder 24 to a hydraulic source such as an external hydraulic pump during the vibration test. Therefore, according to the present embodiment, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table table 18, and the vibration test can be easily carried out. The hydraulic control means of the present invention is not limited to the proportional control solenoid valve 34, and may be a servo valve that performs feedback control with respect to the target displacement.

The control device 20 functions as an operation interlocking means for interlocking the operation of the hydraulic cylinder 24 and the operations of the exciters 14A to 14D, and is provided at a remote place that does not hinder the movement of the shaking table table 18. The control device 20 is connected to each of the exciters 14A to 14D and the proportional control solenoid valve 34 by a wireless or wired communication line. As described above, the operations of the vibrators 14A to 14D and the proportional control solenoid valve 34 are controlled by predetermined vibration control signals and valve opening control signals transmitted from the control device 20, respectively.

Here, the valve opening control signal of the proportional control solenoid valve 34 corresponds to information (displacement control signal) regarding the expansion / contraction displacement of the rod 30 of the hydraulic cylinder 24, and the hydraulic cylinder 24 is changed by changing the valve opening control signal. The flow rate of the hydraulic oil supplied to the rod 30 is continuously controlled in the range of 0 to 100% with respect to the maximum flow rate to control the expansion and contraction operation of the rod 30. Further, the vibration control signal and the valve opening control signal sent from the control device 20 are synchronized signals, and the hydraulic cylinder 24 and the vibration machines 14A to 14D controlled by these signals operate in conjunction with each other. ..

The operation and operation of the above configuration will be described.
When a predetermined vibration control signal is sent from the control device 20 to the vibrators 14A to 14D and a predetermined valve opening control signal synchronized with this is sent to the proportional control solenoid valve 34, the vibration control signal is used for the vibration device. 14A-14D vibrate the shaking table 18, and the desired vibration is applied to the test piece C on the loading table 22 via the shaking table 18. On the other hand, the rod 30 of the hydraulic cylinder 24 expands and contracts according to the valve opening degree control signal, and the loading table 22 is relatively displaced in the left-right direction along the linear guide 28. This displacement is applied to the test body C on the loading table 22 as a simulated fault displacement.

Here, when an observed seismic wave including a fault displacement is used as the input seismic wave of the vibration test, the observed seismic wave is divided into a simulated fault displacement component (δ2) and other seismic displacement components (δ1). Divide in advance into. FIG. 2 (1) is an example of the time waveform of the target ground motion (δ = δ1 + δ2) before division, FIG. 2 (2) is the time waveform of δ1 after division, and FIG. 2 (3) is an example of the time waveform of δ2 after division. is there. Then, the displacement control signal corresponding to δ2 in the figure, that is, the valve opening control signal is input to the rod 30 of the hydraulic cylinder 24, and the vibration control signal corresponding to δ1 is input to the vibrators 14A to 14D in synchronization with each other. , The target seismic motion (δ = δ1 + δ2) can be given to the test body C on the loading table 22.

When the hydraulic cylinder 24 is operated by using the oil pressure in the accumulator cylinder 26, closed loop control (feedback control by a displacement sensor) using a servo valve is generally used. In the case of the above form, since it is limited to the function of giving a simulated fault displacement, it is possible to perform simpler open-loop control. For example, after performing a preliminary test for determining the opening / closing pattern of the proportional control solenoid valve 34 before the vibration test, the proportional control solenoid valve 34 is loaded by opening / closing control from the control device 20 with the determined opening / closing pattern during the vibration test. A target simulated fault displacement can be given to the table 22.

Further, as a conventional vibration test device, as described above, a device having a shaking table in which two layers are stacked in order to increase displacement and a shaking table that amplifies vibration by using inertial mass is known. In the present embodiment, the existing shaking table is used as the shaking table 18, and the loading table 22, the hydraulic cylinder 24, etc. are installed on the shaking table, and the hydraulic cylinder 24, etc. is used during the operation of the vibrating means. A simulated fault displacement can be reliably applied to the loading table 22. Therefore, it is possible to inexpensively and reliably reproduce the seismic motion accompanied by a large fault displacement as observed in the Kumamoto earthquake, and it is possible to inexpensively manufacture the vibration test device 10 that reproduces the seismic motion including the fault displacement. In addition, the vibration test device 10 of the present embodiment can easily carry out a vibration test of a building constructed near a fault, which has been difficult so far, so that a higher level seismic resistance evaluation of the building becomes possible. For example, it can contribute to the development of buildings having high seismic performance even in the vicinity of faults.

(Vibration test method)
Next, an embodiment of the vibration test method according to the present invention will be described.

The vibration test method according to the present invention is a method of performing a vibration test using the vibration test device 10 described above. More specifically, before the vibration test, the accumulator cylinder 26 and an external hydraulic source are connected to accumulate hydraulic oil in the accumulator cylinder 26, and then the connection between the accumulator cylinder 26 and the external hydraulic source is released. Make a vibration test from. According to this, it is not necessary to connect the hydraulic cylinder 24 to a hydraulic source such as an external hydraulic pump during the vibration test. Therefore, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table table 18, and the vibration test can be easily performed.

Further, after performing a preliminary test for determining the opening / closing pattern of the proportional control solenoid valve 34 before the vibration test, the loading table 22 is controlled by opening / closing the proportional control solenoid valve 34 according to the determined opening / closing pattern during the vibration test. May be given a desired relative displacement. In this way, the loading table 22 can be given a target simulated fault displacement.

As described above, according to the vibration test device according to the present invention, the vibration test device includes a shaking table and a vibration means for vibrating the shaking table, and is horizontal on the shaking table. A loading table that is fixed so as to be movable in a direction and on which a test piece is placed, a displacement applying means that displaces the loading table relative to the shaking table in the horizontal direction, an operation of the displacement applying means, and an operation of the vibration means Since the motion interlocking means for interlocking with the above is further provided, it is possible to reliably apply the displacement simulating the fault displacement to the loading table by the displacement applying means during the operation of the vibrating means. Moreover, according to this configuration, it is possible to reproduce seismic motion including fault displacement by utilizing the existing shaking table. Therefore, according to the present invention, seismic motion including fault displacement can be reliably reproduced at low cost.

Further, according to another vibration test apparatus according to the present invention, the displacement applying means is composed of a hydraulic cylinder fixed on the shaking table and relatively displaces the loading table in the horizontal direction. Therefore, the operation of the hydraulic cylinder causes a fault. A displacement that simulates the displacement can be given to the loading table.

Further, according to another vibration test apparatus according to the present invention, a pressure accumulating means provided on the shaking table and accumulating hydraulic oil is further provided, and the hydraulic cylinder is operated by the hydraulic oil supplied from the accumulating means. It is no longer necessary to connect the hydraulic cylinder to an external hydraulic source such as a hydraulic pump during the vibration test. Therefore, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table, and the vibration test can be easily performed.

Further, according to another vibration test apparatus according to the present invention, since the hydraulic control means for controlling the hydraulic pressure of the hydraulic oil supplied from the accumulator means to the hydraulic cylinder is further provided, the load is loaded by controlling the hydraulic pressure with the hydraulic control means. The table can be given a simulated fault displacement of interest.

Further, according to the vibration test method according to the present invention, the vibration test is performed using the vibration test apparatus described above, and the pressure accumulating means and the external hydraulic source are connected to operate the pressure accumulating means before the vibration test. Since the vibration test is performed after the oil is accumulated and then the connection between the pressure accumulating means and the external hydraulic source is disconnected, it is necessary to connect the hydraulic cylinder to the external hydraulic pump or other hydraulic source during the vibration test. Absent. Therefore, it is not necessary to prepare a connecting pipe or the like that does not hinder the displacement of the shaking table, and the vibration test can be easily performed.

Further, according to another vibration test method according to the present invention, it is a method of performing a vibration test using the above-mentioned vibration test apparatus, and the hydraulic control means is configured to include a proportional control solenoid valve and vibrates. After conducting a preliminary test to determine the opening / closing pattern of the proportional control solenoid valve before the test, the desired relative displacement is applied to the loading table by controlling the opening / closing of the proportional control solenoid valve with the determined opening / closing pattern during the vibration test. Since it is given, it is possible to give a target simulated fault displacement to the loading table.

As described above, the vibration test apparatus and the vibration test method according to the present invention are useful for vibration tests of structures such as buildings, and are particularly suitable for inexpensively and reliably reproducing seismic motion including fault displacement. ..

10 Vibration test device 12 Support stand 14A-14D Vibration machine (vibration means)
16A to 16D Bearing 18 Shaking table 20 Control device (operation interlocking means)
22 Loading table 24 Hydraulic cylinder (displacement imparting means)
26 Accumulation cylinder (accumulation means)
28 Linear guide 30 Rod 32 Pipe line 34 Proportional control solenoid valve C Specimen

Claims (3)

It is a method of performing a vibration test using a vibration test device including a shaking table and a vibration means for vibrating the shaking table.
The vibration test device is
A loading table said movably secured horizontally on a vibrating table table Rutotomoni specimen is placed,
A displacement applying means for relative displacement in the horizontal direction with respect to the vibration table table the loading table,
And operation interlock means for interlocking the operations of said excitation means of the displacement applying means,
Further provided on the shaking table and with a pressure accumulating means for accumulating hydraulic oil .
The displacement applying means includes a hydraulic cylinder that is fixed on the shaking table and relatively displaces the loading table in the horizontal direction, and the hydraulic cylinder is operated by hydraulic oil supplied from the accumulating means. Yes,
Before the vibration test, the accumulator means and the external hydraulic source are connected to accumulate hydraulic oil in the accumulator means, and then the connection between the accumulator means and the external hydraulic source is disconnected, and then the vibration test is performed. A vibration test method characterized by. The vibration test device, vibration test method according to claim 1, further comprising a pressure control means for controlling the hydraulic pressure of the hydraulic fluid supplied to the hydraulic cylinder from the accumulator means. The hydraulic control means is configured to include a proportional control solenoid valve.
After preliminary tests to determine the opening and closing pattern of the proportional control solenoid valves before vibration test, during vibration testing, by opening and closing controls the proportional control solenoid valve at the determined closing pattern desired on the loading table The vibration test method according to claim 2, wherein the relative displacement of is applied.

Images