JPH0635935B2 - Seismic intensity measurement method and measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for measuring and displaying the intensity of seismic motion by means of a spectral intensity SI value.

Conventional technology Acceleration seismometer is used to measure and record the seismic acceleration at the site (indoor or outdoor). Next, this acceleration record is processed by a computer in the room and The SI value (spectral intensity) is calculated based on Specifically, the response calculation of a one-mass point spring-mass system having each natural period and damping is performed to find the Sv value, and then the period 0.
It is calculated by integrating from 1 to 2.5 seconds. The Sv is a velocity response spectrum of seismic motion.

Problems to be Solved by the Invention The above-mentioned conventional technique has the following problems.

(1) It is necessary to digitize the seismic records once recorded by the seismograph and perform complicated calculations using a computer.

(2) A large amount of memory is required for waveforms, and it takes a lot of work to record the data and analyze it after the fact.

It is an object of the present invention to provide a measuring method and a measuring device that can easily calculate an SI value (spectral intensity) without complicated calculations after measuring earthquake motion.

Means for solving the problems Using a series of single mass pendulums with a certain damping constant and natural period (each period between 0.1 and 2.5 seconds), each pendulum when an earthquake motion arrives The movement (maximum velocity amplitude) is measured. At this time, the movement of each pendulum is measured by being converted into an electric signal proportional to the speed of the pendulum by a moving coil type exciter.

Then, in the memory, only the maximum value of each pendulum is stored one after another. At this point, the maximum value of each pendulum is equal to the Sv value corresponding to the natural period of the pendulum.

Next, input each maximum value into the numerical operation circuit and
The SI value can be calculated by performing integration on (0.1 to 2.5 seconds). Finally, record and display this.

The working SI value is a quantity that represents the intensity of seismic motion at the observation point, and is known as a value closely related to earthquake damage. The SI value is given by the following equation using the velocity response spectrum (Sv value) of the earthquake motion.

Substituting the maximum value of each pendulum as Sv in the above equation,
The SI value can be calculated by integrating with respect to (0.1 to 2.5 seconds).

Example In FIG. 1, the vibration detection device A has a natural period of 0.1 seconds to 2.5 seconds and has a specific damping rate a.
It consists of one mass pendulum. The exciter B is a dynamic coil exciter that detects the movement of each pendulum of the vibration detection device A as a velocity value and outputs the value as an electric signal (voltage). The arithmetic processing unit of C has a value for _a electric signals (y ₁ , y _2, ..., ya) sent from the exciter B at predetermined intervals after the occurrence of an earthquake. , A device composed of a digital processing device such as a microcomputer for judging whether or not it is greater than a value before that time. The storage device of D is a device for storing the maximum value of each pendulum, which is judged by the arithmetic processing device C, and this memory has a storage areas, and a new maximum value is input every time. The old information overflows and disappears, and when the final data is transmitted and completed, the next device E is moved to. The arithmetic processing unit E is composed of a digital processing unit such as a microcomputer, and is a unit for performing integral calculation (B formula). The display device of F is
An apparatus comprising an electric circuit for displaying the SI value obtained by the arithmetic processing unit E and a display board. The G storage device is a device that stores the SI value obtained by the arithmetic processing device E.

Fig. 2 is an explanatory diagram of the seismic motion detector A. It is based on the principle of swaying of a mass pendulum having a different natural period from 0.1 to 2.5 seconds. the same as the principle of the have), the period from T ₁
It is a vibration detection device consisting of a pendulums set up to T _a .

In such a device, when the earthquake motion arrives, the earthquake detection device A measures the motion (maximum velocity amplitude) of each pendulum. At this time, the movement of each pendulum is converted into an electrical signal proportional to the speed of the pendulum by the moving coil type vibration eliminator B.

Only the maximum value of each pendulum is sequentially stored in the storage device D via the arithmetic processing device C. At this point, the maximum value of each pendulum is equal to the Sv value corresponding to the natural period of the pendulum.

Next, the hydrochloric acid device E inputs each maximum value, Therefore, if integration is performed for each cycle (0.1 to 2.5 seconds), S
The I value can be calculated. The SI value is displayed and stored by the display device F and the storage device G.

Note that FIG. 3 shows the above operation in a flow chart.

EFFECTS OF THE INVENTION The present invention converts the motions of a plurality of mass pendulums for sensing seismic motion acceleration into electric signals and compares the electric signal values with the values before that time to determine whether or not the values are large. Only the maximum value is stored to obtain the velocity response spectrum Sv value, By obtaining the spectrum intensity SI value, the following effects can be obtained.

(1) By installing the device of the present invention, the intensity of seismic motion at that point can be detected on the spot.

(2) SI values can be calculated without complicated calculations and without using seismographs.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to the present invention, FIG. 2 is an explanatory view of the vibration detecting apparatus in FIG. 1, and FIG. 3 is an S according to the present invention.
It is an I value detection flow chart. A ... vibration detection device, B ... exciter, C, E ... arithmetic processing device, D ... storage device, F ... display device

Claims (2)

[Claims] 1. The maximum value is obtained by converting the movements of a plurality of mass pendulums for detecting seismic motion acceleration into electric signals, comparing the electric signal values with the values before that time, and judging whether the values are large or not. Memorize only the speed response spectrum Sv value, The method for measuring the intensity of seismic motions is characterized in that the SI value of the spectrum intensity is calculated by 2. A vibration detecting device comprising a plurality of mass pendulums, a vibrator for detecting the movement of each pendulum at a velocity value and outputting an electric signal, and the value of the electric signal before that time. A calculation / storage device for comparing and storing the maximum value of each pendulum; a calculation processing device for obtaining a spectrum intensity SI value from the data of the calculation / storage device; and a display device for displaying the spectrum intensity SI value. An earthquake motion intensity measuring device.