JP4818010B2 - Early prediction method of earthquake magnitude and early prediction program of earthquake magnitude based on building deformation during earthquake - Google Patents

Description

  The present invention relates to a method for early prediction of earthquake magnitude, in which the main strain direction obtained by analyzing the strain data calculated from the amount of deformation of the building during an earthquake determines the earthquake magnitude based on the length of time for which the specific direction is continued. And an early prediction program of earthquake magnitude.

  As a method of determining the earthquake magnitude indicating the magnitude of the earthquake, the Japan Meteorological Agency has adopted the “method using displacement amplitude” for large earthquakes and the “method using velocity amplitude” for small earthquakes. Using the maximum displacement amplitude from the displacement seismometer in the former case and the maximum velocity amplitude from the velocity seismometer in the latter case, taking into account attenuation due to the distance from the epicenter, Seismic magnitude is determined. On the other hand, Okubo et al. Analyzed the deformation of the rock mass by a borehole type strain gauge installed in the deep underground rock at the 2005 Joint Conference on Geosciences of Earth and Planetary Sciences (S098-004). It is reported that the seismic moment can be estimated from the change of strain direction.

  A normal earthquake has a small tremor followed by a large tremor, but it is difficult to predict the magnitude of the major tremor that follows during the initial period of small tremors. The seismic magnitude is usually predicted, and the magnitude of the subsequent tremor is estimated from the predicted seismic magnitude. However, prediction of earthquake magnitude is not easy. In the method of determining the seismic magnitude adopted by the Japan Meteorological Agency, the maximum magnitude recorded at the observation point is the information related to the seismic magnitude determination. The displacement amplitude and velocity amplitude of the ground motion used by the Japan Meteorological Agency to determine the seismic magnitude vary greatly depending on the ground structure of the observation point, and the error is large when the seismic magnitude is determined only by recording a single observation point. Become. For this reason, it was necessary to analyze the records of multiple observation points and reduce the seismic magnitude determination error. Moreover, since the seismic magnitude cannot be determined without using the maximum displacement amplitude and velocity amplitude, the information about seismic magnitude could not be transmitted before the main shaking arrived.

  For earthquake disaster prevention of buildings, etc., it is necessary to know the earthquake magnitude as soon as possible and predict the magnitude of the maximum earthquake motion coming. In the conventional technology, information on the shaking of the earthquake obtained at the observation point close to the hypocenter is received via a telemeter, etc., and the earthquake magnitude is determined based on the records of the plurality of observation points, so that prior information for earthquake disaster prevention is obtained. It is used as. However, with this method, if the telemeter or the like breaks down, it is not possible to obtain information on the earthquake shaking that determines the earthquake magnitude.

  On the other hand, Okubo et al. (2005) proposed a method for estimating seismic magnitude using the measurement results of rock mass deformation. However, the method using the deformation of the rock is difficult to use in cities. This is because deep boreholes must be drilled to obtain measurement results of rock deformation in cities. For example, in the case of Tokyo, it is necessary to drill a borehole to a depth of about 3000m to reach the underground bedrock, and the excavation cost becomes enormous. In addition, there are few vacant areas in the city, and it is difficult to secure a space for installing a boring machine, which is indispensable when excavating a borehole.

  The present invention has been conceived based on the above situation, and when a building is receiving a seismic wave called a P-wave with small shaking, the deformation amount of the building is measured and the deformation is measured. Seismic magnitude is predicted by converting quantity into strain and analyzing strain. Based on the predicted magnitude of the earthquake, the maximum amplitude of the incoming S wave is estimated and used for earthquake disaster prevention. In the present invention, the deformation of the building, not the deformation of the rock mass, is converted into strain and analyzed as input data. For this reason, it is not necessary to drill the borehole to the deep underground to obtain the strain that is the input data necessary for estimating the magnitude of the seismic magnitude.

  The Japan Meteorological Agency determines the earthquake magnitude using the maximum displacement amplitude and velocity amplitude based on the shaking of the building during the earthquake. The invention of claim 1 measures the amount of deformation that occurs in a building during an earthquake, converts the amount of deformation into strain, performs strain analysis, determines the direction of the main strain, and the main strain direction continues in a specific direction. A method for early prediction of seismic magnitude based on the amount of deformation of a building at the time of an earthquake, which determines the seismic magnitude from time, comprising at least three directions of deformation amount measuring means provided for the building being measured, and the measuring means Means for analyzing strain data based on the amount of deformation of the building measured at the time of the earthquake, and arranging the means for measuring the amount of deformation so as to analyze the strain in a specific plane. It is characterized by obtaining the time during which the direction of strain continues in a specific direction and predicting the earthquake magnitude from the length of that time.

  Under normal conditions, the building does not receive any large external force other than gravity acting in the vertical direction, and the main in-plane strain direction obtained by strain analysis is randomly disturbed. However, when an earthquake occurs, a force acts on the underground part of the building from the direction of the epicenter, causing the underground part of the building to deform. The main strain direction obtained by analyzing the deformation of the underground part of the building is the direction in which the force acts. While the destruction is ongoing in the epicenter area (in other words, while the fault movement continues and the epicenter area is expanding), the force from the epicenter direction acts on the ground below the building. The main axis of the strain is kept constant.

  The location for measuring the amount of deformation in the building or on the surface of the building needs to be subjected to a force from the ground, and if the building is in contact with the rock, it should be measured in the vicinity. It is desirable to measure at the foundation of a building in the ground. However, the place where the earth reflects the action of the force received from the epicenter is not necessarily required.

  While fault motion continues in the epicenter and the expansion of the epicenter continues, the force from the epicenter direction acts on the building. For this reason, while the fault movement continues, the building is subjected to a force in a certain direction, and the main strain direction continues in a specific direction. The specific direction obtained in this way depends on the structure of the building, so depending on the measurement location, it does not necessarily match the direction of the force acting on the ground from the source direction.

  In the method according to the present invention, the criterion for prediction of seismic magnitude is the length of the duration in which the principal strain direction is a specific direction. Therefore, the main strain direction may be different from the direction of the force received by the building, and even when analyzing the strain based on the deformation obtained at the top of the building, the main strain direction is calculated by strain analysis. The main strain direction only needs to be maintained in a specific direction, and the calculated main strain direction does not necessarily have to face the epicenter.

  According to a second aspect of the present invention, in the first aspect of the invention, the deformation amount measuring means is arranged so that a horizontal strain analysis can be performed, and a time for which the direction of the main strain obtained by the strain analysis continues the epicenter direction is set. It is characterized by predicting the epicenter direction and the earthquake magnitude from the length of time. If the strain analysis is performed using the strain based on the amount of deformation obtained from the three-direction displacement measuring means arranged in the horizontal direction as input data, the principal strain direction becomes the direction of the force acting on the building, that is, the epicenter direction.

  The invention according to claim 3 is the direction in which the deformation amount measuring means according to claim 1 and claim 2 is arranged so as to be able to analyze the strain in a specific plane, preferably in a direction oblique to the plane. A fourth deformation amount measuring means is provided in the direction orthogonal to the surface, and the deformation amount having angle information between the surface and the epicenter direction is obtained. In addition to the three-direction deformation measurement means arranged in the horizontal direction, if there is a deformation measurement means in a direction oblique to the surface, information on the depth of the epicenter can be obtained from the deformation. If the fourth deformation measurement means is in a direction perpendicular to the horizontal direction, it is easy to obtain information related to the depth of the epicenter.

  According to a fourth aspect of the present invention, in the first to third aspects of the invention, the deformation amount measuring means is a displacement detecting means capable of detecting minute displacement changes such as a magnetic sensor, a differential transformer, and an eddy current sensor. Features.

  The invention of claim 5 is characterized in that, in the invention of claims 1 to 3, the deformation amount measuring means is an optical means.

  According to a sixth aspect of the present invention, in the first to third aspects of the invention, the deformation amount measuring means converts the deformation amount of the building into a change in electric force corresponding to the deformation amount. It is characterized by measuring.

  The invention of claim 7 is characterized in that, in the invention of claims 1 to 3, the deformation amount measuring means is a strain gauge.

  The invention according to claim 8 is the invention according to claims 1 to 3, wherein the deformation amount measuring means converts the deformation amount of the building into the volume change of the liquid corresponding to the deformation amount, and measures the volume as the volume. It is characterized by.

  The invention according to claim 9 is the invention according to claims 1 to 3, wherein the deformation amount measuring means converts the deformation amount of the building into a change in electric capacity corresponding to the deformation amount, It is characterized by measuring.

  The earthquake magnitude early prediction program based on the amount of deformation of a building at the time of an earthquake relating to the invention of claim 10 measures the amount of deformation of the building that occurs at the time of the earthquake, converts the obtained amount of deformation into strain, and converts it into the strain. This is an early earthquake magnitude prediction program for early prediction of earthquake magnitude based on the amount of deformation of the building during the earthquake from the time that main strain direction is determined based on the strain analysis based on In the process of analyzing strain data calculated from the amount of deformation of the building that occurs during an earthquake, the process of calculating the strain from the amount of deformation in at least three directions, the process of calculating the main strain direction from the strain by the strain analysis, and the calculation Processing to identify the duration in the main strain direction, read out information indicating the correspondence between the duration and the earthquake magnitude recorded in advance in memory, and Processing for output, characterized in that for the execution.

  The inventions of claims 1 to 9 measure the amount of deformation of the building when the building is subjected to an earthquake motion with a small initial shake called a P wave, and convert the obtained amount of deformation into strain, The strain analysis was performed using the strain as input data, the principal strain direction was identified, and the magnitude of the principal strain direction continued for the specified direction was used to predict the earthquake magnitude early. The magnitude of the maximum tremor during an earthquake that directly causes earthquake disasters corresponds to the magnitude of the earthquake magnitude. Therefore, if the earthquake magnitude can be known when the shaking is small, the maximum shaking magnitude of the incoming earthquake motion can be estimated. The method according to the present invention takes into account attenuation due to distance from the epicenter using the maximum displacement amplitude from the displacement seismometer or the maximum velocity amplitude from the velocity seismometer, as implemented by the Japan Meteorological Agency. However, it is different from the method of determining seismic magnitude based on the records of multiple observation points.

  That is, in the configuration of the present invention, the amount of deformation of a building that occurs during an earthquake is measured, the amount of deformation is converted into strain data, and the strain analysis is performed in real time to calculate the main strain direction. The principal strain direction obtained by this analysis method is a physical quantity that depends on the direction of the force acting on the building, and the force acts regardless of whether the force changes in the fast cycle or the slow cycle. The direction can be obtained, and the error in determining the direction is small. The seismic motion generated while the rupture progresses and the fault motion continues in the hypocenter region propagates to the surroundings with the information of the direction of the fault motion. If the fault motion stops, the earthquake motion reflecting the fault motion will not be generated. The P-wave generated by the fault motion propagates faster than the S-wave generated by the fault motion, so the P-wave with a small fluctuation comes first in the distance. When the P wave arrives at the building and the shaking is excited, the force from the epicenter direction acts on the building corresponding to the duration of the fault movement. For this reason, the main strain direction obtained as a result of the strain analysis of the P wave part continues in a specific direction. In the present invention, the seismic magnitude is determined from the length of this duration. The invention of claim 10 is. This is a program for calculating the seismic magnitude by obtaining the time that the main strain direction continues in a specific direction.

  When a building is shaken by a P wave, even if the acting force is small, if the strain change due to the force exceeds the normal strain change that can be regarded as a noise level, the main strain direction obtained by the strain analysis is the force acting. It becomes the direction to do. If the amount of deformation of the building is known, the strain can be easily obtained, and the strain analysis can be performed in real time. Thus, the principal strain direction is a physical quantity that is easy to monitor in real time. The duration corresponds to the duration of the fault movement, and the earthquake magnitude can be predicted from the duration. The information used for the prediction of the earthquake magnitude is the initial motion part where the amplitude of the ground motion called P wave is small, and the method according to the present invention can be used in real time even if there is no information about the earthquake from other observation points. It is useful for earthquake disaster prevention because the earthquake magnitude can be calculated.

  If the duration exceeds a certain length, the lower limit of the earthquake magnitude can be estimated at that time, and the lower limit information of the earthquake magnitude at that time can be used for earthquake disaster prevention. Even if the earthquake occurs far away and the vibration of the ground motion called P-wave is small, if the earthquake magnitude is large, the force from the seismic source acting on the building is dominant, and the main strain obtained by analyzing the strain ground motion is obtained. Since the direction continues in a specific direction, the duration can be judged. If the duration is longer, the lower limit of the earthquake magnitude is predicted as time passes, and the information on earthquake disaster prevention that has been upgraded can be transmitted sequentially. As mentioned earlier, the seismic magnitude recorded directly under the building can be used to understand the earthquake magnitude directly in real time and predict the maximum magnitude of the subsequent S wave that is important for earthquake disaster prevention information. it can.

  With the conventional technology, if the information about the magnitude of the shaking associated with the earthquake obtained at the observation point close to the epicenter is not received via a telemeter, the earthquake magnitude cannot be determined, and information on earthquake disaster prevention is obtained. I couldn't. However, according to the present invention, information on seismic magnitude is obtained at the observation point itself, information from other observation points is not necessarily required, and it is effective for voluntary disaster prevention.

  Of course, at the point near the epicenter where the seismic wave arrives earlier, the lower limit of the earthquake magnitude and the prediction of the seismic magnitude can be predicted earlier than the point far from the epicenter, and if the information is transmitted to the area far from the epicenter, in the far away, It can be used as information for earthquake disaster prevention earlier.

  The method by Okubo et al. (2005) is a method for determining the principal strain direction using the deformation of the rock mass during an earthquake, and it is necessary to drill a borehole. In Tokyo, etc., the borehole must be drilled to a depth of 3000 m. You must. However, in the method according to the present invention, since the main strain direction is obtained by using the deformation amount of the building at the time of the earthquake, it is not always necessary to drill a borehole, and the main strain direction can be specified as necessary information at low cost.

  According to the definition described on page 230 of the geodesic appearance (published by the Geodetic Society of Japan in 1974), the strain gauge (extensometer) used in the present invention has the configuration shown in FIG. As shown in Fig. 1, one end B (fixed end) of the measure (fixed scale) AB is fixed to the fixed point D on the ground, and the change in the distance between the free end A and another fixed point C on the ground is expanded. It is an instrument to record. " Distortion is obtained by dividing the distance change recorded by the extensometer by the distance between the standard AB. In general, small extensometers are often written as strain gauges, and are referred to as strain gauges in the present invention.

The first embodiment will be described with reference to FIGS.
Fig. 2 is a side view of the state of the strain gauge installed on a reinforced concrete foundation 3 that is horizontal on an arbitrary plane of the building, for example, in the basement of the building. The pedestal 1 and the pedestal 2 are fixed to a base portion 3, and one end of an elastic body 4 as a rod-shaped reference scale is fixed to the pedestal 1, and a displacement sensor 5 is provided at the tip. With such a strain gauge, it is possible to measure the amount of displacement between the table 1 and the table 2 in the direction parallel to the paper surface.

  When the base part 3 receives pressure 6 from a direction parallel to the paper surface, the base part 3 contracts, and the distance between the base 1 and the base 2 is shortened. A displacement sensor 5 attached to the tip of an elastic body 4 as a reference scale fixed to the table 1 is integrated with the table 1. For this reason, the displacement sensor 5 moves in the same manner as the table 1, and the displacement between the table 1 and the table 2 can be measured by the displacement sensor 5. If the change Δd between the table 1 and the table 2 is detected by the displacement sensor 5 and the change Δd is divided by the distance D between the table 1 and the table 2, the distortion in the direction connecting the table 1 and the table 2 is obtained.

  When the foundation part of the building is deformed by the action of the force from the epicenter direction, the strain change between the base 1 and the base 2 is performed by the above method at the sampling interval (100 Hz, for example) at which the seismic motion band data is obtained. If measured, the strain change of the seismic motion band can be obtained, and the strain motion records in this direction.

  FIG. 3 is a first embodiment in which the strain gauge shown in FIG. 2 is installed in three directions, and the state is seen from above. As can be seen in FIG. 3, there are elastic bodies 14, 15, and 16 as reference scales fixed to the base 10 in three directions from the base 10 to the base 11, the base 12, and the base 13, and the displacement sensors 17, 18 are provided at the tips thereof. , 19 are provided.

  When the horizontal base portion 3 parallel to the paper surface receives a pressure 6 from a direction parallel to the paper surface, the base portion 3 contracts in the direction of the pressure and expands in a direction perpendicular to that direction. . The amount of displacement that extends is a proportion corresponding to the Poisson's ratio, which depends on the material of the foundation. Dividing the amount of shrinkage and extension by the distance between the platforms in each direction gives the strain change in each direction. Even if the arrangement of the reference scales fixed to the table does not necessarily match the assumed plane, if the distortion is obtained from the length and the amount of deformation projected on the plane, it can be assumed using that distortion. In-plane strain analysis can be performed, and the principal strain direction is obtained. Also, the measurement direction of the deformation does not need to be 45 degrees or orthogonal, as long as the direction of distortion analysis can be developed.

  When the foundation part of the building is deformed by the action of the force from the epicenter direction, at the sampling interval at which data of the seismic motion band is obtained, the distance between the table 10, the table 11, the table 12, and the table 13 is obtained by the above method. If the strain change is measured, it becomes a strain ground motion record that is the strain change of the ground motion band in each direction. By analyzing the strain earthquake motion records obtained in this way, it is possible to determine from which direction the force in the seismic motion band is received in the plane with the three strain meters attached.

  In the first embodiment, the three-direction strain gauge was considered that the foundation of the building was in the horizontal plane. However, if there is a vertical strain gauge that is perpendicular to this plane, preferably perpendicular to this plane. From the rate of deformation, information on the depth direction where the force acts can be obtained. Fig. 4 shows a conceptual diagram of the second embodiment in which a reference scale is added to the first embodiment. In this case, a base 20 is provided on a column or wall that is vertical in the reinforced concrete foundation portion of the building, an elastic body 21 is attached as a reference scale along the column or wall, and a displacement sensor 22 is attached to the tip of the base. To measure vertical strain earthquake motion.

  Fig. 5 shows a schematic diagram of the Michelson interferometer quoted from the 1st volume of the Global Environment Survey and Measurement Dictionary (P351). In the second embodiment, an example is shown in which a displacement sensor is used to detect strain earthquake motion. However, instead of the displacement sensors 17, 18, 19, and 22, optical means such as light interference is used (sensor unit). Then, the amount of deformation is measured using the means shown in FIG. 5), and there is also a method as in the third embodiment. Since the third embodiment is similar to the second embodiment except for the sensor part, it is not shown here.

  Fig. 6 shows a schematic diagram of a food-back seismometer quoted from the 1st volume of the Global Environment Survey and Measurement Dictionary Volume 1 (P559). In the second embodiment, an example is shown in which a displacement sensor is used to detect strain earthquake motion. However, instead of the displacement sensors 17, 18, 19, and 22, for example, as shown in the example of FIG. There is also a method as in the fourth embodiment in which the amount of deformation is measured as the magnitude of the electric force by converting it into a change in electric force corresponding to the amount. In this case, an electric force corresponding to the amount of displacement is usually generated and adjusted so that the displacement remains zero, and the amount of deformation is converted into a magnitude of the electric force. Since the fourth embodiment is similar to the second embodiment except for the sensor part, it is not shown here.

  In the second embodiment, an example is shown in which a displacement sensor is used to detect strain earthquake motion. However, for example, a strain gauge 24 is used instead of the displacement sensors 17, 18, 19, and 21, and the second embodiment shown in FIG. There is also a method as in the fifth embodiment. When using strain gauges, measure the seismic ground motion by attaching multiple strain gauges on the surface or inside of the building without providing a platform. When the surface or interior of a building is deformed, the electrical signal from the strain gauge changes in proportion to the amount of deformation. The change of this electric signal is measured.

  Fig. 8 shows a schematic diagram of the Sakata-type three-component strain meter quoted from the Global Environment Survey and Measurement Dictionary, Volume 1, Land Edition (P517). In the second embodiment, an example is shown in which a displacement sensor is used to detect strained ground motion. However, instead of the displacement sensors 17, 18, 19, and 21, for example, the amount of deformation is changed to the amount of deformation as in the example of FIG. There is also a method as in the sixth embodiment, in which the volume is converted into a change in volume of the liquid corresponding to 1 and the volume is measured as 25. In FIG. 8, the internal volume changes when the displacement detector receives a force from the side. This change in volume is measured as a volume change. Since the sixth embodiment is similar to the schematic diagram shown in FIG. 8, it is not shown here.

  Fig. 9 shows a conceptual diagram of the capacity change type transducer quoted from the 1st volume of the Global Environment Survey and Measurement Dictionary (P555). In the second embodiment, an example is shown in which a displacement sensor is used to detect strain earthquake motion. However, instead of the displacement sensors 17, 18, 19, and 22, a capacitance change type transducer is used (in the sensor unit, FIG. 9). There is also a method as in the seventh embodiment, in which the deformation amount is measured using the means shown in FIG. Since the seventh embodiment is similar to the second embodiment except for the sensor part, it is not shown here.

  Fig. 10 shows a conceptual diagram of the combined crustal activity observation device quoted from the Global Environment Survey and Measurement Dictionary, Volume 1, Land Edition (P518). Even if the strain gauge is provided inside the container like the borehole strain gauge incorporated in this observation apparatus and installed inside the building, preferably inside the foundation, and the deformation amount of the building is measured, The same results as in the example are obtained. As shown in this example, if the strain gauge is placed in a container and fixed inside the building, it is less susceptible to short-term temperature changes and the data quality is improved.

  An example of a strain gauge that directly measures displacement is described above (however, the example shown in FIG. 8 is different). Fig. 11 shows a conceptual diagram of the displacement magnifying device of the strain gauge incorporated in the combined crustal activity observation device shown in Fig. 10. Similarly to this example, if the strain gauge is configured to mechanically expand the displacement, the displacement can be detected with high accuracy, a highly accurate strain analysis can be performed, and the strain gauge can be made compact.

Specific processing for predicting the earthquake magnitude from the amount of deformation by the calculation means will be described with reference to FIG. In this case, the relational expression between the duration and the earthquake magnitude, which is calculated based on the deformation amount of the building measured by the strainmeter according to the present invention, and the main strain direction continues in a specific direction, or the correspondence table is It is assumed that it has been prepared in advance. When a P wave arrives during an earthquake and the structure is deformed due to the action of an earthquake force, the calculation process is executed in the following order.
1) In S1, measure the amount of deformation of the building in at least three directions.
1) Convert the deformation measured in S2 into strain.
2) The main strain direction is calculated from the combination of strains in the three directions at S3.
3) Determine whether the main strain direction calculated in S4 is a specific direction within the error range.
4) In S5, the length of time during which the main strain direction continues in a specific direction within the error range is determined.
5) Read the relational expression of the main strain direction prepared in S6 and S6 'in advance in a specific direction and the earthquake magnitude, or the correspondence table, and read the lower limit value of the predicted earthquake magnitude or the earthquake magnitude. Decide.
6) Output information related to earthquake magnitude at S7 and S7 '.
7) Then, return to S1 and prepare for the prediction of the next earthquake magnitude.
While continuing the above processing, when the main strain direction does not continue in a specific direction in S5, the duration is determined, the final earthquake magnitude is determined, and the information is output in S7 and S7 ′.

  During the time when the rupture proceeds and the fault movement continues in the hypocenter area, seismic waves reflecting the movement are emitted to the surrounding area. In places far from the epicenter, a seismic wave called a fast P wave arrives first. The building is deformed by the action of the P wave from the source direction, but the building shakes in the direction of the P wave, in other words, the source direction. For this reason, if the strain is obtained from the amount of deformation of the building obtained at the time of the earthquake and the strain analysis is performed, the direction of the main strain is generally directed toward the epicenter. However, depending on the shape and location of the building, the maximum shaking of the building may not always be in the direction of P-wave travel. In addition, depending on where the amount of deformation is measured, the main strain direction obtained by strain analysis is not always the epicenter direction. However, regardless of the direction itself, it suffices to find the duration for which the main strain direction maintains a specific direction, and the seismic magnitude increases as the duration increases. It can be done every moment.

  The above main strain direction can be calculated at the initial motion part of the P wave, where the earthquake caused a small shaking of the building, and the seismic magnitude is estimated before the maximum S wave shaking, which is the main cause of the earthquake disaster, arrives. it can. If the earthquake magnitude is known, the magnitude of the incoming S-wave amplitude can be estimated. Therefore, the information of the length of time that the main strain direction maintains a specific direction is a guideline for knowing the maximum magnitude of the S wave of the coming earthquake, so it is extremely useful for earthquake disaster prevention. This information can be used as information for small-scale disaster prevention systems for individual buildings, for factories that include multiple buildings, and for large speed reductions of Shinkansen and emergency shutdown of nuclear power plants.

  In addition, if a small measurement system using a solar battery as a power source is installed along the railroad or road, the magnitude of the earthquake can be predicted in advance at that point. Based on this information, trains and cars can be kept away from high-risk areas such as landslides and disasters can be prevented in advance. Seismic magnitude can be determined more accurately if a strain gauge is installed in the exposed rock mass.

  Diagram showing the principle of extensometer (from Japanese geodesic appearance).   Principle diagram of a strain gauge using a displacement sensor. (View from the side)   A schematic diagram of a strain gauge placed so that the amount of deformation in three directions can be measured on a plane. (View from above).   A schematic diagram of a strain gauge placed on the strain gauge of Fig. 3 so that the amount of deformation in the vertical direction can be measured.   Schematic diagram of Michelson interferometer quoted from the Global Environment Survey and Measurement Dictionary.   A schematic diagram of a food bag seismometer quoted from the Global Environmental Survey and Measurement Dictionary.   A schematic diagram of a strain gauge using a strain gauge.   A schematic diagram of the Sakata three-component strain meter quoted from the Global Environmental Survey and Measurement Dictionary.   Schematic diagram of a capacity-changing transducer, cited from the Global Environment Survey and Measurement Dictionary.   Schematic diagram of a complex crustal activity observation device, cited from the Global Environment Survey and Measurement Dictionary.   Schematic diagram of Ishii-type borehole three-component strain gauge displacement magnifying device, cited from the Global Environment Survey and Measurement Dictionary.   Flow chart showing the calculation process to determine the earthquake magnitude from the amount of building deformation during the earthquake.

Explanation of symbols

1, 2, 10, 11, 12, 13, 20 ... base 3 ... base part 4, 14, 15, 16, 21 ... elastic body 5, 17, 18, 19, 22 ... displacement sensor 6 ... pressure 24 ... strain gauge

Claims (10)

Measuring the amount of deformation occurring in the building during an earthquake, and converts the deformation amount strain, performed strain analysis, determines the direction of the main strain, from the time that the principal strain direction continues, determine earthquake magnitude, earthquake An early prediction method of earthquake magnitude based on the amount of building deformation of
Means for measuring the amount of deformation in at least three directions provided for the building to be measured; and
Means for strain analysis of strain data based on the deformation amount of the building during an earthquake measured by the measuring means;
The deformation amount measuring means is arranged so as to be able to analyze the strain in a specific plane,
An early prediction method of seismic magnitude based on the amount of deformation of a building during an earthquake, characterized in that the main strain direction obtained by strain analysis is obtained and the seismic magnitude is predicted from the length of that time. The deformation measuring means according to claim 1 is arranged so that a horizontal strain analysis can be performed, a time for which the direction of the main strain obtained by the strain analysis continues is obtained, and an earthquake magnitude is calculated from the length of the time. An early prediction method of seismic magnitude based on the amount of building deformation during an earthquake, which predicts and predicts the epicenter direction based on the principal strain direction .   The deformation amount measuring means according to claim 1 and claim 2 is arranged so as to be able to analyze a strain in a specific plane, and is arranged in a direction oblique to the plane, preferably in a direction perpendicular to the plane. 4. An early prediction method of earthquake magnitude based on the amount of deformation of a building at the time of earthquake, comprising the amount of deformation measuring means of 4 and obtaining the amount of deformation having angle information between the surface and the direction of the epicenter.   The method for early prediction of earthquake magnitude based on the amount of deformation of a building at the time of an earthquake according to claim 1, wherein the deformation measurement unit is a displacement detection unit.   The method for early prediction of seismic magnitude based on the amount of deformation of a building at the time of an earthquake according to claim 1, wherein the deformation amount measuring means is an optical means.   The deformation amount measuring means converts the deformation amount of the building into a change in electric force corresponding to the deformation amount, and measures the change as the magnitude of the electric force. An early prediction method of seismic magnitude based on the amount of building deformation during an earthquake.   The early prediction method of earthquake magnitude based on the amount of deformation of a building according to claim 1, wherein the deformation measuring means is a strain gauge.   The deformation amount measuring means converts a deformation amount of a building into a volume change of a liquid corresponding to the deformation amount, and measures the change as a volume size. An early prediction method of earthquake magnitude based on the amount of building deformation.   4. An earthquake according to claim 1, wherein said deformation amount measuring means converts the deformation amount of a building into a change in electric capacity corresponding to the deformation amount, and measures the change as the magnitude of the electric capacity. Method for early prediction of earthquake magnitude based on the amount of deformation of buildings. Measure the amount of deformation of the building that occurs during an earthquake, convert the obtained amount of deformation into strain, analyze the strain based on the strain, determine the direction of the main strain, and from the time the main strain direction continues , An early earthquake magnitude prediction program for early prediction of earthquake magnitude based on the amount of building deformation
In the process of analyzing strain data calculated from the amount of deformation of the building that occurs during an earthquake,
Processing to calculate the deformation amount in at least three directions,
Processing to calculate the main strain direction from strain by strain analysis,
Processing to identify the calculated duration in the main strain direction,
A process for reading the information indicating the correspondence between the duration and the earthquake magnitude recorded in the memory in advance and calculating the earthquake magnitude,
An early earthquake magnitude prediction program based on the amount of building deformation during an earthquake.

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