Prediction device, prediction method, and program

Abstract

This system accurately predicts the degree of ground vibration at a target location when the type of ground changes along the path of vibration propagation from the vibration source to the target location. [Solution] When the prediction device's processor has a change point between the location of the vibration source and the target location where the type of ground changes, it identifies a first distance from the location of the vibration source to the target location and a second distance from the location of the vibration source to the change point, determines a first value relating to the characteristics of the vibration waves reaching the target location and a second value corresponding to the type of ground at the target location, sets a third value based on the amount of change in the degree of ground vibration at the change point due to the change in the type of ground, and predicts the degree of ground vibration L(r) at the target location using the following formula from the first distance r, the second distance r1, a constant Z, the first value n, the second value α, the third value β, and the degree of ground vibration L(r1) at the change point. L(r) = L(r1) - 20n log 10 (r / r1)-αZ(r-r1)+β

Description

[Technical Field]

[0001] The present invention relates to a prediction device, a prediction method, and a program, and more particularly to a prediction device, a prediction method, and a program that predict the degree of ground vibration at a target location based on the principle of distance attenuation. [Background technology]

[0002] One method for investigating ground vibrations occurring at a building construction site or planned construction site is to measure the degree of ground vibration at that specific location (target site). However, this method is time-consuming and can be costly. In particular, the larger the area of ​​the construction site or planned construction site, the more measurement points are required for ground vibration, and consequently, the higher the investigation costs.

[0003] On the other hand, another method for investigating ground vibration involves acquiring various types of data and predicting the degree of ground vibration at a target location based on that data. This method allows for the evaluation of the degree of ground vibration at a target location without unnecessarily increasing the number of measurement points, thereby reducing investigation costs.

[0004] When predicting the degree of ground vibration at a target location, measurement data on ground vibration in the vicinity of the target location is typically obtained, and these measurement values ​​are input into a vibration prediction formula. Examples of vibration prediction formulas include distance attenuation formulas, which are prediction formulas based on vibration damping from the vibration source to the target location. Furthermore, among distance attenuation formulas, there are formulas that take into account the ground characteristics of the target location, specifically ground conditions such as soil type (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-27984 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Conventional distance attenuation formulas that consider ground characteristics predict the degree of vibration based on a single type of ground, for example, the type of ground at the target location. However, the characteristics of the ground at and around the target location are not necessarily uniform, and the type of ground may change along the path of vibration propagation from the vibration source to the target location. In such cases, conventional distance attenuation formulas that consider only one type of ground make it difficult to guarantee the accuracy of predictions regarding the degree of ground vibration at the target location.

[0007] Therefore, the present invention has been made in view of the above problems, and its objective is to provide a prediction device, prediction method, and program for accurately predicting the degree of ground vibration at a target location, taking into account when the type of ground changes along the path in which vibration propagates from the vibration source to the target location. [Means for solving the problem]

[0008] The above problems are solved by the prediction device of the present invention, which includes a processor and predicts the degree of ground vibration at a target location, wherein the processor performs the following processes when there is a change point between the location where the vibration source is located and the target location where the type of ground changes: a process to identify a first distance from the location where the vibration source is located to the target location and a second distance from the location where the vibration source is located to the change point; a process to determine a first value relating to the characteristics of the vibration waves reaching the target location and a second value corresponding to the type of ground at the target location; a process to set a third value based on the amount of change in the degree of ground vibration at the change point due to the change in the type of ground; and a process to predict the degree of ground vibration L(r) at the target location using the following equation (1), where the first distance is r, the second distance is r1, a predetermined constant is Z, the first value is n, the second value is α, the third value is β, the degree of ground vibration at the target location is L(r), and the degree of ground vibration at the change point is L(r1). L(r) = L(r1) - 20n log 10 (r / r1) -αZ(r-r1)+β (1)

[0009] By using the prediction device of the present invention configured as described above, it is possible to accurately predict the degree of ground vibration at a target location, even if the type of ground changes along the path of vibration propagation from the vibration source to the target location.

[0010] Furthermore, in the above-described prediction device, the degree of ground vibration may be measured at a measurement point set between the change point and the target point, where the type of ground is the same as that of the target point. In this case, the processor further performs the process of obtaining the measured value of the degree of ground vibration at the measurement point and the process of identifying the third distance from the change point to the measurement point. In the process of setting the third value β, it is preferable to calculate the calculated value γ using the following equation (2), with the third distance being rw, and set the third value β based on the difference between the measured value and the calculated value γ. γ = L(r1) - 20nlog 10 (rw / r1) -αZ(rw-r1) (2) With the above configuration, the third value β can be appropriately set, and by using this third value β, the degree of ground vibration at the target location can be accurately predicted when the type of ground changes along the path of vibration propagation from the vibration source to the target location.

[0011] Furthermore, in the above-described prediction device, it is even more preferable that the processor further performs a process to determine whether or not a change point exists between the location where the vibration source is located and the target location, based on data indicating the type of ground at both the location where the vibration source is located and the target location. With the above configuration, it is possible to accurately predict the degree of ground vibration at the target location by appropriately determining whether the type of ground changes along the path of vibration propagation from the vibration source to the target location.

[0012] Furthermore, the aforementioned problems are solved by the prediction method of the present invention, which is a prediction method for predicting the degree of ground vibration at a target location, wherein the processor performs the following processes when there is a change point between the location where the vibration source is located and the target location where the type of ground changes: a process to identify a first distance from the location where the vibration source is located to the target location and a second distance from the location where the vibration source is located to the change point; a process to determine a first value relating to the characteristics of the vibration waves reaching the target location and a second value corresponding to the type of ground at the target location; a process to set a third value based on the amount of change in the degree of ground vibration at the change point due to the change in the type of ground; and a process to predict the degree of ground vibration L(r) at the target location by the following equation (1), where the first distance is r, the second distance is r1, a predetermined constant is Z, the first value is n, the second value is α, the third value is β, the degree of ground vibration at the target location is L(r), and the degree of ground vibration at the change point is L(r1). L(r) = L(r1) - 20n log 10 (r / r1) -αZ(r-r1)+β (1) According to the prediction method described above, even if the type of ground changes along the path of vibration propagation from the vibration source to the target location, the degree of ground vibration at the target location can be predicted with high accuracy.

[0013] Further, according to the program of the present invention, the above problem is solved by a program for predicting the degree of ground vibration at a target point, which causes a processor to perform the following processes when there is a change point where the type of ground changes between the point where the vibration source exists and the target point: a process of specifying a first distance from the point where the vibration source exists to the target point and a second distance from the point where the vibration source exists to the change point; a process of determining a first value related to the characteristics of the vibration wave reaching the target point and a second value corresponding to the type of ground at the target point; a process of setting a third value based on the amount of change in the degree of ground vibration at the change point due to the change in the type of ground; setting the first distance as r, the second distance as r1, a predetermined constant as Z, the first value as n, the second value as α, the third value as β, the degree of ground vibration at the target point as L(r), and the degree of ground vibration at the change point as L(r1), and predicting the degree of ground vibration L(r) at the target point by the following formula (1). L(r)= L(r1)-20nlog 10 (r / r1) -αZ(r - r1)+β (1) By executing the above program, even when the type of ground changes on the way of the path where vibration propagates from the vibration source to the target point, the degree of ground vibration at the target point can be accurately predicted.

Effect of the Invention

[0014] According to the present invention, when the type of ground changes on the way of the path where vibration propagates from the vibration source to the target point, it is possible to accurately predict the degree of ground vibration at the target point in consideration of this fact.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing the configuration of a vibration prediction device according to an embodiment of the present invention. [Figure 2] It is a diagram showing an example of a map of an investigation area. [Figure 3] It is a diagram showing the relationship between the distance from the vibration source and the degree of ground vibration. [Figure 4] It is a diagram showing the flow of the vibration prediction process.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, one embodiment of the present invention (hereinafter, this embodiment) will be described with reference to the accompanying drawings. Note that the concept of "device" described in this specification includes a single device that exhibits a specific function by itself, as well as a plurality of devices that are distributed and exist independently but cooperate (work together) to exhibit a specific function.

[0017] In addition, in this specification, unless otherwise specified, the term "location" means a location on a map (specifically, a two-dimensional map), that is, a location that can be specified by latitude and longitude. Also, a location may have a certain extent (for example, an area of several tens of meters 2 ~ several hundreds of meters 2 in size).

[0018] <<Overview of the Vibration Prediction Device According to One Embodiment of the Present Invention>> The vibration prediction device according to this embodiment (hereinafter, vibration prediction device 10) corresponds to the "prediction device" of the present invention and predicts the degree of ground vibration at a target location. The target location is a location set as a prediction target, for example, a construction site or a planned construction site of a building. Ground vibration is the vibration on the ground surface that occurs at the target location when vibration waves propagate from a vibration source to the target location. The degree of ground vibration is a concept representing the scale and intensity of ground vibration. In this embodiment, it is the acceleration of ground vibration (strictly speaking, the relative level value of acceleration, unit: dB). However, it is not limited to this, and other index values such as magnitude may be predicted as the degree of ground vibration.

[0019] In this embodiment, the vibration source is the source of environmental vibration (excitation source), specifically vibrations caused by factory operations, road traffic, or construction work, which are transmitted to the target location. However, it is not limited to this; the vibration source may also be the source of an earthquake (epicenter), in which case the degree of ground vibration at the target location during an earthquake will be predicted.

[0020] Furthermore, this embodiment assumes that vibrations (vibration waves) from the vibration source propagate in one direction toward the target point. In other words, in this embodiment, vibrations from multiple directions are unlikely to enter the target point, and the degree of vibration propagated to the target point is relatively small. In the following explanation, "the location where the vibration source is located" refers to a point on the ground surface. If the vibration source is located below the ground surface, it means the point where the vibration source intersects the ground surface when moved directly upwards.

[0021] Furthermore, in this embodiment, the degree of ground vibration (specifically, the acceleration level) around the target site is measured using a known vibration sensor. Hereinafter, the location where the degree of ground vibration is measured will also be referred to as the "measurement point." The measurement point is a location where the degree of ground vibration is predicted by the vibration prediction device 10, i.e., a location different from the target site.

[0022] The vibration prediction device 10 predicts the degree of ground vibration at a target location using actual measurement data of the degree of ground vibration at measurement points near the target location. In this embodiment, by predicting the degree of ground vibration at the target location without actually measuring it, the number of measurement points for the degree of ground vibration can be reduced, and as a result, the burden and cost of investigations related to ground vibration can be reduced.

[0023] In this embodiment, a distance attenuation formula for the propagation of ground vibration is used to predict the degree of ground vibration. The distance attenuation formula is an equation that shows that the degree of vibration decreases as the distance from the vibration source increases, and is based on Bornitz's equation, and is used to predict the vibration acceleration level.

[0024] The distance attenuation formula, as shown in equation f1 below, includes a term for attenuation according to the characteristics of the vibration waves reaching the target point, and a term for attenuation according to the type of ground (more specifically, soil type). L(r) = L(r0) - 20n log 10 (r / r0) -αZ(r-r0) (formula f1) In the above equation f1, L(r) represents the degree of ground vibration at the target point and is a function of the distance r from the vibration source to the target point. L(r0) represents the degree of ground vibration at a point a predetermined distance r0 away from the point where the vibration source is located, in the direction toward the target point. The predetermined distance r0 is determined according to the type of ground vibration; for example, in the case of construction vibration, r0 is set to 5m. A predetermined value is adopted for L(r0), specifically, an eigenvalue determined for each type of construction is used. Note that the distance r from the vibration source to the target point is greater than the predetermined distance r0.

[0025] Furthermore, in the above equation f1, n represents a first value relating to the characteristics of the vibration wave reaching the target point, Z represents a constant, and α represents a second value corresponding to the type of ground at the target point (more specifically, the soil type). The first value n is the geometric damping constant and is in the range of 0.5 to 1.0. Specifically, if the vibration wave reaching the target point is a surface wave, the first value n is 0.5; if the vibration wave is a body wave, the first value n is 1.0; and if the vibration wave has characteristics intermediate between a surface wave and a body wave, the first value n is 0.75. In addition, whether the vibration wave reaching the target point is a surface wave, a body wave, or has characteristics intermediate between these two waves can be determined based on the type and height of the building to be constructed at the target point, and specifically, it can be determined according to the depth of the foundation layer when constructing a building at the target point.

[0026] The constant Z is predetermined to an appropriate value in the distance attenuation formula, for example, 8.68. The second value α is an attenuation constant specific to the type of ground (more specifically, soil type), for example, 0.001 for consolidated ground consisting of gravel, 0.019 for unconsolidated ground, and 0.04 for clayey ground. Here, it is assumed that the correspondence between the type of ground and the second value α is known.

[0027] The generally known distance attenuation formula is expressed by the above formula f1, but this formula f1 is applicable only when the type of ground (specifically, soil type) is uniform and does not change over the range from the vibration source to the target location. On the other hand, the type of ground may change along the vibration propagation path from the vibration source to the target location, and in such cases, it becomes difficult to accurately predict the degree of ground vibration at the target location using only the above formula f1.

[0028] Therefore, in this embodiment, if the type of ground changes from the point where the vibration source is located to the target point, in other words, if there is a point of change where the type of ground changes between the point where the vibration source is located and the target point, the degree of ground vibration at the target point is predicted by the following f2, which is an improved version of the above formula f1. L(r) = L(r1) - 20n log 10 (r / r1) -αZ(r-r1)+β (Equation f2)

[0029] The above equation f2 corresponds to "Equation (1)" of the present invention. In the above equation f2, distance r represents the distance from the point where the vibration source is located to the target point, and will be referred to as the first distance below. Also, in the above equation f2, r1 is the distance from the point where the vibration source is located to the point of change, and will be referred to as the second distance below. Here, the units of the first distance r and the second distance r1 are m, and the first distance r is greater than the second distance r1.

[0030] In the above equation f2, L(r1) represents the degree of ground vibration at the change point. For the degree of ground vibration L(r1) at the change point, the value obtained by actually measuring the degree of ground vibration at the change point (measured value) may be used, or the value calculated by the above equation f1 may be used. When calculating L(r1) using equation f1, substitute r1 for r in equation f1, use a value for the first value n that corresponds to the characteristics of the vibration wave reaching the change point, and use a value for the second value α that corresponds to the same type of ground as the location where the vibration source exists.

[0031] Furthermore, in the above equation f2, β is a third value based on the amount of change in the degree of ground vibration at the change point due to the change in the type of ground, and is an adjustment coefficient (in dB) based on the change in the type of ground at the change point. At the change point, the degree of ground vibration changes (shifts) due to the change in the type of ground, and a value corresponding to the amount of that change (shift) is set as the third value β. The method for setting the third value β will be explained in a later section.

[0032] Furthermore, in this embodiment, by using the above-described equation f2, it is possible to appropriately predict the degree of ground vibration at the target location even if the type of ground changes along the path of vibration propagation from the vibration source to the target location.

[0033] <<Example of the configuration of the vibration prediction device according to this embodiment>> Next, an example of the configuration of the vibration prediction device 10 will be explained with reference to Figure 1. In this embodiment, the vibration prediction device 10 is computer-based and used by the user. The user uses the vibration prediction device 10 to predict the degree of ground vibration at a target location and performs tasks (for example, building design) based on the prediction results.

[0034] The computer comprising the vibration prediction device 10 may be a personal computer (PC) or workstation for personal use, or it may be a server computer. If a server computer constitutes the vibration prediction device 10, that server computer may be a server computer for ASP (Application Service Provider), SaaS (Software as a Service), PaaS (Platform as a Service), or IaaS (Infrastructure as a Service). In this case, when the necessary information is entered on the client terminal, the server computer performs various processes and calculations based on the input information, and the calculation results are output on the client terminal side. In other words, the functions of the server computer, which is the vibration prediction device 10, can be used on the client terminal side. The vibration prediction device 10 may be composed of a single computer, or it may be composed of multiple computers arranged in parallel and distributed.

[0035] The computer comprising the vibration prediction device 10 has a processor 11, memory 12, storage 13, and a communication interface 14, as shown in Figure 1.

[0036] The processor 11 is composed of, for example, a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), an MCU (Micro Controller Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), a TPU (Tensor Processing Unit), an NPU (Neural Network Processing Unit), or an ASIC (Application Specific Integrated Circuit). The memory 12 is composed of semiconductor memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0037] The storage 13 consists of, for example, flash memory, HDD (Hard Disc Drive), SSD (Solid State Drive), FD (Flexible Disc), MO disk (Magneto-Optical disc), CD (Compact Disc), DVD (Digital Versatile Disc), SD card (Secure Digital card), or USB memory (Universal Serial Bus memory). The storage 13 may be built into the computer body that constitutes the vibration prediction device 10, or it may be attached to the computer body as an external device.

[0038] The communication interface 14 may be configured, for example, as a network interface card or a communication interface board. The computer constituting the vibration prediction device 10 can communicate data with other devices connected to the Internet or a mobile communication line, etc., via the communication interface 14. Devices that can communicate with the vibration prediction device 10 include, for example, information provision servers operated by government agencies, etc., and computers used by those conducting ground investigations.

[0039] Furthermore, the computer constituting the vibration prediction device 10 has software installed, including an operating system (OS) program and an application program for vibration prediction. These programs correspond to the "programs" of the present invention and are read and executed by the processor 11. As a result, the computer constituting the vibration prediction device 10 performs its functions, specifically by executing a series of processes to predict the degree of ground vibration at the target location.

[0040] Furthermore, the vibration prediction device 10 may be connected to various output devices, and these output devices may include, for example, a user-accessible display 15. In this case, the prediction results from the vibration prediction device 10 can be displayed on the display 15.

[0041] Furthermore, in this embodiment, the vibration prediction device 10 has a database 16. The database 16 may be built on, for example, the storage 13 provided by the vibration prediction device 10, or it may be built on a database server that can communicate with the vibration prediction device 10.

[0042] Database 16 stores various types of information necessary for the vibration prediction device 10 to predict the degree of ground vibration at the target location. The information stored in Database 16 includes map information of the area including the target location (hereinafter also referred to as the survey area).

[0043] The map information for the survey area includes the latitude, longitude, and ground survey results for each point within the survey area. Specifically, for example, the map information for the survey area may be a color-coded display of the ground type (more precisely, soil type) at each point within the survey area, as shown in Figure 2. Also, as shown in Figure 2, the survey area includes locations where vibration sources exist (indicated by stars in the figure), measurement points (indicated by X marks in the figure), and target points (indicated by black or white circles in the figure). In other words, the map information is data indicating the ground type at each point within the survey area, including locations where vibration sources exist, measurement points, and target points. Map information can be obtained from administrative agencies such as the Geospatial Information Authority of Japan and local governments that have jurisdiction over the survey area. For more details, you can obtain the information by communicating with the server that distributes the map information.

[0044] Furthermore, database 16 stores table data showing the correspondence between ground type (soil type) and the second value α. By referring to this table data, if the ground type is identified at a point within the survey area, the second value α applicable to that point can be determined.

[0045] Furthermore, for one or more measurement points within the survey area, their location information (specifically, longitude and latitude), as well as actual measurement data of the degree of ground vibration at those measurement points, are stored in database 16. In addition, for vibration sources within the survey area, the longitude and latitude of the location where the vibration source is located, and a value indicating the degree of ground vibration at a point a predetermined distance r0 away from that location, are stored in database 16.

[0046] <<Regarding the prediction method according to this embodiment>> Next, referring to Figure 4, the procedure for predicting the degree of ground vibration at a target location using the vibration prediction device 10 (hereinafter referred to as the prediction flow) will be explained. The prediction flow employs the prediction method of the present invention and proceeds according to the flow shown in Figure 4. In other words, each step in the flow shown in Figure 4 corresponds to each element that constitutes the prediction method of the present invention. Note that the flow shown in Figure 4 is merely an example, and unnecessary steps may be deleted, new steps added, or the order of steps rearranged, without departing from the spirit of the present invention.

[0047] In the prediction flow, the processor 11 of the computer constituting the vibration prediction device 10 executes the corresponding calculation process at each step in the prediction flow shown in Figure 4. Specifically, the processor 11 executes the first identification process S001 and the determination process S002.

[0048] In the first identification process, the processor 11 receives the user's specification of the survey area and target points, then accesses the database 16 and reads the map information of the survey area specified by the user from the database 16. Subsequently, the processor 11 identifies the longitude, latitude, and ground type (specifically, soil type) of the target points specified by the user from the read map information of the survey area. In the first identification process, the processor 11 also identifies the longitude, latitude, and ground type (specifically, soil type) of the locations within the survey area where vibration sources exist from the map information. Then, in the first identification process, the processor 11 determines the distance from the locations where vibration sources exist to the target points, i.e., the first distance r, based on the longitude and latitude of each location.

[0049] In the determination process, the processor 11 determines whether or not a change point exists between the location of the vibration source and the target location, based on the type of ground (soil type) identified for both the location of the vibration source and the target location. To explain using the map information shown in Figure 2 as an example, in the survey area shown by this map information, if you follow the straight path connecting the location of the vibration source (indicated by a star in the figure) and the target location (indicated by a black or white circle in the figure), the type of ground (more specifically, the soil type) changes along that path. For example, in the case shown in Figure 2, if the location indicated by the white circle is the target location, then a change point exists between the location of the vibration source and the target location.

[0050] In the prediction flow, the flow after the determination process changes depending on the determination result (S003) in the determination process, as shown in Figure 4. If it is determined that there is no change point between the location where the vibration source is located and the target location, that is, that the location where the vibration source is located and the target location are on the same ground (No in S003), the processor 11 executes the decision process S004. In the decision process S004, the processor 11 determines the first value n, the second value α, and the degree of ground vibration L(r0) at a location a predetermined distance r0 away from the location where the vibration source is located.

[0051] To explain the decision process S004 in more detail, the processor 11 determines, based on the depth of the foundation layer when a building is constructed at the target site, whether the vibration waves reaching the target site are surface waves, body waves, or have characteristics intermediate between these two waves, and determines the first value n according to the determination result. The processor 11 also determines the second value α corresponding to the type of ground at the target site by referring to table data showing the correspondence between the type of ground (more specifically, soil type) and the second value α stored in the database 16. Furthermore, the processor 11 reads the degree of ground vibration L(r0) at a point a predetermined distance r0 away from the point where the vibration source exists from the database 16 and determines its value.

[0052] Subsequently, processor 11 executes prediction process S005 to predict the degree of ground vibration L(r) at the target location, more specifically, the degree of ground vibration at the target location (indicated by the black circle in Figure 2) where the ground type is the same as the location where the vibration source exists. In prediction process S005 when the location where the vibration source exists and the target location are on the same ground, the above-mentioned equation f1 is used. Specifically, by substituting the first distance r identified in the first identification process and the three values ​​n, α, and L(r0) determined in the determination process into equation f1, the degree of ground vibration L(r) at the target location is predicted.

[0053] Subsequently, the processor 11 executes output processing S006, outputs the prediction results from prediction processing S005, and displays, for example, the predicted degree of ground vibration L(r) at the target location on the user-accessible display 15.

[0054] On the other hand, if the determination process determines that a change point exists between the location where the vibration source is located and the target location (Yes in S003), the processor 11 executes the second identification process S007. In the second identification process, the processor 11 searches for the change point from the map information of the survey area and identifies the longitude and latitude of the change point. Then, based on the longitude and latitude of the identified change point, and the latitude and longitude of the location where the vibration source is located identified in the first identification process, the processor 11 identifies the distance from the location where the vibration source is located to the change point, i.e., the second distance r1.

[0055] Furthermore, if a change point exists between the location where the vibration source is located and the target location, the processor 11 executes the determination process S008 and the setting process S009. In the determination process S008, the first value n and the second value α are determined in the same manner as in the determination process S004 when there is no change point between the location where the vibration source is located and the target location.

[0056] In the setting process S009, the processor 11 sets the third value β in the aforementioned equation f2. In the setting process S009, the processor 11 executes the acquisition process S021, the third identification process S022, and the third value setting process S023, as shown in Figure 4.

[0057] In the acquisition process, the processor 11 reads the information of intermediate measurement points from the information of multiple measurement points stored in the database 16, and identifies and acquires the measured value of the degree of ground vibration at the intermediate measurement point from the read information. Here, an intermediate measurement point is a measurement point that is set between the change point and the target point (more precisely, on the straight line connecting the change point and the target point) among the multiple measurement points that exist within the survey area, and is the same type of ground as the target point. In the map information shown in Figure 2, the points marked with an "X" correspond to intermediate measurement points. Also, in the graph shown in Figure 3, the measured value of the degree of ground vibration at the intermediate measurement point corresponds to Lw in the figure.

[0058] FIG. 3 is a diagram regarding the distance attenuation of ground vibration. Specifically, it is a graph showing the correspondence between the distance from the vibration source and the degree of ground vibration. The horizontal axis represents the distance from the vibration source (unit: m), and the vertical axis represents the acceleration level of ground vibration (unit: dB). In FIG. 3, there are graphs for the case where the type of ground at each point in the vibration propagation path is the same as the type of ground at the point where the vibration source exists (denoted as g1 in the figure), and for the case where the type of ground changes at an intermediate position in the vibration propagation path (denoted as g2 in the figure).

[0059] In the third specific process, the processor 11 identifies the longitude, latitude, and type of ground (specifically, soil quality), etc. for the above intermediate measurement points from the map information of the survey area, and identifies the distance from the change point to the intermediate measurement point based on the respective longitudes and latitudes. Hereinafter, the distance from the change point to the intermediate measurement point will be referred to as the third distance.

[0060] In the third value setting process, the processor 11 calculates a calculated value γ according to the following formula f3. γ = L(r1) - 20nlog 10 (rw / r1) -αZ(rw - r1) (formula f3) The above formula f3 corresponds to the 'formula (2)' of the present invention. In formula f3, rw represents the third distance. Here, the unit of the third distance rw is m, and the third distance rw is greater than the second distance r1.

[0061] When calculating the calculated value γ, the second distance specified in the above-mentioned second specific process is substituted for r1 in formula f3, the first value and the second value determined in the above-mentioned determination process are substituted for n and α, and the third distance specified in the above-mentioned third specific process is substituted for rw. Also, for L(r1) in formula f3, the value (actual measurement value) when the degree of ground vibration is actually measured at the change point may be substituted, or the value calculated by the above formula f1 for the degree of ground vibration at the change point may be substituted.

[0062] As can be seen by comparing it with equation f1, equation f3 is obtained by substituting L(r0) with L(r1) in equation f1. Specifically, it is a distance attenuation formula that corresponds to the distance from the point of change, assuming that the type of ground does not change at the point of change. Therefore, the calculated value γ obtained from equation f3 represents the degree of vibration at a point a third distance rw from the point of change, assuming that the type of ground is uniform over the range from the point where the vibration source exists to the point of change. In other words, the calculated value γ lies on the graph shown by the solid line in Figure 3, which means it corresponds to the degree of ground vibration at the intermediate measurement point, which is determined by the distance attenuation formula based on the distance from the point of change.

[0063] Finally, in the third value setting process, the processor 11 calculates the difference between the measured value Lw of the degree of ground vibration at the intermediate measurement point acquired in the acquisition process and the calculated value γ above, and sets the third value β based on the calculated difference. Specifically, in this embodiment, the value corresponding to the above difference is set as the third value β.

[0064] After the third value β is set, the processor 11 executes the prediction process S010 to predict the degree of ground vibration L(r) at the target location, specifically the degree of ground vibration at the target location (indicated by the white circle in Figure 2) where the type of ground is different from that at the location where the vibration source is located. In the prediction process when there is a change point between the location where the vibration source is located and the target location, the above-described equation f2 is used. Specifically, by substituting the first distance r identified in the first identification process, the second distance r1 identified in the second identification process, the first value n and second value α determined in the determination process, the degree of ground vibration L(r1) at the change point obtained by measurement or calculation, and the third value β set in the setting process into equation f2, the degree of ground vibration L(r) at the target location is predicted.

[0065] Subsequently, the processor 11 executes output processing S006, outputs the prediction results from prediction processing S010, and displays, for example, the predicted degree of ground vibration L(r) at the target location on the user-accessible display 15.

[0066] The prediction flow ends when each process in the prediction flow described above is completed, or more specifically, when the prediction result for the degree of ground vibration L(r) at the target location is output in the output process.

[0067] As explained above, in this embodiment, the vibration prediction device 10 performs the prediction flow according to the procedure described above, and when the type of ground changes along the path of vibration propagation from the vibration source to the target site, it takes this into account and predicts the degree of ground vibration at the target site. As a result, the prediction accuracy of the degree of ground vibration at the target site can be improved.

[0068] Furthermore, in this embodiment, even if the type of ground changes at the point of change, the degree of ground vibration at the target point can be predicted using the above equation f2 for target points within the range where the changed type of ground is maintained. In other words, in this embodiment, the degree of ground vibration at the target point can be predicted by substituting the distance from the point where the vibration source is located to the target point, i.e., the first distance r, as a parameter into the above equation f2. This is because the distance attenuation formula can be applied continuously from the vibration source by adjusting the amount of change (shift) in the degree of ground vibration based on the change in the type of ground at the point of change using the third value β. For this reason, in this embodiment, the degree of ground vibration at the target point can be predicted more simply and accurately without having to redefine the distance attenuation formula each time the position of the target point changes, or more specifically, without having to re-determine the first value n and the second value α in the formula.

[0069] <<Regarding other embodiments>> Although one embodiment of the prediction device, prediction method, and program of the present invention has been described above, the above embodiment is merely an example to facilitate understanding of the present invention and does not limit it. In other words, the present invention can be modified and improved without departing from its spirit. Furthermore, it goes without saying that the present invention includes equivalents thereof.

[0070] Furthermore, in the above embodiment, map information of the survey area including the location of the vibration source and the target location is obtained, and the type of ground at each of the locations of the vibration source and the target location is identified from the map information. However, the information referenced when identifying the type of ground at each of the locations of the vibration source and the target location may be information other than map information, for example, LUT (Look Up Table) data that defines the location and type of ground at each point within the survey area may also be used. [Explanation of Symbols]

[0071] 10. Vibration prediction device (prediction device) 11 processors 12 memory 13 Storage 14. Communication Interfaces 15 displays 16 Databases

Claims

1. A predictive device equipped with a processor that predicts the degree of ground vibration at a target location, The aforementioned processor, When there is a point of change where the type of ground changes between the point where the vibration source is located and the target point, the process of determining a first distance from the point where the vibration source is located to the target point and a second distance from the point where the vibration source is located to the point of change, A process for determining a first value relating to the characteristics of vibration waves reaching the target point, and a second value corresponding to the type of ground at the target point, A process to set a third value based on the amount of change in the degree of ground vibration at the aforementioned change point due to a change in the type of ground, Let the first distance be r, the second distance be r1, a predetermined constant be Z, the first value be n, the second value be α, the third value be β, the degree of ground vibration at the target point be L(r), and the degree of ground vibration at the change point be L(r1), and the process of predicting the degree of ground vibration L(r) at the target point using the following equation (1), A prediction device that performs this operation. L(r)= L(r1)-20nlog １０ (r / r1) -αZ(r-r1)+β (1)

2. When the degree of ground vibration is measured at a measurement point set between the aforementioned change point and the aforementioned target point, and where the type of ground is the same as that of the aforementioned target point, the processor shall: A process to obtain the measured value of the degree of ground vibration at the aforementioned measurement point, Further, the process of determining a third distance from the change point to the measurement point is performed, The prediction device according to claim 1, wherein in the process of setting the third value β, the third distance is rw, a calculated value γ is calculated by the following formula (2), and the third value β is set based on the difference between the measured value and the calculated value γ. γ=L(r1)-20nlos １０ (rw / rq) -αZ(rw-r1) (2)

3. The prediction device according to claim 1, wherein the processor further performs a process to determine whether or not the change point exists between the location where the vibration source exists and the target location, based on data indicating the type of ground at the location where the vibration source exists and the target location, respectively.

4. A prediction method for predicting the degree of ground vibration at a target location, The processor, When there is a point of change where the type of ground changes between the point where the vibration source is located and the target point, the process of determining a first distance from the point where the vibration source is located to the target point and a second distance from the point where the vibration source is located to the point of change, A process for determining a first value relating to the characteristics of vibration waves reaching the target point, and a second value corresponding to the type of ground at the target point, A process to set a third value based on the amount of change in the degree of ground vibration at the aforementioned change point due to a change in the type of ground, Let the first distance be r, the second distance be r1, a predetermined constant be Z, the first value be n, the second value be α, the third value be β, the degree of ground vibration at the target point be L(r), and the degree of ground vibration at the change point be L(r1), and the process of predicting the degree of ground vibration L(r) at the target point using the following equation (1), A prediction method that performs this operation. L(r)= L(r1)-20nlog １０ (r / r1) -αZ(r-r1)+β (1)

5. This is a program for predicting the degree of ground vibration at a target location. In the processor, When there is a point of change where the type of ground changes between the point where the vibration source is located and the target point, the process of determining a first distance from the point where the vibration source is located to the target point and a second distance from the point where the vibration source is located to the point of change, A process for determining a first value relating to the characteristics of vibration waves reaching the target point, and a second value corresponding to the type of ground at the target point, A process to set a third value based on the amount of change in the degree of ground vibration at the aforementioned change point due to a change in the type of ground, Let the first distance be r, the second distance be r1, a predetermined constant be Z, the first value be n, the second value be α, the third value be β, the degree of ground vibration at the target point be L(r), and the degree of ground vibration at the change point be L(r1), and the process of predicting the degree of ground vibration L(r) at the target point using the following equation (1), A program that executes the command. L(r)= L(r1)-20nlog １０ (r / r1) -αZ(r-r1)+β (1)

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