Evaluation support device and evaluation support method

Abstract

To provide an evaluation support device and an evaluation support method for supporting confirmation of the condition of the hard ground where piles are to be installed.SOLUTION: A management device 20 that supports confirmation of the hard ground includes a measurement information storage unit 22 that stores measurement values of the frequency of ground vibration in association with measurement positions of ground vibration, and a control unit 21 connected to a display device. The control unit 21 calculates a frequency distribution of a spectral ratio obtained by dividing the spectrum of a horizontal component by the spectrum of a vertical component from the measurement values recorded in the measurement information storage unit 22, and converts the frequency of the frequency distribution into depth. The control unit 21 outputs to the display device a map that displays depth distribution information for the measurement positions, with the display format changed according to the spectral ratio.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an evaluation support device and an evaluation support method that support checking the condition of a support layer on which piles are to be installed. [Background technology]

[0002] When constructing a structure, multiple piles are driven into hard ground (bearing layer) to support the load of the structure through the piles. In this case, the pile holes into which the piles are inserted must reach all the way to the hard ground. For this reason, a boring survey is conducted to determine the depth of the hard ground.

[0003] Furthermore, an evaluation support device for supporting the evaluation of the ground at a proposed building construction site is also under consideration (see, for example, Patent Document 1). The evaluation support device described in Patent Document 1 acquires a three-dimensional geological layer estimation model generated based on geological layer information from a modeling device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-144684 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology described in Patent Document 1 does not allow reliable determination of the depth of the bearing layer made of hard ground. [Means for solving the problem]

[0006] The evaluation support device for solving the above-mentioned problems includes a measurement information storage unit that stores measurement values ​​of the frequency of ground vibration associated with measurement positions of ground vibration, and a control unit connected to a display device, and supports checking of the ground. The control unit calculates a frequency distribution of a spectral ratio obtained by dividing the spectrum of a horizontal component by the spectrum of a vertical component from the measurement values ​​recorded in the measurement information storage unit, converts the frequencies of the frequency distribution into depths, and outputs to the display device a map showing depth distribution information for the measurement positions, the display format of which is changed according to the spectral ratios. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to assist in checking the condition of the ground. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram illustrating a schematic configuration of an evaluation support system according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram of a hardware configuration of the embodiment. [Figure 3] FIG. 4 is an explanatory diagram of measurement information in the embodiment. [Figure 4] FIG. 2 is an explanatory diagram of a processing procedure according to an embodiment. [Figure 5] 1A and 1B are explanatory diagrams of constant microtremors in an embodiment, where FIG. 1A is an explanatory diagram when the dominant frequency is clear, and FIG. 1B is an explanatory diagram when the dominant frequency is unclear. [Figure 6] FIG. 2 is an explanatory diagram of a display screen in the embodiment. [Figure 7] 1A and 1B are explanatory diagrams of a display screen in an embodiment, in which FIG. 1A shows a stratum estimation model, and FIG. 1B shows a display screen in which a columnar model and a stratum estimation model are superimposed. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of an evaluation support device and an evaluation support method will be described below with reference to Figures 1 to 7. In this embodiment, it is assumed that a map showing the depth of hard ground is displayed in order to excavate a pile hole.

[0010] In this embodiment, the characteristics of the ground are estimated by measuring minute vibrations (microtremors) that are always present on the ground surface, without using any artificial vibration source. Here, three components, two horizontal components and a vertical component, are measured simultaneously. The spectral ratio (H / V spectrum) of the microtremors on the ground surface between the horizontal and vertical components is then calculated, and the frequency at which the ground is likely to shake (dominant frequency) is estimated using the H / V spectrum.

[0011] For this purpose, as shown in FIG. 1, the evaluation support system A1 includes a ground estimation system C1, a microtremor meter 10, and a management device 20 (evaluation support device), which are connected via a network.

[0012] (Example of hardware configuration) FIG. 2 shows an example of the hardware configuration of the information processing device H10 that functions as the management device 20 of the ground estimation system C1. The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and the information processing device H10 may include other hardware.

[0013] The communication device H11 is an interface that establishes a communication path with other devices and transmits and receives data. The input device H12 is a device that accepts input from the user.

[0014] The display device H13 is a display, a touch panel, or the like that displays various information. The storage device H14 stores data and various programs for executing various functions of the ground estimation system C1 and the management device 20. Examples of the storage device H14 include a ROM, a RAM, and a hard disk. The processor H15 controls each process in the ground estimation system C1 and the management device 20 using the programs and data stored in the storage device H14.

[0015] (Configuration of each functional part) Next, each functional unit that realizes the evaluation support method will be described. In this embodiment, the management device 20 realizes the evaluation support method using various information acquired from the ground estimation system C1 and the microtremor meter 10.

[0016] (Ground Estimation System C1) The ground estimation system C1 shown in Fig. 1 is a computer system that generates geological layer information that estimates the geological layers that make up the ground. In this embodiment, the ground estimation system C1 estimates the geological layers of the ground based on the results of boring at a construction site and generates a geological layer estimation model expressed as a 3D model. This ground estimation system C1 uses 3D CAD (computer-aided design) technology to perform modeling processing (3D CAD processing) that expresses each element related to the geological layers that make up the ground as a 3D model (object) placed in a 3D virtual space.

[0017] In this modeling, a cylindrical 3D model (boring model) is generated for each borehole position coordinate. The borehole model is a 3D model that represents the geological layer at the borehole position as a column in the depth direction.

[0018] This ground estimation system C1 estimates the layer boundary surface so as to connect common layers in the surrounding cylindrical three-dimensional models. In this case, the layer surface is smoothed by an approximation method. Then, the ground estimation system C1 generates a three-dimensional model (layer estimation model) in which the estimated layer boundary surfaces are set.

[0019] (Microtremometer 10) The microtremor meter 10 shown in Fig. 1 is a highly sensitive seismometer that continuously observes microtremors. It simultaneously measures three components (for example, north-south, east-west, and up-down directions): two horizontal components (X-axis and Y-axis) and a vertical component (Z-axis). For this reason, the microtremor meter 10 is equipped with three-component acceleration sensors and a logger (recording device).

[0020] (Management device 20) The management device 20 shown in FIG. 1 is a computer system used by a construction site manager to manage ground conditions.

[0021] As shown in FIG. 1, the management device 20 includes a control unit 21, a measurement information storage unit 22, and a ground information storage unit . The control unit 21 performs various processes (processes at an acquisition stage, an analysis stage, a display stage, etc.) To this end, the control unit 21 functions as an acquisition unit 211, an analysis unit 212, and a display unit 213 by executing an evaluation support program stored in the memory.

[0022] The acquisition unit 211 acquires measurement information from the microtremor meter 10 and executes a process of registering the information in the measurement information storage unit 22 . The analysis unit 212 analyzes the microtremors and performs processing to estimate the depth of the hard ground. This analysis unit 212 holds information on a shear wave velocity calculation formula for calculating the shear wave velocity from the N value and a calculation formula for calculating the depth from the frequency. The display unit 213 executes a process of outputting the analysis results to the display device H13.

[0023] Measurement management information about microtremors at the construction site is recorded in the measurement information storage unit 22. This measurement management information is recorded when it is acquired from the microtremor meter 10. The measurement management information includes measurement position information and microtremor information.

[0024] The measurement position information is information relating to the position coordinates (for example, latitude and longitude) where the microtremor meter 10 is placed and measures the microtremors. The microtremor information is information relating to the measurement values ​​of vibrations measured at this measurement position for a predetermined period (approximately several tens of minutes to several tens of hours). As shown in FIG. 3, the measurement management information 220 records the amplitudes of the horizontal X-axis, Y-axis, and vertical Z-axis in association with the measurement positions.

[0025] The ground information storage unit 23 stores layer model information of the layers that make up the ground. This layer model information is stored when a layer estimation model is acquired from the ground estimation system C1. The layer model information includes the object ID, element model, placement information, and attribute information of each layer.

[0026] The object ID is information about an identifier for identifying the three-dimensional shape (three-dimensional model) that constitutes the stratum. The element model is information relating to a three-dimensional object (three-dimensional model) that constitutes a stratum. In this embodiment, a stratum estimation model is used as the element model.

[0027] The placement information includes information about the placement of the three-dimensional model (coordinates in the three-dimensional virtual space). The attribute information includes the details of each element model. The attribute information of the stratum estimation model includes a soil type that indicates the classification of the soil type of the stratum. This soil type type identifies the hard ground that the pile hole will reach.

[0028] (Support processing) Next, the support process will be described with reference to FIG. First, the control unit 21 of the management device 20 executes a process of acquiring various information (step S11). Specifically, the acquisition unit 211 of the control unit 21 acquires the measurement position and measurement information from the microtremor meter 10. Then, the acquisition unit 211 records the measurement management information in which the microtremor information is associated with the measurement position in the measurement information storage unit 22.

[0029] Furthermore, the acquisition unit 211 acquires the N value obtained by the standard penetration test from the input device H12. Then, the acquisition unit 211 inputs the N value into the shear wave velocity calculation formula to calculate the shear wave velocity.

[0030] Next, the control unit 21 of the management device 20 identifies a processing target at each measurement position, and repeats the following processing for each measurement position. Here, the control unit 21 of the management device 20 executes a process for identifying the hard ground position (step S12). Specifically, the analysis unit 212 of the control unit 21 calculates the spectral ratio of the horizontal component to the vertical component of the microtremor (H / V spectrum) in the microtremor information to be processed.

[0031] Here, in the microtremor information, vibrations on the horizontal plane (X-axis, Y-axis) are individually Fourier transformed to calculate the X-axis and Y-axis spectra, and the horizontal spectrum is calculated using the average value of each horizontal vibration. Furthermore, vibrations in the vertical direction (Z-axis) are Fourier transformed to calculate the vertical direction (Z-axis) spectrum. Then, the horizontal spectrum is divided by the vertical direction (Z-axis) spectrum to calculate the frequency distribution of the H / V spectrum. Next, the analysis unit 212 estimates the frequency of the highest peak (dominant frequency) in the frequency distribution of the H / V spectrum. In this case, the H / V spectrum shown in Fig. 5 is calculated. Here, Fig. 5(a) shows the case where the dominant frequency is clear, and Fig. 5(b) shows the case where it is unclear.

[0032] Next, the analysis unit 212 calculates the depth (D) of the hard ground from the dominant frequency (f) and shear wave velocity (Vs) using the following formula (quarter wavelength rule). D=Vs / 4f…Equation (1)

[0033] Next, the control unit 21 of the management device 20 executes an H / V spectrum allocation process (step S13). Specifically, the analysis unit 212 of the control unit 21 converts the frequency of the H / V spectrum into depth using equation (1). Then, the analysis unit 212 generates a columnar model in which color mapping according to the depth of the H / V spectrum is performed as depth distribution information with a changed display format.

[0034] Here, the color scheme of the H / V spectrum is determined using a color scale 30 shown in Fig. 5. In this color scale 30, different RGB values ​​are set according to the H / V spectrum. Furthermore, the analysis unit 212 converts the frequency axis of the H / V spectrum into depth using equation (1), thereby generating a depth distribution of a color scheme according to the H / V spectrum. Then, the control unit 21 of the management device 20 repeats the above process until it is completed for all measurement positions.

[0035] Next, the control unit 21 of the management device 20 executes a map display process (step S14). Specifically, the display unit 213 of the control unit 21 outputs a three-dimensional map in which the columnar models are arranged in a three-dimensional space to the display device H13. In this case, the color scheme determined by the color scale 30 is assigned at a depth calculated from the frequency of the frequency distribution of the H / V spectrum.

[0036] In this case, the display screen 500 shown in Fig. 6 is generated. In this display screen 500, a color scheme according to the H / V spectrum is pasted as a texture onto a columnar model 501 placed at the microtremor measurement position in three-dimensional space.

[0037] Next, the control unit 21 of the management device 20 executes a display process of the ground information (step S15). Specifically, the display unit 213 of the control unit 21 acquires a geological formation estimation model from the ground estimation system C1, superimposes it on the 3D map, and outputs it to the display device H13.

[0038] As shown in Fig. 7(a), a stratum estimation model 511 is arranged in a three-dimensional space on a display screen 510. Then, as shown in Fig. 7(b), a display screen 520 including the columnar model 501 and the stratum estimation model 511 is output.

[0039] (Action of this embodiment) The H / V spectrum reflects the ground conditions, so the distribution of ground conditions is displayed according to the depth distribution of the H / V spectrum.

[0040] (Effects of this embodiment) (1) In this embodiment, the control unit 21 of the management device 20 executes a process for acquiring various information (step S11). This allows the microtremor measurement position to be identified within the construction site. By using the microtremors, the ground condition can be evaluated without using a vibration source.

[0041] (2) In this embodiment, the control unit 21 of the management device 20 executes a process for identifying the hard ground position (step S12). This makes it possible to predict the depth of the hard ground using the dominant frequency of the H / V spectrum.

[0042] (3) In this embodiment, the control unit 21 of the management device 20 executes the H / V spectrum allocation process (step S13). This allows the H / V spectrum to be displayed at the microtremor measurement position. If the peak of the dominant frequency is not significant, it may be difficult to determine whether the bearing layer has been reached during drilling of a pile hole. However, this situation can be taken into consideration when performing drilling work.

[0043] (4) In this embodiment, the control unit 21 of the management device 20 executes a map display process (step S14). This makes it possible to confirm the distribution of hard ground below the ground surface by mapping the H / V spectrum.

[0044] (5) In this embodiment, the control unit 21 of the management device 20 executes a process for displaying ground information (step S15). This allows the geological layer estimated based on the boring results to be compared with the distribution of hard ground.

[0045] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. In the above embodiment, microtremors are used as the ground vibrations, but vibrations from an artificial vibration source may also be used.

[0046] In the above embodiment, the ground estimation system C1 and the management device 20 are used, but the hardware configuration is not limited to these. For example, they may be constructed as an integrated computer system.

[0047] In the above embodiment, the control unit 21 of the management device 20 executes a process for acquiring various information (step S11). Here, the N value is input into a shear wave velocity calculation formula to calculate the shear wave velocity. In this case, the shear wave velocity may be corrected using a correction formula according to the geology of the boring results.

[0048] Alternatively, standard penetration tests may be performed at multiple locations to calculate the N-value distribution. In this case, the shear wave velocity calculated from the N-value at the nearest standard penetration test location is used. Alternatively, the N value may be estimated from the geological structure of the geological formation estimation model obtained from the ground estimation system C1, and the shear wave velocity at each measurement position may be calculated. Alternatively, the shear wave velocity may be directly obtained by ground investigation such as PS logging.

[0049] In the above embodiment, the control unit 21 of the management device 20 executes H / V spectrum allocation processing (step S13). Here, the frequency of the H / V spectrum is converted to depth using equation (1), and color mapping is performed in the columnar model according to the depth of the H / V spectrum. In this case, if the H / V spectrum can be displayed, the H / V spectrum may be normalized. For example, normalization using the amplitude ratio of a predetermined frequency other than the peak allows relative comparison of the H / V spectrum of the dominant frequency.

[0050] In the above embodiment, the control unit 21 of the management device 20 executes a map display process (step S14). Here, a marker may be added to the depth of the hard ground estimated from the predominant frequency. Alternatively, the depth of the hard ground may be predicted from a geological formation estimation model acquired from the ground estimation system C1, and the depth calculated from the predominant frequency may be adjusted. In this case, too, the clarity of the depth of the hard ground can be evaluated using a display format according to the H / V spectrum.

[0051] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) The evaluation support device according to claim 1, characterized in that the control unit uses microtremors as the ground vibration.

[0052] (b) the control unit Identifying a dominant frequency in the frequency distribution of the H / V spectrum; 2. The evaluation support device according to claim 1 or (a) above, wherein the depth of the hard ground is calculated using the predominant frequency and output to the display device.

[0053] (c) The evaluation support device described in any one of (a) and (b) above, characterized in that the control unit changes the display form using a color scheme determined according to the spectral ratio of the horizontal component / vertical component.

[0054] (d) The evaluation support device described in any one of (a) to (c) above, characterized in that the control unit superimposes and outputs a geological formation estimation model that estimates the three-dimensional arrangement of the geological formations estimated based on the drilling results.

[0055] (e) The evaluation support device described in (d) above, characterized in that the control unit changes the display format by adjusting the depth calculated from the dominant frequency in the frequency distribution of the spectral ratio using the depth of the hard ground in the geological layer estimation model. [Explanation of symbols]

[0056] A1...evaluation support system, C1...ground estimation system, 10...microtremor meter, 20...management device, 21...control unit, 211...acquisition unit, 212...analysis unit, 213...display unit, 22...measurement information storage unit, 23...ground information storage unit.

Claims

1. An evaluation support device that supports confirmation of hard ground, comprising: a measurement information storage unit that stores measurement values ​​of ground vibration frequencies in association with measurement positions of ground vibration; and a control unit connected to a display device, The control unit calculating a frequency distribution of a spectrum ratio obtained by dividing the spectrum of a horizontal component by the spectrum of a vertical component from the measurement values ​​recorded in the measurement information storage unit; converting the frequencies of the frequency distribution into depths; An evaluation support device characterized in that a map displaying depth distribution information, the display format of which is changed according to the spectral ratio, for the measurement position is output to the display device.

2. A method for supporting confirmation of hard ground using an evaluation support device including a measurement information storage unit that stores measurement values ​​of ground vibration frequencies in association with measurement positions of ground vibration, and a control unit connected to a display device, the method comprising: The control unit calculating a frequency distribution of a spectrum ratio obtained by dividing the spectrum of a horizontal component by the spectrum of a vertical component from the measurement values ​​recorded in the measurement information storage unit; converting the frequencies of the frequency distribution into depths; An evaluation support method, comprising: outputting to the display device a map showing depth distribution information for the measurement position, the display format of which is changed according to the spectral ratio.

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