Quality control system and quality control method

Abstract

To improve accuracy of quality management by evaluating a ground compaction state of the whole construction face in a planar manner in a civil engineering work.SOLUTION: A quality control system comprises: an acceleration sensor 12 obtaining vibration acceleration of a vibration roller 2 compacting a ground; GNSS 11 obtaining positional information of the vibration roller 2; a rolling compaction number calculating unit 14 partitioning a ground into a plurality of regions Gn and calculating a rolling compaction number Rn in the regions Gn by the vibration roller 2; compaction index value calculating units 15, 16 respectively calculating index values Ft, E exhibiting a ground compaction state for each region Gn by performing frequency analysis of the vibration acceleration; a database 44 linking the calculated index values Ft, E to the rolling compaction number Rn per region Gn to store; and an output processing unit 45 capable of respectively outputting the rolling compaction number Rn and the index values Ft, E stored in the database 44 for each of the plurality of regions Gn.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a quality control system and a quality control method, and in particular to a technique suitable for quality control of the compaction state of ground in earthworks. [Background technology]

[0002] Generally, in earthworks such as road embankments, fill dams, river levees, and residential land development, rolling compaction work is performed using a vibrating roller, and quality control to evaluate the compaction state of the ground is important. Conventional quality control methods for earthworks include measuring wet density using the sand displacement method or water displacement method, measuring water content using the oven drying method or RI method, and measuring ground stiffness using a plate loading test (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-146692 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-010568 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional measurement methods all have the drawback that they are only capable of post-construction measurements, and that it takes time for measurement results to be obtained. As a result, by the time insufficient compaction is discovered, construction work has often already progressed to a certain extent, and attempts to take any follow-up measures in areas where compaction is insufficient require significant rework and rework. Furthermore, the above-mentioned conventional measurement methods all involve discrete measurements, and are unable to measure the entire construction surface at multiple points or across a surface, which means that construction quality cannot be evaluated with high precision.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to improve the accuracy of quality control in earthworks by evaluating the compaction state of the ground across the entire construction surface. [Means for solving the problem]

[0006] The quality control system of the present disclosure includes: an acceleration acquiring means for acquiring vibration acceleration of a vibrating roller that compacts the ground by transmitting vibration to the ground; a position information acquisition means capable of acquiring position information of the vibration compactor; a rolling number calculation means for dividing the surface of the ground into a plurality of areas and calculating the number of times each of the areas has been rolled by the vibrating rolling machine based on the position information acquired by the position information acquisition means; a compaction index value calculation means for calculating an index value indicating the compaction state of the ground compacted by the vibrating roller for each of the plurality of regions by performing frequency analysis on the vibration acceleration acquired by the acceleration acquisition means; a database that stores the index value calculated by the compaction index value calculation means in association with the number of times of compaction for each of the plurality of regions; The present invention is characterized by comprising an output processing means capable of outputting the number of times of compaction and the index value stored in the database for each of the plurality of regions.

[0007] Another aspect of the quality control system of the present disclosure is: The method further includes a subsidence amount acquisition means capable of acquiring a subsidence amount, which is a vertical displacement amount of the ground compacted by the vibrating compactor, for at least each of the plurality of regions, The database stores the subsidence amount acquired by the subsidence amount acquisition means in association with the number of times of compaction for each of the plurality of regions, It is preferable that the output processing means is capable of outputting the subsidence amount stored in the database for each of the plurality of regions.

[0008] Another aspect of the quality control system of the present disclosure is: It is preferable to further provide a compaction determination means for determining whether the ground has been compacted based on the convergence tendency of the index value calculated by the compaction index value calculation means and / or the convergence tendency of the subsidence amount acquired by the subsidence amount acquisition means.

[0009] Another aspect of the quality control system of the present disclosure is: The apparatus further includes a moisture content acquisition means capable of acquiring the moisture content of the ground compacted by the vibrating roller for at least each of the plurality of regions, The database stores the moisture content acquired by the moisture content acquisition means in association with the number of times of compaction for each of the plurality of regions, It is preferable that the output processing means is capable of outputting the water content ratio stored in the database for each of the plurality of regions.

[0010] Another aspect of the quality control system of the present disclosure is: It is preferable to further include a material change determination means for determining whether or not the soil material has changed for each of the plurality of regions based on the change in the water content acquired by the water content acquisition means.

[0011] Another aspect of the quality control system of the present disclosure is: The moisture content acquisition means is preferably mounted on a mobile body that can travel autonomously or follow the travel path of the vibrating roller.

[0012] In another aspect of the quality control system of the present disclosure, The compaction index value calculation means If the transmission depth of the vibration force of the vibrating roller is deeper than the thickness of the construction layer that can be compacted in one compaction operation, it is preferable to perform a correction process to remove the influence of the lower layer when calculating the index value of the current construction layer.

[0013] In another aspect of the quality control system of the present disclosure, The compaction index value calculation means It is preferable to use a first predetermined number of vibration acceleration data as the processing unit required for one frequency analysis, and each time a second predetermined number of vibration acceleration data that is smaller than the processing unit is acquired, perform frequency analysis using the vibration acceleration data of the processing unit that includes the second predetermined number of vibration acceleration data most recently acquired, thereby executing a shift process that makes the calculation period of the index value shorter than the sampling period of the vibration acceleration data.

[0014] In another aspect of the quality control system of the present disclosure, The compaction index value calculation means preferably calculates, as the index value, an acceleration response value obtained by the frequency analysis and a ground deformation coefficient obtained from the acceleration response value.

[0015] The quality control method of the present disclosure includes: A rolling compaction work is carried out to compact the ground using a vibrating rolling machine that transmits vibrations to the ground, Acquire position information of the vibrating roller in parallel with the rolling compaction, The ground is divided into a plurality of areas, and the number of times each of the areas is compacted by the vibrating compactor is calculated based on the position information; acquiring the vibration acceleration of the vibrating roller and performing frequency analysis on the acquired vibration acceleration, thereby calculating an index value indicating the compaction state of the ground compacted by the vibrating roller for each of the plurality of regions; constructing a database that stores the index values calculated for each of the plurality of regions in association with the number of times of compaction; The number of times of compaction and the index value stored in the database are output for each of the plurality of regions. [Effects of the Invention]

[0016] According to the quality control system and quality control method disclosed herein, the accuracy of quality control can be improved by evaluating the compaction state of the ground across the entire construction surface in earthworks. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic functional block diagram showing a quality control system according to an embodiment of the present invention; [Figure 2] 1 is a schematic diagram showing an example of a site to which a quality control system according to an embodiment of the present invention is applied, and a vibrating roller; [Figure 3] FIG. 10 is a schematic diagram showing an example of a rolling compaction count map according to the present embodiment. [Figure 4] 4 is a graph schematically showing an acceleration waveform of a vibrating roller and the results of frequency analysis of the acceleration waveform. [Figure 5] 10 is a time chart illustrating a specific example of shift processing in frequency analysis according to the present embodiment. [Figure 6] FIG. 1 is a conceptual diagram illustrating a two-layer structure model used for two-layer ground correction according to this embodiment. [Figure 7] FIG. 2 is a schematic diagram illustrating the overall configuration of a subsidence amount acquisition unit according to the present embodiment. [Figure 8] FIG. 2 is a schematic diagram illustrating the overall configuration of a water content acquisition unit according to the present embodiment. [Figure 9] FIG. 1 is a schematic diagram for explaining an example of an outline of a multidimensional database according to an embodiment of the present invention. [Figure 10] 1 is a flowchart illustrating a quality control method according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] The quality control system and quality control method according to the present embodiment will be described below with reference to the accompanying drawings. The same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0019] [Quality Control System] Fig. 1 is a schematic functional block diagram showing a quality control system 1 according to this embodiment, and Fig. 2 is a schematic diagram showing an example of a work site to which the quality control system 1 according to this embodiment is applied, and a vibrating roller 2. Note that, hereinafter, the quality control system 1 may also be simply referred to as "the present embodiment apparatus."

[0020] As shown in FIG. 1, the quality control system 1 includes a compaction count / acceleration analysis unit 10, a subsidence acquisition unit 20 (subsidence acquisition means), a moisture content acquisition unit 30 (moisture content acquisition means), a quality control processing unit 40, a display unit 50, and an input unit 60. In this embodiment, the compaction count / acceleration analysis unit 10 is mounted on a vibrating roller 2 (see FIG. 2) that compacts the ground at the construction site. The quality control processing unit 40 is, for example, configured by an information processing device such as a personal computer or server installed in a management office 8 (see FIG. 2), and is communicatively connected to the compaction count / acceleration analysis unit 10, the subsidence acquisition unit 20, the moisture content acquisition unit 30, the display unit 50, and the input unit 60. The management office 8 may be located at the construction site or may be located away from the construction site.

[0021] The compaction count / acceleration analysis unit 10 includes a position information acquisition device 11 (position information acquisition means), an acceleration sensor 12 (acceleration acquisition means), and a calculation processing unit 13. The position information acquisition device 11, acceleration sensor 12, and calculation processing unit 13 are connected to each other so that they can communicate with each other via wire or wirelessly. In addition, an on-board display 18 and an input device 19, which are provided in the driver's cab 7 of the vibrating roller 2, are each connected to the calculation processing unit 13.

[0022] The position information acquisition unit 11 is, for example, a GNSS (Global Navigation Satellite System) that receives signals from multiple positioning satellites via an antenna 11A to acquire position information of the vibrating roller 2. Note that the position information acquisition unit 11 may also use a satellite positioning system other than the GNSS, for example, a GPS (Global Positioning System). The position information of the vibrating roller 2 acquired by the position information acquisition unit 11 is transmitted to the arithmetic processing unit 13 and sequentially stored in a memory unit of the arithmetic processing unit 13.

[0023] The acceleration sensor 12 is attached to the vibratory roller 2 and detects the vibration acceleration of the vibratory roller 2 in the vertical direction. Here, the schematic configuration of the vibratory roller 2 will be explained based on Fig. 2(B). The vibratory roller 2 (an example of a vibratory compactor) comprises a vehicle body 4 having drive wheels 3, a roller wheel 5 equipped with a vibration exciter (not shown), a support frame 6 that supports the roller wheel 5, and a driver's cab 7 provided on the vehicle body 4. The roller wheel 5 is made of steel, for example, and compacts the ground by vibrating in the vertical direction due to the excitation force transmitted from the vibration exciter.

[0024] In this embodiment, the acceleration sensor 12 is attached to, for example, a non-damping portion of the roller wheel 5 (support frame 6 in the illustrated example), and is capable of detecting the vertical acceleration (hereinafter simply referred to as vibration acceleration A) of the roller wheel 5. The vibration acceleration A acquired by the acceleration sensor 12 is transmitted to the calculation processing unit 13 and stored sequentially in the memory unit of the calculation processing unit 13.

[0025] Returning to Fig. 1, the arithmetic processing unit 13 includes a processing unit such as a CPU, a storage unit such as a RAM or ROM, an input / output interface, an auxiliary storage device, etc., and is configured using an information processing device such as a personal computer. The arithmetic processing unit 13 functions as a device including a compaction count calculation unit 14 (compaction count calculation means), an acceleration response value calculation unit 15 (compaction index value calculation means), a ground deformation coefficient calculation unit 16 (compaction index value calculation means), and a two-layer correction processing unit 17, by the CPU executing an analysis program stored in the ROM.

[0026] In this embodiment, the arithmetic processing unit 13 is provided on the vibrating roller 2 side, but similar to the quality control processing unit 40, the arithmetic processing unit 13 can also be provided in an information processing device on the management office 8 side. In this case, the arithmetic processing unit 13 is simply connected to each of the position information acquisition device 11 and the acceleration sensor 12 so as to be able to communicate wirelessly.

[0027] [Number of compactions] The rolling number calculation unit 14 calculates the number of times Rn that the vibrating roller 2 has rolled the ground G to be worked on, based on the position information (traveling trajectory) of the vibrating roller 2 acquired by the position information acquisition unit 11. Specifically, as shown in Fig. 2(A), the rolling number calculation unit 14 divides the ground G (surface) to be worked on at the site into a mesh-like pattern, for example, into a plurality of 1 m square regions G1, G2, ... Gn, and calculates the number of times Rn of compaction for each region G1, G2, ... Gn. When the rolling count calculation unit 14 detects that the vibrating roller 2 has passed through (or entered) a specific area (for example, area G1) once based on the position information of the vibrating roller 2 acquired by the position information acquisition unit 11, it counts the number of rollings Rn of the area (area G1) as one, and thereafter calculates the number of rollings Rn of the area (area G1) by sequentially adding the number of times each time the vibrating roller 2 passes through (or enters) the area (area G1). The rolling counts Rn calculated by the rolling count calculation unit 14 are linked to the areas G1, G2, ... Gn, respectively, and stored in the memory unit of the arithmetic processing unit 13, and are also transmitted to the quality control processing unit 40 in real time.

[0028] FIG. 3 shows an example of a rolling count map M (heat map) created based on the rolling count Rn calculated by the rolling count calculation unit 14. As shown in FIG. 3, the rolling count map M displays the number of rollings Rn performed by the vibrating roller 2 for each of a plurality of regions G1, G2, ..., Gn so that the number of rollings Rn can be visually grasped. As shown in the illustrated example, the number of rollings Rn for the regions G1, G2, ..., Gn may be displayed in a darker color the greater the number of rollings Rn, or the specific number of rollings Rn (numerical value) may be displayed for each of the regions G1, G2, ..., Gn. The rolling count map M may be displayed on an on-board display 18 provided in the driver's cab 7 of the vibrating roller 2, or on a display unit 50 at the management office 8. In this way, by displaying in real time the compaction count map M showing the number of compactions Rn by the vibrating roller 2 for each region G1, G2, ... Gn, it becomes possible to grasp the areas in the ground G where compaction is sufficient and the areas where compaction is insufficient while construction is in progress, thereby enabling the quality of construction to be improved.

[0029] [Acceleration response value] The acceleration response value calculation unit 15 calculates the acceleration response value Ft (the rate of fluctuation in acceleration data that increases as the ground is compacted) based on the vibration acceleration A acquired by the acceleration sensor 12. Here, the vibrating roller 2 compacts the target ground G by vibrating the roller wheels 5 in the vertical direction using a vibration excitation device. The acceleration waveform of the roller wheels 5 when compacting the ground becomes more distorted as the ground stiffness increases with ground compaction, and high-frequency components become prominent as a spectrum (see Figure 4). The acceleration response value calculation unit 15 calculates the acceleration response value Ft at a predetermined calculation period using a so-called vibration acceleration response method that focuses on this property.

[0030] Specifically, the acceleration response value calculation unit 15 performs a fast Fourier transform (hereinafter referred to as FFT analysis) on the signal from the acceleration sensor 12 to obtain a harmonic spectrum Si and a 1 / 2 subharmonic spectrum Si′, and calculates the acceleration response value Ft based on the following formula (1).

number

[0031] [Shift Processing] Here, FFT analysis calculates the frequency components of input data, so a certain amount of data (for example, 1024 pieces) is required to maintain resolution. In FFT analysis processing, if the required amount of data is acquired at a high sampling rate, wideband analysis can be achieved, but if the sampling rate is increased too much, the load on the CPU increases. For this reason, it is desirable to lower the sampling rate to a certain extent so as not to affect the CPU's processing power, but since it takes time to gather the amount of data required for FFT analysis, there is the problem that it takes a long time to output the calculation results.

[0032] From this perspective, the present embodiment of the present invention acquires 1024 pieces of data (first predetermined number) per second, and uses the 1024 pieces of data as a processing unit required for FFT analysis. Each time 512 pieces of data (second predetermined number), which is half the processing unit, are acquired, a "shift process" is performed in which FFT analysis is performed using the most recent 1024 pieces of data. A specific example of the shift process will be described below with reference to the time chart in FIG. 5.

[0033] As shown in Figure 5, the nth FFT analysis is performed at time t0, when 1024 pieces of data have been acquired. Next, the (n+1)th FFT analysis is performed at time t1, 0.5 seconds after time t0, when 512 pieces of data, half the processing unit, have been acquired. At this time, the FFT analysis is performed by shifting half of the data to be processed to the immediately previous data (the data used in the nth FFT analysis), thereby ensuring the number of data necessary for the FFT analysis. Similarly, the (n+2)th and subsequent FFT analyses are performed by shifting half of the data to be processed to the immediately previous data, with the calculation results being output sequentially every 0.5 seconds.

[0034] In other words, by performing shift processing to shift half of the data to be processed to the most recent data, the system is configured to ensure the number of data required for FFT analysis while outputting calculation results at a cycle shorter than the sampling period. This effectively improves the responsiveness of calculation processing without reducing the resolution during FFT analysis.

[0035] The processing unit for FFT analysis is not limited to 1024, and can be set to an appropriate value depending on the CPU capacity and RAM capacity of the calculation processing unit 13, the performance of the acceleration sensor 12, etc. Also, although the shift processing shifts half of the processing target, the shift amount can also be set to a value greater than half or less than half depending on the target sampling period and calculation period.

[0036] [Ground deformation coefficient] 1 again, the ground deformation coefficient calculation unit 16 calculates the ground deformation coefficient E (ground rigidity) based on the relational expression between the acceleration response value and the ground deformation coefficient, which has been obtained in advance through an experiment, etc. Specifically, the ground deformation coefficient calculation unit 16 calculates the ground deformation coefficient E by substituting the acceleration response value Ft calculated by the acceleration response value calculation unit 15 and the specification values of the vibrating roller 2 into the following formula (2).

number

[0037] In this embodiment, the acceleration response value Ft and the ground deformation coefficient E are linked to the position information of the vibrating roller 2 acquired by the position information acquisition unit 11 and stored in the memory unit of the calculation processing unit 13. That is, similar to the above-described rolling count map M (see FIG. 3), the acceleration response value Ft and the ground deformation coefficient E corresponding to each region G1, G2, ..., Gn can be displayed as a heat map. For example, the heat map may be displayed in a darker color for a region with a larger acceleration response value Ft, or specific numerical values of the acceleration response value Ft and the ground deformation coefficient E for each region G1, G2, ..., Gn may be displayed. Displaying the heat map of the acceleration response value Ft and the ground deformation coefficient E thus created together with the rolling count map M allows the user to easily grasp the ground compaction state and the rolling count Rn for each region G1, G2, ..., Gn in real time.

[0038] [Two-layer ground correction] In general earthworks, ground compaction is carried out in stages over multiple layers, with each layer being compacted to a thickness of approximately 30 cm for construction management reasons. On the other hand, vibratory rollers 2 are often high-performance, and the vibrations transmitted to the ground from the roller wheels 5 are transmitted to layers below the layer currently being compacted (hereinafter referred to as the current construction layer).

[0039] The inventors have conducted a variety of experiments and simulations and have found that the acceleration response value Ft and ground deformation coefficient E obtained by the vibration acceleration response method are average values within a range of approximately 60 cm from the ground surface of the current construction layer. In other words, as shown in Figure 6, the inventors have found that if the on-site ground is modeled as a two-layer structure consisting of an upper current construction layer L1 and a lower layer L2 directly below it, and the influence of the lower layer L2 is eliminated when calculating the acceleration response value Ft and ground deformation coefficient E of the current construction layer L1, then the ground stiffness of the current construction layer L1 can be calculated with high accuracy.

[0040] From this perspective, the calculation processing unit 13 of the present embodiment of the apparatus includes a two-layer correction processing unit 17 for performing a correction process to eliminate the influence of the lower layer L2 when calculating the acceleration response value Ft and ground deformation coefficient E of the current construction layer L1. The correction process may be performed based on a model formula that takes into account the acceleration response values, ground deformation coefficient, Poisson's ratio, and vibration stress transmission angle of the current construction layer L1 and the lower layer L2, or by referencing a lookup table previously prepared through experiments. The acceleration response value and ground deformation coefficient of the lower layer L2 can be obtained by reading data calculated by the calculation processing unit 13 during compaction of the lower layer L2 and then performing compaction of the current construction layer L1. In this way, performing a two-layer correction process to eliminate the influence of the layer immediately below enables highly accurate calculation of the acceleration response value Ft and ground deformation coefficient E of the current construction layer L1. Note that while the present embodiment of the apparatus uses a two-layer structure model as an example, correction processes may be performed using a model with a three- or more layer structure if the vibratory roller 2 has higher performance.

[0041] [Subsidence measurement] The subsidence amount acquisition unit 20 includes a laser scanner 21 as a surveying instrument. Specifically, as shown in Fig. 7, the laser scanner 21 includes a laser sensor unit 22 that emits laser light and receives reflected light, a support unit 23 that supports the laser sensor unit 22, and a tripod 24 to which the support unit 23 is attached at its upper part. The laser scanner 21 is configured so that the three-dimensional coordinates (x, y, z) of a measurement point on the ground surface can be measured by the support unit 23 rotating the laser sensor unit 22 in a direction horizontal to the ground surface and in a direction vertical to the ground surface.

[0042] In this embodiment, the laser scanner 21 defines the travel path of the vibrating roller 2 acquired by the position information acquisition unit 11 as a measurement line L, and by scanning laser light along the measurement line L, acquires the three-dimensional coordinates of multiple measurement points Pz1, Pz2, ..., Pzn defined on the measurement line L as point cloud data.

[0043] Here, measurements by the laser scanner 21 are carried out during the period from when the vibrating roller 2 compacts the ground to when the ground is next compacted. That is, point cloud data for each measurement point Pz1, Pz2, ... Pzn is acquired each time the vibrating roller 2 compacts the ground. This makes it possible to grasp the vertical displacement (subsidence) corresponding to the number of compactions Rn of each measurement point Pz1, Pz2, ... Pzn in parallel with the compaction work. There must be at least one measurement point Pz1, Pz2, ... Pzn for each region G1, G2, ... Gn, and there may be multiple measurement points for each region G1, G2, ... Gn. The point cloud data of each survey point Pz1, Pz2, ... Pzn measured by the laser scanner 21 is transmitted to the quality control processing unit 40 and stored in the memory unit of the quality control processing unit 40, linked to the number of compactions Rn for each region G1, G2, ... Gn.

[0044] [Moisture content measurement] The moisture content acquisition unit 30 is equipped with a scattering-type RI moisture density meter 31 as a measuring instrument. Specifically, as shown in Fig. 8, the moisture content acquisition unit 30 has a mobile unit 33 equipped with the RI moisture density meter 31. The mobile unit 33 is also equipped with a GNSS 32 as a position information acquisition device.

[0045] The running body 33 is equipped with a plurality of wheels 34. The plurality of wheels 34 includes drive wheels and steered wheels. The running body 33 is also equipped with a running motor that transmits power to the drive wheels, a steering motor that steers the steered wheels, a battery that supplies power to these motors, and the like. In this embodiment, the running body 33 is configured to be able to run along the running trajectory of the vibrating roller 2. The running method of the running body 33 may be either an autonomous running type that automatically runs along a target trajectory set based on the running trajectory of the vibrating roller 2, or a follow-up running type that runs by following the vibrating roller 2.

[0046] The RI moisture density meter 31 mainly comprises a radiation source 31A that emits radiation into the ground and a detector 31B that detects radiation that enters and scatters in the ground, and measures the moisture density and wet density of the ground. The RI moisture density meter 31 also obtains the dry density from the measured moisture density and wet density, and acquires the moisture content w of the measured ground by calculating the ratio of the dry density to the moisture density.

[0047] In this embodiment, the moisture content acquisition unit 30 performs measurements using the RI moisture density meter 31 at predetermined measurement points Pw1, Pw2, ..., Pwn while running the traveling body 33 along the travel path of the vibrating roller 2. Specifically, measurements using the RI moisture density meter 31 are performed during the period from when the vibrating roller 2 compacts the ground to be measured until the next time the ground is compacted. In other words, the moisture content w of each measurement point Pw1, Pw2, ..., Pwn is acquired each time the ground to be measured is compacted by the vibrating roller 2. This makes it possible to grasp changes in the moisture content w at each measurement point Pw1, Pw2, ..., Pwn according to the number of compactions n performed, in parallel with construction work.

[0048] There must be at least one measurement point Pw1, Pw2, Pwn for each of the regions G1, G2, Gn, and there may be multiple measurement points for each of the regions G1, G2, Gn. The moisture content w of each measurement point Pw1, Pw2, Pwn obtained by the RI moisture density meter 31 is transmitted to the quality control processing unit 40 and stored in the memory of the quality control processing unit 40 in association with the number of compactions n for each of the regions G1, G2, Gn.

[0049] [Quality control processing] 1, the quality control processing unit 40 is equipped with a processing unit such as a CPU, a storage unit such as RAM or ROM, an input / output interface, an auxiliary storage device, etc., and is configured as an information processing device such as a personal computer or a server. By the CPU executing a quality control program stored in the ROM, the quality control processing unit 40 functions as a device equipped with a convergence determination unit 41 (compaction determination means), a material change determination unit 42 (material change determination means), a data input processing unit 43, a multidimensional database 44, and a data output processing unit 45 (output processing means). In addition, a display unit 50 such as a display and an input unit 60 such as a keyboard and a mouse are connected to the quality control processing unit 40.

[0050] The convergence determination unit 41 determines whether the ground has been sufficiently compacted based on the acceleration response value Ft of each region G1, G2, ... Gn, the ground deformation coefficient E, and the vertical displacement of the ground obtained from the point cloud data (hereinafter referred to as the settlement amount Z) from the convergence tendency of this information. Specifically, every time each region G1, G2, ... Gn is compacted by the vibrating roller 2, the convergence determination unit 41 calculates the change ΔFt in the acceleration response value Ft, the change ΔE in the ground deformation coefficient E, and the change ΔZ in the settlement amount Z in each of these regions G1, G2, ... Gn. Here, each change (ΔFt, ΔE, ΔZ) is calculated based on the value (ΔFt n ,ΔE n ,ΔZ n ) to the value obtained at the previous compaction (ΔFt n-1 ,ΔE n-1 ,ΔZ n-1 ) can be calculated by subtracting

[0051] The convergence determination unit 41 determines that the compaction of the ground in the region G1, G2, ... Gn is sufficient when all of the following convergence conditions are satisfied: a first convergence condition that the absolute value of the change ΔFt in the acceleration response value Ft is equal to or less than a predetermined acceleration response threshold Fv; a second convergence condition that the absolute value of the change ΔE in the ground deformation coefficient E is equal to or less than a predetermined deformation coefficient threshold Ev; and a third convergence condition that the absolute value of the change ΔZ in the subsidence Z is equal to or less than a predetermined subsidence threshold Zv. On the other hand, if any of the first to third convergence conditions is not satisfied, the convergence determination unit 41 determines that the compaction of the ground in the region G1, G2, ... Gn is insufficient. Note that the determination does not necessarily have to be made based on all three of the first to third convergence conditions, and any one or two of these three conditions may be used. The convergence condition to be used may be selected depending on the soil material and ground conditions at the construction site.

[0052] The results of the judgment by the convergence judgment unit 41 can be displayed for each region G1, G2, ... Gn, similar to the compaction count map M shown in Figure 3 above. The judgment results may be displayed in text, or different colors may be used to indicate regions with sufficient compaction and regions with insufficient compaction. In this way, by displaying the judgment results based on the convergence tendency for each region G1, G2, ... Gn on the map, it becomes possible to grasp regions with sufficient compaction and regions with insufficient compaction for each region G1, G2, ... Gn while construction is underway, thereby enabling improvement in construction quality.

[0053] The material change determination unit 42 determines whether the soil material at the construction site (e.g., soil grain size, dry density, etc.) has changed based on the moisture content w transmitted from the moisture content acquisition unit 30. In earthworks, ground compaction is carried out in stages across multiple layers. As a result, there are cases where the soil material spread and compacted in the upper layer is different from the soil material used in the lower layer. Each soil material has an optimal moisture content at which it is most compacted, and it is desirable to manage the construction work during ground compaction near the optimal moisture content (e.g., a predetermined moisture content range including the optimal moisture content).

[0054] The material change determination unit 42 acquires the moisture content w of each of the regions G1, G2, ... Gn each time the region G1, G2, ... Gn is compacted by the vibrating roller 2, and if the acquired moisture content w is not within a predetermined moisture content range, it determines that the soil material of the corresponding region G1, G2, ... Gn has changed. The predetermined moisture content range may be set based on the soil material selected depending on the site use (road embankment, river levee, etc.) and ground conditions. The determination of material change is based on the moisture content w acquired during the current compaction. n and the moisture content w obtained during the previous compaction n-1 and if the difference between them is equal to or greater than a predetermined value, it may be determined that the soil material has changed.

[0055] The results of the determination by the material change determination unit 42 can be displayed for each region G1, G2, ... Gn, similar to the compaction count map M shown in Figure 3 above. The results of the determination may be displayed in text, or different colors may be used to indicate regions where the soil material has changed and regions where it has not. By displaying the results of the material change determination for each region G1, G2, ... Gn on the map in this way, it becomes easy to grasp the regions that have been compacted with different soil materials, and it becomes possible to improve construction quality by adjusting the moisture content of those regions, for example.

[0056] The data input processing unit 43 stores the number of compactions Rn, acceleration response value Ft, and ground deformation coefficient E transmitted from the number of compactions / acceleration analysis unit 10, the amount of subsidence Z calculated based on the point cloud data transmitted from the subsidence amount acquisition unit 20, and the moisture content w transmitted from the moisture content acquisition unit 30 in a multidimensional database 44.

[0057] 9 is a schematic diagram illustrating an example of the multidimensional database 44. The multidimensional database 44 is constructed using, for example, data on the "number of compactions Rn" and "area Gn" as dimensions (hierarchies), and data on the "acceleration response value Ft," "ground deformation coefficient E," "subsidence Z," and "moisture content w" as measures. By using the slicing function of the multidimensional database 44 to slice the data at a cross section of the hierarchy, it is possible to read out the acceleration response value Ft, ground deformation coefficient E, subsidence Z, and moisture content w corresponding to the number of compactions Rn for each area G.

[0058] In response to an operator's operation of the input unit 60, the data output processing unit 45 displays the data read from the multidimensional database 44 on the display unit 50, or outputs it as a report (document) from a printer (not shown). For example, when a specific area G or number of compactions Rn is specified from the input unit 60, the data output processing unit 45 outputs the acceleration response value Ft, ground deformation coefficient E, amount of settlement Z, and water content w for each number of compactions Rn for the specified area G. This allows the operator to quickly and easily grasp the compaction status and consolidation status in each area of the construction site, making it possible to improve quality control.

[0059] [Quality control method] Next, a quality control method using this implementation device will be described based on the flow shown in Figure 10. Each of the steps S100 to S150 described below is repeatedly executed for each construction layer until the embankment reaches the desired design height.

[0060] In step S100, the banking material of the current construction layer Ln is spread evenly and compacted by the vibrating roller 2, and the number of times Rn of compaction of each region Gn is counted.

[0061] In step S110, the acceleration response value Ft and the ground deformation coefficient E of each region Gn are calculated in parallel with the rolling by the vibrating roller 2. Note that, for the sake of convenience, steps S100 and S110 are described as two steps, but these steps can be performed substantially simultaneously.

[0062] In step S120, the amount of settlement Z of each area Gn compacted by the vibrating roller 2 is measured, and the moisture content w of each area Gn is also measured. The measurement of the amount of settlement Z and the measurement of the moisture content w can be performed in any order, and they can also be performed substantially simultaneously.

[0063] Next, in step S130, a material change determination, a convergence determination, and an evaluation of the rolling compaction status and the compaction status are performed using the multidimensional database 44. If, as a result of these determinations and evaluations, it is determined in step S140 that there is no insufficient rolling compaction area (or material change) in the current construction layer Ln, the process proceeds to step S150, where construction of the current construction layer Ln is terminated, and rolling construction of the next construction layer Ln+1 is started.

[0064] On the other hand, if it is determined in step S140 that there are areas of insufficient compaction in the current construction layer Ln, the process proceeds to step S145, where the areas of the current construction layer Ln that are insufficiently compacted are re-compacted. After re-compaction, steps S110 to S130 are performed again. If it is determined in step S140 that there are no more areas of insufficient compaction, the process proceeds to step S150, where construction of the current construction layer Ln is terminated and compaction of the next construction layer Ln+1 is started. Thereafter, the processes of steps S100 to S150 described above are repeated until the embankment reaches the desired design height.

[0065] According to the present embodiment described above, when performing compaction using the vibrating roller 2, the surface of the ground G to be compacted is divided into multiple regions G1, G2, ..., Gn, and the vibration acceleration A in each region G1, G2, ..., Gn is frequency-analyzed to calculate index values (acceleration response value Ft, ground deformation coefficient E) indicating the compaction state of the ground. Furthermore, a database 44 is constructed that stores the number of compactions Rn of the vibrating roller 2 and the index values (acceleration response value Ft, ground deformation coefficient E) associated with each region G1, G2, ..., Gn. The number of compactions Rn and the index values (acceleration response value Ft, ground deformation coefficient E) stored in the database 44 can be output to a display unit 50 or the like for each region G1, G2, ..., Gn. This makes it possible to evaluate the compaction state of the vibrating roller 2 at multiple points or across a surface while the compaction is being performed, thereby improving the accuracy of quality control.

[0066] The system is also configured to be able to obtain the amount of settlement Z of each of the areas G1, G2, ... Gn by scanning the laser scanner 21 along the travel path of the vibrating roller 2 and obtaining, as point cloud data, the three-dimensional coordinates of each of the areas G1, G2, ... Gn compacted by the vibrating roller 2. This makes it possible to evaluate the convergence tendency of the amount of settlement Z of each of the areas G1, G2, ... Gn at multiple points or in a planar manner, in parallel with the compaction work.

[0067] Furthermore, according to this embodiment, a scattering-type RI moisture density meter 31 is mounted on a running body 33 that can travel along the running path of the vibrating roller 2, and the moisture content w of each of the regions G1, G2, ... Gn compacted by the vibrating roller 2 is measured by the RI moisture density meter 31, thereby making it possible to determine changes in the soil material of the construction layer from changes in the measured moisture content w. This makes it possible to grasp changes in the soil material at multiple points or across the entire construction surface while compaction is being carried out, thereby improving the quality of construction.

[0068] [others] The present disclosure is not limited to the above-described embodiments, and can be appropriately modified and implemented within the scope of the present disclosure.

[0069] For example, in the above embodiment, the multidimensional database 44 has been described as storing the acceleration response value Ft, the ground deformation coefficient E, the settlement amount Z, and the moisture content w as measures, but it may also be configured to store the moisture density and wet density measured by the RI moisture density meter 31, and the dry density calculated from these. Also, while the present disclosure has been described using the vibrating roller 2 as an example of a vibrating compactor, it can be widely applied to other heavy machinery that can transmit vibrations to the ground to compact it. [Explanation of symbols]

[0070] 1...Quality control system, 2...Vibration roller (vibration compactor), 5...Compaction wheel, 8...Administrative office, 10...Compaction count / acceleration analysis unit, 11...Position information acquisition device (Position information acquisition means), 12...Acceleration sensor (Acceleration acquisition means), 13...Calculation processing device, 14...Compaction count calculation unit (Compaction count calculation means), 15...Acceleration response value calculation unit (Compaction index value calculation means), 16...Ground deformation coefficient calculation unit (Compaction index value calculation means), 17...Two-layer correction processing unit, 18...In-vehicle display, 19...Input device, 20...Subsidence amount acquisition unit, 21...Laser scanner, 30...Moisture content acquisition unit, 31...RI moisture density meter, 33...Traveling body, 40...Quality control processing unit, 41...Convergence determination unit (Compaction determination means), 42...Material change determination unit (Material change determination means), 43...Data input processing unit, 44...Multidimensional database, 45...Data output processing unit (Output processing means)

Claims

1. an acceleration acquiring means for acquiring vibration acceleration of a vibrating roller that compacts the ground by transmitting vibration to the ground; a position information acquisition means capable of acquiring position information of the vibration compactor; a rolling number calculation means for dividing the surface of the ground into a plurality of areas and calculating the number of times each of the areas has been rolled by the vibrating rolling machine based on the position information acquired by the position information acquisition means; a compaction index value calculation means for calculating an index value indicating the compaction state of the ground compacted by the vibrating roller for each of the plurality of regions by performing frequency analysis on the vibration acceleration acquired by the acceleration acquisition means; a moisture content acquiring means for acquiring the moisture content of the ground compacted by the vibrating roller for at least each of the plurality of regions; a database that stores the index value calculated by the compaction index value calculation means and the moisture content ratio acquired by the moisture content ratio acquisition means in association with the number of times of compaction for each of the plurality of regions; and an output processing means capable of outputting the number of times of compaction, the index value, and the moisture content ratio stored in the database for each of the plurality of regions. A quality control system characterized by:

2. The method further includes a material change determination means for determining whether or not the soil material has changed for each of the plurality of regions based on the change in the water content acquired by the water content acquisition means. The quality control system of claim 1 .

3. The moisture content acquisition means is mounted on a mobile body that can travel autonomously or follow the travel path of the vibration compactor. The quality control system according to claim 1 or 2.

4. an acceleration acquiring means for acquiring vibration acceleration of a vibrating roller that compacts the ground by transmitting vibration to the ground; a position information acquisition means capable of acquiring position information of the vibration compactor; a rolling number calculation means for dividing the surface of the ground into a plurality of areas and calculating the number of times each of the areas has been rolled by the vibrating rolling machine based on the position information acquired by the position information acquisition means; a compaction index value calculation means for calculating an index value indicating the compaction state of the ground compacted by the vibrating roller for each of the plurality of regions by performing frequency analysis on the vibration acceleration acquired by the acceleration acquisition means; a database that stores the index value calculated by the compaction index value calculation means in association with the number of times of compaction for each of the plurality of regions; an output processing means capable of outputting the number of times of compaction and the index value stored in the database for each of the plurality of regions, The compaction index value calculation means If the transmission depth of the vibration force of the vibrating roller is deeper than the thickness of the construction layer that can be compacted in one compaction operation, a correction process is performed to remove the influence of the lower layer when calculating the index value of the current construction layer. A quality control system characterized by:

5. The method further includes a subsidence amount acquisition means capable of acquiring a subsidence amount, which is a vertical displacement amount of the ground compacted by the vibrating compactor, for at least each of the plurality of regions, The database stores the subsidence amount acquired by the subsidence amount acquisition means in association with the number of times of compaction for each of the plurality of regions, The output processing means is capable of outputting the subsidence amounts stored in the database for each of the plurality of regions. A quality control system according to any one of claims 1 to 4.

6. The compaction determination means further includes a compaction determination means for determining whether the ground has been compacted based on the convergence tendency of the index value calculated by the compaction index value calculation means and / or the convergence tendency of the subsidence amount acquired by the subsidence amount acquisition means. The quality control system according to claim 5.

7. The compaction index value calculation means A first predetermined number of vibration acceleration data is defined as a processing unit required for one frequency analysis, and every time a second predetermined number of vibration acceleration data smaller than the processing unit is acquired, frequency analysis is performed using the vibration acceleration data of the processing unit including the second predetermined number of vibration acceleration data most recently acquired, thereby executing a shift process to make the calculation period of the index value shorter than the sampling period of the vibration acceleration data. A quality control system according to any one of claims 1 to 6.

8. The compaction index value calculation means calculates, as the index value, an acceleration response value obtained by the frequency analysis and a ground deformation coefficient obtained from the acceleration response value. A quality control system according to any one of claims 1 to 7.

9. A rolling compaction work is carried out to compact the ground using a vibrating rolling machine that transmits vibrations to the ground, Acquire position information of the vibrating roller in parallel with the rolling compaction, The ground is divided into a plurality of areas, and the number of times each of the areas is compacted by the vibrating compactor is calculated based on the position information; acquiring the vibration acceleration of the vibrating roller and performing frequency analysis on the acquired vibration acceleration, thereby calculating an index value indicating the compaction state of the ground compacted by the vibrating roller for each of the plurality of regions; Obtaining the water content of the ground compacted by the vibrating roller for at least each of the plurality of regions; constructing a database that stores the index value calculated for each of the plurality of regions and the moisture content ratio obtained for each of the plurality of regions in association with the number of times of compaction; The number of times of compaction, the index value, and the moisture content ratio stored in the database are output for each of the plurality of regions. A quality control method characterized by:

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