Journal of Japan Society of Civil Engineers, Ser. F3 (Civil Engineering Informatics)
Online ISSN : 2185-6591
ISSN-L : 2185-6591
Volume 76, Issue 1
Displaying 1-7 of 7 articles from this issue
Paper (In Japanese)
  • Keiichi YASUDA, Shiken CHO, Hideyuki KONISHI, Motoya YAMASAKI
    2020 Volume 76 Issue 1 Pages 1-17
    Published: 2020
    Released on J-STAGE: January 20, 2020
    JOURNAL FREE ACCESS

     The CIM implemented by the Ministry of Land, Infrastructure and Transportation JAPAN is an attempt to improve the construction production process by integrally sharing and utilizing 3-dimensional models at each stage of survey planning, design, construction, maintenance and maintenance. In recent years, examples of road management using MMS that is point cloud data are increasing. For example, it is used for 3D surveying around the intersection to be improved, confirmation of a specific structure such as a bridge, and the like.

     In this study, it is aimed to improve the comfort of the road at the maintenance stage. The purpose of the research is to propose a method for grasping the comfort evaluation on the three-dimensional model by changing road components such as slope surface and planting. By changing the road component on the 3-dimensional model, it becomes possible to immediately grasp the change of the road component and its evaluation. Furthermore, it is checked the validity of the 3D model by verifying the evaluation difference between the moving image before and after the change of the road component and the 3D model.

    Download PDF (5254K)
  • Yu FUJIWARA, Seiya YOKOTA, Akira TAKEISHI, Koichiro IIJIMA, Masafumi E ...
    2020 Volume 76 Issue 1 Pages 18-31
    Published: 2020
    Released on J-STAGE: January 20, 2020
    JOURNAL FREE ACCESS

     When changes in the condition of road-slope face occur, affected by landslides and other causes, measurement devices to monitor the progress of such displacements may be installed to determine what countermeasures to take or if temporary evacuation is necessary. In 1988, the Express Highway Research Foundation of Japan conducted a fact-finding survey on field observations of slope-face defects at expressways and proposed standard values for controlling slope face displacements, after sorting out past research findings on predicting slope collapses. Since these standard control values are intended for measuring instruments, like an extensometer, they are not applicable to technologies that measure displacement from position information such as that of GNSS positioning. This paper analyzes the measurement accuracy of and behavior peculiarities of regular displacements seen in displacement measurements taken by RTK (Real-Time Kinematic)-GNSS for slope face control and when applying the measurements.

    Download PDF (3729K)
  • Yumi NAGAYA, Masami KIKU
    2020 Volume 76 Issue 1 Pages 32-41
    Published: 2020
    Released on J-STAGE: February 20, 2020
    JOURNAL FREE ACCESS

     Recently, it is practical to adopt new surveying techniques such as UAV-SfM/MVS surveys. However, the accuracy and method of UAV-SfM/MVS surveys are unclear. The purpose of this study is to investigate the optimal surveys and analysis methods for UAV-SfM/MVS survey.

     In the National Institute of Technology, Gifu College, aerial photos were taken in various conditions changing the camera angle, overlap rate, and sidelap rate using an UAV, and the survey was carried out using a GNSS and a total station. Three-dimensional (3D) models were created using Metashape, which was a software for constructing 3D models using SfM/MVS technology.

     As a result, it was revealed that although the use of only vertical downward aerial photos ware inappropriate because of the formation of cavities in the 3D models, the modeling of the structure was improved by adding diagonal aerial photos. Consequently, the use of diagonal aerial photos are important to improve the distance accuracy and modeling of 3D models.

    Download PDF (4354K)
  • Ikko UCHIDA, Hirohito KOJIMA
    2020 Volume 76 Issue 1 Pages 42-52
    Published: 2020
    Released on J-STAGE: June 20, 2020
    JOURNAL FREE ACCESS

     Pointing out the necessity of evaluating hazardous areas affected by different types of multiple simultaneous slope failures, this paper proposes a slope failure type classification algorithm based on multigroup discriminant analysis of the Hayashi’s quantification method type II. Three kinds of training data sets of “surface slope failure, deep-seated slope failure and landslide in Nagaoka area” induced by the Niigata Chuetsu earthquake are prepared. Quantitative model constructs the relationship between those training data sets of endogenous variables and causal factors of exogeneous variables (i.e. Soil, Surface geology, Topography, Vegetation index, Slope, Aspect, Drainage, Elevation, and Relief). The scatter diagram based on multigroup quantification method type II indicates that the training samples can be grouped into three classes corresponding to above slope failure types. As a final outcome, a slope failure type classification map (termed FTC map) with overall accuracy of 84% and kappa coefficient of 0.76 can be produced through cluster analysis of nearest neighbor method. The FTC map is superior to previous susceptibility map for specified type of slope failure in evaluating hazardous areas affected by different types of multiple simultaneous slope failures.

    Download PDF (5809K)
  • Genki TAKAHASHI, Hiroshi MASUDA
    2020 Volume 76 Issue 1 Pages 63-73
    Published: 2020
    Released on J-STAGE: October 20, 2020
    JOURNAL FREE ACCESS

     With the progress and spread of autonomous driving technology, the importance of autonomous driving maps has been increasing. A U-shaped gutter with a lid is one type of road edge in autonomous driving maps. Since the U-shaped gutter with a lid has poor characteristics in terms of shape, not only has it been difficult to be drawn automatically, but manual drawing has also been laborsome. In this paper, we propose a method to automatically extract the U-shaped gutter with a lid. Our method focuses on the holes of the lid, which enables us to extract the gutter from a scan-line of a Mobile Mapping System (MMS) LiDAR. Although there is a high possibility that a detected hole is an error given that the hole is very small, our method, which utilizes the property that lids are aligned at equal intervals, achieves good accuracy. In our experiment in a real-world environment, the extraction accuracy of U-shaped gutters with a lid is 81.2%. Since not only the accuracy is high but also the processing time is realistic, we believe that our method can be an actual solution to improve the efficiency in producing autonomous driving maps. As a result, manual mapping is automated, and the labor and cost required for mapping can be expected to be reduced.

    Download PDF (1428K)
  • Keisuke MAEDA, Ryota SAITO, Sho TAKAHASHI, Takahiro OGAWA, Miki HASEYA ...
    2020 Volume 76 Issue 1 Pages 74-86
    Published: 2020
    Released on J-STAGE: December 20, 2020
    JOURNAL FREE ACCESS

     This paper presents a retrieval method of similar inspection records using inspectors’ eye tracking data for supporting more efficient and advanced maintenance of road structures such as bridges and tunnels. In the proposed method, inspectors’ eye tracking data for distress images are obtained, and Canonical Correlation Analysis (CCA) between features extracted from eye tracking data and inspection records is performed. CCA gives projections which maximize correlation between those features and transforms them into new feature spaces. The similarities between inspection records can be calculated based on the transformed features. Furthermore, the obtained projections enable calculation of features based on inspectors’ eye tracking data even if new eye tracking data are not obtained as in future inspection. Then the proposed method provides inspection records similar to input records on the basis of inspectors’ eye tracking data. Therefore, inspectors can evaluate distresses referring to past similar records retrieved by the proposed method. As a result, the proposed method can expect more efficient and advanced maintenance inspection. In the last of this paper, the experiments with real data verify the effectiveness of the proposed method.

    Download PDF (1802K)
Technical Report (In Japanese)
  • Hidehiko SEKIYA, Takeshi KINOMOTO, Masato TAKAKI, Osamu MARUYAMA, Chit ...
    2020 Volume 76 Issue 1 Pages 53-62
    Published: 2020
    Released on J-STAGE: September 20, 2020
    JOURNAL FREE ACCESS

     In steel bridge maintenance, it is important to measure the strain responses under live loads because fatigue damage in steel bridge is caused by repetitive high stress. However, the workability of the wired strain measurement systems which are usually used in the measurement of steel bridge are poor because they require wiring. Therefore, wireless strain measurement system are demanded.

     In the present study, a wireless strain measurement system using LoRa® which has recently become available on the unlicensed band was first developed. Then, by conducting field measurements of an in-service steel box girder bridge, the effectiveness of the developed system was verified. The field measurement results showed that the developed system could transfer the measurement data to about 130 meters away from the test bridge. The data transfer rate was about 96% of that in a place of good visibility. Finally, based on the measured strain responses, fatigue environments of two different cross sections in the test bridge were evaluated.

    Download PDF (2772K)
feedback
Top