Journal of Japan Society of Civil Engineers, Ser. F4 (Construction and Management)
Online ISSN : 2185-6605
ISSN-L : 2185-6605
Volume 77, Issue 2
Displaying 1-6 of 6 articles from this issue
Special Issue(Paper)
  • Yuichi Yashiro, Gang Wang, Fumio Haori, Nobuyoshi Yabuki
    2021 Volume 77 Issue 2 Pages I_1-I_15
    Published: 2021
    Released on J-STAGE: January 27, 2022
    JOURNAL RESTRICTED ACCESS

     In the Japanese construction industry, the declining birthrate and aging population, and the decrease in skilled workers are problems. There is an urgent need to build a mechanism to effectively extract, accumulate, and pass on the know-how that has been personalized before a large number of skilled workers retire in the near future. In this research, we focused on the extraction of physical information of skilled workers at construction sites and targeted the measurement of gaze information, which is the initial action of the process in which the supervisor uses his know-how to make accurate decisions. Applying to one of the most important tasks in plant construction, lifting work, and comparing gaze information of skilled and unskilled workers, the difference in gaze tendency in each work process could be visualized on the analysis map. In addition, it was found that about 90% of all gazes of skilled workers are related to know-how, and they use 1.4 times more know-how than non-skilled workers to carry out their work.

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  • Kouta TAKABAYASHI, Masahide HORITA
    2021 Volume 77 Issue 2 Pages I_16-I_29
    Published: 2021
    Released on J-STAGE: January 27, 2022
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     Local governments are often influenced by neighboring governments in the policy making processes, and the process to set the price of water is no exception. We have investigated the interactions among Japanese municipalities on water pricing from both national and local perspectives. From a national view-point, it is demonstrated that the spatial interaction on water pricing is statistically significant according to a spatial dependence model, confirming the existing studies on yardstick competition. The local tendency is analyzed by categorizing municipalities into 4 groups based on their own and their neighbors’ prices of water, and regional differences in the spatial interaction have been revealed.

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  • Hitoshi NINOMIYA
    2021 Volume 77 Issue 2 Pages I_30-I_41
    Published: 2021
    Released on J-STAGE: January 27, 2022
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     The Water Supply Law was amended on December 6, 2018, and in the water supply business in Japan, a contract "concession method" that transfers the operating right of public facilities to a private company for a certain period of time became possible. On the other hand, in overseas PPP-promoting countries, water services were publicized in 267 cities in 33 countries from 2000 to 2016 due to soaring water charges and uncertain management. Contracts and operations are required based on the characteristics of public services. The purpose of this study is to examine the possibility of introducing concession contracts in Japan's water supply business. We proposed a virtual management simulation model that takes risks into consideration with reference to existing water supply companies, and attempted to analyze issues in the water supply business concession.

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  • Masaki OTAKA, Takahiro SUZUKI, Masahide HORITA
    2021 Volume 77 Issue 2 Pages I_42-I_56
    Published: 2021
    Released on J-STAGE: January 27, 2022
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     This paper proposes an alternative method for tackling geological risks such as cave-ins and ground subsidence. A real option model has been developed to determine the optimal timing of decision making on whether the additional geological surveys should be conducted, while continuously updating the ground risk information based on Bayes’ theorem as the construction strages progress. The model has then been applied to the scenarios and the data concerning the cave-in caused by Fukuoka City Subway Nanakuma Line, and discussed the reasons why sufficient geological surveys had not been carried out at that time.

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  • Hitoshi NINOMIYA, Yoshiki GOTO, Tsunemi WATANABE
    2021 Volume 77 Issue 2 Pages I_57-I_69
    Published: 2021
    Released on J-STAGE: January 27, 2022
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     In the construction industry, the shortage of engineers is becoming more serious due to the mass retirement of engineers, the slump in the employment rate of young people, and the high turnover rate. Until now, productivity has been improved by promoting ICT, and the working environment has been improved. but the motivation of construction engineers is declining due to the increase in work due to disaster recovery and infrastructure renewal, and the sudden change in the working environment due to the spread of COVID-19. Improving work motivation is an extremely important issue in further improving productivity. The purpose of this study is to propose a method for analyzing and evaluating the work motivation structure of construction engineers, and to consider a method for improving motivation and management through case studies. We attempted to construct a new evaluation grid diagram using the organic integration theory and to evaluate the autonomy and motivation used for the RAI index.

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  • Masato SASAKI, Ken SUSHIDA, Hidefumi SAKURAI, Shunzo KAWAJIRI, Yoichi ...
    2021 Volume 77 Issue 2 Pages I_70-I_89
    Published: 2021
    Released on J-STAGE: January 27, 2022
    JOURNAL RESTRICTED ACCESS

     As a result of the 2018 Hokkaido Iburi Earthquake, the Satozuka district of Kiyota Ward in Sapporo was suffered tremendous damage. For example, a huge volume of earth and sand spilled at the end of the embankment, with significant ground subsidence reaching more than 2 meters. After the earthquake, about half of 140 residents were forced to evacuate, and the existence and sustainability of the local community was threatened. In order to handle this severe situation, the City of Sapporo had made efforts to gain the local community’s trust and accelerated disaster recovery and restoration, sticking resolutely to “speed” in the light of the lessons learned from past earthquakes. Three months later from the earthquake, the consent of local residents regarding restoration work was obtained, and a half year later, restoration work was started and a clear vision of the work was presented. Only two years after the earthquake, restoration work was completed, providing information proactively to support rebuilding homes and personalized follow-up services for disaster victims at a local office in the disaster area. As a result, about 90% of disaster victims wished to rebuild their houses in the area, and most of the reconstruction of their houses was finished after two years and a half from the earthquake, leading to a speedy restoration of urban areas.

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