While Japan has implemented many infrastructure projects with its ODA, the technologies of Japan cannot be directly applied in many cases to the environment of developing countries where natural conditions, local engineering situations, maintenance capacity, etc. are different. In each of the countries, it is necessary to devise technology suitable to the uniqueness of its own environment that are different from Japan (hereinafter “appropriate technology”). However, this situation has not been fully understood in Japan, and appropriate technology devised so far have not been properly evaluated.Therefore, the experience and lessons learned haven’t been fully reflected to new projects.
In this research, a case study was conducted on Japanese ODA's infrastructure projects in which appropriate technology was applied. Risks associated with its application were analyzed from the perspective of both the donors and host countries, and a new approach to the evaluation methodology on the technology was examined. In addition, needs for sharing / systematizing the knowledge of the technology together with mainstreaming activities on it in education / research fields was discussed. The motivation of engineers involved in the application of the appropriate technology was also referred to.
From the 1930s to the present, the ratio of construction industry to fatalities in all industries has been high and the need for countermeasures is high. One of the countermeasures is the use of case studies categorized by the nature of the work, but the number of categorized case studies is very small and does not lead to sufficient learning.
In this study, the classification tendency and classification method of the work contents were examined by using the document data of the disaster situation common to all the case studies, paying attention to the quantitative text analysis as a method to classify the existing construction accident case studies by the work contents.
As a result, by checking the co-occurrence of parts of speech related to actions and materials and work locations in the entire civil engineering industry data, we were able to extract work content relevant to the main types of accidents. A classification method focusing on co-occurrence was examined, and a classification method by work content using quantitative text analysis was organized for the major cases in the case collection.
This study addresses the problems of bridge inspection when utilizing inspection robots in order to realize efficient maintenance of aging bridges in Japan against the background of lack of skilled workers in the field of civil engineering. The approach is from the computer vision field.
In this paper, we have summarized the current bridge inspection methods, proposed a "bridge inspection method utilizes 3D data" that utilizes inspection robots and computer vision, and summarized the expected application effects. Based on the verification results of the proposed method, the requirements for inspection robots and image management software are summarized. In addition, we will also discuss the problems when linking the inspection results of the proposed method to the national transportation data platform based on the utilization of 3D data.
The estimated tsunami inundation changed due to the regional development laws to prevent tsunamis enacted after the Great East Japan Earthquake. In cities facing the ocean, it is necessary to create urban planning considering population decline and aging society, and tsunami hazard risk.
This study aims to verify the hypothesis that tsunami countermeasures can reduce CO2 emission by the simple environmental impact simulation. Kochi City, Japan, which is estimated to have flooded most of the city's downtown area due to the tsunami, was selected as the case study area. This study distributed the questionnaire survey about housing choice in the future in the city.
The estimation result of CO2 emission supported the hypothesis. Also, quantitative analysis showed that tsunami countermeasures could reduce 11 percent/person/year in 2050.
In urban areas, it is expected that the number of businesses such as reconstruction, renewal, and the construction of new structures will be increased in areas where there is a large volume of remarkably deteriorated infrastructure equipment and underground buried objects. However existing structures are usually managed by two-dimensional drawings, it is difficult to determine the position and height of underground objects during construction works.
The purpose of this research is to establish efficient correction system for the existing 2D drawings, by improving the simple 3D model generation method for underground buried objects.In this research, the authors applied a 2-D drawing update method using the system developed for improving the correction efficiency in the realization field, and compared and verified the working time of the conventional method and the devised update method for practicality.As a result, it was confirmed that the image data can be extracted from the generated 3D model and superposed on the existing 2D drawing to correct the drawing quickly.
We have studied methods of model spacing for constructing and practice utilizing as a method to advance the business efficiently in the AEC industry, and to achieve the agreement formation between parties concerned. In addition, we also have proposed that the CIM team is necessary for the management of the business, furthermore, making their role clear is also needed.
In the guidelines which announced by the Ministry of Land, Infrastructure, Transport and Tourism, construction methods of 3-D model, such as the terrain model and the structural model, and examples of use in parts such as design and installation are shown. However, the usage example at the business unit level is not indicated because of the confidentiality of business.
In this paper, we analyzed that the example of the business using the ICT shown in the previous study, and the utilization method and the state of the model space handled by BIM/CIM.
From that analyzation, we propose a comprehensive model space for the model space which we will operate in the business, and describe the contents on the basis of hearing for a contractor.
Twenty years have passed since the enforcement of “Act on Promotion of Private Finance Initiative” in Japan, and further promotion of Public Private Partnerships to infrastructure projects is expected in the future. When considering a PPP with new infrastructure development, after satisfying the criteria of economic analysis from the viewpoint of national economy, it is necessary to structure project scheme based on financial analysis from the scope of private businesses, bankability analysis of private finance from the perspective of lenders, and public expenditure analysis from the viewpoint of the public sector. Although these four analyzes are closely related to each other, it is difficult to structure a scheme from a comprehensive viewpoint because they are implemented individually from each viewpoint. Therefore, the purpose of this study is to propose an analysis approach that integrates economic, financial, bankability and public expenditures in order to efficiently conduct comparative evaluation of various business schemes including PPP. First, the basic idea of the integrated analysis is explained in detail, and after developing each analysis table on a spreadsheet basis, an integrated analysis table is derived by interconnecting the tables. In addition, with an integrated analysis table prepared for a virtual new toll road project, the usefulness of the integrated analysis approach for structuring the project scheme is confirmed through case studies.
The purpose of this study is to improve efficiency of design process with contractor based on the experience in accrual MLIT public works projects applied technical proposal and negotiation method. The results of this study revealed the idea on standard procedure and work allocation among designer, contractor and MLIT for design process in early contractor involvement. Based on the proposed idea, different from existing methods such as design-bid-build, the guideline on technical proposal and negotiation method for MLIT public works projects was revised in Jan, 2020.
In recent years, the time for recovery from disaster tends to be prolonged. It is useful for those who make the disaster prevention strategy to understand the influence of the daily life if the recovery is delayed. However, it is not always easy to grasp the influence on the life in affected areas during recovery because the life consists of many aspects. In this study, we construct a method for comprehensively grasping the influence on the life during recovery using local newspaper articles. Then we discuss how the life in affected areas may be influenced if the recovery is delayed and the manpower in the construction industry is decreased.
Due to the aging of construction workers and young workers’ population decrease, construction skills inheritance to younger generations is facing a challenge. This study analyzed how construction workers’ skills have been inherited from generation to generation and how the workers have improved the skills, focusing on a local construction company. With the aim of identifying the skill inheritance process, this study applies MDS (multi-dimensional scaling) to scale a variety of stimuli that are related to construction skill inheritance and to extract specific patterns of the skill inheritance in the target local company. The analysis results indicate that the skills have been mainly inherited on construction sites and the lessons that young construction workers learned at the site are playing a principal role to improve their technical skills. Formerly, the construction workers tended to learn the skills by themselves at work sites. Currently, they are studying, making use of various occasions such as workshops or construction site observations. It indicates that the process of construction skill inheritance may be changing.
Many engineers and workers of construction companies and construction consultants who were familiar with the area tried to grasp the suffering situation and worked on the emergency restoration night and day in the Hokkaido heavy rain disaster in August, 2016. Furthermore, they continued correspondence for the restoration such as Nissho mountain pass under the severe condition over the next year. During this time, in them, there were a lot of people who had a hard time in lack of experience and lack of information sharing for disaster in addition to continuation of the duty for a long time.
In this report, we carried out questionnaire survey about the emergency restoration work for local construction companies, arranged problems based on experiences and considered measures in the working group consisting of the industry-university co-operation official, and clarify roles and problems that local construction industry should perform for a large-scale disaster in the future.
In order to maintain road bridges appropriately, it is necessary to develop human resources strategically with clear goals so that engineers who have the technical capabilities necessary for the actions and decision-making required for entitles involved in maintenance can be continuously secured. On the other hand, the development of tools to support maintenance, such as non-destructive testing techniques and monitoring techniques, has been promoted. The quality of maintenance is not necessarily improved by blindly applying the tools. Therefore, being able to utilize the tools is one of the technical capabilities required for engineers.
In order to realize strategic human resource development, this study attempts to elucidate the technical capabilities to utilize technical support tools to improve the quality of maintenance of road bridges by using the framework of "Bloom's taxonomy" developed in the field of education based on cognitive psychology.
In the case of Hanshin Expressway, cracks on orthotropic steel slabs are managed with a database. Among these cracks, the cracks on orthotropic steel decks with U-shaped ribs underwent correlation analysis, and factors that induce cracks were investigated. In detail, the existence of cracks and fatigue life were set as objective variables, and the cumulative number of passing of a 10-ton axle and the specifications of vertical and horizontal ribs were set as explanatory variables. Different methods for correlation analysis were used according to the characteristics of objective and explanatory variables. The characteristics of correlation between objective and explanatory variables were evaluated with simple equations, under the assumption that fatigue cracks follow Miner's Rule. Lastly, in order to study the effects of the spans of vertical and horizontal ribs on stress amplitude, numerical analysis was carried out, and its results were compared with those of the statistical analysis, and they were discussed.
Jet fans installed for ventilation and smoke exhaust in the tunnel are overhauled every 5-10 years. In place of the jet fans that were removed for disassembly and maintenance, maintained jet fans are diverted and installed. Since jet fans have different installation structure depending on a manufacturer, it is necessary to produce new hanging brackets for hanging jet fans from the tunnel frame every time jet fans are diverted and installed. Therefore, there are concerns about the safety while jet fans are removed and the cost increase due to new productions of hanging brackets. In this study, we proposed the common hanging bracket which enabled the installation of jet fans with different installation structures depending on a manufacturer, and we examined a possibility of using the common hanging bracket. In addition, we mentioned the future maintenance of jet fans, which is expected to change significantly with the introduction of the common hanging bracket.
There are some broadly used public procurement systems in the UK that are not major in Japan, such as Framework Agreement, Joint Procurement and Centralised Purchasing. These systems have been introduced and became widely used with the intention of not only making procedures more efficient but also reforming the U.K. construction industry itself.
In this paper, examples of details and actual operation of these systems are reported based on information gathered in a consultant company in the U.K., and benefits obtained by applying the systems are also reported. Finally, ideas of ways to take the advantages into Japan are suggested.
Based on the annual road maintenance report, municipalities lag behind the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) in the implementation of bridge repair nationwide, and delays in bridge repair in municipalities are a problem. In this paper, a case study on the bridge repairing project in Tamana City government is presented as an example of an original project under the constraint of financial resources. Next, we discuss the need for further improvement of the approach. This paper describes a separate ordering of bridge repair by utilizing the existing technology of the local construction industry to supplement the manpower shortage of the city hall staff, and the labor saving of the ordering process. Finally, a case study of a bridge repair in Tamana City is presented.