Due to low birth rate and aging population, the lack of working force is one of the severe challenges to be solved in construction industry. In the field of port construction, multibeam echo sounding has been introduced to dredgeing works for improving the productivity. However, multibeam echo sounding has not yet been used in foundation works, and the finished survey for rubble rock foundation is still carried out by divers. This study aims to introduce multibeam echo sounding to the finished survey for rubble rock foundation. The field experiment is carried out to examine the accuracy of the measurement of multibeam echo sounding. Moreover, a control point is set on the seabed to improve the accuracy of the measurement. Also, acoustical ray tracing method is used to investigate the difference between the measurement results by divers and multibeam echo sounding. Based on the results of the field experiment, this study proposes the methods to calibrate the measurement of multibeam echo sounding.

 An earthquake area disaster prevention plan is made as the official document which listed the measures at the time of the earthquake disaster for each local government for each local government in our country. However, the example that an excessive burden suffered from the on-site staff is reported without being able to utilize a local disaster prevention plan at the time of the disaster enough.

 However, it is reported that the on-site staffs suffered from excessive burdens without being able to utilize a local disaster prevention plan at the time of the past disaster. In this study, we discussed effective measures at the time of a disaster in what a quantitative comparison to pay the attention to secondary disaster and road traffic, refuge measures from an enormous local disaster prevention plan in this study, and to visualize problems analyzed. It was shown that the contents of the plan differ depending on the local characteristic of the local government and the listed measures without enough examination are existed in the disaster prevention plan through the hearing investigation. In addition, an emergency transportation measure in the case study area at the time of tsunami disaster was examined with microscopic traffic simulation, and it was revealed that introducing a roundabout with left turn channelizing road to the bottleneck intersecton has an effect on the improvement in traffic flow around bottleneck intersection and transport of emergency relief goods.

 In recent years, in the construction industry, as a large number of elderly engineers retire, the employment rate of young people is declining, and the turnover rate is becoming more serious. 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. This research proposes a method for measuring and evaluating the work motivation of construction engineers using organismic integration theory. Through case studies, we attempt to analyze the effects of work experience such as ICT construction on autonomy by using Mixed Methods Research, and consider its application to motivation management.

 As of November 2021, more than 150 countries, including Japan, have declared carbon neutrality targets with a timeframe such as 2050. In order to contribute to these goals, the construction sector as well as other industries needs to consider low-carbon initiatives that include not only construction work but also the supply chain. This paper is aiming to provide a study on measures required to ensure low-carbon construction procurement in Japan, based on the measures implemented in other countries. To achieve this, in this paper, the authors firstly picked out 193 cases from the reports and documents prepared by international organizations and other existing literatures regarding low-carbon public procurement in the construction sector. Then, considering the population and the scale of the construction investment, the authors focused on the United States, Germany, the Netherlands, the United Kingdom, South Korea, and Spain as countries that are considered to have leading initiatives related to the low-carbon public procurement in the construction sector, and surveyed the initiatives led by the governments of these six countries. Finally, the authors clarified the measures required to ensure the implementation of low-carbon construction procurement in Japan as in the leading countries.

 In recent years, there has been a movement to introduce comprehensive management project in the field of road maintenance. In comprehensive road management project, it is important to monitor to confirm whether the provision of appropriate and reliable services is ensured by private businesses. The purpose of this study is to analyze the actual condition of road patrol work using management data, and to set performance indicators and make trial calculations using management data of Fuchu City which started full-scale operation of the comprehensive road management project in 2021. Results of the study are as follows. The total number of troble during road patrols and complaints from citizens is high in cleaning, plantimal management, and repair work. The level and monthly fluctuations of the road surface abnormality detection rate (index (1)) differ depending on the work, and the detection rate tends to increase over time. During the period from request reception to implementation of measures (index (2)), cleaning and planting management work is relatively short, while repair work requires a certain number of days.

 The purpose of this study is to propose a new application and improvement method using diversified procurement method such as comprehensive evaluation method, technical proposal and negotiation method, no-bid contract and designated bidding for disaster recovery and framework method. The result of this study revealed the importance of partnership between the public and private sectors as well as competitiveness of procurement system by comparing historical transition of public procurement in Japan and overseas.

 The purpose of this paper is to understand the current situation and the impact of single-party bidding for construction consultant services. This paper is an analysis based on the Kanto Regional Development Bureau's bidding data for construction consultancy services from FY 2008 to FY 2018, and found that single-party bidding accounts for around 40% of all bidding for construction consultancy services. This is due to two factors: the percentage of second-time bidders and the situation before and after the introduction of competitive bidding. It was not the case that there was only one bidder as a result of the severe calculation of the expected price. One of the measures to avoid one-bidder bidding and high bidder ratio is to evaluate the technical aspects of the project more appropriately and to increase the size of the project to some extent.

 Many of Japan's public roads were constructed during the period of high economic growth and are aging. The maintenance and management of bridges, in particular, is a pressing issue. Public-private partnerships have been attracting attention in the field of infrastructure maintenance and management, although concession schemes are not applicable to non-toll roads.

 In this study, a PPP project for non-toll road bridges is assumed, and a model is developed assuming that the operator repairs and renews bridges at its own discretion and the government pays according to the condition of the bridges. The results show that it is possible to encourage operators to voluntarily perform preventive maintenance by setting a payment scheme. In addition, a trade-off between the performance when the deterioration prediction is accurate and the robustness against the inaccuracy of the deterioration prediction is shown.

 The international standard of management system for asset management (ISO55000 series) defines asset management as "coordinated activities of an organization to realize value from assets." It requires not only the reduction of future project-based maintenance and renewal costs, but also the increase of asset value as much as possible, considering the role and performance of infrastructure. This paper points out that the term "asset value" is a composite concept envisioning two different meanings of assets: "value from assets" and "value of assets, " and models methodological mechanism for asset management, which aims to increase asset value, by use of a framework of logic model. The paper investigates problems underlying asset management exercises in three countries, i.e., UK, US and Japan, and discusses practical subjects to be discussed for development of asset value evaluation for infrastructure management.

 Since ports are essential infrastructures for maintaining the national economy and local community, it has been among the priority technical agenda to mobilize the port infrastructure management information for curtailing construction and maintenance cost and facilitating operational efficiency. This paper undertakes structuring port facility administration and management system on a lifetime basis, identifying the input-output information characteristics and tracking information linkage for discussing the possible development of an electric data exchange framework for improving port infrastructure asset management. The results showed the need to equip an information linkage system with push-type information linkage or pull-type search functions depending on the attributes of the information.

 The "vacant house problem" is becoming serious in Japan. As a solution to this problem, "small-scale chain rezoning projects" have been attracting attention as a way to improve the condition of roads and shapes of parcels by involving the front roads and adjacent land. In this study, we modeled a small-scale chain rezoning project to determine the optimal strategy of the organization (land bank) that conducts the project (i.e., in which order and for which residential lots) and the optimal policy of the local government (i.e., how to design subsidies and taxation systems). The analysis revealed that the optimal strategy of the land bank and the optimal policy to be implemented by the municipality in each specific case do not necessarily coincide with the overall optimal one that maximizes the sum of the benefits of each, based on which a set of conditions have been derived in order for the optimal strategy of the land bank to become feasible in reality.