In construction projects, the increase in construction costs due to the geotechnical risks is still frequent, and while the need for geotechnical risk management by geotechnical engineers has been pointed out, there is room for further utilization of the technical skills of geotechnical engineers.

 In this study, we quantified the effectiveness of geotechnical risk management using the Sharpley value, a kind of cooperative game theory, and analyzed cases of construction projects with high management effectiveness. As a result, it was shown that management effectivensess under large-scale landslide risk are high, and we also summarized the characteristics of such cases.

 Then, the Geotechnical Baseline Report (GBR), a method for sharing geotechnical risk between client and contractor used by such as FIDIC, was formulated using contract theory in order to clarify the relationship between the characteristics of the construction projects and the optimal risk sharing. By using the model, it is shown that setting GBR after the occurrence of deformation, which is a precursor of landslide, may be effective as a geotechnical risk-sharing method for construction projects with large-scale landslide risk.

 The use of digital technology in tunnel construction is highly expected to contribute to efficiency and cost reduction. In Europe and the U.S., which are the leading DX countries, BIM has been adopted as the core of DX technology, not only for 3D modeling but also for information acquisition, information management, improvement of operational processes, and collaboration are actively promoted. This paper introduces some of the tunnel projects in Europe and the U.S. and describes how BIM is being utilized to address issues for construction project works. Some of the issues recognized are the BIM application that considers tunnels attribute including its long structure and interiors which are influenced by surrounding ground and strata state, the absence of integrated BIM tunnel software, and the importance of collaboration with fields other than civil engineering, such as mechanical, electrical, and plumbing. Even though the effectiveness and possibilities of BIM are high, there are still problems to be solved to improve BIM utilization.

 The area of pavement rehabilitation work on expressways is determined based on the results of road surface condition surveys. However, the intervals between surveys and construction orders are different, and there is a problem that the most recent survey data is insufficient when formulating an order plan. Therefore, this study examines a method to support the planning of pavement rehabilitation work orders using statistical deterioration prediction methods. Specifically, based on the fact that deterioration management indices and repair target value of expressway pavement are managed as continuous values, a method of estimating a deterioration hazard model using continuous quantities is adopted. At this time, an analysis focusing on the relationship between IRI and asphalt layer thickness is performed using a large amount of road surface condition survey data used in practice. Furthermore, the effect of missing information on the repair history on the estimated results of the deterioration performance curves is discussed.

 The machine learning-based prediction models for bridge deterioration due to segmentation of deck, alkali-silica reaction (ASR) and frost damage are developed using environmental and meteorological data of bridges located in Tohoku region. LightGBM algorithm is applied to develop the models for solving the binary classification problem of deterioration/non-deterioration classes. The Shapley value is used to measure the contributions of input features to the output of the LightGBM prediction models for segmentation of deck, ASR and frost damage of bridges. The deterioration prediction models are validated based on the consistency between the deterioration factors determined by the Shapley values and the deterioration mechanism. Then, considering the changes in meteorological conditions under various climate change scenarios, the future deterioration trend of bridges located in Tohoku region is predicted using the machine learning-based prediction models. The prediction results with and without considering the effects of climate change demonstrate that the number of deteriorating bridges in the future depends on the climate change scenario. In addition, it is found that the bridges which would be deteriorated in the future are likely to be distributed around the bridges which are already deteriorated.

 Significant changes have not been made to the design process for public works and the contents of “Standard Specifications for Civil Engineering Design Work” despite the diversification of ordering methods; the implementation of i-Construction and BIM/CIM; and the advances in measurement, design, and construction techniques. In this research, the current situation of road design was examined through review and confirmation of the design processes and “Standard Specifications for Civil Engineering Design Work” for the Ministry of Land, Infrastructure, Transport and Tourism and Metropolitan Expressway Co., Ltd. As a result of this analysis, it was confirmed that there are differences between the design process and contents of implementation in the “Standard Specifications for Civil Engineering Design Work” for the Ministry of Land, Infrastructure, Transport and Tourism and Metropolitan Expressway Co., Ltd., as well as confirming that there are differences with the design process followed in the United States.A questionnaire survey of road design practitioners was also conducted regarding the level of comprehension of the “Standard Specifications for Civil Engineering Design Work” and issues related to the design process. Based on these results, improvements to the road design process to increase efficiency are proposed.

 Having achieved comparability with the introduction of the Unified accounting standard for public accounting among local municipalities, this research shows that financial statements under double-entry bookkeeping have different features compared to previously legislated indexes based on cash-flows. Principal component analysis is applied for this comparison between different sets of financial indexes. With cluster analysis, those municipalites deemed to have issues with fiscal sustainability were separated into 5 clusters with different characteristics that call for different measures.

 General National Highway No. 337, Doo-area connecting road between Naganuma and Ebetsu, up to 1,360 dump trucks per month were transporting construction materials at peak times, causing traffic congestion and long queues on the transport routes and at the deposition sites. This posed a significant challenge in addressing complaints from drivers and nearby residents. To solve this problem, the Dump Truck Operation Management System "MeDDel" was adopted to manage the entire process from order receipt to loading of soil and sand on the cloud, making it possible to establish efficient loading schedules. Moreover, the introduction of license plate recognition cameras helped improve driver awareness and driving manners, leading to significant improvements in addressing the issue. In addition, the problem of loading errors caused by a lack of information sharing between drivers and loading operators was also resolved, enabling efficient loading operations

 In Japanese construction industry, foreign skilled workers are increasingly employed as one of countermeasures against the shortage of human resources. The Specified Skilled Worker System was established in 2018 as a new system following the Technical Intern Training System. This study focused on the Specified Skilled Worker System, and aimed to identify the actual condition of employing foreign skilled workers and its operational issues by questionnaire and interview surveys with construction companies. In these surveys with construction companies accepting foreign skilled workers, as examples of good practices, cases on 1) recruitment, 2) OJT, 3) skill improvement, 4) Japanese language proficiency, were identified.

 In this study, we used multi-agent simulation (MAS) to quantify disadvantages of local residents due to bridge consolidation. In Japan, the consolidation and abolition of bridges is unavoidable due to tight local finances. Although, there is a delay in building a consensus with the residents regarding the demolition and the consolidation plan. We constructed the model that can estimate disadvantages of local residents when the nearby bridge removed using MAS. One of the features of this model is that residents (agents) have access to predefined functions that express the burden of moving. They would optimize these functions by selecting the type of transportation and the routes taken. Simulations were con-ducted with and without the target bridge, and the difference in the total value of each agent’s utility functions would indicate the importance of the bridges. The simulations were performed for three different observation times: morning on weekdays, daytime on weekdays, and daytime during holidays. The target bridges are 19 bridges that cross the Itachi River in Toyama City. The results of this study revealed that Tatsuizumi Bridge and Chitose Bridge had the highest importance, whereas Sousen Bridge and Higashi Bridge had the lowest importance. The results, which indicate the priority of the bridges from the residents’ point of view, is beneficial in terms of the planning of bridge maintenance, particularly in deciding which bridges to prioritize in the future.

 The business environment of the water supply business is becoming severer, such as the decrease in water charge income due to the decrease in water demand, the increase in expenses due to the repair of aging facilities and the earthquake resistance. In order to continue the service while suppressing the price increase, it is necessary to optimize and downsize the scale of the facility according to the water demand. The purpose of this study is to analyze the project cost reduction effect of downsizing water pipelines. Through a simulation using a water supply business model that considers business risks, we attempted to consider the impact of two downsizing methods, pipe diameter reduction and water supply area reduction, on sustainable business management.

 The development of local scour around piers during floods often causes damage, such as tilting piers. Establishing a system that can accurately determine which piers are at high scour risk is important to prevent such damage. Conventional scour damage risk assessment is conducted using the data of scour depth surveys around piers. In this study, to select information to improve the efficiency of scour damage risk assessment, we investigated the relationship between the dynamics of sandbars and the data on scour depth around bridge piers over time. The results indicate a clear relationship between the development of local scour around piers and the movement and stabilization of sandbars. This paper showed that understanding sandbar dynamics around bridges could be determined from easily obtained aerial photographs in conjunction with the periodic work of scour depth around bridge piers leads to more efficient bridge damage risk management.

 Numerous methodologies have been proposed to estimate Markov transition probabilities using visual inspection data and to describe the deterioration process using Markov chain models. However, there is a dearth of comparative examples that evaluate the effectiveness and applicability of these estimation methods using actual data. Consequently, the criteria for selecting a degradation prediction method are unclear when implementing asset management in practice. Additionally, certain estimation methods pose mathematical and technical barriers that prevent practitioners from applying them on their own. This study aims to address these gaps by summerizing the features and constrains of various estimation methods based on previous research. Markov transition probabilities are then estimated using actual inspection data under assumed conditions and analyze the circumstances under which these methods are effective, as well as when thier application may be inappropriate.

 One strategy for efficiently managing aging infrastructures is to manage infrastructures in multiple fields in a cross-sectoral manner. This study discusses advantages and disadvantages of cross-sectoral management of infrastructure facilities. In addition, it summarizes changes in the external environment which may support the realization of cross-sectoral management, and argues that while systematic challenges such as barriers between different ministries and the obligation to return subsidies for the revisions of use remain, the state of promotion of technologies and systems for introducing the cross-sectoral management has been improved with the development of the public accounting, PFI legislation, and development of DX. Simulations are conducted to quantitatively evaluate the effect of introducing cross-sectoral management, which shows the possibility of risk financing through inter-sectoral flexibility and flattening renewal costs through the effect of dispersion of renewal timing.

 Since the enactment of the PFI Law, various public-private partnerships have been promoted in local governments in Japan. Even when it comes to public-private partnerships, local governments vary in size, environment, and target events. The Subcommittee on Infrastructure PFI/PPP Promotion established in the Construction Management Committee of the Japan Society of Civil Engineers (JSCE) has organized the current situation to be considered in order to study desirable public-private partnership projects by hearing the voices of local government officials involved in public-private partnership projects, and has examined issues to be considered in the future. The results of the survey showed that local governments are not always willing to take on public-private partnerships. As a result, it was found that there are various motivations for local governments to implement public-private partnership projects that cannot be interpreted only in terms of so-called narrowly defined VFM. In addition, in all local governments, price adjustments due to design changes and price fluctuations require a resolution of the local council, which makes contract adjustment inflexible.

 Construction-related companies play an important role in the early recovery of infrastructure immediately after a disaster and contribute to minimizing the impact of the disaster. In order to implement effective disaster response measures, it is essential to coordinate the appropriate allocation of available human and material resources according to the disaster situation. Effective coordination requires shared relationships and rules among construction companies, and this is often done through construction-related business associations. It is important for future disaster resilience measures to be widely shared among construction-related companies to recognize the challenges they face in the disaster response phase. This paper clarifies the social system environment in which construction-related companies are placed by summarizing the role of the construction industry and the history of system revision and reports on the concerning issues identified through interviews with local construction companies.