Reform of the way of working is being promoted with the aim of correcting long working hours. While these efforts are mainly focused on the working environment, it is important to promote efforts to make the industry as a whole more attractive by increasing the motivation factor of employees. The purpose of this study is to clarify motivation factor and its factors through a survey of general contractor employees. Episodes related to motivation factor were extracted from all 17 subjects, who were selected in consideration of various work styles (in-house work and overseas experience) and attributes (position, gender, and nationality), and six types of motivaton factors and five types of hygiene factors were extracted. The analysis of the motivation factors showed suggestions on how to work to enhance motivation factor for each position in terms of 1) position, 2) changes in motivation factor, 3) influential persons, and 4) matters and efforts to enhance motivation factor.

 Geotechnical risk management is an important activity that reduces serious cost loss to often occur in civil engineering projects, but has not progressed inserting to projects. This may be caused by non-understanding of the effect of risk management, because it is not sure that the risk sources and the uncertainty improved by risk management, also difference between normal geotechnical survey and risk management. In this study, based on a review of the literature and observation of business practice, we clarify the uncertainty improved by risk management, by classification of the geotechnical uncertainty(probability) on geotechnical risk source. And with arranging features of each management processes, we suggest that -geotechnical risk might increase caused by change circumstance of project, and it is necessary that inserting a process of management design at a view of geotechnical risk, for effective management.

 The shortage of labor has long been a problem in Japan's construction and transportation industries. To solve this shortage, we need to make the industries more attractive to work in. For this purpose, we consider how to increase the mental satisfaction of workers. Therefore, it is necessary to understand the structure of consciousness of workers in the industries. In this study, a questionnaire survey was conducted and analyzed to clarify the consciousness of workers in construction and transportation. Grouping and comparison of means and correlation analysis were conducted to show the relationship between happiness and unhappiness of workers, their views on work (“jobs”, “careers”, and “callings”), perceptions of the construction and transportation industry, and their relationships with local citizens. It was found that those who were like “callings” were more likely to feel happy than those who were like “jobs” or “careers”.

 In recent years, there has been a diversification of ordering methods for public civil design as well as a shift in design method from specification-based design to performance-based design and revision of the standard terms and conditions for public engineering design contracts. Against this background, there is growing interest in contract management and a real necessity to properly understand and operate in accordance with terms and conditions for public works design contracts. In this study, comparative analysis was conducted to compare the sections of the terms and conditions for public civil design contracts (including public building and private building design contracts, etc.) related to copyright and the Design Act. As a result of the comparative analysis, it was confirmed that the contents of the terms and conditions of each type of contract differed regarding copyright and design rights. The contents of FIDIC’s Client/Consultant Model Services Agreement (White Book) also differed. Revisions to terms and conditions for public works design contracts regarding design rights and copyright responding to changes to design method and new deliverables are proposed based on this analysis.

 Dealing with low-priced bids and awarding bids by lottery remain important issues in the execution of public works projects in Japan. The latter runs the risk of inhibiting the growth of “honest company'' who are trusted by the local community and society. To manage this risk properly, a fundamental reform of the public works execution system is considered essential. One of references is “Kochi Prefecture version: Public procurement regulations (draft) general conditions for civil engineering complete construction.” Fundamental institutional reform brings with it great anxiety among those involved, so it is desirable to proceed with reform while alleviating those concerns. In this study, we investigated what risks local public owners perceive regarding public works execution and the construction industry, and what concepts and specific provisions of public procurement regulations should be used to reduce and eliminate them.

 The ability of a road network to perform its expected function in the event of a disaster is important from the viewpoint of social consensus on the social impact of its dysfunction. Road structures, which are closely related to road functions, are designed to achieve performance that does not fall below the required level, reflecting the existence of many uncertainties. In addition, the performance of road structures deteriorates after they are put into service due to deterioration and damage. Therefore, it is difficult to accurately predict the damage caused by natural disasters to road structures. On the other hand, the applied standards and structural characteristics may affect the risk of damage and damage patterns of road structures.

 Therefore, in this study, a prototype method was developed to estimate the damage risk of bridges and earthwork structures based on their applied standards, structural features, and inspection results. We also discussed whether the proposed method is useful for risk assessment of roadway functions for infrastructure asset management.

 In setting the ceiling price for public works, it is important to ensure fair profits for the contractor in addition to the cost necessary to meet the required performance of the construction work. However, inconsistencies between design documents and the site conditions and the client estimates that is not consistent with the actual conditions are cited as major issues. This study focuses on the design and cost estimation of the Ministry of Land, Infrastructure, Transport and Tourism, which represents the client estimates in Japan, and analyzes the relationship between the bidder's estimate and the client's estimate, and the situation in which the client’s cost estimation standards affect construction. It has been confirmed that the tender process for tunnel and dam construction, which compete on advanced technologies, is akin to a "game of guessing the minimum price" determined by the client. In many cases at the construction stage, the construction method described in the client cost-estimation standard was prioritized. To solve these problems, we have considered ways to flexibly utilize the client cost-estimation standards and proposed some cost estimation methods that can accommodate various construction methods including new technologies and ensure construction safety and fair profits for contractors.

 Japan is currently facing a labor shortage caused by an aging society with a declining birthrate. In particular, the construction industry is suffering from serious problems such as a decrease in the number of workers, the departure of experienced engineers, and a shortage of next-generation workers. Under these circumstances, in order to quickly complete earthquake disaster reconstruction projects, it is essential to train construction engineers and pass on their skills in a short period of time. In order to solve these problems, this study proposes a method for improving the tacit knowing ability of construction engineers with little experience and acquiring knowledge in a short period of time. This method involves interviewing engineers who worked on reconstruction projects following the Great East Japan Earthquake, and examining the findings from their own experience based on the results of analysis using qualitative research methods used in the social sciences. By putting this method into practice in the future, it is expected that it will help realize the early completion of earthquake disaster reconstruction projects.

 As the population ages, a shortage of human resources is a major issue in the infrastructure sector. While the introduction of DX (Digital Transformation) using i-construction promoted by the Ministry of Land, Infrastructure, efficient operation requires skills in mathematics, data science, AI, and the like. Hokkaido University is promoting recurrent education for working adults, which extends the education of such skills not only to students but also to working adults, as part of its mid-term plan.This paper summarizes the challenges and responses to them through the DX recurrent education Program for Social Infrastructure Fields" implemented by the Education and Research Center for Mathematical and Data Sciences at Hokkaido University for as a project supported by the Ministry of Education in the fiscal year 2023, and discusses it as a consideration for further advancing DX recurrent education in the infrastructure field, which is expected to become even more active in the future.

 At the time of regular inspection of bridges, simple repair is sometimes conducted for the purposes of safety improvement and preventive maintenance. It is important to evaluate how much simple repair can inhibit deterioration, but simple repair is conducted for damaged members that deteriorate at a relatively rapid pace, so it is impossible to obtain inspection data for the case where simple repair is not conducted. Accordingly, there is the bias due to the sample dropping. In this study, this problem is solved by utilizing a deterioration prediction model that takes into account the sample dropping bias, and the deterioration processes of the members that have undergone simple repair and the members that have not undergone simple repair are compared, to conduct quantitative ex-post evaluation of the effects of simple repair for inhibiting deterioration. Lastly, by studying the cases where visual inspection data are used for viaducts of expressways, the effects of simple repair for inhibiting deterioration are evaluated quantitatively, and the timing of simple repair is discussed.

 In order to improve the productivity of the entire construction production system, i-Construction is being promoted, in which 3D digital topographic data is transferred and used in each construction process, including surveying, design, construction, and maintenance management. However, the accuracy and point cloud density of the 3D data required in the maintenance management process have not been considered, and as a result, the number of cases in which 3D data is used in the process has not been increasing. This paper describes the research results for the practical application of a slope maintenance management method using mobile mapping system (MMS) as indicated in the BIM/CIM guidelines. Specifically, by verifying the basic characteristics of MMS with map information level 500 specifications, which is widely used for creating and updating a road ledger, etc., we will be able to determine the size of slopes to which maintenance management methods using MMS can be applied. Moreover, we demonstrated the usefulness of a method for quantifying deformation using laser point clouds from two different periods on this slope.

 Quality infrastructure is the key to overseas development of infrastructure systems, but it is not possible without Japanese technology as a base. DX is currently spreading worldwide, and it is important to investigate the construction achievements of competing countries, including whether the advanced DX technology represented by i-Construction can be positioned as one of Japan's technologies. In this study, it is introduced several applications of DX technology for tunnels constructed by China, one of the competing countries for infrastructure export, and compares them with similar cases in Japan. Specifically, the application of BIM-4D and BIM-5D construction, data exchange by IFC, integration of BIM and GIS, roaming display by iPad, and QR code generation and tracking platform.

 We investigated a method to easily evaluate the natural period of the surface ground using open data on the average S-wave velocity and geomorphologic classification of the surface ground in the Kanto region. Based on the index converted from the average S-wave velocity in the surface layer of 30 m and the grouping by geomorphologic classification, a prediction formula for the natural period of the surface ground was derived, and it corresponded well with the observed values obtained from PS logging. The results of calculating the natural period using the proposed prediction formula for locations in Tokyo and Chiba Prefecture, it was found that the predicted values and observed values correspond well. Furthermore, it was shown that the proposed formula can evaluate the natural period of the surface ground with higher accuracy than the practical method.