The multi-span cable-stayed bridge has smaller deflection rigidity than the cable-stayed bridge with 2 towers, which tends to increase the vertical deflection of the main girder, the main girder stress, the cable tension and the bending moment at the bottom of main tower due to the live load. This is often the problem at design time. This paper proposes a new cable system to effectively improve the deflection stiffness of cable-stayed bridges with three main spans (span length of 650 m), and compares its effectiveness with existing cable systems. Furthermore, the results of optimization of the proposed cable system are presented. We also confirmed the effect of earthquake action on the response of the structure with the proposed cable system.

 A series of experiments and numerical simulations were conducted to investigate the mechanism of change in axial forces of high-strength bolts subjected to induction heating for paint-coating removal. The shorter the time for reaching the target temperature of paint-coating removal (around 200 ℃) was, the larger the difference in temperature between the nut and the bolt became. The mismatch between the nut and the bolt threads caused by the temperature difference induced the reduction of bolt axial forces. The experimental and analytical results indicated the possibility of reducing the bolt axial forces within 4–6 % of the initial axial forces by keeping the heating time 15–30 seconds.

 Linear-shaped convective systems (LCSs), accompanied by band-shaped areas of heavy rainfall with a length of 50-300 km and a width of 20-50 km, are one of the extreme weather phenomena that can generate record-breaking heavy rainfall in Japan. Early warning information of LCSs considering the meteorological aspects of observation and numerical simulation is essential in ensuring lead time for flooding controls and evacuation. The current study examines the diagnostic approach of multifractality of 3D atmospheric field for LCSs using a cloud-resolving model (CRM) with 500-m horizontal resolution. Multifractal is defined as power laws of 3D spatial scale for water vapor flux (QVF) and turbulence kinetic energy (TKE). The CRM simulation of LCS at Kyoto on 15 July 2012 represented the process that convective clouds organized into a band-shaped cluster. QVF and TKE showed intense multifractality corresponding to convection initiation and the development of a back-building-like convective cluster. To define the period of the organization of LCS, we estimate the temporal variation of convective mass flux (CMF) which is the total volume of upward moisture flux and fractal dimension of updraft (FDU). When the isolated convective clouds initiated FDU showed a gradual increasing tendency. CMF and FDU increase as merging convective clouds and forming LCS and we defined this period as the organization of LCS. Our analyses revealed multifractal signals on QVF and TKE that appeared about 1-h before LCS was organized. The similar characteristics were also observed in the LCS event at Hiroshima on 20 August 2014. We conducted the ensemble forecast experiment of Kameoka LCS event to evaluate the robustness of precedent multifractal behavior. The composite analysis for 10 members with larger accumulated rainfall indicated increasing FDU and intense multifractal features on QVF and TKE before the organization of LCSs.

 In recent years, a lot of housing retaining walls have been damaged by huge earthquakes in Japan. The reinforcement method, in which the reinforcement is driven into sloping ground from the top of slope vertically, is applicable even in densely packed residential areas. However, the construction cost tends to be too high for applying to housing retaining walls since many straight piles and tilting piles are used. Therefore, we suggest a method in which only tilting piles are used and the top of them are connected to the top of the prefabricated retaining wall for reinforcement, substituting the prefabricated retaining wall for straight piles. In this research, aiming to confirm how the different number of reinforcing members, and reinforcing mechanism by integrating the top of the retaining wall and reinforcement bar which are single bars and braided bars, we conducted a series of background loading experiments using a small centrifugal model experiment device. As a result, a reduction in the number of reinforcement bars can apply a large axial force in the tensile direction to the reinforcement while suppressing bending deformation of the reinforcement.

 In recent years, heavy rains and typhoons have become increasingly severe due to climate change, resulting in accelerated scour of river-crossing bridges supported by shallow foundations. Local scour causes the soil on the upstream side of the pier to be excavated and washed away by the river flow, destabilizing the foundation, and causing it to settle and slope upstream. Therefore, there is a need to improve the accuracy of predicting the extent of scouring damage in advance and the evaluating of bearing capacity after the damage. In this study, we conducted model tests using aluminum rods ground model, through a series of processes from scouring phenomena to bearing capacity tests. The purpose of this study is to propose two methods. The first is to estimate the scour scale that leads to large-scale damage that causes piers to collapse in terms of the bearing capacity of the ground. The other is a method to evaluate the residual bearing capacity after medium-scale damage where residual settlement and tilting have occurred without collapse. As a result, it was shown that the extent of scouring leading to large-scale damage can be quantitatively evaluated in terms of the relationship between the width of the foundation perpendicular to the bridge axis and the height of the center of gravity of the piers, and it was also shown that it is possible to quickly restore the functionality of the bridge (i.e., resume its use) by simple emergency repair of the damaged foundations if the residual eccentricity ratio estimated from the residual inclination angle after medium-scale damage is within 1/10.

 The number of flexible office spaces shared with other users without any lease agreement has increased rapidly in recent years. Consideration of future urban policies necessitates clarification of the actual situations of flexible office space. For this study, we conducted an independent survey, categorizing flexible office space users according to their use. We then analyzed regional differences and differences in satisfaction for each category we created. Results showed the following: 1) flexible office space has not only the function of an office but also the function of a third place; 2) differences exist in use purposes among regions; and 3) differences exist in satisfaction levels among different use types. Many respondents in the category of conducting business around work, home, and commuting routes were not satisfied with meeting rooms, lockers, and low fees. Those using the facilities as a third place were generally less satisfied with them.

 Due to deregulation of farmland-related laws, corporate-run kitchen gardens are increasing in metropolitan areas in Japan. Compared to conventional public kitchen gardens, corporate-run kitchen gardens offer better facilities and services and charge higher fees. Multiple regression analysis of corporate-run kitchen gardens shows that the fees are set from the perspective of urban land use, such as access by rail, distance from the city center, and population of the surrounding area, in addition to the facilities and services provided. This is a land use that has been overlooked in the conventional argument that agriculture does not exist in urban areas because of the difference in the value curves between agricultural land use and urban land use. If urban land use curves could be established for urban farmland, it could contribute to the reduction of farmland conversion and the agricultural use of underutilized urban land. In addition, it is expected that public gardens will focus on those that are more public, such as farms for the Disabled.

 Under the declining population, it is important to plan wide-area bases based on a common understanding among multiple municipalities. On the other hand, the x-minute city has attracted worldwide attention since COVID-19, and the viewpoint of fairness will become mainstream in the planning. In this study, we analyzed candidate centers selected across municipalities in order to implement a policy to prevent the overcrowding of centers and to provide relief to those who are vulnerable to accessing daily service facilities. As a result, we 1) proposed and showed the validity of an indicator of the possibility of improving accessibility of surrounding residentce by guiding facilities to the centers, 2) clarified the sustainability of facilities in 2040 based on the population in the reachable area, and 3) revealed that there are some centers where neither 1) nor 2) are compatible despite the planning policy of "guiding" facilities. It was indicated the importance of reviewing the current guidance policy based on residence from the viewpoint of a wide area.

 When introducing a new transport service, it is necessary to forecast demand and design service levels in advance. Demand forecasting was conducted using the Multi-Agent-based Urban Mobility Simulator (MAUMS), which implements a conversion model estimated using data from a survey of preferences for the Arao "Omoyai Taxi", an on-demand shared-ride taxi service. The results showed that the simulation estimates overestimated the observed values for the number of users.

 This study proposed a method to update the parameters of the modal conversion model implemented in MAUMS by data assimilation using the observed number of users obtained from the reservation log data. As a result of applying this method to the estimation of demand for Omoyai Taxis, the MAUMS estimates of the number of users by time of day were close to the observed values.

 Recent household travel surveys in Japan reported a declining percentage of mobile persons, especially among younger generations, and the reason should be carefully examined. In this study, we investigated the impact of different survey methods on the reporting of young people’s trips on weekends. Data from various surveys, including the nationwide person trip survey and the survey on time use and leisure activities, were used for the examination. Additionally, we conducted a web-based survey on weekend trips by university students to explore the effect of survey formats. The results indicated that the format requiring the record of the detailed trip information is more susceptible to soft refusal than the format asking whether individuals go out or not, especially among males. The results also suggested that asking for recording step counting could reduce the soft refusals.

 In the case of natural public objects such as slopes, it is difficult even for specialist engineers to detect anomalies early due to the significant influence of uncertainty in deterioration. Under such circumstances, it is effective to detect anomalies on slopes using spatially high-density point cloud data. In civil engineering, laser measurement technology used for point cloud data measurement represented by the Mobile Mapping System (MMS) has been developed. However, point cloud data are not yet fully utilized for decision-making in practice as it is not possible to easily grasp the deformation and changes of each feature. In this study, the authors propose a local anomaly detection method for slopes based on point-cloud deep learning with point cloud data as input. Furthermore, we make attempts to detect the frame blocks with local anomalies such as deformation and protrusion, and empirically analyze the effectiveness of the method proposed in this study.

 In post-earthquake inspections of road bridges, it is necessary to quickly ascertain damaged bridges from a vast number of them and to determine the necessity of measures for each of them under the constraints of limited time, equipment, human resources, and other factors. We studied a method of expressing the process of engineering judgment making based on explicit knowledge in accordance with logical rules, with the aim of enabling road administrators to show accountability within these constraints, and to make efficient and effective decisions by using rule-based reasoning. We conducted research on how to express the process of judgment based on explicit knowledge in accordance with the rules of logic. As a result, the context in which the accountability of the road administrator's decision to allow or deny traffic can be expressed was shown. On the other hand, the limitations of logical decisions based only on explicit knowledge were clarified, and the scope of what is composed of tacit knowledge in logic was also revealed.

 Against the backdrop of a chronic shortage of IT talent in Japan, medium-sized organizations are required to come up with ways to advance digital transformation (DX) with limited personnel. This study aims to evaluate a project in which a system development novice, within a medium-sized organization known as Mutsuzawa SWT, undertook reskilling with organizational support and developed a Facility Management (FM) support system utilizing 3D models. The evaluation compared the system’s size, construction period, man-hours, quality, and cost against the average values from JUAS statistical surveys. The results showed that the construction period was about three months longer than the standard, with the construction period ratio and man-hour ratio in the requirement definition phase being significantly higher. However, it was revealed that it is possible to develop a system of satisfactory quality to users at an average cost, including the cost of reskilling. From these findings, it is suggested that even novice, with the support of experienced individuals, can develop a useful system at an average cost, although the project timeline may be longer compared to the standard.

 PSInSAR analysis was conducted using C-band Sentinel-1 SAR data for up to 5 years and 9 months from April 2017 to December 2022 for both ascending and descending orbits for six large rockfill dams, which are in the stable period and have small deformation with a maximum displacement of about 2 mm per year. The results of the PSInSAR analysis were compared with the external deformation measured by the survey conducted once every three months to evaluate the accuracy of the analysis. The results show that PSInSAR analysis can also be used for monitoring external deformation in the maintenance of rockfill dams with small displacement.