In offshore construction using hoists, techniques for reducing the motion of suspended loads contribute greatly to improving the safety and operability of the work. The heave compensator is one of the methods used to reduce the motion of a suspended load, but it cannot reduce the motion of a suspended load in the direction of the surges and sway. It is desirable to use the crane’s slewing, hoisting, and lowering motions to reduce the motion of a suspended load, but the crane cannot follow the motion of the suspended load because the slewing and lowering motions of a hoist vessel are designed to be small for lifting heavy loads. Therefore, this study investigates a method to reduce the motion of a lifting load only by lifting and lowering movements, using phase differences based on the principle of parameter excitation. It was found that varying the wire rope length can reduce the motion of a suspended load significantly.

 This study investigates the occurrence of particle breakage in volcanic coarse-grained soil during undrained cyclic shear and its effects on static strength after cyclic loading. Stress-controlled and strain-controlled cyclic loading tests were conducted using a hollow torsion testing device, and the amount of particle breakage was observed. The results revealed that volcanic ash coarse-grained soil, adjusted to contain only coarse sand particles, experiences particle breakage due to undrained cyclic shear. This particle breakage does not occur at the beginning of the loading but rather in the latter half, when the effective stress decreases due to the rise in excess pore water pressure. Specifically, this breakage occurs significantly under the phenomenon of cyclic mobility, where effective stress crosses the phase transformation line and fluctuates between zero effective stress (liquefaction) and rigidity recovery while approaching the failure line. Furthermore, test specimens that experienced particle breakage due to cyclic shear history exhibited a decrease in residual strength during subsequent monotonic shear tests.

 The rotational spring constants calculation methods for segment joints in calculating shield tunnel response values have been organized for bolted joints; however, there has been an increase in the development and construction of segments using joints without bolted connections in recent years. In this study, joint bending tests and finite element analyses were carried out at the stress level at which the joint steel yields, to contribute to modeling the behavior of segment joints beyond the allowable stress level, targeting joints without bolted connections. In this consideration, the gap at the joint surface and the yielding/slip of the joint were extracted as factors influencing joint behavior, and the effect of the joint behavior and its mechanism were investigated.

 In some local cities, reorganization of bus routes into trunk lines and branch lines is considered in order to improve the level of public transportation service and operating efficiency. However, there are many cases in which route reorganization plans do not proceed smoothly due to concerns such as a decrease in the number of passengers due to transfers, which may be caused by insufficient analysis of the effects and impacts of route reorganization. An integrated analysis that takes into account the relationship between the reorganization of bus routes and the study of road space reorganization for walkable cities, which has been the focus of attention in recent years, would also be beneficial. This study the actual bus operational delay situation in Mito City and the benefits of bus route reorganization using bus passenger OD data by taking into account the perspective of road space reorganization, and quantitatively clarified the merits and demerits of route reorganization by entity.

 This study undertakes a comprehensive analysis of the “Tokugawa Jikki”, the official history of the Edo Shogunate, focusing on social infrastructure development and other institutions in the Edo area, with the aim of elucidating the realities of such development. The findings revealed that frequent occurrences of fires occasioned the continuous issuance of legal measures mandating the conversion of thatched and shingle roofs to tiled roofing. There was also a recommendation to use oyster shells for roofing, but this practice was only observed for a period of just over seven years. The establishment of firebreaks (open spaces in Edo town intended for fire prevention) was also an ongoing project, and legal measures were issued to maintain these areas as vacant land. The issuance of regulations concerning the excavation of new waterways (and moats) used for boat transportation and other purposes was concentrated in the early Edo period, with the focus shifting over time to regulations concerned with waterway maintenance and management. The study also revealed the regular issuance of legal measures intended to prohibit illegal dumping and concerning the dredging of waterways.

 The margin of performance, which is a newly developed concept to comprehend change in required structural performances seamlessly, has been examined. This study exhibits the process to determine an appropriate remedial measure for retrofitted railway viaduct by comprehending the percentages of safety margin (M_S) and durability margin (M_D) with change in the required performances of structure. The calculated M_S for each member were overabundance when applying the method that a seismic wall was constructed additionally. The correlation diagram between M_S and M_D of members demonstrated that the method by applying the steel plates was appropriate one, which minimized M_S and M_D in all examined phases. The examples of application revealed that new concept based on margin of performance contributed freely selection of remedial measures of repair or strengthening for adopted design concepts and required performance levels, which should be satisfied.

 The chloride ion diffusion in marine concrete structures is predicted by using Fick’s second low with two parameters, the surface chloride ion concentration C₀ and the apparent diffusion coefficient D_ap, which are obtained from the measured chloride ion concentration distribution. This study investigated the influence of materials and environmental conditions on the prediction accuracy of this conventional method, and conducted factor analysis by numerical simulation. The result showed that D_ap varies with the time series behavior of C₀, and it affects the prediction accuracy of the method. In particular, in the case where C₀ gradually increases, it was found that the prediction may be underestimated. Furthermore, prediction method using the diffusion coefficient with considering the time-series behavior of C₀ was proposed and it could solve the underestimation by the conventional method.

 The purpose of this study was to understand the effect of the applied surface treatment method on the corrosion environment of rebar on an existing RC structure supplied with water from the back not in a severe corrosive environment. In order to evaluate corrosion possibility, electrochemical monitoring, moisture and chloride ion content were conducted using mortar specimens under various conditions. As a result, in the case without carbonation, low possibility of corrosion was confirmed regardless of the environment conditions and whether or not the surface coating was applied. On the other hand, in the case with carbonation, the corrosion suppression effect was different depending on the type of surface treatment. In addition, the corrosion suppression effect could not be confirmed for the case with surface coating regardless of the environmental conditions.

 Small municipalities have needs for appointing external human resources to deal with various policy issues. Although the Government of Japan has established a system to support appointing such human resources, the factors that lead to successful appointments have not yet been clarified. Based on the corresponding author’s own experience as an advisor in Kumiyama Town, Kyoto Prefecture, this study summarizes the success factors for appointments of external human resources in policy process of small municipalities. Specifically, there are both factors related to the abilities of the personnel themselves and to the operation of the system respectively.

 Due to the climate change, the possibility of extreme snowfall in a short period of time is increasing. Therefore, it is recognized that snow removal is important to maintain daily life. However, due to the shortage of workers in the construction industry, it is difficult to uniformly remove snow from all roads. In this background, assuming heavy snowfall, it is effective to determine in advance a contingency plan indicating which roads to remove snow and which roads to postpone snow removal according to the amount of snowfall expected in the future. In this study, we develop a model that reproduces the operation of a snowplow using mixed integer programming, and propose a method to formulate a contingency plan for snowplow using the results obtained from the model. In addition, we will attempt to formulate contingency plans for actual regions.

 Structures receive thermal energy from solar radiation, and temperature differences occur between structural members due to differences in solar exposure and heat capacity. This study attempted to generate electricity from this structural thermal energy, particularly targeting the temperature difference between the pavement and decks of steel deck bridges. The thermal environment of a full-scale steel deck bridge specimen was measured, and a thermal conduction analysis using a finite element model was conducted to explore the structural design for efficiently transferring heat to thermoelectric modules. The installation position that is advantageous for power generation in steel deck bridges was investigated through experiments and heat conduction analysis, followed by power generation simulations. Finally, prototype thermoelectric energy harvesters were installed on the target steel deck bridge and verification experiments demonstrated the potential for utilizing thermal energy in structures.

 In Japan, there are two types of parking permit systems to ensure a smooth mobility environment for persons with disabilities. One is a system administered by the Prefectural Public Safety Commission and is applied on-street, and the other is a voluntary system without penalties and administered by local governments and is applied to off-street. In this paper, these systems are collectively referred to as the parking permit system, and through comparisons with systems in other countries, we clarified issues and suggested improvements to the systems. In particular, regarding off-street parking, we found that at least in the United Kingdom(England) and Germany(State of North Rhine-Westphalia), there is no applicable system and no penalties for inappropriate use of accessible parking spaces. At least in the U.S.(State of California, etc.) and France, there are systems that apply to public facilities such as commercial facilities, and there are penalties, but this does not necessarily mean that the facilities are managed properly, and the penalties are not always effective. The above findings indicate that inappropriate use of accessible parking spaces is a common issue in all countries. On the other hand, we found the possibility that penalties and other measures may be applicable to off-street parking in Japan despite legal and practical problems.

 Japan’s Strategy for Sustainable Food Systems will pave the way for enhancing agricultural productivity and promoting innovation to reduce the life cycle environmental impacts. While many demonstration tests of CO₂ enrichment on horticultural crops have been conducted aiming at yield increase and improvement of agricultural product quality, there is a lack of accumulated case studies focusing on the effect on GHG emissions reduction. In this study, we quantitatively evaluated the effects of CO₂ enrichment methods and cultivation management on GHG emissions reduction in horticulture. The results showed that 1) CO₂ enrichment could reduce GHG emissions per unit yield compared to CO₂ non-enrichment, 2) CO₂ enrichment through multi-step utilization of fossil fuels had a higher GHG reduction rate than other methods (combustion and vaporization), and 3) the combination of CO₂ enrichment and temperature control by heating system could increase GHG emission reduction rates.