Existing steel girder bridges have often suffered damage in the girder ends during large-scale earthquakes. In this paper, nonlinear finite element analysis was conducted for a composite simple-span steel girder bridge to investigate the seismic performance of the superstructure subjected to lateral loading. Pushover analysis for the superstructure was performed in the longitudinal and the transverse directions with different structural details of the girder ends as analytical cases. As a result, the damage process of the components at girder ends and the strength limit states of the entire superstructure were clarified from the viewpoints of elastic limit and stiffness reduction, respectively.

 The bond behavior between steel member and carbon fiber sheet is subject to variations based on construction conditions, such as surface preparation methods and curing temperatures. However, there exists considerable uncertainty regarding how these conditions affect the bonding characteristics of carbon fiber sheets, thereby posing challenges in determining the optimal design and construction parameters for reinforcement methods. This study conducted a comparative analysis of four surface treatment methods to assess their effects on the surface properties and adhesive properties of steel substrates. It was also examined the shear strength between steel plates and composite materials. Besides, the study delved into aspects such as the hardening rate, mechanical properties, thermal properties, and fiber penetration of the impregnation resin under different environmental temperatures. Furthermore, an initial isothermal curing model of epoxy resin was constructed, while the vitrification process related to thermal history was speculated. The enhancement brought by the post-curing process on the diverse material properties of epoxy resin was evaluated. The insights of this study have the potential to significantly enhance the bond performance of steel members strengthened with CFRP materials.

 In order to collect basic data on the long-term load-bearing performance of adhesive post-installed anchors, experimental studies were conducted on the load-bearing performance of polyester resin post-installed anchors that had been used on a Metropolitan Expressway bridge for 39 years. All tensile tests failed due to bond failure between resin and concrete or a combination of bond failure and concrete cone failure. It was confirmed that the maximum loads of the tensile tests were lower than the newly installed anchor and the calculated value of bond strength (without considering of member coefficients). However, it is considered that the designed load-bearing performance is still ensured as the maximum load exceeds the allowable value used in the design.

 This paper presents a computational fluid dynamics (CFD) analysis method to evaluate the behavior of a ship in regular waves, assuming that the floating load is a pendulum. Evaluating the behavior of a ship in waves is very important from the point of view of safety and availability; in the CFD analysis, the overset grid method, which superimposes multiple meshes, is used to reproduce the motion of the ship. Periodic external forces are applied to the jib points to account for the effects of suspended load motion. The coupled motions of a hull and a lifting barge were calculated using the MBD (Multibody Dynamics) calculation method. The objective of this study is to develop a coupled motion simulation method that integrates an MBD solver and a CFD solver. Hydraulic experiments were also conducted to verify the accuracy of the analysis and to develop a two-way weak coupled analysis method to solve the time evolution of the hull and lifting motion in a wave field.

 In the design of a geological disposal facility for radioactive waste, it is essential to predict the long-term performance of the engineered barrier system. This is our motivation to develop a Finite Element code known as MACBECE. In this research, we modified the code to evaluate the mechanical behavior of the engineered barrier system after the closure of the repository. The heat generation of the waste and the reflooding process were considered. These were made possible by incorporating an elasto-plastic constitutive model for unsaturated soils and a coupling with external thermal-hydraulic analysis. The code was validated against the in-situ experiment for full-scale engineered barrier system performance experiment at Horonobe Underground Research Laboratory. The observed data were well reproduced with slight difference that may be caused by a limitation of two-dimensional analysis.

 The design of temporally retaining wall is designed through the check about the displacement/stress of the wall, the stability of the excavation bottom against heaving. The ground improvement is one of the general heaving suppressions. However, the excavation bottom is normally full-face improved, since the behavior of partially improved bottom is not clarified. In this paper, we worked on the model experiment and simulation analysis for the grid shape improved bottom. As a result, we clarified that the unimproved area of the grid shape improved bottom behaves as same as the same width unimproved bottom. In addition, we show the trial calculation about heaving of grid shape improved bottom by using the calculation method considering the above knowledge.

 Japan faces the risk of huge earthquakes such as the Nankai trough giant earthquake and earthquake centered directory under the capital. These earthquake could cause huge damage to human and property. However, long-term economic damage of GDP caused by these earthquake are not sufficiently predicted. Therefore, in this research, we try to estimate long-term economic damage caused by the Nankai trough giant earthquake and earthqouake centered directory under the capital. As a result, the 20-year economic damage coused by the Nankai trough giant earthquake and earthqouake centered directory under the capital are estimated to be 1048 trillion yen and 678 trillion yen, respectively.

 Along east-side of the Lake Biwa, the embankment constructed mainly for flood control. In addition, roadway, parks and bicycle paths were constructed along the embankment. It has transformed into an artificial landscape. Municipalities along the lake clearly states the necessity of preserving original natural lakeshore. However, evaluation criteria and conservation rules for artificial landscape are not mentioned. First, we clarified the landscape elements that each municipality places importance on landscape planning. Next, we clarified the land use after embankment construction. Finally, we clarified the diversity of the newly formed landscape and the landscape elements that would affect the impression by conducting an impression evaluation experiment.

 In 2018, a traffic accident occurred at a bus stop in Yokohama City. A 10-year-old girl who got off the bus and crossed behind the bus was struck by an oncoming vehicle. In response to it, bus stops have been relocated or removed to improve safety at bus stops in Japan. However, there has been no widespread use of cautionary measures at bus stops targeting regular drivers. In addition, previous studies and surveys have focused on crossings outside of crosswalks at bus stops, not crossings from the shadows of buses and crossings while attempting to get on a bus. This study aims to clarify the actual situation of crossings by bus passengers, focusing on crossings from the shadows of buses and on crossings while attempting to get on buses. Observations from inside buses suggested that the rate of crossing at 10 m in front of and behind buses was high at the bus stops in front of stations. Multiple linear regression analysis revealed that the rate of crossing at 10 m in front of and behind buses is higher when the speed limit is 30 km/h, when the traffic signal is far away, and when there is a non-signalized intersection on the opposite side of the road. Based on the results of this analysis, we suggested that road markings should be provided at bus stops with non-signalized intersections because they reduce the danger of both crossings from the shadow of buses and crossings from the shadow of non-signalized intersections.

 This study systematizes the promotion plans for utilizing vacant land of private properties under the land readjustment project completion in the reconstruction city area after the Great East Japan Earthquake.

 Major findings are as follows: 1) The promotion plans remained major measures even after the reconstruction project completion. 2) The promotion plans tend to publish vacant land information and to be coordinated with real estate contractors. 3)The promotion plans can be more effective measures by using relationships with landowners in reconstruction projects and implementing t with measures to promote migration and settlement.

 In this study, the distribution of shipyards and former shipyard sites in Japan was investigated, and the use of the sites and the water area were examined according to the location. As a result, shipyards and former shipyard sites were distributed mainly in western Japan. The former shipyards were located in remote areas relatively far from the city center, and the former shipyard sites in particular were located in areas where industrial land use or zoning was not defined. The trend in the use of former shipyard sites was that those located closer to the city center and the nearest train station tended to be converted to other uses. Some of the former shipyard sites were converted to waterfront parks and mooring facilities for ships, making full use of the characteristics of their location at the sea's edge.

 Digitalizing the data on intersections is essential to promote digital transformation in the field of road traffic management and governance. In this study, we developed semantic segmentation model to automatically determine the intersection components such as roadways, sidewalks, lane segment lines, stop lines, median strips, vehicles, occlusion, and others based on aerial photographs. First, we prepared the annotated data set with 11 components of intersections on aerial photographs with a ground resolution of 5 cm. Then, SegFormer-B5, which is based on transformers, was fine-tuned with our-prepared annotation data based on a pre-trained model. It was found that the SegFormer-B5 could determine the intersection components with high accuracy, while prediction accuracy gets lower for intersections where road marking is poorly managed, is located in industrial area, and has four and more legs. Regarding the robustness of prediction accuracy against the quality of the aerial photographs as input data, it was found that prediction accuracy based on the 10-cm ground resolution was comparable to the 5-cm ground resolution, while the 20-cm ground resolution dramatically deteriorates the prediction accuracy. In addition, it was revealed that the semantic segmentation model should not be applied to the aerial photographs of which the ground resolution was unknown. This suggested the importance of the robustness of the prediction model against the ground resolution, which was recommended for future work.

 To drive new services that cater to various needs during the construction phase, it is important to develop an integration platform that facilitates the interconnection of applications, as well as applications and devices, enabling seamless integration. This research focuses on the development of an API integration platform that enables seamless integration between this system and other applications. Specifically, emphasis is placed on RESTful APIs, which are commonly implemented in web applications. The requirements of an API integration platform are defined, and the workflow is systematically organized in this research. Furthermore, the necessary functionalities are developed to fulfill these requirements. To validate the developed API integration platform, scenario tests and load tests are conducted to verify the defined requirements and functionalities. Through these comprehensive evaluations, it is ensured that the implemented API integration foundation satisfactorily meets the specified requirements and functionalities.

 In order to examine the reduction plan and direction of greenhouse gases (GHGs) emissions for the decarbonization of Johkasou, we conducted a simulation analysis of GHGs emissions based on the estimation of the number of installed Johkasou based on changes in technological development and diffusion of Johkasou in Japan from FY1990 to FY2030. Based on the results, GHGs emissions from the entire Johkasou sector in FY2030 based on the BAU scenario are estimated to be -25% of FY 2013, and even if the 46% reduction in GHGs emissions in the energy sector due to the energy shift is taken into account, it is estimated that the reduction will be only 43% and the domestic target (46% reduction compared to FY2013) will not be achieved. Therefore, in Johkasou sector, technological development and new diffusional policies aimed at further reduction of GHGs are necessary.