The inclined braceless excavation support method is a self-standing type earth retaining structure in which the active earth pressure is reduced by inclining the temporary earth retaining wall normally installed vertically, omitting the shoring such as struts and king posts. In order to apply the inclined braceless excavation support to deep excavations, the authors devised a new method of inclined braceless excavation support with inclined buttress, which is expected to increase the wall stiffness and reduce the displacement due to shear resistance of the ground, proposed design and construction methods, and verified the results of the actual construction work. With respect to the design method, the authors proposed a method that considers the earth pressure acting on the inclined retaining wall and effects of the inclined buttress wall, and its applicability was verified based on the results of centrifugal model experiments, measurements during the actual construction, and inverse analysis. In addition, the effect of the inclined buttress on the suppression of displacement was confirmed by three-dimensional FEM analysis. The applicability of the pro- posed construction method to the actual construction work was confirmed by using a press-in machine to construct the inclined buttress using steel sheet piles.

 In recent years, there has been a series of heavy rains damage was observed in Japan and they have caused serious damage such as inundation of urban areas, river overflows, and landslides. There is a need to further countermeasure for flood. On the other hand, the number of people and households in the expected inundation zones defined by the Ministry of Land, Infrastructure, Transport and Tourism and prefectural governments has been increasing nationwide, in spite of the implementation of the Master Plan for Urban Planning, which aims to avoid disaster risks and to consolidate urban functions. From this background, we examine the impact of flooding on land prices, population, and number of households in areas that have experienced flooding, using DID analysis. The results show that flood damage has a positive effect on population and land prices, indicating that the experience of flooding does not necessarily lead to a decrease in the local population.

 The case of the undergrounding of the extension of the Yokohane Line of the Metropolitan Motorway into central Yokohama is a change to the motorway project once the urban planning decision had been legally made. The Ministry of Construction which was then in charge of the Metropolitan Motorway, the Ministry of Transport which was in charge of the municipal subway system that competed with the motorway, the Metropolitan Motorway Authority and Kanagawa Prefecture, and the City of Yokohama which envisioned Odori Park as the axis of redevelopment of the city center on the same location of the motorway and subway, led a comprehensive coordination process that lasted one year from 1968. The municipality of Yokohama comprehensively coordinated those urban infrastructure projects that were competing in terms of routes and structures, based on the regional value of preserving the urban landscape supported by the citizens. In order to comprehensively implement urban development based on local values, the municipal administration led by mayor Ichio Asuka invited urban planner Akira Tamura to set up the Planning and Coordination Office, which served as the secretariat for comprehensive coordination. The purpose of this study is to clarify the comprehensive coordination process for the undergrounding of the motorway, while the details of which were unknown until when this research started.

 Many cities are hollowing out due to the progress of motorization, population decline and aging. To revitalize local socio-economic activities and solve the current situation and problems of large cities, the creation of bustling towns is being studied repeatedly. In past studies, there are many studies that focus on commerce and pedestrian space maintenance. However, the analysis of public facilities is still insufficient. Therefore, in this study, targeting cities in the Tokyo metropolitan area, we evaluated the location of each public facility around the four bases of residence, administration, transportation, and commerce, and clarified the relationship between the location of public facilities and the bustle of the city. The importance of not only the location analysis of commercial facilities but also the location analysis of public facilities is shown when urban development is carried out in the future.

 This study develops a quantitative urban model based on Fujita and Ogawa (1982) that considers traffic congestion. To this end, we show the existence of a potential function in the developed model and present an efficient numerical analysis method using the properties of the potential function. We then show that the model can explain the endogenous formation of polycentric urban configurations by analyzing the developed model in a two-dimensional lattice space. Furthermore, through an example analysis of the Kanazawa urban employment area, which consists of 1, 656 districts and 110, 000 links, it is shown that the model can efficiently perform calculations for complex road networks.

 This study summarizes analytical investigations of existing structures in a corrosive environment with a view to promoting efficient maintenance in the future. A multi-scale integrated analysis coupling material and structure was applied to evaluate the progress of salt damage deterioration on RC jetty superstructure that has been in service for more than 35 years. In addition to the previous deterioration surveys, measurements of the amount of salt that came into the structure and meteorological measurements around the structure were additionally conducted to estimate an equivalent action history for long-term evaluation. This allows to reproduce the current damage and to predict the future situation under several scenarios. Furthermore, as an example of load capacity evaluation, static loading analysis was conducted for the slab at 100 years of age to evaluate the residual load carrying capacity after material deterioration due to salt damage.

 In a replacement work of bridge deck pavements, cutting of asphalt layers causes considerable damage to the existing waterproof membrane and slab concrete. In addition, even though the waterproofing is not damaged, it will be inevitably reconstructed at that time. The present study investigated a method for repairing and reusing the thin binder layer that remains after cutting the bridge deck pavement. The cutting residual layer always has damage such as cracking and chipping, but it can be used as an interlayer by restoring the water impermeability when the existing waterproofing and slab concrete are sound. Based on this idea, the restoration method of water impermeability was assessed for the residual layer. As a result, the present study confirmed that the asphalt emulsion penetration method can close the cracks in the residual layer and restore the impermeability.

 It is important to execute appropriate traffic regulations for ensuring user’s safety against slope disaster caused by rainfall. In this study, the authors improve the framework of a methodology to determine traffic regulation standard which is proposed for setting a rainfall index value that is standard for traffic regulation. Specifically, a hazard model is proposed as a model for predicting an occurrence of slope disasters. This model can deals with unobservability, which means that a time of disaster occurrence cannot be accurately grasped. In addition, the rainfall index that should be used for traffic regulation is discussed in terms of soil moisture content and rainfall intensity. Furthermore, ”Number of missed cases” and ”regulation time” are adopted as risk management indicators suitable for this hazard model, and the regulation standard setting model is formulated. Lastly, the effectiveness of the proposed methodology is discussed by using the actual records (slope disaster, patrol inspection and rainfall) in an expressway section.

 In road management in snowy and cold regions, it is crucial to adequately evaluate existing snow protection measures. UAV-SfM surveying, increasingly used in recent years, is an efficient method for measuring snow blowdown around snow protection facilities. However, the conditions peculiar to snow cover may prevent the formation of point clouds or reduce accuracy. In this study, we focused on snow quality, downward shortwave radiation (brightness criterion), and reflectance of the snow surface. We verified the feasibility and accuracy of generated point clouds by varying the sensor size of the camera used and the altitude at which the image was captured. It was confirmed that point clouds could be created in snowy and snow-free environments without missing points. A comparison of the estimated and measured values yielded a mean relative error of −4% with a standard deviation of 2%, indicating no problem in practical use when the target is a snow blowdown.