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Kiryu S.,JR East Consultants Company | Murono Y.,Railway Technical Research Institute | Morikawa H.,Tokyo Institute of Technology
Earthquake Engineering and Structural Dynamics | Year: 2012

An effective method for the seismic retrofitting of the sidewalls of cut-and-cover tunnels has not yet been established. Thus, a new method of seismic retrofitting for cut-and-cover tunnels, called the 'polymer isolation method', is developed here. In this method, thin walls made of polymer materials, called 'isolation walls', are inserted between the ground and the sidewalls of a tunnel. We demonstrate the effectiveness of the proposed method in reducing the seismic response of tunnels by using some numerical simulations. It is found that the proposed method depends on the thickness of the soil cover over the tunnel and the ratio of the stiffness between the soil and the structure. Furthermore, a simple chart is proposed for convenience to represent the applicability of the polymer isolation method to the design of seismic retrofits for cut-and-cover tunnels. Although this particular chart has been obtained through a limited case, some other typical cases in which the chart can also be implemented for special conditions are addressed, and the applicability and the limitations of this chart are suggested for possible conditions of the ground and of tunnel structures. © 2012 John Wiley & Sons, Ltd. Source

Mathubara T.,JR East Consultants Company | Hiroe M.,Kobayasi Institute of Physical Research | Nagakura K.,Railway Technical Research Institute
39th International Congress on Noise Control Engineering 2010, INTER-NOISE 2010 | Year: 2010

In this paper, we propose the new method, which is based on the prediction model of Railway Technical Research Institute, to predict sound exposure levels (LAE) of conventional railway at the high-rise buildings. In order to grasp vertical distribution of LAE at the high-rise buildings, field examinations were carried out at areas, in the range of 1.2 m to 25 m high from the ground and 4 m to 30 m distant from the near-side track, along two different railway lines with no barriers. From the vertical distributions of the measured LAE, we introduced the correction corresponding to the vertical directivity, which is expressed by a quadratic function of the elevation angle, to the RTRI prediction model. From verifications of the precision of noise levels predicted by the new method at these two lines, it became clear that noise levels in the high-rise buildings could be predicted within an error of about 2 dB. Source

Kimura K.,Takasago Thermal Engineering Co. | Shibata K.,Takasago Thermal Engineering Co. | Tanita N.,East Japan Railway Company | Sato M.,JR East Consultants Company | Kondo Y.,Tokyo City University
Journal of Environmental Engineering (Japan) | Year: 2015

The actual cooling load of underground stations in recent years has been much lower than the designed load thirty years ago. Therefore, it is important to estimate the actual load in the planning of cooling systems. In this study the cooling load caused by train wind in an underground station was discussed and a field measurement and computational fluid dynamics (CFD) simulation were conducted. The main conclusions are as follows: (1) The measurement showed that air volume of the train wind was greatly affected by the train speed and the tunnel structure (single or double track). (2) In the CFD simulation, the train was modeled as a moving body to simulate train wind. The CFD simulation with a pressure loss model in the tunnel could reproduce the measurement. (3) The influence of train wind on the platform cooling system was examined by the CFD simulation in terms of an influence coefficient. In the Shin-Nihombashi station, the influence coefficient was approximately 0.38 in the area connecting to the tunnel while the coefficient was about 0.24 in the center area. Source

Masumoto S.,Osaka City University | Nonogaki S.,Geological Survey of Japan | Nemoto T.,Osaka City University | Sakurai K.,Osaka Information and Computer Science College | And 5 more authors.
International Journal of Geoinformatics | Year: 2012

The purpose of the present study is to develop a three dimensional geologic modeling system on Web-GIS and to define the basic elements of the model for providing geologic information accurately and effectively. The prototype system has been developed to perform acquisition of geologic data, construction of models, and visualization of the modeling results on Web. The base system of the prototype is constructed by the integration of a mapping engine, Web-GIS client, GIS and relational database using typical FOSS4G (Free and Open Source Software for Geoinformatics) products. The main system for the geologic modeling is composed of nine functional modules. The basic elements of the three dimensional geologic model have been defined according to the arrangement of data flow of this modeling system. Further, this system has been established by the subsurface modeling using real borehole data from the Western Osaka Plain in Japan. © Geoinformatics International. Source

Matsumaru T.,Foundation and Geotechnical Engineering Laboratory | Kojima K.,Foundation and Geotechnical Engineering Laboratory | Tanaka Y.,JR East Consultants Company | Kuriyama R.,Fukken Engineering Co.
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2014

Monitoring of the deformation of earth retaining walls for excavating work is vital in order to protect the surrounding environment and to ensure the safety of structures during construction. Since it is difficult to evaluate the overall behavior with only partial measurement, it is expedient to introduce multipoint measurement. However, this method tends to be expensive. This paper introduces a system developed for evaluating and visualizing retaining walls as a three-dimensional curved surface. In order to confirm the effectiveness of the proposed system in actual monitoring, the system was applied to the on-site measurement. This paper also proposes a method of monitoring retaining walls by combining this system and simple inclinometers. Source

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