Concrete Structures Laboratory

Concrete, Japan

Concrete Structures Laboratory

Concrete, Japan
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Nihei T.,Steel and Hybrid Structures Laboratory | Kito N.,Concrete Structures Laboratory | Kito N.,Central Japan Railway Company | Okamoto M.,Concrete Structures Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2016

A new retrofit method was developed, geared mainly for cantilever rigid-frame viaducts, which involves the installation of RC beams in each of the viaduct's columns to improve cantilever performance against strong wind loads, generated by noise prevention barriers which are higher than before. This paper describes the experiments and FEM analyses conducted to evaluate the effectiveness of this method. Firstly, confirmation was obtained that this method can be used on cantilever viaducts to increase resistance. Secondly verifications were made to ensure that that this method allows cantilevers to support barriers of about 5 m. Finally, a method was proposed which can be used to calculated the allowable bending strength using this method.


Ohno Y.,Concrete Structures Laboratory | Watanabe K.,Concrete Structures Laboratory | Kito N.,Concrete Structures Laboratory | Kito N.,Central Japan Railway Company
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2016

The application of blast-furnace slag cement concrete (BC) to PC girders is one good method to prevent ASR; however, its shrinkage and creep have not been evaluated. This paper summarizes the result of the compression creep tests executed, and shows that the shrinkage and creep of BC can be evaluated through conventional equations, usually used for normal cement concrete (NC). In addition, the analysis results indicate that even if BC is applied, the deflection and prestress loss of PC girder differ only a little from that of NC.


Tokunaga M.,Structural Mechanics Laboratory | Sogabe M.,Structural Mechanics Laboratory | Uehan F.,Structural Mechanics Laboratory | Tanimura H.,Concrete Structures Laboratory | And 2 more authors.
Quarterly Report of RTRI (Railway Technical Research Institute) (Japan) | Year: 2012

The object of this paper is to propose a method to estimate the equivalent natural period with micro-tremor measurements on the basis of the correlation between the natural frequency and the yield frequency. A method, combining the Eigensystem Realization Algorithm and some empirical hypotheses of vibration modes, was proposed for identifying the first natural vibration modes of structures. A ratio of the yield frequency to the natural frequency was mostly a certain constant value and the average value of the ratio depends on the type of structures. This paper proposes a simple procedure for estimating the yield frequency with micro-tremor measurements.


Nakata Y.,Concrete Structures Laboratory | Watanabe K.,Concrete Structures Laboratory | Tadokoro T.,Concrete Structures Laboratory | Okamoto M.,Concrete Structures Laboratory | Ikeda M.,Steel and Hybrid Structures Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2014

A number of calculation equations for the design shear capacity of steel reinforced concrete (SRC) members with simple support are given in the Design Standards for Railway Structures and Commentary (Steel-Concrete Hybrid Structures). However, there are some equations that are applicable to a certain member because the scope of application for these equations is unclear. In addition, support conditions for transverse beams on railway viaducts are different from simple supports because both transverse beam ends are fixed. In this study, the scope of application for existing equations was clarified, and an equation to calculate the shear capacity of SRC beams under antisymmetric moment distribution was proposed.

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