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Atsubetsu ku, Japan

Fukuda T.,Geoscience Research Laboratory Co. | Takahashi T.,East Nippon Expressway Ltd. | Yamada H.,Konoike Construction Co. | Jiang Y.,Nagasaki University
Harmonising Rock Engineering and the Environment - Proceedings of the 12th ISRM International Congress on Rock Mechanics

In the design phase of the tunnel, various mechanical constants and their distribution are estimated after comparing research and exploration results with rock mass classification. Based on the estimation, the support pattern is selected and appropriate materials are suggested by numerical analysis, if necessary. In this study, from the perspective of advanced observational construction, we describe the identification of rock physical properties by back analysis and the predictive analysis of long-term deformation of tunnel lining targeting on the tunnel with large deformation. As a result, the most appropriate support pattern was determined by identifying rock physical properties, and an example of long-term predictions of tunnel lining deformation could be presented. © 2012 Taylor & Francis Group, London. Source

Porous asphalt has spread widely across Japanese expressways as the standard surface course material since 1998, greatly contributing to the decrease in the number of traffic accidents on wet surface conditions. On the other hand, due to rainwater penetration through the porous surface, water sensitivity of the binder course layer becomes a key issue to secure its durability. This paper summarises the successful performance of porous asphalt surface courses based on a long-term survey over nearly 15 years in fields, also describing the negative impacts of porous asphalt. The experience shows that the durability of the binder course should be taken into consideration when a porous asphalt surface course is applied over old existing roads. This is vitally important if porous asphalt is to perform its excellent functions over a full service life by avoiding unexpected damage of the pavement. © 2013 Copyright Taylor and Francis Group, LLC. Source

Hagiwara M.,East Nippon Expressway Ltd. | Mizuno A.,Kogakuin University | Tsutaki T.,Kogakuin University | Takahashi K.,FITUT Laboratory Co.
BHR Group - 14th International Symposium on Aerodynamics and Ventilation of Tunnels

In the semi-underground portions there is an exchange of air through the gaps of the structure over them caused by the traffic and natural wind. This breathing phenomenon has been studied and estimated so far, but they don't refer to the influence of the structure over expressways on the breathing. We adapt the 3D numerical simulations with the traffic included in it to a certain semi-underground road with a complex overhead structure such as beams and roofs in order to estimate their influence on the breathing. In this paper we present some of the results and then discuss them. © BHR Group 2011. Source

Akiyama M.,Waseda University | Abe S.,Obayashi Corporation | Aoki N.,East Nippon Expressway Ltd. | Suzuki M.,Tohoku University
Engineering Structures

In this study, a prestressed reinforced concrete pile that uses high-strength material to increase the pile's flexural capacity was developed. The main structural characteristics of the developed pile include (1) the neutral axis is constantly near the centroidal axis of the pile, even if the longitudinal reinforcement yields due to a flexural moment, because the pile has a high axial compressive force that is induced by prestressed steel bars, and hence, the concrete in the compression region can contribute to increasing the flexural strength of the pile; and (2) the flexural strength of the pile increases because the high-strength concrete is confined by high-strength spirals and carbon-fiber sheets in combination with concrete infilling, and, together, these modifications provide a sufficiently high lateral-confinement pressure. The results of bending tests demonstrate that the proposed prestressed reinforced concrete pile with carbon-fiber sheets and concrete infilling had a much higher flexural capacity than a conventional precast concrete pile. In addition, an analytical approach is presented that can be used to obtain the relationship between the bending moment and the curvature of the proposed pile. Even if concrete bridge systems are constructed on strata that can experience soil liquefaction, such as very soft soil, bridge foundations that use the proposed piles could remain undamaged under the design seismic action. © 2011 Elsevier Ltd. Source

Fukada S.,Kanazawa University | Usui K.,Fuji Engineering Co. | Yoshimura T.,Kobe Steel | Okada T.,Kobe Steel | And 2 more authors.
Journal of Civil Structural Health Monitoring

An environmental vibration problem occurred at a house near a highway bridge on soft ground. Vibration experiments with a test truck were performed to investigate the cause of the problem and the vibration characteristics of the bridge and house. Experimental results showed that the house was resonating with the bridge. As a measure to reduce vibration, viscoelastic dampers were installed at the ends of the bridge girders. The effectiveness of this measure was evaluated by comparing the data gathered before and after the installation of the dampers using ordinary trucks running over the bridge. Moreover, a dynamic response analysis was carried out to investigate the vibration reduction as a function of the number of installed dampers as well as the various analytical conditions employed. Simulation results showed that the vibration reduction depends on the boundary condition, running position, and torsion modes that have a coupling vibration between the superstructure and the piers. © 2012 Springer-Verlag. Source

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