Toyo Construction Co.

Nishinomiya, Japan

Toyo Construction Co.

Nishinomiya, Japan
SEARCH FILTERS
Time filter
Source Type

Yoneya N.,Tokyo Institute of Technology | Akira Y.,Toyo Construction Co. | Tashiro K.,Nippon Corrosion Engineering Co. | Iida T.,Nippon Corrosion Engineering Co. | And 2 more authors.
Zairyo to Kankyo/ Corrosion Engineering | Year: 2014

A new method for forecasting the current of sacrificial anodes using data assimilation was developed. In our system, In the framework of data assimilation, the system model forecasts the future state by the technical knowledge gained from experiments. The observation model corrects the forecasted result by the measurement information. In order to demonstrate the effectiveness and efficiency of our system, the verification experiment was performed at the real marine steel structures. The proposed method is expected to be a new approach for corrosion protection maintenance.


Cao Y.,Tongji University | Peng F.,Tongji University | Kotake N.,Toyo Construction Co. | Tatsuoka F.,Tokyo University of Science
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The results from the laboratory model test on reinforced sand slope were simulated numerically by the nonlinear elastoplastic finite element method(FEM) considering the strain localization; and they were compared with the results from the unreinforced sand slope. Then, the elastoplastic finite element analysis of a reinforced sand slope with facing plates was also performed numerically to understand the effect of facing by adding the facing plates into the finite element model for reinforced sand slope. In the finite element analysis, strain localization(or shear banding), strain-hardening, strain-softening, strength anisotropy and pressure dependency were considered for sandy soil. It was found that the presented finite element analysis could properly simulate the local stress-strain distribution and development of shear bands within the slopes, which could better understand the progressive failure characteristics of reinforced sand slopes, reinforcing mechanism of strips and the facing effect.


Peng F.,Tongji University | Cao Y.,Tongji University | Kotake N.,Toyo Construction Co. | Siddiquee M.S.A.,Bangladesh University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

The plane strain compression tests of dense sand reinforced with a smooth brass plate are simulated numerically with a finite element method(FEM). Considering the slippage at the interface between the sand and the reinforcement, Goodman joint elements are used as interface elements in the numerical simulation. In the finite element analysis, the effects of the following factors for sand are also taken into account:(1) correlation of confining pressure; (2) anisotropy of strength; (3) nonlinear characteristics of pre-peak strain-hardening and post-peak strain-softening; (4) dilatancy; and (5) strain localization and forming characteristics of shear zone. The results indicate that the strain-stress relationship obtained by the proposed finite element analysis is generally in good agreement with that of plane strain compression tests. It is found that the maximum stress ratio and pre-peak stiffness in the finite element analysis are quite close to the results of tests. In addition, the results also indicate that the progressive failure of reinforced sand with a development of shear zone can be reasonably examined by the proposed finite element analysis, and the interaction between sand reinforcement at the interface can be well understood.


Tatsuya I.,Nagoya Institute of Technology | Kenichi M.,Nagoya Institute of Technology | Michio M.,Toyo Construction Co. | Kazuhiro T.,Toyo Construction Co. | And 2 more authors.
Geotechnical Special Publication | Year: 2014

A coastal area in the Tohoku District was fatally damaged by the Great Tohoku Earthquake that occurred in Japan. However, the mechanism of the tsunami disaster for the coastal structure has not yet been completely revealed. In this paper, we discuss the tsunami disaster and how the multi-scaling problems and multi-phase interactions among the soil and water affect structures. Based on centrifuge tests and smoothed-particle hydrodynamics (SPH) simulations with tsunami-soil-structure interactions, the breakwater caused destabilization by scouring the seabed soil, which was a result of the tsunami seepage flow and, consequently, the ground strength decreased. Therefore, a bearing-capacity failure may occur in a breakwater exposed to long-acting tsunami forces due to the decrease in the rigidity of the seabed soil. © 2014 American Society of Civil Engineers.


Tsurugasaki K.,Toyo Construction Co. | Miyamoto J.,Toyo Construction Co. | Hem R.,Toyo Construction Co. | Nakase H.,Tokyo Electric Power Company | Iwamoto T.,Tokyo Electric Power Company
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2016

The collapse mechanism of breakwater and countermeasures under the continuous tsunami overflow were investigated using a drum centrifuge. A 1/70-scaled model, representing a 10 m high prototype breakwater, was set in the waterway in the drum centrifuge to 1) reproduce the caisson collapse mechanism and 2) investigate the effect of countermeasure by placing the embankment over the breakwater foundation mound using rubble materials and filter units. The study found that the caisson failure was due to the scouring of rubble mound and the seepage flow. Moreover, placing the embankment over the mound by using rubble materials or filter units was confirmed effective against breakwater instability. © Copyright 2016 by the International Society of Offshore and Polar Engineers (ISOPE).


Araki S.,Osaka University | Kunimatsu W.,Osaka University | Nishiyama S.,Osaka University | Furuse T.,Osaka University | And 2 more authors.
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2016

Damage to storage tanks in large industrial complexes can lead to a spill of gas or oil. In order to prevent damage to storage tanks, tsunami wave load acting on model cylindrical storage tanks are measured. The measured results show that the buoyancy is predominant in the vertical component of the tsunami wave load. The measured horizontal component of the tsunami wave load is compared with the wave load calculated by equations including a term representing velocity. © Copyright 2016 by the International Society of Offshore and Polar Engineers (ISOPE).


Matsuda T.,Toyohashi University of Technology | Maeda K.,Nagoya Institute of Technology | Miyake M.,Toyo Construction Co. | Miyamoto J.,Toyo Construction Co. | And 2 more authors.
International Journal of Geomechanics | Year: 2016

The Tohoku coastal area in Japan suffered massive damage in the Great Tohoku Earthquake, in which a prolonged major earthquake was followed by a large tsunami. The damage mechanisms of coastal structures during earthquake-tsunami events have not been fully explained. Thus, this study elucidates the damage mechanism of breakwaters by focusing on the interactions among earthquake-tsunami events, caisson structures, and soil composed of rubble mounds and seabed components. Centrifuge model tests, finite-element analyses, and smoothed particle hydrodynamics simulations with tsunami-soil-structure interactions were performed. The simulated breakwater was destabilized by not only wave pressure, but also long-acting tsunami seepage flow and overflow into the rubble mound and the seabed. These processes resulted in scour and fluidization/liquefaction, which decreased the bearing capacity. Moreover, the liquefaction resulting from earthquake motion caused caisson subsidence and excess pore water pressure in the soil components before the tsunami occurred. These problems decrease the ability of breakwaters to provide protection against tsunamis. © 2016 American Society of Civil Engineers.


Matsuda T.,Toyohashi University of Technology | Maeda K.,Toyohashi University of Technology | Miyake M.,Toyo Construction Co. | Tsurugasaki K.,Toyo Construction Co. | And 2 more authors.
15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2015: New Innovations and Sustainability | Year: 2015

In 2011, the Great East Japan Earthquake occurred and it generated a long-period earthquake motion and tsunami. Many coastal structures were damaged with instability of the bearing ground under structure due to earthquake and tsunami. However, the mechanism of the earthquake-tsunami disaster for the coastal structure has not yet been completely revealed. This paper focused on the destabilization of breakwater due to an earthquake and a tsunami. Additionally, destabilization of a breakwater due to earthquake motion and liquefaction were examined using a soil-water coupled finite element analysis based on the elasto-plasticity constitutive equation and tsunami simulation was calculated by using the particle method. In the case of a complex disaster caused by a huge earthquake followed by tsunami, when the earthquake includes long-period motion on a breakwater for a long time, the excessive pore water pressure was generated in the sandy ground and consequently liquefaction occurred. As the result, the breakwater was settled. Therefore, tsunami will overflow on the breakwater. Next, we investigated stability of breakwater that received tsunami force after the earthquake acted. The margin of bearing capacity on the breakwater was loss by the decreasing of strength in the sandy ground due to tsunami seepage when tsunami acted on it. Moreover, we discussed on the performance of the breakwater by use of numerical simulation result of tsunami flood depth in the land with damage level of the breakwater.


Enomoto T.,Toyo Construction Co.
Proceedings WODCON XX - Congress and Exhibition: The Art of Dredging | Year: 2013

Radioactive materials released into the atmosphere following the accident at the Fukushima Daiichi Nuclear Power Plant fell across a wide region of Japan. A significant portion of this radioactive fallout was adsorbed into soil particles and carried into streams and rivers, eventually accumulated on the bottoms of lakes, reservoirs, and other bodies of water. Little is known at this point regarding the distribution and characteristics of the radioactive materials and the soil particles to which they were adsorbed. Our research seeks to identify and develop technologies for decontaminating such benthic sediment and reducing the volumes of contaminated soil. As part of these efforts, rather than drawing on new and special mechanisms, we explored ways to achieve the decontamination desired by modifying and combining existing dredging and dehydration technologies. This study focuses on the following aspects of soil decontamination and soil volume reduction technologies: (1) Understanding the distribution of radioactive contaminants (2) Soil decontamination technologies (3) Soil volume reduction technologies. © 2013 WODA.


Miyamoto J.,Toyo Construction Co. | Miyake M.,Toyo Construction Co. | Tsurugasaki K.,Toyo Construction Co. | Sumida H.,Toyo Construction Co. | And 3 more authors.
Proceedings of the International Offshore and Polar Engineering Conference | Year: 2015

This paper discusses the experimental findings pertaining to the instability of breakwater foundation during huge tsunamis. A tsunami experiment system in a drum centrifuge was applied to reproducing the tsunami-induced seepage flow in the mound. The emphasis is placed on observations of the occurrence of seepage-induced instabilities in the mound around the toe of the caisson. It was found that the seepage-induced instability of the foundation could bring about the significant displacement of the caisson, leading to the breakwater failure. The scour of the rubble mound and erosion of the sand bed were also observed under continued tsunami overflow. Copyright © 2015 by the International Society of Offshore and Polar Engineers (ISOPE).

Loading Toyo Construction Co. collaborators
Loading Toyo Construction Co. collaborators