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Nishi-Tokyo-shi, Japan

Goto K.,Tohoku University | Takahashi J.,Tohoku University | Takahashi J.,Tohoku Electric Power Co. | Oie T.,Tohoku University | And 2 more authors.
Geomorphology | Year: 2011

We investigated bathymetric data obtained at Kirinda Harbor, Sri Lanka one month before and 2 and 11. months after the 2004 Indian Ocean tsunami. Our bathymetric surveyed data and numerical modeling results suggest that the first run-up tsunami wave transported huge amounts of offshore sea bottom sediment and deposited it in a layer up to 4. m thick along the shoreface slope. In some places, this accreted sediment was not eroded by the backwash because of the particular arrangement of artificial structures and sand dunes. Especially, the sedimentation process and the volume of the sediment transported by the run-up waves can be examined where the influence of the backwash flow was very minor. Remarkable sedimentation attributable to the run-up wave would have occurred mainly by the deposition of the sediment particles along the slope by the run-up waves; the slope was developed toward the stoss side rather than by the settlement of the sediment from the suspension load. We estimated that considerable amounts of sediment were transported by the tsunami from the offshore sea bottom, but most were deposited not on land but in the sea. Eleven months after the tsunami, the harbor bathymetry had almost undergone complete reversion to its pre-tsunami condition, implying that the tsunami impact on permanent geomorphological landforms was limited at this harbor. © 2010 Elsevier B.V.

Kimori T.,Pacific Consultants Co.
SAVE Value Summit 2014 - SAVE International Annual Conference | Year: 2014

VE is widely applied to road and river projects since many improvement ideas can be generated in a short period of time by the participation of people in various disciplines to engage in concentrated discussions. Because of this, there are many requests to incorporate VE approaches on other projects. This paper examines the points to remember and effects of applying VE in the planning phase of new projects including both disaster prevention and environmental areas, discusses where to be improved, and presents a case study of actual workshop. Through this case study, the future application of VE in planning phase in public works will be presented.

Kimori T.,Pacific Consultants Co.
SAVE Value Summit 2015 | Year: 2015

In recent years, in order for early recognition of project effectiveness, public works projects in Japan have relied on methods that focus on the development of highly effective infrastructure. Furthermore, from the perspective of achieving project effectiveness early on, the importance of giving consideration to the shortening of construction periods during the project planning phase cannot be ignored. However, due to the many uncertainties with respect to construction times during the planning phase, the effective study of how to shorten construction periods is not an easy task. The author has devised a new evaluation method called the Direct Path Method (D.P.M.) which applies VE to the analysis of shortening construction periods during the project planning phase. D.P.M. is a method of extracting functions from the construction schedule to consider creative alternative plans based on those functions, allowing for the effective examination of the reduction of work time in a short period. This paper looks at the approach of this method as well as presenting a practical case example. © Copyright (2015) by SAVE International All rights reserved.

Naka A.,Pacific Consultants Co.
SAVE Value Summit 2013 | Year: 2013

Many operators are involved in providing public services in modern society. Because so many operators are involved, it is sometimes difficult to identify problems even if they exist. Although operators are sometimes aware of problems, they may not clearly specify the problems. It is not difficult for operators to get together to point out problems; however, identifying the clear definition and underlying cause of any given problem are not easy since simple discussion cannot lead to these. The technique to clarify the root cause of problems by organizing the problems using VE technique is discussed in this article. The proposed technique can be used to transform the problems into functions. Consensus building among the operators in a short period of time is achieved. The procedure and the effectiveness of the application are presented in this paper.

Tabelin C.B.,Hokkaido University | Igarashi T.,Hokkaido University | Arima T.,Nippon Oil Corporation | Sato D.,Shimizu Corporation | And 2 more authors.
Geoderma | Year: 2014

Construction of tunnels in Hokkaido, Japan often excavates rocks containing substantial amounts of arsenic (As) and boron (B). When these rocks are exposed to the environment, As and B are leached out that could potentially contaminate the surrounding soil and groundwater. Natural geologic materials contain minerals like Al-/Fe-oxyhydroxides/oxides that have As and B adsorption capabilities. Because these materials are widespread and readily available, they could be utilized in the mitigation of As and B leached out from these sources. This paper describes the ability of three natural geologic materials (i.e., pumiceous tuffs, partly-weathered volcanic ashes and coastal marine sediments) to sequester As and B from aqueous solutions and the actual leachate of a hydrothermally altered rock. The adsorption of As fitted well with either the Langmuir or Freundlich isotherm while that of B followed the Henry-type model (linear). Among the samples, those containing substantial amorphous Al and Fe exhibited higher As adsorption. However, the distribution coefficient of B only had a moderate positive correlation with these amorphous phases. The best adsorbent among these natural geologic materials was utilized in the adsorption layer of the column experiments. Adsorption of As was more effective the thicker the adsorption layer, but this retardation was only temporary due to significant changes in the pH. In contrast, the adsorption layer only retarded the migration of B to a limited extent. © 2013 Elsevier B.V.

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