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Yokoyama J.,Hokkaido Regional Development Bureau | Kasai H.,Hokkaido University | Furuya A.,Hokkaido University | Yoshimizu M.,Hokkaido University
Nippon Suisan Gakkaishi (Japanese Edition)

To control the hygienic conditions of fishery products from catching to landing and processing, both qualitative and quantitative bacterial observations at fishing ports must be considered. Thirty-six fishing ports in Hokkaido, northern Japan, were selected and the distributions of coli form bacteria were studied at these sites. Coli forms were observed from all fishing ports, and Escherichia coli were observed from 30 fishing ports. Especially, in relation to the number of coli form bacteria and E. coli, fishing ports which are located near a river show higher levels than any other fishing ports. Source

Saito H.,Hokkaido Regional Development Bureau | Date K.,Kajima Corporation | Narita N.,Kajima Corporation | Yamamoto T.,Kajima Corporation | And 2 more authors.
ISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014

The Kitanomine Tunnel (tentative name) will be a 2928m-long tunnel in Furano City, part of the Asahikawa-Tokachi Road running N-S in central Hokkaido. The area that surrounds the tunnel is rich in water resources. Thus, a 740m-long watertight structure is designed in the middle of the tunnel alignment to minimize the impact of the tunnel excavation on the groundwater environment. It is expected that the groundwater level will be recovered in the long term due to the watertight structure which does not allow the groundwater to flow into the tunnel. At the south end of the watertight structure section, pre-grouting had been conducted from the ground surface before the section was excavated. The length of the pre-grouting section was 200m. Nano-fine cement grout and chemical grout were injected into sandy soil and highly weathered welded tuff to decrease the permeability and improve the stability of the ground. In this paper, we report the quality assessment of the grouting effect conducted by resistivity tomography and in-situ permeability tests. The results of the both investigations concluded that the grout had been injected into the ground homogeneously as designed and the pre-grouting actually decreased the permeability of the original ground. Furthermore, we report the result of the excavation of the pre-grouting and non-pre-grouting sections. By observing the tunnel face continuously, it was reconfirmed that the nano-fine cement grout permeated homogeneously into sandy soil and highly weathered welded tuff as designed. In addition, the amount of water inflow was smaller than management standard value. In the non-pre-grouting section, however, the water inflow into the tunnel significantly increased, which required additional grouting from the tunnel face. © 2014 by Japanese Committee for Rock Mechanics. Source

Miyafuji H.,Chiyoda Corporation | Hirai Y.,Civil Engineering Research Institute CERI | Suzuki Y.,Hokkaido Regional Development Bureau
Journal of Disaster Research

The Hokkaido Regional Development Bureau organized the Committee for Conservation of the River Environment in the Kushiro Wetland in 1999. The Committee summarized and released an epoch-making proposal for conservation of the river environment of the Kushiro Wetland in 2001. Governments and other organizations have since conducted measures based on the proposal for restoring and conserving the Kushiro Wetland. In 2011, river restoration in the Kayanuma area, one of the most symbolically important measures, was completed and various monitoring research is being executed. This report discusses specific effects of the project. The Kushiro Wetland has the function of a natural flood control basin and reduces the risk of damage by flooding. Work to restore and conserve the KushiroWetland thus greatly contributes to maintaining the function of flood control. This report also discusses specific contributions to flood control by the Kushiro Wetland. Source

Hayashi H.,Japan Civil Engineering Research Institute for Cold Region | Nishimoto S.,Japan Civil Engineering Research Institute for Cold Region | Yamanashi T.,Hokkaido Regional Development Bureau
Soils and Foundations

This paper describes the applicability of a method, proposed by Noto (1991a), to the prediction of the settlement of a peaty ground from an engineering viewpoint. The settlement of peaty grounds cannot be fully explained by Terzaghi's theory. Noto proposed a method for predicting the settlement behavior in peaty grounds on the basis of the statistical analyses of numerous oedometer test results. For the purpose of verifying the applicability of the Noto method, data on the settlement of full-scale test embankments, built in Hokkaido, Japan, were compared with predictions obtained by this method. The comparison quantitatively revealed the primary consolidation rate and the coefficient of secondary consolidation of the peaty ground as well as the prediction accuracy of the Noto method. © 2016 Japanese Geotechnical Society. Source

Munehiro K.,Japan Civil Engineering Research Institute for Cold Region | Kageyama H.,Traffic Engineering Research Team | Takahashi N.,Traffic Engineering Research Team | Watanabe M.,Traffic Engineering Research Team | And 2 more authors.
19th Intelligent Transport Systems World Congress, ITS 2012

Traffic smoothness must be ensured through winter road management. The average travel speed is an index of traffic smoothness. In this study, we used taxi probe data to obtain average travel speeds in the Sapporo urban area for a year, and analyzed the relationship between the average travel speed and various winter weather and road surface conditions. Also, we calculated the monetary value of the increase in average travel speed afforded by snow and ice control operations. We had acquired taxi probe data 365 days from April 1st, 2007 to March 31st, 2008, with the cooperation of a taxi company. Differences in average travel speed between the winter season and the non-winter season have been found to vary depending on weather and road surface conditions. Our survey has found that snow and ice control operations increase the average travel speed of road users. Improved average travel speed increases the benefit of the road for road users. Our cost-benefit analysis of snow and ice control operations for national highways in Sapporo found that the estimated benefit of snow and ice control operations exceeded the cost of such operations. Source

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