Takahide Honda

An Experimental Study on Resistance of Coastal Dike with Lean Cement Mixed Soil

The tsunami generated by the 2011 off the pacific coast of tohoku earthquake caused massive damage to coastal dikes. It is required for coastal dikes to increase the resistance of tsunami. Although some coastal dikes resistant to tsunami are proposed, embankment materials which can enhance the resistance of coastal dikes are not identified clearly. In this study, embankment materials of a coastal dike which can enhance its resistance are investigated by conducting hydraulic physical model tests. The results of hydraulic tests showed that embankment mixed by cement or clay could enhance the resistance of tsunami. The numerical simulation was also conducted to clarify the erosion process of lean cement mixed soil.

Construction Techniques for Deep-water Immersed Tunnel Using Real-time Sea Strait Current Forecast

The Marmaray Project (Lykke and Belkaya 2005) in Istanbul, which provides an upgraded urban railway system approximately 76 km long with a 13.4 km underground section (see Fig. 1), is under construction to overcome Istanbul’s chronic traffic congestion. Istanbul is divided into a European side and an Asian side by the Bosphorus Strait, thus the new railway system needs to cross the strait. An immersed tunnel method was applied for the construction of the tunnel, called Bosphorus Crossing Immersed Tunnel, and it is at the present time the world’s deepest immersed tube tunnel. The tunnel elements were prefabricated off-site and towed by ship to the work-site for installation and connection to the previously installed underwater elements. The remaining parts on the Asian side and the European side are being constructed using TBMs (tunnel boring machines) and are to be connected to both ends of the immersed tunnel, which consists of 11 individual submarine elements each approximately 135 m long, 15.3 m wide and 8.6 m tall. The total length of the immersed tunnel is 1,387 m and the maximum depth of the bottom of the tunnel is 60 m under the water of the Bosphorus Strait.

REAL-TIME CURRENT FORECAST FOR TUNNEL IMMERSION WORK OF BOSPHORUS RAIL TUBE CROSSING PROJECT, TURKEY

Yukinobu Oda, Technology Center, Taisei Co., od-ykn00@pub.taisei.co.jp Takahide Honda, Technology Center, Taisei Co., hndtkh01@pub.taisei.co.jp Kazunori Ito, Technology Center, Taisei Co., kazunori.ito@sakura.taisei.co.jp Seizo Ueno, Technology Center, Taisei Co., seizo.ueno@sakura.taisei.co.jp Fumio Koyama, International Operations Headquarters, Taisei Co., f-koyama@ce.taisei.co.jp Hideki Sakaeda, Pacific Consultants International, sakaedah@pcitokyo.co.jp Claus Iversen, Avrasyaconsult, civersen@avrasyaconsult.com Steen Likke, Avrasyaconsult, slykke@avrasyaconsult.com