A REPORT ON THE CONSTRUCTION OF SAKANASHI TUNNEL ON TOHOKU EXPRESSWAY - WATER NON-SPRINKLING SNOW MELTING

Japan's national expressways are constructed and operated by Japan highway public corporation (nihon doro kodan) and the order of construction is given by the construction minister. The total length of expressways completed for the fiscal year 1986 is 3910 km, which is about half of the planned expressway network. The tohoku expressway is a 674.7 km long national expressway which has its origin in Tokyo metropolitan area and ends at aomori city, running from South to North through the northern part of Japan. The whole of the expressway was opened in July 1986. A new snow melting system was introduced to the 4.2 km long sakanashi tunnel which is located in one of the most severely cold weather regions along the tohoku expressway. This system is the first of its kind to be adopted for expressways to melt snow on roadway surface by using ground water flowing out from a tunnel. This article reports on the system. (TRRL)