TUNNELLING UNDER DIFFICULT CONDITIONS. PROCEEDINGS OF THE INTERNATIONAL TUNNEL SYMPOSIUM, TOKYO, 1978

(Continued from TRIS No. 325112). Construction of the enasan tunnel and the design of the second stage (yano,t, yamada,w and suzuki,i); excavation of tunnel through fractured zone with large quantity and big head of ground water (fujita,k, ueda,k and gomi,m); prevention of accidents in difficult tunnelling conditions by means of specialized techniques such as grouting, drainage, umbrella arch methods (jurge,gr and mouxaux,j); tunnelling under high water pressure in soft ground (yokoyama,a); problems associated with heavy water leakage during construction of large area tunnels in granite, limestone and chalk (jansson,g); application of the natm to the nakayama tunnel (yagi,y); underground securing system with synthetic resin anchors reinforced of glass fiber (brandstetter,fp); chemical grouting treatment to allow the excavation of tunnels in rocks affected by infiltrations of toxic gas under pressure (restelli,ab); construction of railway trunk line tunnels under major cities using the shield method (niwa,t); construction problems in water tunnels in the republic of South Africa (keyser,dj and krige,nm); tunnel excavations in faulted gneiss (kalkani,ec and labropoulos,cd); examples and research aspect for dearth of water caused by railway tunnelling in Japan (ishizaki,a); rock tunnelling in urban areas with preservation of ground-water table (braennfors,s and nord,g); boring device for recording soil data to avoid pollution due to grouting and to predict unfavorable tunnelling conditions (mouxaux,j); blast vibration control in residential area (nagano,h and ishii,t); new subway construction processes aimed at reducing environmental destruction to a minimum (watanabe,t); tunnel excavation through bad soil in urban area (kitayama, n and fukumitsu, k). Continued on TRIS 325114. (TRRL)