133A

elastoplastic effects. It is concluded that temperature or pres- sure cycling will invalidate solutions based on conventional approaches with only monotonic pressure and temperature changes.

Tunnels

See also: 932100, 932265

932474 Kun-etsu Tunnel, the longest highway tunnel in Japan In: Rock Mechanics in Japan, Vohane VI P96-98. Publ Tokyo: Japanese Committee for ISRM, 1991

The twin bore tunnel, approximately 1 lkm long, runs through predominantly quartz diorite and hornfels rocks which have undergone complex orogenic movement and remain highly stressed. Rockburst was encountered when driving the first tunnel at overburden thickness about 700m. AE monitoring of the second bore allowed rockburst prediction and suitable pre- ventative support installation was undertaken. Average pene- tration rate of 150m/month was achieved in the second bore.

932475 Construction of underground space by a new shield tunnelling method: spiral tunnelling and ramification of multi-circular face shield Sonoda, T; Hagiwara, H; Osaki, H; Noguchi, T; Nakamura, M Tannlg Underground Space Teclmol V7, N4, Oct 1992, P355- 361

Cost and space restraints favour the use of multi-circular shield tunnelling in certain circumstances. The H & V (Hori- zontal and Vertical) Machine concept is illustrated. Two articulated shield tunnelling machines are jointed together such that their cutter face plates will be in the same plane. The front bodies may be articulated separately and a cross articu- lation mechanism allows alignment to be changed so the tun- nels are vertically separated, horizontally separated, or allowed to diverge. Linings for joined or separate-type drives are described. Examples of the use of the machine are illustrated.

932476 Tunnelling the Cairo Metro Line No. 2 Abdel Salam, M E Tannlg Underground Space Teclmol V7, N4, Oct 1992, P407- 413

The Cairo Metro Line No.2, currently under construction, will pass under a high water table and through alluvial soil of complex nature. The route crosses crowded urban areas. The geological profile along the proposed alignment is illustrated. Design criteria and criteria for the choice of construction method - cut and cover or shield tunnelling - are discussed.

932477 Tunnelling using earth pressure balance machines for the Boulae Spine Sewers of the Greater Cairo Wastewater Project Flint, G R Tunnig Underground Space Tecimol V7, N4, Oct 1992, P415- 424

6.2km of 2.87m and 2.20m internal diameter tunnel has been driven under Cairo by two Earth Pressure Balanced Tunnel- ling Machines for the Boulac Spine Branch Sewer. Tunnel design and the specially developed lining segments, machine design, and overall and maximum driving rates achieved are

described. Settlement effects in the crowded urban area were minor and not generally significant. Machine performance exceeded expectations.

932478 Lesotho Highlands Water Project: Doable benefit for southern Mrica Darling, P Tun Tannlg V24, N9, Sept 1992, P20-24

The background and initial stages of construction of this major project are outlined. Over 70km of tunnel will be exca- vated, about 40km in the Lesotho Formation (mainly basaltic lava), about 20km in the Clarens Formation (mainly sand- stone) and the remainder in Elliot, Molteno, or Beaufort Group sedimentary rocks. The project will be developed in 4 stages. The bulk of the tunnelling will be by TBM, with drill and blast or cut and cover for syphon sections and lead-ins. The proposed construction scheduling is described.

932479 Hi-tech head start in Liverpool Abott, R Tann Tanalg V24, N9, Sept 1992, P27-29

The Mersey Estuary Pollution Alleviation Scheme (MEPAS) is a 21km long tunnelling project along the shores of the estu- ary. It is beipg constructed in 5 phases. Stage 2 in the city centre area is described. The 4.3km long, 2.4m final diameter section was driven using a computer controlled, laser guided, shielded roadheader to cut through the Sherwood Sandstone. Bolted tapered trapezoidal segments form the lining. The only area of geotechnical difficulty, an old tributary of the Mersey, was foreseen, and breasting plates were used to traverse the soft silty ground.

93248O High-speed tunnelling through the Chilean Andes Darling, P Tunn Tannlg V24, N9, Sept 1992, P39-41

The construction of a supply tunnel to maintain the level of Lake Chapo and ensure adequate water for the Cantutillar Hydroplant is described. The Rio Lenca Tunnel, 9.2km long and 10 sq m section, will run through granite, diorite, and gabbro. The ground is similar to that of the original power plant tunnels and pre-excavation work was kept to a mini- mum. High speed drill and blast is being used as this is consid- ered safer than TBM drivage where geology is not well established, and has enabled almost immediate start of tunnel- ling. Support is by shotcrete, bolts, and mesh.

932481 Trenchless pipe installation for house connections up to diameter 150mm with guided and unguided boring systems Hupertz, H Proc 2nd International Symposium on Microtuanelling, Munich, 8 April, 1992 P23-25. Publ Rotterdam: A A Balkema, 1992

Trenchless installation of pipes up to 100ram diameter and 30m in length is usually possible with an unguided system based on a soil displacement hammer. Where greater length and diameter, curved drives, or perfect installation accuracy are required, steerable systems are necessary. Suitable machin- ery is described: a lightweight fluid-assisted drilling system for sand, clay, and loam soils with minimal stone content and a combined hydraulic pushing unit and percussive hammer for use in gravelly and stony grounds.

© 1993 Pergamon Press Ltd. Reproduction not permitted