188A

894150 Comparative stress measurement by two overcoring methods in deep holes in Siilinjarvi Mine, Finland Vaatainen, A; Sarkka, P Proc 6th International Conference on Rock Mechanics, Montreal, 30 Aug-10 Sept 1987 V2. P1289-1294. Publ Rotterdam." A A Balkema, 1987

Triaxial stress measurements were made using the techniques of the Swedish State Power Board with the Leeman Hiltscher gauge and that of Interfels, both of which are based on the Leeman calculation method. Results are presented and dis- cussed in terms of field practicality, costs,ease of use and likeli- hood of stress results.

Remote sensing and photographic techniques

894154 Bayes classification of terrain cover using normalised polarimetric data Yueh, H A; Swartz, A A; Kong, J A; Shin, R T; Novak, L M J Geophys Res V93, NB12. 10 Dec 1988, P15261-15267

Multifrequency, incidence and polarisation backscatter data from airborne or satellite radar are available for geological mapping or vegetation discrimination. A normalised polarisa- tion classifier based on Bayesian principles is described, which is seen to generate classification errors smaller than those which employ only magnitude ratios or phase differences.

894151 Two examples of stress measurements by the HTPF method Cornet, F H Key Questions in Rock Mechanics: Proc 29th US Symposium, Minneapolis, 13-15 June 1988 P615-623. Publ Rotterdam: A A Balkema. 1988

The Hydraulic Tests in Preexisting Fractures (HTPF) tech- nique is discussed, and two examples illustrate how in situ stress measurement costs can be reduced by concentrating only on the relevant components of the stress tensor. The first considers a pressure tunnel in a mountain flank where none of the principal stresses is vertical; the second is in a heterogene- ous potash deposit, in which the stress field does not vary linearly with depth.

894152 Application of hydraulic fracturing to the assessment of lining requirements for a pressure tunnel Enever, J; Wooltorton, B; Johnson, M Proc 6th Australian Tunnelling Conference, Melbourne, March 1987 VI, P109-I18. Publ Parkt'ille: AuslMM, 1987

Hydraulic fracturing stress measurements were made in sur- face drill holes along the alignment of the King River Power Tunnel. A significant horizontal stress field was found remote from the power plant, with a corresponding absolute mini- mum stress magnitude approximating to depth of cover over- burden pressure. Closer to the plant, towards the bottom of the valley, a destressed region with minimum stress less than overburden pressure was detected. The possible requirement of steel lining to prevent loss of hydraulic head in this region is assessed.

Site Investigation and Field Observation

See also: 894285. 894372, 894404, 894405, 894406, 894420

Structural and geotechnical mapping

See also: 894219

894155 First R.M. Hardy Memorial Lecture: Fracture lineament research and application on the western Canadian plains Mollard, J D Can Geoteeh J V25, N4. Not" 1988. P749-767

Fracture lineaments are composite linear features mapped from the air whose patterns seem linked to crustal movements reflecting fracture systems and structures in the underlying rocks. Work over the last 40 years into their origins and char- acteristics is outlined. Characteristics described include surface expressions, hierarchical ordering, set orientations and stress regimes and pattern anomalies. Correlation of fracture linea- ments and subsurface data is described. Application of photolineaments in problems such as slope stability, petro- leum exploration, groundwater investigation and waste dispo- sal is discussed. 113 refs.

894156 Engineering geological mapping as part of the NATM (In German) Naumann, G; Prinz, H Felsbau, V6, N4, Nov 1988. P174-183

Safety during NATM excavations should be controlled not only by continuous monitoring and in situ measurement, but also by continuous engineering geological mapping. Methods of systematically organising mapping are illustrated, and com- bining this information with previous geotechnical models and continuous updating as excavation progresses is discussed with reference to case studies.

894153 Analysing soil test results from the field and laboratory for foundation purposes - Nigerian experience Aborowa, R Proc Ninth Regional Conference for Africa on Soil Mechanics and Foundation Engineering, Lagos, September 1987 VI, P263.269. Publ Rotterdam: A A Balkema, 1987

A general review of field and laboratory tests used to deter- mine soil geotechnical properties is presented. Three case stud- ies of foundation analysis in Nigeria, and techniques employed, are discussed.

894157 Microcomputer-assisted drawing of geologic cross sections Guth, P L Math Geol V20, N8. Not, 1988, P991-1000

The program CROSSX which automates much of the process of drawing geological cross sections is described. The program can calculate and display stratigraphic thickness, allow calcu- lation of structural information from the Digital Elevation Model (DEM) and draw a properly scaled topographic profile. The DEM, program operation and technical details are outlined.

1989 Pergamon Press plc. Reproduction not permitted