Rock mass classification by fuzzy sets

Rock mass classification by fuzzy sets

186A 865 ! 29 Preliminary rock classification for tunnel support requirements on the Delivery tunnel of the Lesotho Highlands Water Project de Witt, M...

102KB Sizes 3 Downloads 198 Views

186A 865 ! 29 Preliminary rock classification for tunnel support requirements on the Delivery tunnel of the Lesotho Highlands Water Project de Witt, M J; Klecan, W F: Sharp, J C Proc o f the Symposium on Rock Alass Characterization, Randburg, South .4frica, 8 "Vor 1985 P67-75 Publ South Africa: ISRM, 1985

The Delivery Tunnel for the Lesotho Highlands Water Project will be driven through weak, fine grained sedimentary rocks of the upper Karoo Sequence under relatively high cover. Requirements for rock support and speed of excavation will be strongly influenced by stress effects and the propensity for rapid degradation exhibited by the more argillaceous units. Site and laboratory investigations, rock mass characterisation and the design, to feasibility level, of rock support measures are described. The integration of the results of analyses of tunnel behaviour with geological classes identified for the scheme and with the proposed excavation methods leading to the development of guidelines for tunnel support requirements is presented. Auth.

865130 Applications of rock classifications in geological engineering Bieniawski, Z T Proc Conf on Updating Surface Samplings o f Soils and Rocks and their In-Situ Testing, Santa Barbara, California, 3-8 Jan 1982 P213-225. Puhl New York. Engineering Foundation. 1985

The major rock classifications currently in use and their classification parameters are introduced. Their applications to the engineering of tunnels, chambers and mines are discussed and it is demonstrated how rock classifications enable estimation of the strength and deformability of rock masses. Recent developments are described, including correlations between different classifications, the use of boreholc data, monitoring during construction and the use of analytical studies to back empirical techniques.

865131 Propagation of acoustic waves through cracked rock Zimmerman, R W: King, M S In: Research and Engineering Applications in Rock Alasses (paper to the 26th US Symposium on Rock Mechanics, Rapid City, 26-28 June 1985) V2. P739-745. Publ Rotterdam: A. A. Balkema. 1985

The predictions of Salganik (1973) have been shown to be consistent with the behaviour of cracked rock, after comparing changes in P and S wave velocity with pressure for various rock specimens. These equations, together with reasonable assumptions concerning the effects of fluid saturation, have been used to predict the degree of microcracking from acoustic velocity measurements in a basaltic rock mass. Some simplifications have been made. such as assumed isotropy, but the theory may be modified to account for anisotropy, at the cost of extended computing time. Initial results are plausible and appear more meaningful than simple qualitative or subjective measures of rock quality.

865132 Rock mass classification by fuzzy sets Nguyen, V U; Ashworth. E In: Research and Engineering Applications in Rock z~,lasses (paper to the 26th US Symposium on Rock Alechanics, Rapid City, 26-28 June 1985) ~ . P937-945. Publ Rotterdam: A. A. Balkema. 1985

Fuzzy set theory, in particular the aggregation procedure of Bellman and Zadeh (1970) for multicriteria decision modelling, is applied to an alternative derivation of the CSIR rock mass classification scheme, in which expert knowledge is incorporated. It is seen to give results in excellent agreement with the conventional summation scheme.

In Situ Stress Measurement of in situ stress 865133 In-situ stress determination at Ruttan mine, Sherritt Gordon Mines Ltd Pakalnis, R; Miller, H; Madill. T CIM Bull V78. N884. Dec 1985. P47-52

A methodical approach to the estimation of the orientation and the magnitude of in situ stresses is described. It was used at Ruttan Mine, Manitoba, Canada. It involves an initial estimate based upon structural interpretation, and virgin stress measurements conducted elsewhere. The verification of the prevailing stress regime was made by conducting CSIRO hollow inclusion overcoring measurements. Analytical procedures employed at Ruttan in evaluating the in situ stress magnitude and orientation, based on three overcore tests, are described.

865134 Holographic in situ stress measurement Bass, J D; Schmitt, D; Ahrens. T J Geophys J R Astr Soc 1/85. NI. April 1986. P13-41

A new instrument for measuring in situ stress in boreholes is described. The final design of this 29cm diameter in situ stressmeter, which utilizes the technique of holographic interferometry for recording data, is presented. The theoretical basis for the measurement technique, details of several calibration tests, the methodology employed in reducing and interpreting holographic data, and the results of a field deployment of the instrument in a horizontal borehole is outlined.

865135 Horizontal stress interpretation of pressuremeter tests Denby, G M; Hughes, J M O Proc Conf on Updating Surface Samplings o f Soils and Rocks and their in-Situ Testing, Santa Barbara, California, 3-8 Jan 1982 P227-244. Publ New York: Engineering Foundation. 1985

The self boring pressuremeter is proposed for measurement of horizontal stress in sampling-sensitive soils. Six methods of interpretation of results are described and their principles and limitations discussed. A case study of the use of the instrument to measure horizontal stress in oil-impregnated diatomite is presented. Horizontal stresses determined using five out of the six applicable methods are compared.

.~ 1986 Pergamon Journals Ltd. Reproduction not permitted