212A IN SITU STRESS:MEASUREMENT

965165 Oscillatory soil response and liquefaction in an unsaturated layered seabed J. g . C. Hsu, D. S. Jeng & C. P. Lee, International Journal for Numerical & Analytical Methods in Geomechanics, 19(12), 1995, pp 825-849. A semi-analytical approach is presented for obtaining solu- tions for the pore pressure and effective stresses in a non- cohesive layered seabed of finite thickness subject to a system of three-dimensional waves. Based on the numerical results for a layered seabed, influences of soil characteristics (relative layer thickness, permeability ratio and shear modulus) on seabed responses are described. Special attention is given to the effect of placing a coarser material as a top layer for protecting an underlayer of freer sediment. The procedure can be extended to a multi-layered soil system and to the two- dimensional progressive or standing wave systems. (from Authors)

965166 Variation in a acoustic properties of rock subject to dllatuncy under snblimiting dynamic loading A. V. Mikhalyuk & E. A. Mukhin, Journal of Mining Science, 31(2), 1995, pp 97-103; translated from: Fiziko- Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, 2, 1995, pp 23-29. The dilatancy of rock under sublimiting levels of dynamic loading is accompanied by a significant reduction in their acoustic properties, which is associated with an increase in free porosity. The dependence of the acoustic properties of the rocks on their dilatance softening is stable and can be used during production for the acoustic monitoring of a change in the physical state of the mass under sublimiting dynamic loads. (from Journal translation)

965167 An elastodynamic interpretation of impact test apparatus for soils T. G. Davies & U. F. Karim, Geoteclmique, 45(4), 1995, pp 691-700. The hand-operated Odin hammer and Clegg meter apparatus and the trailer-drawn falling weight defiectometer apparatus are analysed using a model to assess their usefulness for determining dynamic in situ shear moduli. (Authors)

965168 Behavior of crystals in kimberlite and ice under the action of shock waves V. N. Beloborodov, A. L. Isakov, N. P. Kramskov & E. N. Sher, Journal of Mining Science, 31(2), 1995, pp 109-113; translation from: Fiziko- Tektmicheskie Problemy Razrabotki Poleznykh Iskopaemykh, 2, 1995, pp 35-40. Suggests that ice is a medium with high damping indices for high-frequency vibration and, hence, is a viscous material. Most salt deposits must also have the same properties. This means that the presence of large inclusions and cavities filled with ice or rock salt, say, in rock reduces the high-frequency components of the energy spectrum in the explosive wave, which means that crystals extracted by means of explosive energy remain more intact. (from Journal translation)

965169 Shock capacity of the 'southern' polymetullic deposit in Prtmor'ye Yu. Yu. Pilenkov, Journal of Mining Science, 31(2), 1995, pp 87-96; translated from: Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, 2, 1995, pp 11-22. The susceptibility of the rock mass to mine shocks is a result of leftward-shifting tectonic dislocations of the earth's core, caused by the following: recrystallization of rocks as a result of their contact metamorphism, an accumulation of potential tectonic-strain energy in the body of the intrusion; and, discrete settlement of the underworked structural blocks in the worked space of the deposit. The development of mine shocks in the deposit is basically the result of activation of the

neotectonic mobility of disjunctive faults making up the Eldorado fault zone, and definable working of the ore veins. Seasonal influxes of surface water to mine workings increases the number of manifestations of mine pressure in dynamic form. (from Journal translation)

Identification and classification

965170 The misclassification matrix: a tool for validating geotech- nical data C. P. Nathanail & M. S. gosenbaum, Quarterly Journal of Engineering Geology, 28(4), 1995, pp 381-384. The misclassification matrix offers a powerful way to establish how reliable are the measurements of a geotechnical property and how well defined are the categories in a classification scheme. Using soil strength in a case history, pore agreement was generally observed between the field description of soil consistency and the underdralned shear strength as measured in quick undrained triaxial tests on 'undisturbed' samples. A misclassification matrix was used to show the disparity between description and measurement. The sampfing process tended to result in weakening probably due to stress relief and sample disturbance effects. (from Authors)

965171 Natural classification of the high-rank coal pore structure and its application (in Chinese) Qin Yong, Xu Zhiwei & Zhang Jing, Journal - China Coal Society, 20(3), 1995, pp 266-271. Based on the existing classification of coal pore structure and data from 50 samples from 16 coal mine areas where high rank coals occurred, a classification system of the pore structure suitable to high rank coal was proposed. Pore diameter of high rank coals falls into four categories: micropore (< 15 nm), transitional pore (15-50 nm), mesopore (50-400 nm) and macropore (> 400 nm) in the light of the natural distribution of the pore structure. On the basis of the classification, the evolution and distribution of properties of pore of the high rank coal in China were discussed. (from English summary)

I N S I T U STRESS

Causes and nature of in situ stress

965172 Role of topography u d anisotropy when selecting unlined pressure-tunnel alignment B. Amadei & E. Pan, Journal of Geotechnical Engineering - ASCE, 121(12), 1995, pp 879-885. This paper shows how analytical solutions, proposed by the writers to predict in-situ stresses in rock masses with smooth and irregular topographies, can help in the selection of the alignment of unlined pressure tunnels near slopese and valley walls. It is found that the safe alignment of unlined pressure tunnels depends greatly on the extent of tensile regions in valley walls, which itself depends on parameters such as valley geometry, the degree of rock auisotropy, orientation of the planes of rock anisotropy, and the in-situ loading conditions (gravity, gravity and tectonic). (from Authors)

Measurement of in situ stress

965173 A critical review of an/n situ stress monitoring program I. H. Clark & G. L. Boyd, in: Applications of computers and operations research in the minerals industries. Conference, Brisbane, 1995, ed ANON (AusIMM), 1995, pp 451-456. Stress measurement is at the core of most stability design analyses. It is demonstrated that contrary to accepted