49A
Texture,structure,composition and density See also abstract: 605.
462 LONG, RP UNIV. CONNECTICUT, STORRS, USA ZIMMIE, TF Mean pore sizes from flow measurements. Technical n o t e ; 1F, IT,8R. J. SOIL MECH. FOUND.DIV. V99, $47,1973, P583" 587. A method is described for the determination of the mean pore size of a porous plug from direct current measurements amd hydraulic flows. The st1~dy deals with fritted glass disks having properties s~m~lar to a spectrum of soils remgirg from a fine sand to a silty clay, The method is applicable to soils in the same size r a r ~ and appears promisimg for inactive clays,
463 AL HASHIMI,K UNTV. AS~N, BIRMI~HAM, GB CHAPLIN, TE UNIV. BIRMINGHAM, GB An experimental study of deformation stud fracture of soil c~m~ent; 16F,2T,12R. G~QUE, V23, N4, DEC. 1973, P541- 550. Soil-cement specimens of various cement/ss~n~clay contents have been st%~lled under the action of compressive cyclic loading. An investigation has been carried ok~ into the effect of soil composition on the mode of failure. The transition from brittle mode of failure to quasi-brlt-~le as a result of c h a r ~ mg the sarzl content in %he soil is sttzlied, An experimental investigation of the elastic constants has been carried out by measuring the axial and radial str ains-~ Auth:-
hole inclusion iminciple for in-situ stress measurement in fractured rock or coal, The instrument can be checked and calibrated before use to reduce the incidence of a.nr,mal ous o r misleading instrumental results. The monograph describes laboratory developmerit only. Field applications are continuir~ at
present.
467 BOHDIA, SK PPC LTD, AMJHORE, BIHAR, IND Mechanics of fracture of rock, Proc. S~mposlum on Rock Mech. Dhanbad, Irzlia, July 1972. 4F,19R. THE INSTN. OF ENGRS, CAI~LrfrA,INDIA, 1973, P39-48. The author underlines the imlx~tance of the uniaxial compression test with an e r r a n t for measuring axial and lateral strains:
468 KCMAR, CA FROHNE, E~ Factors controlling fracture orientation in sandstone.- 48th Ann, Fall Meeting Soc. Petrol. Engng, AIME, Las Vegas, Sept-Oct. 1973. AIME, SPE PREPRINT 4~7,1973,8P. Labaratory-scaled hydraulic fracture tests were conducted on d i r e c t i o ~ l y oriented sandstone materialj along with measurements of dlrectiorml rock properties such as tensile strength, permeability, sonic velocityj and dy~m~ c elastic constants. This study shows that the expected influence of horizontal earth stress on the orientation of an imduced hydraulic fracture becomes negligible wherever the magnitude of the difference between the compressive stresses is 200 psi or less, When this occurs, fracture orientation is controlled by the directional propertie: of the rock, primarily permeability and tensile strength.
464 MOORE, DW GEORGIA INST. TECKNOL. ATLANTA, USA ORR, C GEORGIA INST. TECHNOL .ATIANgA, USA The influence of diffusion on sedimentational particle size analysis:- 5F, IT, g2. POWDER TECHNOL.VS, NI-2~ 1973, P13-17. Particle size analysis of submicrometer particles by gravity sedimentation is investigated to establish the influence of Brownian motion, Size distribution data from electron microscopic measurements are evaluated in terms of theoretical diffusion equations to determine the effect of diffusion. Auth.
Fracture processes in rocks
469. TERHLrNE,EW UNIV. OALIF •LIVEHMORE, USA SHAW, JG UNIV. CALIF. LIVERMC~E, USA Calculation of rock fracturing from multiple nuclear explosive sources. DEP. NAT. TECH. INF. S~qV. OCT. UCRL- 74017, OCT. 197 2, 38P. SOC calculations that agree with experimental measurements of t h e cavity radii, fracture initiation, and maxi~m~n extent of fracturing for the Gasbuggy and Bulison experiments are presented. Most importantly, a criterion is established that relates the n~nber of times a zore in the calculations is fractured, to those regions around the detonation where extensive fracturing is observed experlmentally. Auth.
h65 HABIB, P
Fracture of rock masses, In French, IIF,6R. ANN.INST.TECH.BATIM.ET T R A V . P U H L . ~ TO,
Strength characteristics
N306,1973,7P.
47o LAMA, RD UNIV. KAELSRUHE, D The mechanics of Jointed rocks. Proc. Symposium on Rock Mech. Dhanbad, Irzlia, July 1972. 20F,~R. THE INSTN. OF ENGRS. CALCb'fTA,INDIA, 197B, B60-85 • A review of theoretical results on behaviour of Joint~ rock masses is discussed. The interl~etations are based on the Mohr-Coulomb theory of slidlr~ alor~ Joir~ Doubts are expressed as to the applicability of this theory to brittle rocks despite of modifications introduced to fit the experimental results with the theory. The theoretical results do not take into account the complex stress distribution occurring in the Jointed materials which has been shown to chamge with the development of deformation in the Jointed syste~n; As such, the failure of the material does not take place simply by sliding alomg the existil plane due to shear alone but also due to rotation ani bendir~. The theoretical interpretations are therefor, approximate, amd give only qualitative idea about the s t r e r ~ reduction as a result of the preserve of frac~
The mechanical properties of rocks and rock masses, whether with respect to deformability or to failure stremgth, are essentially linked to cracking. The occurrence of cracks amd their development before dislocation condition the mechanical behaviour ard the permeability, hence the pore presst~es and, in part the weatherir~ of the minerals. The klmetics of slide movmnents in the m~sses depends on the possibilities of displacements allowed by the natural cracks. The exploration of a rock site is therefare intended to situate the main orientations and to find the mechanical qualities of the Joints. 466 BLACKWOOD, RL ENEVER, JR A device for measuring the complete state of stress in a rock mass. 22F,1T,13R. MAC QUARIE UNIVERSITY, SYDNEY, JAN. 1973,33P. An instrument has been developed using the soft bore-