Struggle with permafrost. In Russian

3F,4T,14R. KYOTO U ~ I V . D I S A ~ PREVENT.RES.INST.BULL.V23,N2, AUG. 1973, P27-45. The results of observations of vibrational strains in esrthquskes using strain seismographs are presented. The data, from 1966, has been analysed amd the maximum amplitudes of these strains are related to their seismic magnitudes and focal distances. According to this relation the coefficients with respect to attez~tions of maximum amplitudes f~r focal distances are almost equal to i except for a few events of the near earthquakes. 1384 TAYLOR, CL WOODWARD-LUNDGREN, 0AEIAND, CALIF. USA BROGAN, GE WOODWARD-LUNDGREN, OAKLAND, CALIF. USA Classification of fault activity for engineerimg purposes. Proc. llth Ann.Symposi~n Engng.Geol. ard Soils Emgng. Idaho, 1973. Abstract only. IDAHO DEPT. HIGHWAYS, NOV. 1973, P123. A classification of the degree of fault activity based upon geological, seismologicalj anl historical criteria is presented. The historical criteria are developed from a review of evidence contained in existing literature. Four main categaries of fault activity roam be assigned: active, potentially active, activity uncertain, ar~ inactive. Depeniing upon the assigned categc~y and the significance of the fault to the proJect, it may be necessary to refine the classification by comdueting f t u ~ e r studies. This system of classification provides the capability to define the degree of fault activity from available data and to refine the classification as additional and more reliable information becomes available.

1385 GUPTA, HK NAT. GEOPHYS. INST. HYDERABAD, IND RASTOGI, EK NAT. GEOPHYS. INST. HYDERABAD, IND Will anothar damaging earthquake occur in Koyna. IF, TRo NA~JRE,V248, ~5~5,15 MAR.1974,P215-Z16. It is now well known that fillir~ of large artificial lakes behind high dams can trigger earthquakes. Before the construction of the Koyna Dam in the western part of the Peminsular Shield of ludia no s~gnlflcant tremor had been recorded. Soon after the impoumdlmg of the Koyna reservoir in 1962 r e l x ~ S on tremors started to accumulate. The present seismic activity irzlicates a possibility of a strong earthquske in the Koyna region and the seimmic activity co~relates with the increased reservoir levels.

1388 TEI SSEYRE, R INST. GEOPH. POL. AC. SC I.WARSAW, PL Earthquake processes in a micromorphlc continuum.4R. REV. ROUM. GEOL •GEOGR. SERIE DE GEOFH.VI7, N2,1973, PI45148. The paper introduces a new model of earthquake mechanism based on the theory of micromorphic contir~la. The processes in a focal region are described by deformations of microstrueture in time. The micromorphic mechanics considars the existence of body couples as determined by regional stresses ar~ looks after a response field of stresses, stress moments amd strains in the focal region. It is explained how the mlcrodlslocation field is connected to mierodeformatlons and micromorphic structure. 1389 HA~SON, BC Earthquake related stresses at Ramgely, Colorado. Symposit~m. In New Horizons in Rock Mechanics. 9F, ST, 12R. PROC.14TH SYMPOSIUM ON ROCK MECHANICS, ASCE, NEW YORK, 1973, P689-708 • The investigation of the Rangely oil field has shown that artificially raised reservoir pressure in the neighborhood of a fault could initiate sliding amd trigger earthquakes. The pore pressure along the fault at the site and depth where most earthquake focl were located has been monitored. The hydraulic fracturing method was used to determine the in-situ stresses in the vicinity of the fault at a depth of more than 6,000 ft. below surface. The stress distribution obtained was in accord with the theoretically expected condition for the existing strike-slip fault and its right-lateral slip. The results shc~ed that a serious danger of sliding along the fault would exist if the pore pressure were brought up to about 3500 psi. Pressure monitoring of the seismically active part of the fault confirmed this result. With some limitations, the method of hydraulic fracturing appears to be suitable for stress measurements along other active faults where critical pore pressures could thus be predicted stud hopefully prevented.

Frost action,permafrost and frozen ground See also abstracts: 1376,1483,1521,1539. 1390 FILIPPOV,E Frozen ground excavation. In Rtlssian. ~FROITEL, Ng, 1973, P22 - 23.

130 DROSTE, S INST. GEOPH. POL. AC. SCI .WARSAW, PL TEISSEYRE, R INST.GEOPH. POL. AC. SCI .WARSAW, PL Analysis of the signs of first impulses in the case of a three-dimensional station network. 2F. REV.ROUM.GEOL.GEOGR. SERIE DE GEOPH.V17, N2,1973, P14~153. It is eo~mon to establish seismographs in boreholes, mines or deep tunnels for assessing local seismlcity. Such a station system forms a three-dimensional network. The advantage of a three-dimensional network becomes evident when a system of co-ordinate planes drswn from each station is cutting a seismic region into relatively small parallelepiped blocks. Examples based on data from the Upper Silesia are presented; 1387 MAAZ, R 0ENTR. EARTH PHYS. INST. JENA, DDR PURCARU, G MIN.RES. INST. BUCHAREST, R On the magnitude distribution and prediction of earthquakes ° 25R. REV.ROUM.GEOL.ET GEOGR. S ~ I E DE GEOPH.V17, N2,1973,

P155-163. The pape~ considers the lognormal distribution of the magnitude (energy) from the point of view of earthquake prediction.

1391 ANONYMOUS Frozen ground excavation. In Russian. STROITEL, N I t 1973, P23- 25 •

1392 SOLDATENKOV, V Struggle with permafrost. In Russian. STROITEL, NI0,1973, p24- 25 • 1393 NIKOLSKII, E Determining the effectiveness of methods of artificial thawing of frozen ground. In Russian. STROITEL, NIO, 1973, PB1.

13~ SURIN, NA PRILEI~KO,AI GRITSYKIVI Layers of granulated slag far preventing frost heave. In Russian. PUT ! PUTEVOE KHOZIAISTVO, NI2,1973,1~-I0.