Microearthquake recording for engineering applications

81A understand exactly what ~s measured by these techmques

853113 Analysis of lithologicai descriptions using a simple numerical code D~ckmson, W W J Sediment Petrol V54, N2, June 1984, P638-641 A s~mple three &gat numerical code for the macroscopic descnptton of se&mentary rocks ~s described The code may be used, m conjunction w~th the computer program LOG-PLOT, to graphtcally deptct htholog~es and, w~th addmonal apphcaUon of easily available statistical programs, to process large amounts of core or outcrop data for se&mentolog~cal interpretation

853114 Roller micrometer analysis of grain shape Harrell, J J Sediment Petrol V54, N2, June 1984, P643-645 A roller m~crometer ~s described which will easily determine the smallest dmmeter of sediment grams

853115 Quick field measurement of particle size Bflh, P J Sediment Petrol V54, N2, June 1984, P658-660 The relatwe accuracy of particle s~ze measurement using templates w~th both round and square holes was examined Round hole tests always gave results closer to the curve of particle s~ze measured by calhpers

853116 Engineering classification of rock masses for New Austrian Tunnelling Method Ch~shakl, T, Taguch~, M, Hlrata, T, Smto, M, Takasak~, H, Alkawa, A Mere Fae Engng Kynshu Univ V44, N1, March 1984, t)41-54 Usmg data obtained from prewous use of the NATM, a new rock classification system, based on geology, elastic wave velocity, state of cracks and groundwater flow, has been derived

853117 Derivation of a diggability index for surface mine equipment selection Scoble, M J, Muftuoglu, Y V Min Sci Tecimol V1, N4, Aug 1984, P305-322 A dlggabd~ty rating index has been produced, taking into account weathering, strength, joint and bedding spacing of rocks and mechamcal capabdmes of excavation machinery The work was supported by back analysis of several excavating case stu&es

Geology Environmental effects, weathering and soil formation 853118 Quantitative evaluation of weathering processes in relation to engineering hehaviour of soils Raymahashay, B C In: Engineering Geosciences, edited by B B S Singlml P34-40 Publ Meerut, Indta Sar~ta Prakashan, 1982

Weathered Deccan basalts were examined by gram size analysts and geochemical analysis Specific gravmes, plastic, hqmd and shrinkage hm~ts, water content, actw~ty and degree of decomposmon were measured Under tropical condmons highly plasuc montmonllomte-nch black softs are formed Upland weathering gaves a red soft with a h~gh concentration of ~ron oxides The geochemical mobility of elements is used to explain th~s Slmdar examination of weathered slate from areas prone to and free from landshdes showed shde free areas to have a greater percentage of clay s~ze particles and h~gher water content

853119 Thermodynamic interpretation of weathering indices and its application to engineering properties of rocks Hodder, A P W Engng Geol V20, N3, Aug 1984, P241-251 Weathenng indexes such as the Mmra index (ratio of geochemically mobde to lmmobde elements) can be correlated w~th the free energy of weathering, and w~th other extenswe propertles, for intact and weathered silicate rocks The Parker index (related to the proportion of certain elements and their oxygen bond strength) ~s thought to show susceptlbdlty to further weathering Combining these two ln&ces, values may be estimated for the actwat~on energy for incongruent aqueous &ssolution, which compare w~th experimental determinations For rocks where failure may be attributed to the chemistry itself, a good correlation may be made between the chemtcal weatherablhty index, derived from Mmra and Parker in&ces, and rock durabdlty as measured by the Los Angeles abrasion test

Earthquake mechanisms and effects 853120 Estimation of earthquake magnitude from signal duration Ramaknshna, C V, Gupta, H K In: Engineering Geosciences, edited by B B S Singhal P173180 Publ Meerut, lndza Sartta Prakashan, 1982 A relationship has been proposed describing earthquake magmtude m terms of the duration of surface waves and &stance from ep~centre, rather than trace amphtude For magmtudes 2-6 and eplcentral &stances 70-1000km, there ~s an estimated accuracy of + or -0 3 umts

853121 Microearthquake recording for engineering applications Agrawal, P N, Kumar, A In: Engineering Geosciences, edited by B B S Singhai P 181186 Publ Meerut, Indta Sarzta Prakashan, 1982 M~crose~sm~c data has been recorded at 5 stations over a period of 18 months This has been used to study actw~ty levels m the area, to examine the effect of rinsing the water level m a reservoir on seismic actwlty and to explore the geothermal potential of some areas with hm~ted data and instrumentation It ~s as yet impossible to assess the potential of this techmque

853122 Seismic-induced pore-water pressure records from the Mammoth Lakes, California, earthquake sequence of 25 to 27 May 1980 Harp, E L, Sarmlento, J, Cranswlck, E Bull Seismol Soc Am V74, N4, Aug 1984, P1381-1393 Seismic reduced pore water pressure and acceleratton records were collected from se&ments at Mammoth Lakes, Callforma, USA, which had undergone hquefactlon and subsequent lateral spreading failure dunng an earthquake sequence Pore pressure traces show clear P and S wave phases and are m phase w~th corresponding P wave components of the acceleration records,