- Email: [email protected]
Field measurement of shear wave velocity by crosshole and downhole seismic methods
20A
791170 FIELD M E A ~ N T OF SHEAR WAVE VELOCITY BY CROSSHOLE AND D ~ O L E SEISMIC METHODS Stokoe, K H; Hoar, R J In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dynamic Methods in soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), PI15-137. Publ Rotterdam: A A Balkema, 1978 Variables which affect t h e accuracy of S wave velocity measurement are discussed and their quantitative and qualitative effects presented. Field procedures for each method are outlined. In the cross-hole test, stardard penetration test equipment can be used to generate easily identifiable S waves. With the torsional source, the initial arrival of the S wave can be reversed for easy identification. In the downhole seismic test, a reversible embedded source is Used which is rich in S wave generation. 791171 SHEAR WAVE M E A S U R ~ N T S USING THE SEISMIC UPHOLE METHOD Ludeling, R In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dyrmmlc Methods in Soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P139-148. Publ Rotterdam: A A Balkema, 1978 The theory of the up-hole method is presented briefly. The field tests described make use of an explosive as seismic source. Seismograms obtained from a site in the Rhine valley are discussed to illustrate the problem of differentiating between P and S wave groups. It is shown that the data can be plotted to give a wave front diagram for the S waves. Best results were obtained using blasting caps as seismic source, and a spread of 3-component velocity transducers. 791172 LOCATING AND MAPPING OF CAVITIEs AT SHALLOW DEPTHs BY THE SEI~4IC TRANSMISSION METHOD Dresen, L In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dynamic Methods in Soll and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P149-172. Publ Rotterdam: A A Balkema, 1978 Describes thin location of abandoned and partly filled mine ahafts which form cavities of diameter 1-6 m at 30 m or less below the ground surface and which present safety hazards.
Earlier work on the interpretation of seismic transmission measurements on models is first discUssed. The case study concerns the location of 3 concealed shafts at Eschweilder in Nordrhein-Westfalen, West Germar~. The experimental set-up, data interpretation, and check of seimnic results by other geophysical methods and finally by drilling, are described. 791173 SOME CURRENT APPLICATIONS OF MICROSEI~MIC TECHNIQUES IN GEOMECHANICS Hardy, H R In: Rock Dyrmmlcs and Geophysical Aspects (Papers to Conference on Dynamic Methods in Soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P173-199. Publ Rotterdam: A A Bslkema, 1978 Reviews the basic concepts of acoustic emission/ mlcroseismic activity in relation to geomechardcs. The development of microseismlc techniques is described by reference to field studies reported in the literature, includirg recent applications in coal mines, hard rock mines and underground gas storage reservoirs. The design of a suitable AE/MS monitoring system is outlined, with consideration of the field site, the transducers and their installation, and the use of multlchannel monitoring facilities. A case study of AE/MS activity in a Pennsylvania coal mine is l~esented, the objective being to locate potential zones of instability and to provide a picture of the failure character inherent in longwall mining.
Presentation and interpretation of data 791174 AID TO REPRESEN2ATION OF INCLINED BOREHOLES ON VERTICALLY EXAGGERATED GEOLOGICAL SECTIONS Orr, C M; Kennedy, D Bull Assoc Engng Geol, VI4, N~, 1977, P271276 Presents simple mathematical formulae which allow the rapid computation of the plotting angles and depths of inclined boreholes and ar~ geological features intersected by them.
791170 FIELD M E A ~ N T OF SHEAR WAVE VELOCITY BY CROSSHOLE AND D ~ O L E SEISMIC METHODS Stokoe, K H; Hoar, R J In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dynamic Methods in soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), PI15-137. Publ Rotterdam: A A Balkema, 1978 Variables which affect t h e accuracy of S wave velocity measurement are discussed and their quantitative and qualitative effects presented. Field procedures for each method are outlined. In the cross-hole test, stardard penetration test equipment can be used to generate easily identifiable S waves. With the torsional source, the initial arrival of the S wave can be reversed for easy identification. In the downhole seismic test, a reversible embedded source is Used which is rich in S wave generation. 791171 SHEAR WAVE M E A S U R ~ N T S USING THE SEISMIC UPHOLE METHOD Ludeling, R In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dyrmmlc Methods in Soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P139-148. Publ Rotterdam: A A Balkema, 1978 The theory of the up-hole method is presented briefly. The field tests described make use of an explosive as seismic source. Seismograms obtained from a site in the Rhine valley are discussed to illustrate the problem of differentiating between P and S wave groups. It is shown that the data can be plotted to give a wave front diagram for the S waves. Best results were obtained using blasting caps as seismic source, and a spread of 3-component velocity transducers. 791172 LOCATING AND MAPPING OF CAVITIEs AT SHALLOW DEPTHs BY THE SEI~4IC TRANSMISSION METHOD Dresen, L In: Rock Dynamics and Geophysical Aspects (Papers to Conference on Dynamic Methods in Soll and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P149-172. Publ Rotterdam: A A Balkema, 1978 Describes thin location of abandoned and partly filled mine ahafts which form cavities of diameter 1-6 m at 30 m or less below the ground surface and which present safety hazards.
Earlier work on the interpretation of seismic transmission measurements on models is first discUssed. The case study concerns the location of 3 concealed shafts at Eschweilder in Nordrhein-Westfalen, West Germar~. The experimental set-up, data interpretation, and check of seimnic results by other geophysical methods and finally by drilling, are described. 791173 SOME CURRENT APPLICATIONS OF MICROSEI~MIC TECHNIQUES IN GEOMECHANICS Hardy, H R In: Rock Dyrmmlcs and Geophysical Aspects (Papers to Conference on Dynamic Methods in Soil and Rock Mechanics, Karlsruhe, 5-16 Sept 1977), P173-199. Publ Rotterdam: A A Bslkema, 1978 Reviews the basic concepts of acoustic emission/ mlcroseismic activity in relation to geomechardcs. The development of microseismlc techniques is described by reference to field studies reported in the literature, includirg recent applications in coal mines, hard rock mines and underground gas storage reservoirs. The design of a suitable AE/MS monitoring system is outlined, with consideration of the field site, the transducers and their installation, and the use of multlchannel monitoring facilities. A case study of AE/MS activity in a Pennsylvania coal mine is l~esented, the objective being to locate potential zones of instability and to provide a picture of the failure character inherent in longwall mining.
Presentation and interpretation of data 791174 AID TO REPRESEN2ATION OF INCLINED BOREHOLES ON VERTICALLY EXAGGERATED GEOLOGICAL SECTIONS Orr, C M; Kennedy, D Bull Assoc Engng Geol, VI4, N~, 1977, P271276 Presents simple mathematical formulae which allow the rapid computation of the plotting angles and depths of inclined boreholes and ar~ geological features intersected by them.