- Email: [email protected]
New equipment and techniques for use with the Cambridge self-boring pressuremeter. Technical note
232A 866145 Application of cross-hole seismic measurements in site investigation surveys McCann. D M: Baria. R" Jackson. P D; Green. A S P Geophysics V51. N4. April 1986. P914-929 Case histories illustrate the application of the cross-hole seismic method, using the borehole sparker probe developed by McCann et al (1975) as the seismic source, to site investigation surveys for civil engineering developments. The high-frequency sparker source coupled with digital stacking of the received seismic pulses gave excellent resolution of both lithoo logical changes and anomalous features in the ground conditions between the two boreholes.
866146 Effectof structure and anisotropy on resistivity measurements Matias, M J S; Habberjam. G M Geopliysics V51. N4. April 1986, P964-971 When conducting resistivity investigations over steeply dipping geologic structures, large orientationat variations in resistivity response are commonly encountered. These variations can arise from resistivity contrasts between constituent layers or from anisotropy within the beds. When such structures are concealed, a thorough sampling of these orientational variations must be conducted. Field experience and model studies presented show that such sampling can be conveniently conducted using the crossed-square array and that the orientational variations encountered can be adequately summarized by the anisotro pically defined parameters of apparent resistivity, anisotropy and strike derived from tbesc array measure merits.
866147 Transient electromagnetic sounding for groundwater Fitterman. D V: Stewart, M T Geophysics V51. N4, April 1986 P995-t005 The physical basis for the transient sounding technique is described, and some advantages and disadvantages of the method are given. Several targets of interest for groundwater exploration are noted and results of model calculations for these groundwater targets are discussed. Particular attention is paid to an array where the receiver coil is located at the centre of the transmitter loop. Limitations imposed on the transient sounding method by currently available equipment are discussed.
Borehole and core logging See also. 866033, 866051. 866061. ~66121 866149 Pore water pressure measuring system Carpentier. R: Verdonck. W Civ Engng, London June 1986. P39-41 The stability of a breakwater is related to the shear strength of its foundation layers. To determine this factor, it is necessary to know the pore pressure distribution in these layers. An experimental program was undertaken at Zeebrugge, Belgium. to gather information about pore pressure distribution and pressure changes due to waves or tides. The design, concept and construction of a multiple piezometer probe, the measuring platform and equipment and the telemetry and computer system used are described. 866150 Digital directional survey tool Lovett. C Geodrilling N37, April 1986. P17-20 Description of borehole directional survey equipment as it pertains to mineral exploration boreholes. The significance o f deviation of a borehole from the perpendicular is discussed. The difficulty o f obtaining deviation logs prior to the development of the modern microprocessor-controlled deviation survey tool is mentioned and the modern tool is described. The applicability of deviation surveying to the core drilling industry is discussed. 866151 New equipment and techniques for use with the Cambridge self-boring pressuremeter. Technical note Davidson. J L; Bloomquist, D G Geoteeh Test J vg. N2. June 1986. PI07-112 The following have been developed: a trailer mounted test rig; a self-casing technique for use in cohesionless soils where borehole collapse is a danger; a portable field data recording and dumping unit: and a data reduction program. 866152 Production of borehole logs using a microcomputer Chaplow, R Q J Engng Geol VI9. N3. 1986, P291.299 A software package has been developed a n d implemented on a BBC microcomputer system which allows borehote data to be entered into disc files and full boreholc togs, including both graphical and textual components, to be prepared automatically from the stored data. The design and operation o f the software system is described and examples of logs produced with it are provided.
866148 Evaluation of transient electromagnetic soundings for deep detection of conductive fluids Stewart, M; Gay, M C Ground Water V24. N3, May-June 1986. P351-356
866 ! 53 Effects of soil disturbance in pressuremeter tests Law, K T: Eden. W J Proe Conf on Updating Surface Samplings of Soils and Rocks and their ln-Situ Testing, Santa Barbara, Cah'fornia, 3-8 Jan 1982 P291-303. Publ New York." Engineer#~g Foundation. 1985
Transient electromagnetic sounding (TEM) was used to provide lithological and water quality information at depths of over 200m. and to locate the saltwater interface in the Floridan aquifer, Florida. USA. It is relatively quick and simple to use. TEM data compare well with available DC resistivity and chloride ion data. Currently available equipment does not appear suitable for shallow soundings, less than 40-50m.
Insertion of a pressuremeter probe causes a change in the in situ stress and induces an annular zone of softened soil around the probe. The effects of such disturbance on the results of pressuremeter tests have been examined by a series of field tests using a Cambridge self boring pressuremeter in a clay soil. The effect of in situ stress change was evaluated from tests using oversized, matched and undersized boreholes, whilst the
f~ 1986 Pergamon Journals Ltd. Reproduction not permitted
866146 Effectof structure and anisotropy on resistivity measurements Matias, M J S; Habberjam. G M Geopliysics V51. N4. April 1986, P964-971 When conducting resistivity investigations over steeply dipping geologic structures, large orientationat variations in resistivity response are commonly encountered. These variations can arise from resistivity contrasts between constituent layers or from anisotropy within the beds. When such structures are concealed, a thorough sampling of these orientational variations must be conducted. Field experience and model studies presented show that such sampling can be conveniently conducted using the crossed-square array and that the orientational variations encountered can be adequately summarized by the anisotro pically defined parameters of apparent resistivity, anisotropy and strike derived from tbesc array measure merits.
866147 Transient electromagnetic sounding for groundwater Fitterman. D V: Stewart, M T Geophysics V51. N4, April 1986 P995-t005 The physical basis for the transient sounding technique is described, and some advantages and disadvantages of the method are given. Several targets of interest for groundwater exploration are noted and results of model calculations for these groundwater targets are discussed. Particular attention is paid to an array where the receiver coil is located at the centre of the transmitter loop. Limitations imposed on the transient sounding method by currently available equipment are discussed.
Borehole and core logging See also. 866033, 866051. 866061. ~66121 866149 Pore water pressure measuring system Carpentier. R: Verdonck. W Civ Engng, London June 1986. P39-41 The stability of a breakwater is related to the shear strength of its foundation layers. To determine this factor, it is necessary to know the pore pressure distribution in these layers. An experimental program was undertaken at Zeebrugge, Belgium. to gather information about pore pressure distribution and pressure changes due to waves or tides. The design, concept and construction of a multiple piezometer probe, the measuring platform and equipment and the telemetry and computer system used are described. 866150 Digital directional survey tool Lovett. C Geodrilling N37, April 1986. P17-20 Description of borehole directional survey equipment as it pertains to mineral exploration boreholes. The significance o f deviation of a borehole from the perpendicular is discussed. The difficulty o f obtaining deviation logs prior to the development of the modern microprocessor-controlled deviation survey tool is mentioned and the modern tool is described. The applicability of deviation surveying to the core drilling industry is discussed. 866151 New equipment and techniques for use with the Cambridge self-boring pressuremeter. Technical note Davidson. J L; Bloomquist, D G Geoteeh Test J vg. N2. June 1986. PI07-112 The following have been developed: a trailer mounted test rig; a self-casing technique for use in cohesionless soils where borehole collapse is a danger; a portable field data recording and dumping unit: and a data reduction program. 866152 Production of borehole logs using a microcomputer Chaplow, R Q J Engng Geol VI9. N3. 1986, P291.299 A software package has been developed a n d implemented on a BBC microcomputer system which allows borehote data to be entered into disc files and full boreholc togs, including both graphical and textual components, to be prepared automatically from the stored data. The design and operation o f the software system is described and examples of logs produced with it are provided.
866148 Evaluation of transient electromagnetic soundings for deep detection of conductive fluids Stewart, M; Gay, M C Ground Water V24. N3, May-June 1986. P351-356
866 ! 53 Effects of soil disturbance in pressuremeter tests Law, K T: Eden. W J Proe Conf on Updating Surface Samplings of Soils and Rocks and their ln-Situ Testing, Santa Barbara, Cah'fornia, 3-8 Jan 1982 P291-303. Publ New York." Engineer#~g Foundation. 1985
Transient electromagnetic sounding (TEM) was used to provide lithological and water quality information at depths of over 200m. and to locate the saltwater interface in the Floridan aquifer, Florida. USA. It is relatively quick and simple to use. TEM data compare well with available DC resistivity and chloride ion data. Currently available equipment does not appear suitable for shallow soundings, less than 40-50m.
Insertion of a pressuremeter probe causes a change in the in situ stress and induces an annular zone of softened soil around the probe. The effects of such disturbance on the results of pressuremeter tests have been examined by a series of field tests using a Cambridge self boring pressuremeter in a clay soil. The effect of in situ stress change was evaluated from tests using oversized, matched and undersized boreholes, whilst the
f~ 1986 Pergamon Journals Ltd. Reproduction not permitted