... the confining pressure σ 3 and the differential stress (σ 1 - σ 3 ) at peak was obtained from the results of the brazilian tests and of the triaxial compression test, and the relationship was approximated using bilinear equations as shown in Fig. 1. laboratory test in-situ test gauge Reservoir...

... ABSTRACT: A soft hollow inclusion strain measuring device that employs the overcoring technique of stress relief is described. The instrument has an inflatable rubber membrane with electrical resistance strain gauges mounted on the outer surface. These strain gauges are bonded with epoxy...

... Abstract: The Swedish State Power Board''s (SSPB) equipment for three-dimensional rock stress measurements in vertical boreholes was developed about 10 years ago. It is based on use of strain gauges and overcoring. Measurements have been performed in water-filled boreholes down to a depth...

... ABSTRACT: The rock stress is measured by means of borehole deformation gauge in several test sites in the western region of Tokyo. The accuracy of rock stress measurement with this gauge is discussed from the technical point of view, The state of rock stress determined by this gauge...

... ABSTRACT: For rock stress measurement, a borehole is commonly drilled and sensors, composed of photo elastic borehole plugs, flat jacks, vibrating wire gauges or load cells, are inserted. Conventional sensors generally suffer the shortcoming of being expensive and difficult to install and use...

... Upstream Oil & Gas Brady excavation stress distribution Magnitude Reservoir Characterization strain observation stress tensor determination principal stress orientation experiment stress concentration stress measurement scheme rosette reservoir geomechanics borehole gauge...

..., i.e. the recording of core relaxation by means of a soft-type of instrument and strain gauges glued to the wall of the pilot hole, was appropriate with respect to the applications foreseen. It was also discovered that the equipment suffered from certain technical shortcomings that made...

... ABSTRACT: Three borehole instruments have been investigated for their suitability for monitoring rock stress changes; the yoke gauge, a purpose designed, non-reusable, three component borehole deformeter, and the conventional and thin-wall versions of the CSIRO triaxial hollow inclusion stress...

... ABSTRACT: The in-situ response of an 8 m3 block of jointed biotitic gneiss to uniaxial and biaxial boundary loading was monitored using two types of borehole gauges; the USBM Borehole Deformation Gauge and the LUT Triaxial Strain Cell. From the displacements and strains recorded by the gauges...

... change gauges. From these measurements it was possible to determine the in situ stress field and to Observe the stress redistribution near the excavation face. The latter is of practical significance because the magnitude of stress change and deformation ahead of the face is largely unknown. Because...

... work stoppages, the rock was seldom unsupported for more than 16 to 20 hours. Reservoir Characterization Upstream Oil & Gas mudstone diameter gauge extensometer liner west wall shaft reservoir geomechanics concrete liner shale stress change shaft bottom embedment gauge stress...

... in future. In this report, not only in case'of soft rOck but also in case of hard rock, methods and several results of tests such as A.E. method or O.C. method are described. 2 THE MEASUREMENT-PROCEDURE OF THE OVE~ CORING METHOD ~ne embedded gauge using the over coring method is shown in Fig. 1. This gauge...

... Reservoir Characterization climate test box humidity dial gauge moisture change percentage swell experiment salt solution moisture humidity change temperature change moisture content hygrometer mudrock prism south african mudrock shale gauge irreversible change shrinkage...