US 5,540,101 A · Borehole directional dilatometer

Abstract

A device positionable in a borehole for determining rock mass deformability, comprises a generally cylindrical body having at least one pair of diametrically opposed, elongated expandable wall portions for pressure contact engagement with the borehole wall, the wall portions being radially outwardly expandable in diametrically opposite directions along a predetermined axis extending transversely to the longitudinal axis of the borehole. An elongated core is arranged in the body and extends longitudinally thereof. A chamber is associated with a respective one of the expandable wall portions and is defined between the respective expandable wall portion and the core, the chambers associated with the at least one pair of expandable wall portions being in fluid communication for receiving a fluid under pressure. The device of the invention further includes an inlet for introducing the fluid under pressure into the associated chambers to cause the expandable wall portions to expand radially outwardly against the wall of the borehole, and a linear displacement sensor associated with a respective one of the expandable wall portions and mounted on the core, for measuring outward radial displacement of the respective expandable wall portion. The displacement sensor associated with the at least one pair of expandable wall portions are operative to provide signals indicative of borehole diametral deformation along the predetermined axis and thus of rock mass deformability.

Claims23

Dependent claims

A device positionable in a borehole for determining rock mass deformability, comprising:

a generally cylindrical body having an elongated core extending longitudinally thereof and two pairs of diametrically opposed, elongated expandable wall portions for pressure contact engagement with the borehole wall, said expandable wall portions each comprising an elongated membrane mounted on said core in fluid tight engagement therewith, the membranes of one pair being radially outwardly expandable in diametrically opposite directions along a first axis and the membranes of the other pair being radially outwardly expandable in diametrically opposite directions along a second axis, said first axis and said second axis being orthogonal to one another;
a chamber associated with a respective one of said membranes and defined between each membrane and said core, the chambers associated with each pair of membranes being in fluid communication for receiving a fluid under pressure;
inlet means for introducing said fluid under pressure into the chambers associated with at least one selected pair of membranes to cause the membranes of said at least one selected pair to expand radially outwardly against the wall of said borehole;
and
a linear displacement sensing means associated with a respective one of said membranes and mounted on said core, for measuring outward radial displacement of said respective membrane, the displacement sensing means associated with each pair of membranes being operative to provide signals indicative of borehole diametral deformation along one of said first and second axes and thus of rock mass deformability.

2 more elements

A device positionable in a borehole for determining rock mass deformability, comprising:

a generally cylindrical body having at least one pair of diametrically opposed, elongated expandable wall portions for pressure contact engagement with the borehole wall, said wall portions being radially outwardly expandable in diametrically opposite directions along a predetermined axis extending transversely to a longitudinal axis of said borehole;
an elongated core arrangged in said body and extending longitudinally thereof;
a chamber associated with a respective one of said expandable wall portions and defined between said respective expandable wall portion and said core, the chambers associated with said at least one pair of expandable wall portions being in fluid communication for receiving a fluid under pressure;
inlet means for introducing said fluid under pressure into said associated chambers to cause said expandable wall portions to expand radially outwardly against the wall of said borehole;
and
a linear displacement sensing means associated with a respective one of said expandable wall portions and mounted on said core, for measuring outward radial displacement of said respective expandable wall portion, the displacement sensing means associated with said at least one pair of expandable wall portions being operative to provide signals indicative of borehole diametral deformation along said predetermined axis and thus of rock mass deformability;
wherein said expandable wall portions each comprise an elongated membrane mounted on said core in fluid tight engagement therewith;
wherein each membrane comprises an inwardly extending peripheral flange having a terminal seal lip, and wherein said core comprises an elongated, longitudinally extending central core element and an elongated ridge member mounted on said core element and extending longitudinally thereof between opposed longitudinal portions and end portions of said peripheral flange, said ridge member having a peripheral seal abutment surface in sealing contact engagement with said seal lip;
and
wherein said longitudinal flange portions are each formed with an outer shoulder and said core element is provided with a rib extending along and adjacent each longitudinal flange portion, and wherein an elongated membrane retaining member engages said shoulder to releasably retain said longitudinal flange portion in abutting sealing engagement with said core element and said ridge member, said membrane retaining member being removably fixed to said rib by removable fastening means.

7 more elements

Dependencies are inferred from the claim text.

Borehole directional dilatometer

Life of this patent

Borehole directional dilatometer

Life of this patent

Abstract

Claims23