Int. J. Advanced Structures & Geotechnical Engineering
ISSN 2319-5347, ISI Impact Factor: 0.763
VOLUME 02 NO. 01 JANUARY 2013:
Title: In-situ
stress measurements for confirming the influence of
topography on orientation of desilting chamber - a case
study
Authors: D. S. Subrahmanyam
Abstract: A stress measurement program was
undertaken at Punatsangchhu H.E. Project stage-I during
January 2010 inside desilting chamber for the
determination of in-situ stress tensor by hydro fracture
method. This test was required to freeze the orientation
of desilting chamber vis. a vis. orientation of maximum
compression (H) which was found to be N 150. The
hydrofrac test was carried out at RD 100 and RD 150
inside an exploratory drift at dam-axis and approaching
towards desilting chamber with a rock cover of 100 m. As
it was only 100 to150 m away from the portal a
topography effect on the orientation of (H) was not
completely ruled out. So when the adit to desilting
chamber reached at RD 360 with a rock cover of 410 m, it
was necessary to carry out stress measurement to confirm
the orientation of maximum compression (H). The stress
orientation as evaluated at RD 360m confirms the
orientations revealed from earlier stress measurements
at RD 100 and RD 150m.Thus it is recommended to freeze
the direction of Desilting Chamber along N 150o .It also
confirms thatthe earlier stress measurement results do
not suffer from topography related influence.
Keywords: Stress, Desilting chamber,
Hydrofracture, Adit, Maximum compression, Topography
Pages: 83-86