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Data Collection, Reduction, and Display of
Horizontal Stress Release Experiment
![inclin3.jpg (93344 bytes)](inclin3.jpg) |
At the Acton proposed landfill site, a 2500 square m section of the base
of a quarry with high horizontal stresses was instrumented with inclinometers and
extensiometers, in a large in situ stress release experiment, to address environmental
concerns regarding "pop-ups" and their potential impact on hydraulic
conductivity below the landfill floor. |
![inclin5.jpg (118028 bytes)](inclin5.jpg) |
Inclinometers were set around the outside of the designated excavation
area, through 4.5 m of dolomite, and anchored in the underlying shale. |
![inclin4.jpg (147905 bytes)](inclin4.jpg) |
A 30 m diameter circular area was excavated, and displacements were
measured. |
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![inclin1.jpg (102712 bytes)](inclin1.jpg) |
Software routines were designed to automatically reduce the data and
to plot displacement profiles. The inclinometer measurements in bore hole 19 reveal
radial inward movement at the 3.5 m level, and tangential movement at the base of the
dolomite. |
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![inclin2.jpg (164209 bytes)](inclin2.jpg) |
Software routines were designed to plot time based displacement for
each inclinometer. The excavation took place between 420 and 480 days. |
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![inclin7.jpg (21756 bytes)](inclin7.jpg) |
Software routines were designed to plot displacement vectors at different
elevations, and at different stages. The results show no net inward movements, as
the ground had been de-stressed by blasting previous to this test. |
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