Geology Reference
In-Depth Information
deviator stress will be approximately 15 to 20 min. Continue the
loading to 15% axial strain, except loading may be stopped when
the deviator stress has peaked then dropped 20% or the axial strain
has reached 5% beyond the strain at which the peak in deviator
stress occurred.
(6) Record load and deformation values at about 0.1, 0.2, 0.3,
0.4, and 0.5% strain; then at increments of about 0.5% strain
to 3%; and thereafter at every 1%. Take sufficient readings to
define the stress-strain curve; hence more frequent readings
may be required in the early stages of the test and as failure is
approached.
Note 4 —Alternate intervals for the readings may be used, pro-
vided sufficient points are obtained to define the stress-strain
curve.
(7) After completion of the tests, remove the test specimen from the
chamber. Determine the water content of the test specimen in ac-
cordance with ASTM Method D 2216 (Chapter 4), using the entire
specimen, if possible.
(8) Prior to placing the specimen (or portion thereof ) in the oven to
dry, sketch a picture or take a photograph of the specimen showing
the mode of failure (shear plane, bulging, etc.).
(9) Prepare new specimens, and repeat the entire procedure at
other chamber pressures. If disturbed samples are used, the new
remolded specimens should have approximately the same unit
weight (within 1 to 2 lb/ft 3 ).
Note— Step (9) does not appear in the ASTM procedure; it has been
added by the authors.
Data collected in the unconsolidated undrained triaxial compression
test should include the following:
DATA
[A] Specimen Data
Diameter or side of specimen, D 0 (in.)
Initial height of specimen, H 0 (in.)
Mass of specimen (g)
Water content data:
Mass of wet soil plus can (g)
Mass of dry soil plus can (g)
Mass of can (g)
Search WWH ::




Custom Search