Water content cont
Water content controlled
instead of suction controlled strength tests
Reza Ahmadi-Naghadeh, Nabi
Kartal Toker, Mohammad Ahmadi-Adli
Department of Civil
Engineering, METU, Ankara, Turkey
Abstract: Most
soils that concern geotechnical engineering are in the state of partial water
saturation. Current practice tries to predict engineering properties of
cohesionless soils using data from tests on saturated specimens, regardless of
the saturation in the field. Due to complexity of test setups and high
technical requirements, unsaturated soil tests are not among the common
equipment of soil mechanics laboratory. One of these problems is the existence
of suction, which is a function of water content and affects the strength
behavior of unsaturated soils. Procedures to keep the water content of the
partially saturated specimens constant and homogeneous in conventional soil tests
are not well-established. The exception to this is unsaturated test setups,
which are costly, complicated and found only in research institutions, hence
prohibiting the industry from keeping up with the developments in this field.
This study explores simple modifications to conventional methodologies of
triaxial and direct shear tests, with the ultimate aim of preventing temporal
and spatial variability of specimen water content throughout test duration. For
different modifications, specimens of each test are dissected at the end of the
test, and water content profiles of the specimens are obtained.
[R
Ahmadi-Naghadeh, N. K. Toker, M. Ahmadi-Adli. Water content controlled
instead of suction controlled strength tests. Life
Sci J 2013;10(1):2023-2030] (ISSN:1097-8135). http://www.lifesciencesite.com.
Keywords: Unsaturated soil; soil suction; water content; triaxial test; direct shear test.