TY - GEN
T1 - Volumetric strain in non-plastic silty sand subject to multidirectional cyclic loading
AU - Bhaumik, Lopamudra
AU - Rutherford, Cassandra J.
AU - Cerna-Diaz, Alfonso
AU - Olson, Scott M.
AU - Numanoglu, Ozgun A.
AU - Hashash, Youssef M.A.
AU - Weaver, Thomas
N1 - Publisher Copyright:
© ASCE.
PY - 2017
Y1 - 2017
N2 - Structures founded on dense, compacted sands are currently designed based on the shear stress - shear strain (γcs) - volumetric strain (εv) response of clean sands primarily obtained from unidirectional element tests. This may lead to underestimation of εv under multidirectional seismic loads and incorrect settlement estimation for sands with fines. This paper presents results from first of a kind strain-controlled unidirectional (sinusoidal) and bidirectional (circular, figure-8) cyclic simple shear tests. Clean Ottawa sand and a non-plastic Mississippi River silty sand were tested at modified Proctor relative compactions (RC) of 92 to 99%. At the same RC, presence of non-plastic fines decreased εv. Volumetric strain under bidirectional loading normalized by εv under equivalent unidirectional loading (comparable γcs, RC, overburden pressure) was found to be a function of the number of loading cycles, load path and γcs. A figure-8 loading path yielded higher settlement than an equivalent circular loading path.
AB - Structures founded on dense, compacted sands are currently designed based on the shear stress - shear strain (γcs) - volumetric strain (εv) response of clean sands primarily obtained from unidirectional element tests. This may lead to underestimation of εv under multidirectional seismic loads and incorrect settlement estimation for sands with fines. This paper presents results from first of a kind strain-controlled unidirectional (sinusoidal) and bidirectional (circular, figure-8) cyclic simple shear tests. Clean Ottawa sand and a non-plastic Mississippi River silty sand were tested at modified Proctor relative compactions (RC) of 92 to 99%. At the same RC, presence of non-plastic fines decreased εv. Volumetric strain under bidirectional loading normalized by εv under equivalent unidirectional loading (comparable γcs, RC, overburden pressure) was found to be a function of the number of loading cycles, load path and γcs. A figure-8 loading path yielded higher settlement than an equivalent circular loading path.
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U2 - 10.1061/9780784480489.016
DO - 10.1061/9780784480489.016
M3 - Conference contribution
AN - SCOPUS:85018445565
T3 - Geotechnical Special Publication
SP - 150
EP - 159
BT - Geotechnical Special Publication
A2 - Brandon, Thomas L.
A2 - Valentine, Richard J.
PB - American Society of Civil Engineers
T2 - Geotechnical Frontiers 2017
Y2 - 12 March 2017 through 15 March 2017
ER -