- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Cyclic shear loading response of Fraser River Delta...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Cyclic shear loading response of Fraser River Delta silt Sanin, Maria Victoria
Abstract
The cyclic shear response of silt obtained from a natural channel-fill soil deposit in the Fraser River Delta of British Columbia, Canada, was investigated using the direct simple shear (DSS) test apparatus. Constant volume cyclic DSS tests conducted on undisturbed silt specimens consolidated to a vertical stress similar to, or above, the in situ effective overburden stress exhibited cyclic mobility type progressive strain development and equivalent pore water pressure rise. The observations are similar to the behaviour observed for dense sand by others. The cyclic resistance ratio (CRR) of the tested material indicated no significant sensitivity to the initial confining stress level for stress levels below 200 kPa, suggesting that the response is similar to that of normally consolidated clay. The cyclic resistance ratio of the silt increased with increasing overconsolidation ratio (OCR) for OCR greater than 1.3. The silt specimens that developed high equivalent pore water pressures during cyclic loading, suffered significant volumetric strains during post-cyclic reconsolidation, indicating considerable changes in the particle fabric under cyclic loading. Repeated cyclic loading (re-liquefaction) tests conducted after post-cyclic reconsolidation displayed a reduction in CRR in comparison to that noted under first cyclic loading. The decrease in CRR due to the degradation of particle fabric as a result of previous shearing appears to have overshadowed any gain in CRR that would have taken place due to the reduction of void ratio during re-consolidation. The commonly used empirical liquefaction criteria displayed limitations in describing the cyclic response of the tested silt. Laboratory element testing that allows capturing the effect of most controlling parameters seems to remain as the more reliable approach for estimating liquefaction susceptibility of fine-grained soils.
Item Metadata
Title |
Cyclic shear loading response of Fraser River Delta silt
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
2005
|
Description |
The cyclic shear response of silt obtained from a natural channel-fill soil deposit in the Fraser
River Delta of British Columbia, Canada, was investigated using the direct simple shear (DSS)
test apparatus. Constant volume cyclic DSS tests conducted on undisturbed silt specimens
consolidated to a vertical stress similar to, or above, the in situ effective overburden stress
exhibited cyclic mobility type progressive strain development and equivalent pore water
pressure rise. The observations are similar to the behaviour observed for dense sand by others.
The cyclic resistance ratio (CRR) of the tested material indicated no significant sensitivity to
the initial confining stress level for stress levels below 200 kPa, suggesting that the response is
similar to that of normally consolidated clay. The cyclic resistance ratio of the silt increased
with increasing overconsolidation ratio (OCR) for OCR greater than 1.3. The silt specimens
that developed high equivalent pore water pressures during cyclic loading, suffered significant
volumetric strains during post-cyclic reconsolidation, indicating considerable changes in the
particle fabric under cyclic loading. Repeated cyclic loading (re-liquefaction) tests conducted
after post-cyclic reconsolidation displayed a reduction in CRR in comparison to that noted
under first cyclic loading. The decrease in CRR due to the degradation of particle fabric as a
result of previous shearing appears to have overshadowed any gain in CRR that would have
taken place due to the reduction of void ratio during re-consolidation. The commonly used
empirical liquefaction criteria displayed limitations in describing the cyclic response of the
tested silt. Laboratory element testing that allows capturing the effect of most controlling
parameters seems to remain as the more reliable approach for estimating liquefaction
susceptibility of fine-grained soils.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2009-12-21
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0063358
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
2005-11
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.