Conference paper Embargoed Access
The Lower Tagus River Valley area, in Lisbon, Portugal, has been studied for having
a high potential liquefaction risk, due to the geological and geomorphological settings and the
seismicity associated to the region. This study focuses on the comparison of the cyclic behaviour
of three sands collected on site, using two distinct laboratory procedures. Tests with different
values of Cyclic Stress Ratio were conducted in both cyclic simple shear and cyclic triaxial testing
apparatus to assess the CRR curves of each material in reconstituted conditions. The comparison
of the results highlights the main differences caused by distinct cyclic loading stress paths especially
in view of the results when inversion or rotation of the principal stresses are induced. The
tests also investigate the influence of the fines content and the cycling frequency in the number
of cycles required for liquefaction to occur, while discussing the criteria for limit/instability level.
Files are currently under embargo but will be publicly accessible after June 17, 2020.