Download or read book Postcyclic Behavior of Low-plasticity Silt written by Shuying Wang and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Liquefaction of low-plasticity silt has been reported during earthquakes in the recent past. Excess pore pressure builds up due to the dynamic loading and then dissipates. The postcyclic behavior of low-plasticity silt was investigated in this research for materials obtained from the Mississippi River Valley. The experimental program involved specimen preparation using a slurry consolidation approach. A special technique was developed for specimen movement, reducing the testing program time by half. Both static and cyclic triaxial tests were conducted to confirm the ability to prepare replica specimens. In order to characterize the monotonic behavior, triaxial tests were conducted to determine the effective friction angle, critical state line, and normalized behavior. Then specimens were subjected to cyclic loading to develop the liquefaction curve. After full liquefaction, excess pore pressure was dissipated until various reconsolidation levels. The effect of full liquefaction on the permeability and compressibility was studied. The variation in postcyclic shear strength and stiffness with reconsolidation level and the effect of apparent consolidation on shear behavior were also discussed. The critical state lines for the pre- and postliquefaction conditions were compared and found to be not parallel. After limited liquefaction, two unique conditions were tested, at no reconsolidation and at full reconsolidation. The shear strength and stiffness changed significantly at an excess pore pressure ratio greater than 0.70. The experimental program culminated with the study of the effect of plasticity on the pre- and postcyclic shear behavior. Silt-bentonite mixtures resulted in modified plasticity and the transformation from a dilative to a plastic behavior were captured at relatively low plasticity (PI> 6)--Abstract, leaf iii