Post-liquefaction dissipation

Pre-liquefaction coefficient of consolidation (c ) values for each specimen were calculated based on measured hydraulic conductivity (k) and volume compressibility (m ) data for virgin loading shown in Figure 4a. Post-liquefaction c, values were back-calculated using time histories of pore pressure dissipation and volume change measurements obtained during post-liquefaction dissipation tests for each incremental change in effective stresses. Back-calculations of c were... 

Figures 7a-b show at5q)ical comparison ofthe measured and theoretical dissipation data plots based on pore pressure dissipation and volume change versus time data, respectively, fora 100% silt specimen (oslOO-838) at void ratio of 0.838. The theoretical back-calculated value for c for these numerical simulations is shown in each figure. In both cases, the back-calculated c values are 0.2 cmYs and 0.15 cmYs in close agreement with each other. Figures 7c-d show another typical comparison ofthe measured and theoretical curves for the corresponding back-calculated c for sand andNew Jersey silt, respectively. The data in these figiues correspond to post-liquefaction dissipation test during a period where the effective stress in the specimen increases from 25 to 50 kPa. The c values were also dependent on the effective stress range and they were different for each specimen. Silt content and hydraulic conductivity k of each specimen also influenced the c values.

This article presents results from an experimental study of pre- and post-liquefaction characteristics of non-plastic sand-silt mixes at silt contents from 0% to 100% by weight, and three natural non-plastic silts. Undrained cyclic triaxial tests followed by dissipation of cyclic-induced pore pressures were carried out in order... 

Thevanayagam, S., Martin, G. R., Shenthan, T, Liang, J. (2001). Post-liquefaction pore pressure dissipation and densification in silty soils. In Proceedings of the 4 Inti. Conf. Soil Dynamics Earthq. Eng., San Diego, CA. 

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