Post-liquefaction reconsolidation of sand

Abstract

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

Discussion of “Simplified Procedure for Prediction of Earthquake-Induced Settlements in Partially Saturated Soils” by Abdülhakim Zeybek and Santana Phani Gopal Madabhushi

“…Thus, the use of Eq. (3) is in contrast with the authors' initial argument that sand layers in free-field condition are not likely to experience a fully undrained condition and that partial drainage is likely to occur (i.e., Adamidis and Madabhushi 2016).…”

Sustainable Measures for Protection of Structures Against Earthquake Induced Liquefaction

“…The soil properties outlined in Table 1 were used in these analyses. The variation of co-efficient of consolidation and permeability at very low effective stresses for the Hostun sand were adopted from Haigh et al [29] and Adamidis and Madabhushi [32].…”

CFD-Based Framework for Analysis of Soil–Pipeline Interaction in Reconsolidating Liquefied Sand

“…While the bulk of Terzaghi's theory was held valid, some changes were motivated by the highly non-linear behaviour of sand at very low . Indeed, a number of experimental studies show that, during re-consolidation, both hydraulic conductivity and 1D oedometer stiffness (= 1/ , oedometer compressibility) depend strongly on the current effective stress level and void ratio (Brennan and Madabhushi, 2011;Haigh et al, 2012;Adamidis and Madabhushi, 2016).…”

“…The empirical relationship proposed by Adamidis and Madabhushi (2016) was adopted for the hydraulic conductivity:…”

“…The above pore pressure dissipation model was further tested against the measurements recorded by Adamidis and Madabhushi (2016) during re-consolidation centrifuge tests on Hostun sand -experiment OA2-EQ2. Selected parameters for this case are given in Table 2 -set 2, most of which taken from published values.…”