Performance of Embankments on Liquefiable Soils Improved with Dense Granular Columns: Observations from Case Histories and Centrifuge Experiments

Performance of embankments on liquefiable soil deposits improved with with dense granular columns

“…This led to a slight base isolation effect, reducing the amplitude of accelerations propagating toward the surface. This observation was consistent with the results of prior centrifuge experiments investigating various mitigation mechanisms provided by DGCs below embankments (Tiznado et al 2020).…”

“…The relative densities considered for Ottawa sand, Drc, ranged from 30% to 90%, to account for transition in soil behavior from loose to medium-dense and dense states. The values of Ar (from 0 to 20%) were selected based on the most relevant field observations in the literature using DGCs as a liquefaction countermeasure (summarized by Tiznado et al 2020). The considered values of Gr (from 2 to 8), which were estimated based on pre-shaking values of maximum shear stiffness without consideration of surcharge loads, covered the typical range reported in previous studies (e.g., Baez 1995;Rayamajhi et al 2016a).…”

“…Figure 5.2: Comparison of numerical and experimental results for model BL (Tiznado et al 2020) when varying the domain size from 2.6B ("Small" domain) to 6B ("Large" domain). (particularly during the strongest part of the motion), were also improved.…”

“…Over the past few decades, dense granular columns (DGC) have become a common soil improvement strategy for critical geo-structures founded on potentially liquefiable deposits (Adalier and Elgamal 2004). Case histories from previous earthquakes using DGCs as a liquefaction counter-measure (Hausler 2002;Nikolaou et al 2016) as well as previous experimental and numerical studies (e.g., Elgamal et al 2009;Asgari et al 2013;Rayamajhi et al 2014;Badanagki et al 2018;Badanagki et al 2019;Tiznado et al 2020), have generally shown DGCs to be effective in mitigating the consequences of soil liquefaction.…”

“…3-D nonlinear, solid-fluid, fully-coupled, effective-stress, dynamic FE models using the PDMY02 soil constitutive model implemented in OpenSees were used to simulate the seismic response of embankments founded on liquefiable soil profiles mitigated with DGCs under horizontal earthquake loading. The developed models can be employed in future numerical parametric studies aimed to identify the key predictors of embankment performance on liquefiable sites treated with DGCs and develop predictive models related to deformations of 3.1 Properties of materials used in the centrifuge models (Badanagki et al 2018;Ramirez et al 2018) 4.1: Initial soil conditions in the centrifuge experiment used for numerical model validation (Badanagki et al 2018;Li et al 2018) (Tiznado et al 2020) when varying the domain size from 2.6B ("Small" domain) to 6B ("Large" domain). .............. 118…”