Influence of consolidation properties on the cyclic re-liquefaction potential of sands

Abstract

The relative density can be used as the main indicator to assess the liquefaction resistance of clean sands. As relative density of the sand deposit increases significantly following the initial liquefaction, one should expect that the soil can improve its liquefaction resistance. However, earthquake records indicate that densified sand can be liquefied again (re-liquefied) at smaller cycles by the similar seismic loadings. This work aims to clarify the counterintuitive finding that, after the first liquefaction, the resulting significant increase in relative density (induced by settlements and variation of the water level) do not necessarily imply an increase in the number of loading cycles for re-liquefaction. In this paper, we present a series of experimental results concerning the cyclic liquefaction and the following re-liquefaction of clean sand deposits. The experimental setup is performed by a shaking table, transmitting one-degree of freedom transversal motion to the soil within the 1.5 m high laminar shear box. At four different seismic demands, the input excitation was imposed three times to examine the influence of the initial distributions of the relative density and the consolidation characteristics on the liquefaction potential of the sand. The re-liquefaction cycles of the sand, which previously experienced liquefaction under the same seismic loadings, show that post-liquefaction reconsolidation of the sand deposits affects the re-liquefaction resistance.

Feasible packing of granular materials in discrete-element modelling of cone-penetration testing

“…The effects of the boundary conditions on the recorded CPT data were satisfactory when R d values reported in the literature were considered. More details about the physical modelling, shaking-table system, and the reliability of the measured data can be found at Ecemis (2013) and Ecemis et al (2015).…”

Effects of reconsolidation degree on reliquefaction resistance under mainshock–aftershock sequences: A DEM investigation

“…Previous reliquefaction research focused on reliquefaction behaviors of reconsolidated soil without residual EPWP, including element tests, [15][16][17] shaking table model tests, [18][19][20][21][22][23][24] cyclic biaxial tests, 25 and DEM simulations. [26][27][28] However, the sand deposits may be shaken by the aftershocks when the ever-liquefied deposits are not completely reconsolidated as discussed before.…”

Experimental investigation on liquefaction and post-liquefaction deformation of stratified saturated sand under cyclic loading

“…In more recent studies of soil liquefaction, many scholars have used uniform or uniformly mixed soils as their experimental objects or samples (e.g., Ecemis et al 2015;Mandokhail et al 2017;Javdanian 2019;Dammala et al 2019). In order to determine the liquefaction properties of soils, a number of shaking table liquefaction tests (e.g., Carey et al 2017;Jin et al 2018;Chen et al2019), cyclic triaxial tests (e.g., Pan and Yang 2018;Wang et al 2018) and numerical simulations (e.g., Ye and Wang 2016;Lei and Matthew 2018) were carried out with various forms of soil samples.…”