Conceptualmodels for describing the liquefaction and resolidification of quicksand One-dimensional vertical behavior of a saturated, loosely packed soil column

摘要

Large areas of former Lusatian opencast pits have recently become inaccessible due to gravitational mass movements. To understand the underlying liquefaction process of the overburden dump sand and to describe it on agranular scale, the one-dimensional vertical behavior of asaturated, loosely packed soil column was studied, based on experiments by Wittig and Zander (2014). Considering elevation energy, sphere packing and interfaces, several conceptual models for describing the liquefaction and resolidification of quicksand were developed. The analyses suggest that liquefaction leads to horizontal grain movement and thus to effective stress reduction and increases in pore water pressure. Furthermore, it is hypothesized that grain settlement during the resolidification phase is linked to the relative movement between displaced pore water and the suspended grain filter of the granulate structure. The filter flow can be described by Darcy's law. Hypotheses were derived from the conceptual models, which need to be experimentally validated.