Mechanism of dissipation of excess flow pressures in unsaturated granular soils subjected to seismic excitations

Javad Ghorbani, David Airey

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

Abstract

This paper focuses on the response of unsaturated granular soils under cyclic loading and the subsequent dissipation mechanism of excess air and water pressure which can result in the accumulation of water in the upper layer and increase of saturation degree in these zones. A problem that can be the source of structural instability and leading to problems such as capsizing the ships carrying unsaturated iron cargo and landslide failure. The employed numerical model is based on previous developments by the authors of a finite element (FE) approach that considers the hydraulic hysteresis of Soil Water Characteristic Curves (SWCCs) with a mechanical model based on two-surface plasticity to capture the cyclic mechanical response. We demonstrate that the accumulation of water in unsaturated soils subjected to cyclic motions happens during the consolidation stage and our chosen numerical framework can successfully capture this process. It is also shown that the problem can be explained by considering the difference between the dissipation speed of the water and the air phase and the settlement of the unsaturated soil during the consolidation stage.

Original languageEnglish
Title of host publication7th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT2019)
Pages595-600
Number of pages6
Volume7
Edition2
DOIs
Publication statusPublished - 2019
Externally publishedYes
EventAsia-Pacific Conference on Unsaturated Soils 2019 - Nagoya, Japan
Duration: 23 Aug 201925 Aug 2019
Conference number: 7th
https://www.jstage.jst.go.jp/browse/jgssp/7/2/_contents/-char/en

Publication series

NameJapanese Geotechnical Society Special Publication
PublisherThe Japanese Geotechnical Society
Number2
Volume7
ISSN (Print)2188-8027
ISSN (Electronic)2188-8027

Conference

ConferenceAsia-Pacific Conference on Unsaturated Soils 2019
Abbreviated titleAP-UNSAT 2019
CountryJapan
CityNagoya
Period23/08/1925/08/19
Internet address

Keywords

  • Cyclic loads
  • Finite element modeling
  • Hysteresis
  • Unsaturated soils

Cite this

Ghorbani, J., & Airey, D. (2019). Mechanism of dissipation of excess flow pressures in unsaturated granular soils subjected to seismic excitations. In 7th Asia-Pacific Conference on Unsaturated Soils (AP-UNSAT2019) (2 ed., Vol. 7, pp. 595-600). (Japanese Geotechnical Society Special Publication; Vol. 7, No. 2). https://doi.org/10.3208/jgssp.v07.092