Centrifuge modeling of the seismic responses of sand deposits with an intra-silt layer

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 65; pp. 72 - 88
• Main Authors: Lee, Chung-Jung, Chen, Huei-Tsyr, Lien, Hon-Chen, Wei, Yu-Chen, Hung, Wen-Yi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2014
• Subjects: Centrifuge shaking table test; Centrifuges; Deposition; Deposits; Hydraulic gradient; Intra-silt layer; Liquefaction; Sand; Seismic response; Settlements; Shaking; Water film; Centrifuge shaking table test; Water film; Intra-silt layer; Liquefaction; Hydraulic gradient
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2014.06.002

Three dynamic centrifuge model tests were conducted at an acceleration of 80g to simulate the seismic responses of level sand deposits: an intra-silt layer was embedded in two of these sand deposits at different depths. The effects of a low-permeability intra-silt layer on the build-up and dissipation of excess pore-water pressure, surface settlement, and the related liquefaction mechanism were investigated. An intra-silt layer modifies the seismic response of the sand deposit, reduces the extent of liquefaction, and thus decreases surface settlement. The depth of the intra-silt layer is one of the factors influencing the seismic responses of the sand deposits. The magnitude of the surface settlement is proportional to the degree of liquefaction in the sand deposit. The high positive hydraulic gradients appearing in both the intra-silt layer and in the sand deposit lying on the intra-silt layer can break a thinner or weaker top layer and result in sand boiling. Our visual animation of the ratio of the excess pore-water pressure and the lateral displacement revealed that the liquefaction front travels upward during shaking and the solidification front travels upward after shaking. •This paper presents the liquefaction of sand deposit with an intra-silt layer.•Existence of intra-silt layer modifies the seismic response of the sand deposit.•Existence of intra-silt layer reduces the extent of liquefaction.•Existence of intra-silt layer reduces the surface settlement.•The high positive hydraulic gradient exists in the intra-silt layer.