Wave velocities depending on shear strain, directionality, and excess pore water pressure from wildlife liquefaction array

Tadahiro Kishida, Chi Chin Tsai

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Data from the Wildlife Liquefaction Array, which is located at southern California’s Imperial Valley in the USA, are analyzed. Variations in shear wave (Vs) and compression wave (Vp) velocities are identified during strong motions. Shear strains (γ) are computed from recorded acceleration time series between the sensors. All these variables are compared with the ground-surface accelerations and excess pore water pressure ratio (Ru) at different depths. Results show that Ru starts to accumulate when γ exceeds the threshold strain of 0.01–0.015%. Vs is negatively correlated to Ru and γ. Further investigation shows that Vs degradation depends on maximum horizontal shear strain with the different azimuthal angles at the same time window. By contrast, Vs reduction with Ru is caused by the decrease in effective stress; hence Ru reduces Vs regardless of the azimuthal angles. Vp degradation is limited compared with that of Vs under strong shaking, indicating that the constrain modulus is determined by the combination of soil skeleton and pore fluid.

Original languageBritish English
Pages (from-to)2371-2388
Number of pages18
JournalBulletin of Earthquake Engineering
Volume19
Issue number6
DOIs
StatePublished - Apr 2021

Keywords

  • Downhole array
  • Excess pore water pressure
  • Sand
  • Seismic loading
  • Shear strain
  • Wave velocity

Fingerprint

Dive into the research topics of 'Wave velocities depending on shear strain, directionality, and excess pore water pressure from wildlife liquefaction array'. Together they form a unique fingerprint.

Cite this