Assessment of liquefaction-inducing peak ground velocity and frequency of horizontal ground shaking at onset of phenomenon
✍ Scribed by M.V. Kostadinov; I. Towhata
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 459 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0267-7261
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✦ Synopsis
It is recognized that soil improvement techniques are not economically feasible for mitigation of liquefaction-induced lifeline damages because of the large areas served. Instead, it is more practical to execute an emergency action immediately after an earthquake in order to prevent or minimize possible lifeline failures caused by the soil liquefaction. Essential element in the implementation of such a plan is the real-time identi®cation of lique®ed sites, which can be successfully achieved by analyzing surface strong motion records. In this paper, the thresholds of two ground motion parametersÐthe peak surface velocity and horizontal shaking frequency of the groundÐthat are associated with the soil liquefaction are assessed utilizing the theory of one-dimensional wave propagation in linearly elastic medium. Obtained simple expressions for both parameters are used to estimate their ranges and are examined against several case histories. Minimum level of peak ground velocity (PGV) is veri®ed by experimental data from shaking-table test. Linear relationships between amplitude ground motion parameters at lique®ed-soil sites are also developed. Results suggest that liquefaction is likely to take place when PGV exceeds 0.10 m/s and that the upper bound of horizontal ground vibration frequency after liquefaction occurrence is 1.3±2.3 Hz.