Experimental and Numerical Study on Earthquake-Induced Ground Strains

Abstract eng:
Seismic design of buried structures is mainly based on the evaluation of the ground-motion induced strain field, and of the related seismic action effects on the structure. The main drawback of this approach is that it cannot rely upon a direct measure of the design parameter, strain meters being not generally available in seismic networks. For an indirect measure, simplified formulas relating peak ground strain to peak ground velocity are generally used, based on 1D wave propagation theory in homogeneous media. These formulas, dating back to Newmark’s studies, suffer from several major limitations: i) they should not be applied when the structure crosses strong lateral discontinuities in soil properties; ii) even for homogeneous media they strongly depend on the wave type and on the incidence angle, a kind of information that is not generally available to the designer; iii) they do not account for spatial incoherency of ground motion. Starting from some meaningful results obtained through an experimental procedure for evaluating transient ground strains from dense seismic networks, a summary of the results of a parametric numerical study of wave propagation inside a real basin, the one of the Turkish town of Düzce, hit by two major earthquakes in 1999 that badly affected the buried pipeline network, will be shown. This allows us to give insights into the relative contribution to earthquake induced ground strains of different effects, such as frequency content of input motion, basin-edge induced seismic waves, soil-nonlinearity.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket