Analysis of strong ground motion characteristics recorded on reclaimed soil site

Abstract

This paper discusses the difference between the strong ground motion of reclaimed soil sites and those of free-field ground motion. We determine under what conditions the influence of reclaimed soil can be ignored, and the ground motion on the reclaimed soil site can be regarded as a free field. Finite element models of reclaimed soil were constructed by analyzing the actual situation of strong ground motion observation on reclaim soil sites. Using a “lumped mass explicit dynamic finite element” method, the effects of shear wave velocity and thickness of reclaimed soil on free-field ground motion are analyzed. Replacing thicker reclaimed soil with remolded soil is proposed to reduce the impact of reclaimed soil sites on the ground motion of free field sites, the effects of which are analyzed by numerical simulation. Results show that the ground motion peak and the response spectra of the reclaimed soil site are significantly different from those of the free field site. With increasing reclaimed soil thickness, the influence is more noticeable. The impact of reclaimed soil on the free-field site can be reduced with reclaimed soil being replaced by remolding soil. The conclusions provide a theoretical basis for the rational use of strong ground motion records on the reclaimed soil site and the construction of strong motion stations.