Earthquake soil‐structure interaction of nuclear power plants, differences in response to 3‐D, 3 × 1‐D, and 1‐D excitations

Abstract

Summary In soil‐structure interaction modeling of systems subjected to earthquake motions, it is classically assumed that the incoming wave field, produced by an earthquake, is unidimensional and vertically propagating. This work explores the validity of this assumption by performing earthquake soil‐structure interaction modeling, including explicit modeling of sources, seismic wave propagation, site, and structure. The domain reduction method is used to couple seismic (near‐field) simulations with local soil‐structure interaction response. The response of a generic nuclear power plant model computed using full earthquake soil‐structure interaction simulations is compared with the current state‐of‐the‐art method of deconvolving in depth the (simulated) free‐field motions, recorded at the site of interest, and assuming that the earthquake wave field is spatially unidimensional. Results show that the 1‐D wave‐field assumption does not hold in general. It is shown that the way in which full 3‐D analysis results differ from those which assume a 1‐D wave field is dependent on fault‐to‐site geometry and motion frequency content. It is argued that this is especially important for certain classes of soil‐structure systems of which nuclear power plants subjected to near‐field earthquakes are an example.

Review of Soil-Structure Interaction Based on Continuum Mechanics Theory and Use of High Performance Computing

“…For this reason, the direct approach with three-dimensional high-fidelity models has not been often used. With the advancement of computers, the works applying larger three-dimensional models have been increasing; see [25][26][27][28]. The characteristic of such works is that they applied the solid element models with non-linear property only to the soil domain, not to the structure domain.…”

Development of a general‐purpose parallel finite element method for analyzing earthquake engineering problems

“…The two plate elements were interposed inside each of approximately 9,000 concrete blocks. We used the same material values, including Rayleigh damping, listed by Abell et al 6 The element number, node number, and DOFs were 334,260, 349,793, and 1,004379, respectively. The 1940 El Centro ground motion was applied for a duration of 53.78 s in increments of 0.02 s. The analysis was performed using server was equipped with an Intel Xeon E5-2670 CPU (2.6 GHz, 8 cores per node).…”

Broad-band 3-D earthquake simulation at nuclear site by an all-embracing source-to-structure approach

“…an inevitable increase of potentially dangerous places [1]. Therefore, scientists and regulators are progressively taking advantage of the ever-increasing computational power available, to embrace a holistic modeling strategy that couples the large scale seismological models for the region of interest (including the fault mechanism and the geological properties of the Earth's crust), with local engineering models for geotechnical, site-effect and structural analyses (see, for instance, the well established engineering method called Domain Reduction Method (DRM) [2,3], the Micro-Macro Analysis Method (MMAM) [4,5,6]). To this purpose, one major challenge to be faced resides into the need to enlarge the accuracy of the numerical prediction at higher frequency, so to render a synthetic broad-band On the other hand, seismological studies are struggling with the poor characterization of continental discontinuities and geological interfaces in the Earth's crust, which adds to the huge computational burden required to perform wave propagation/inversion studies in complex and large 3-D domains.…”