Seismic Soil-Structure Interaction Analysis of an Embedded Structure with Partially Bonded Side-Soil

Seismic soil-structure interaction (SSI) analysis is performed for an embedded structure with partially bonded side-soil in support of the seismic probabilistic risk assessment of a nuclear power plant. Adjacent buildings with shallower embedment shield the subject structure on all four sides from soil over their embedded depths, creating a partially bonded condition where soil is not in full contact with the sides of the structure up to grade. An efficient, state-of-the-art, hybrid method employing computer programs SASSI2010 [Ostadan and Deng, (2010)], RIGID2017, and CLASSI [Luco and Wong (1980)], as presented in Johnson et al. (2019), is used for this analysis.

The hybrid method takes advantage of the capability of SASSI2010 and RIGID2017 to analyze embedded structures with partially bonded side-soil and the computational efficiency of CLASSI to rapidly perform the SSI response analysis of large structure models. RIGID2017 imposes rigid constraints in the embedded region to allow for the determination of impedance and scattering functions.

Impedance functions, scattering functions, and in-structure response spectra (ISRS) are compared between analyses that consider various side-soil bonding heights. These comparisons show the effects of partial embedment and substantiate the results.

Read the article.