Effects of embedment including slip and separation on seismic SSI response of a nuclear reactor building

The seismic response of nuclear reactor containment building considering the effects of embedment, slip and separation at soil–structure interface requires modeling of the soil, structure and interface altogether. Slip and separation at the interface causes stress redistribution in the soil and the structure around the interface. The embedment changes the dynamic characteristics of the soil–structure system. Consideration of these aspects allows capturing the realistic response of the structure, which has been a research gap and presented here individually as well as taken together. Finite element analysis has been carried out in time domain to attempt the highly nonlinear problem. The study draws important conclusions useful for design of nuclear reactor containment building.

► Both the slip and separation of reactor base reduce with increase in embedment.
► The slip and separation become insignificant beyond 1/4 and 1/2 embedment respectively.
► The stresses in reactor reduce significantly upto 1/4 embedment.
► The stress reduction with embedment is more pronounced in case of tensile stresses.
► The modeling of interface is important beyond 1/8 embedment as stresses are underestimated otherwise.