Seismic response analysis of nuclear power plant structures considering spatial incoherency of ground motions

This paper presents the application of a newly-developed soil-structure interaction analysis method, which allows the incorporation of general three-dimensional spatial coherency of free-field motions in the seismic input for seismic response analysis of nuclear power plant structures. The method, which has been developed using the conventional 'deterministic' time-history analysis approach, as opposed to the 'probabilistic' random vibrational analysis approach, is introduced. The validation of this deterministic method and the evaluation of its applicability using the Lotung 1/4-scale containment model test results are presented. An example application to a prototypical nuclear power plant containment structure is presented to demonstrate the significance of the spatial incoherence effect on the seismic response of nuclear structures. (author)