The boundary reaction method(BRM) is a substructure time domain method, it removes global iterations between frequency and time domain analyses commonly required in the hybrid approaches, so that it operates as a two-step uncoupled method. The BRM offers a two-step method as follows: (1) the calculation of boundary reaction forces in the frequency domain on an interface of linear and nonlinear regions, (2) solving the wave radiation problem subjected to the boundary reaction forces in the time domain. In the time domain analysis, the near-field soil is modeled to simulate the wave radiation problem. This paper evaluates the performance of the BRM according to modeling extent of near-field soil for the nonlinear SSI analysis of base-isolated NPP structure. For this purpose, parametric studies are performed using equivalent linear SSI problems. The accuracy of the BRM solution is evaluated by comparing the BRM solution with that of conventional SSI seismic technique. The numerical results show that the soil condition affects the modeling range of near-field soil for the BRM analysis as well as the size of the basemat. Finally, the BRM is applied for the nonlinear SSI analysis of a base-isolated NPP structure to demonstrate the accuracy and effectiveness of the method.

해양사고의 약 80% 정도가 인적과실(Human elements)에 의해 발생하고 있으며 특히 우리나라 해양사고의 대부분을 차지하는 해양사고는 충돌사고로 94%에 이른다. 국제해사기구(IMO)와 주요 국가들이 인적요인의 중요성을 인식하고 인간과실 예방에 대한 연구 및 분석을 추진하고 있으나 개념정립과 단편적 정보전달에 국한되고 있어 실용성이 부족한 편이다. 한편 본 연구에서는 실제 발생한 우리나라의 해양사고의 원인을 BRM/ERM 요인을 통해 분석하여 2017년부터 STCW 2010 마닐라 협약의 개정으로 강제화되는 리더십 및 팀워크(BRM/ERM 포함) 교육에 강조될 수 있는 부분을 식별하였다