For the OPR1000, a standard power plant in Korea, an analytical model of the containment building considering voids and deterioration was built with multilayer shell elements. Voids were placed in the vulnerable parts of the analysis model, and the deterioration effects of concrete and rebar were reflected in the material model. To check the impact of voids and deterioration on the seismic performance of the containment building, iterative push-over analysis was performed on four cases of the analytical model with and without voids and deterioration. It was found that the effect of voids with a volume ratio of 0.6% on the seismic performance of the containment building was insignificant. The effect of strength reduction and cross-sectional area loss of reinforcement due to deterioration and the impact of strength increase of concrete due to long-term hardening offset each other, resulting in a slight increase in the lateral resistance of the containment building. To determine the limit state that adequately represents the seismic performance of the containment building considering voids and deterioration, the Ogaki shear strength equation, ASCE 43-05 low shear wall allowable lateral displacement ratio, and JEAC 4601 shear strain limit were compared and examined with the analytically derived failure point (ultimate point) in this study.
Unlike other facilities, maintaining processes is essential in industrial facilities. Pipe racks, which support pipes of various diameters, are important structures used in industrial facilities. Since the transport process of pipes directly affects the operation of industrial facilities, a fragility curve should be derived based on considering not only the pipe racks' structural safety but also the pipes' transport process. There are several studies where the fragility curves have been determined based on the structural behavior of pipe racks. However, few studies consider the damage criteria of pipes to ensure the transportation process, such as local buckling and tensile failure with surface defects. In this study, an analysis model of a typical straight pipe rack used in domestic industrial facilities is constructed, and incremental dynamic analysis using nonlinear response history analysis is performed to estimate the parameters of the fragility curve by the maximum likelihood estimation. In addition, the pipe rack's structural behavior and the pipe's damage criteria are considered the limit state for the fragility curve. The limit states considered in this paper to evaluate fragility curves are more reasonable to ensure the transportation process of the pipe systems.
처짐, 응력 및 휨강도 한계상태에 대한 PSSC(prestressed steel and concrete)거더의 신뢰도해석을 수행한다. PSSC 거더는 시공비용과 형하공간의 확보 면에서 지간 40m이상인 교량에 적용하는데 커다란 장점을 가지고 있는 형식이다. 이 논문에서는 다양한 지간, 단면 및 설계 응력수준을 가지는 PSSC 거더를 설계하여 중앙점 처짐, 응력 및 단면 휨모멘트 해석을 수행하고, 각각에 대한 한계상태를 가정한 후, Monte-Carlo 시뮬레이션과 Rackwitz-Fiessler 방법을 이용하여 신뢰도지수를 구한다. 결과를 분석하면 PSSC 거더에 대한 처짐한계상태는 응력한계상태보다 적절하게 큰 신뢰도지수 값을 보이며, 휨강도에 대한 신뢰도지수가 매우 큼을 알 수 있다.