Probabilistic Seismic Demand Models and Life-Cycle Fragility Estimates for High-Rise Buildings

2021 ◽  
Vol 147 (12) ◽  
Author(s):  
Xiao-Wei Zheng ◽  
Hong-Nan Li ◽  
Paolo Gardoni
Keyword(s):  
Life Cycle ◽  
Seismic Demand ◽  
High Rise ◽  
Demand Models ◽  
Probabilistic Seismic Demand

scholarly journals Optimal Earthquake Intensity Measures for Probabilistic Seismic Demand Models of Base-Isolated Nuclear Power Plant Structures

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5163
Author(s):  
Duy-Duan Nguyen ◽  
Tae-Hyung Lee ◽  
Van-Tien Phan
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Seismic Demand ◽  
Lumped Mass ◽  
Earthquake Intensity ◽  
Intensity Measures ◽  
Demand Models ◽  
Probabilistic Seismic Demand ◽  
Spectrum Intensity

The purpose of this study is to evaluate the optimal earthquake intensity measures (IMs) for probabilistic seismic demand models (PSDMs) of the base-isolated nuclear power plant (NPP) structures. The numerical model of NPP structures is developed using a lumped-mass stick model, in which a bilinear model is employed to simulate the force-displacement relations of base isolators. In this study, 20 different IMs are considered and 90 ground motion records are used to perform time-history analyses. The seismic engineering demand parameters (EDPs) are monitored in terms of maximum floor displacement (MFD), the maximum floor acceleration (MFA) of the structures, and maximum isolator displacement (MID). As a result, a set of PSDMs of the base-isolated structure is developed based on three EDPs (i.e., MFD, MFA, and MID) associated with 20 IMs. Four statistical parameters including the coefficient of determination, efficiency (i.e., standard deviation), practicality, and proficiency are then calculated to evaluate optimal IMs for seismic performances of the isolated NPP structures. The results reveal that the optimal IMs for PSDMs with respect to MFD and MID are velocity spectrum intensity, Housner intensity, peak ground velocity, and spectral velocity at the fundamental period. Meanwhile, peak ground acceleration, acceleration spectrum intensity, A95, effective peak acceleration, and sustained maximum acceleration are efficient IMs for PSDMs with respect to MFA of the base-isolated structures. On the other hand, cumulative absolute velocity is not recommended for determining the exceedance of the operating basis earthquake of base-isolated NPP structures.

A Probabilistic Seismic Demand Model for Regular Highway Bridges

2016 ◽  
Vol 847 ◽  
pp. 307-318 ◽  
Author(s):  
Hai Bin Ma ◽  
Wei Dong Zhuo ◽  
Gu Yin ◽  
Ying Sun ◽  
Li Bo Chen
Keyword(s):  
Probability Distributions ◽  
Highway Bridges ◽  
Seismic Demand ◽  
Site Conditions ◽  
Demand Model ◽  
Demand Models ◽  
Probabilistic Seismic Demand ◽  
Performance Based Seismic Design ◽  
Seismic Demand Model ◽  
And Performance

Probabilistic seismic demand models are important for the design of structures based on the seismic probability and the performance of the structure. In this paper, the probabilistic seismic demands of 8 representative regular highway bridges are calculated using the cloud approach by selecting 2390 earthquake records for 3 different site conditions. These demands are expressed in terms of an intensity measure (IM), which is the spectral acceleration at the fundamental period with 5% damping, and an engineering demand parameter (EDP), which is the drift ratio at the top of pier. The probability distributions of the EDP are established at several IM levels. The results show that the EDPs have reasonably standard beta distributions at different IM levels. A correlation between the mean EDP and the IM is also established using regression analysis. The probabilistic seismic demand model is suitable for 3 different site conditions and can greatly simplify the calculation of seismic demand in the probability-based and performance-based seismic design of regular bridges.

scholarly journals Fragility Curves and Probabilistic Seismic Demand Models on the Seismic Assessment of RC Frames Subjected to Structural Pounding

2021 ◽  
Vol 11 (17) ◽  
pp. 8253
Author(s):  
Maria G. Flenga ◽  
Maria J. Favvata
Keyword(s):  
Fragility Curves ◽  
Seismic Demand ◽  
Rc Structures ◽  
Structural Pounding ◽  
Rc Frames ◽  
Rc Structure ◽  
Demand Models ◽  
Probabilistic Seismic Demand ◽  
Displacement Based ◽  
The Impact

This study aims to evaluate five different methodologies reported in the literature for developing fragility curves to assess the seismic performance of RC structures subjected to structural pounding. In this context, displacement-based and curvature-based fragility curves are developed. The use of probabilistic seismic demand models (PSDMs) on the fragility assessment of the pounding risk is further estimated. Linear and bilinear PSDMs are developed, while the validity of the assumptions commonly used to produce a PSDM is examined. Finally, the influence of the PSDMs’ assumptions on the derivation of fragilities for the structural pounding effect is identified. The examined pounding cases involve the interaction between adjacent RC structures that have equal story heights (floor-to-floor interaction). Results indicate that the fragility assessment of the RC structure that suffers the pounding effect is not affected by the examined methodologies when the performance level that controls the seismic behavior is exceeded at low levels of IM. Thus, the more vulnerable the structure is due to the pounding effect, the more likely that disparities among the fragility curves of the examined methods are eliminated. The use of a linear PSDM fails to properly describe the local inelastic demands of the structural RC member that suffers the impact effect. The PSDM’s assumptions are not always satisfied for the examined engineering demand parameters of this study, and thus may induce errors when fragility curves are developed. Nevertheless, errors induced due to the power law model and the homoscedasticity assumptions of the PSDM can be reduced by using the bilinear regression model.

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