Seismic performance sensitivity and uncertainty analysis of gravity dams

Abstract

SUMMARYUncertainties in structural engineering are often arising from the modeling assumptions and errors, or from variability in input loadings. A practical approach for dealing with them is to perform sensitivity and uncertainty analysis in the framework of stochastic and probabilistic methods. These analyses can be statically and dynamically performed through nonlinear static pushover and IDA techniques, respectively. Of the existing structures, concrete gravity dams are infrastructures which may encounter many uncertainties. In this research, probabilistic analysis of the seismic performance of gravity dams is presented. The main characteristics of the nonlinear tensile behavior of mass concrete, along with the intensity of earthquake excitations are considered as random variables in the probabilistic analysis. Using the tallest non-overflow monolith of the Pine Flat gravity dam as a case study, its response under static and dynamic situations is reliably examined utilizing different combinations of parameters in the material and the seismic loading. The sensitivity analysis reveals the relative importance of each parameter independently. It will be shown that the undamaged modulus of elasticity and tensile strength of mass concrete have more significant roles on the seismic resistance of the dam than the ultimate inelastic tensile strain. In order to propagate the parametric uncertainty to the actual seismic performance of the dam, probabilistic simulation methods such as Monte Carlo simulation with Latin hypercube sampling, and approximate moment estimation techniques will be used. The final results illustrate the possibility of using a mean-parameter dam model to estimate the mean seismic performance of the dam.

On the Dynamic Capacity of Concrete Dams

“…Considering the RTR variability in the IDA capacity functions, they should be summarized using some central values like the mean, median, and 16% and 84% fractiles. [47], (c) gravity dam [48], (d) gravity dam [49], (e) gravity dam [43], (f) arch dam [50], (g) gravity dam [51], and (h) gravity dam [52]. PGA, peak ground acceleration.…”

Seismic performance assessment and potential failure modes of intake towers

“…However, the model was too simple to present seismic failure of the intake tower. Alembagheri and Ghaemian (2012, 2013, 2015 used incremental dynamic analysis (IDA) to determine the seismic performance and different limit states of hydraulic structures, such as gravity and arch dams. For PBSD, IDA (Vamvastsikos 2002) is an emerging method that offers a thorough estimation of the seismic demand and limit state capacity of a structure.…”

Investigating Efficiency of Vector-Valued Intensity Measures in Seismic Demand Assessment of Concrete Dams

“…A vector IM would contain more information about the ground motion than a scalar IM, and it has been shown that it is more effective in predicting the response of building frames and bridges [11][12][13][14][15][16][17]. Probabilistic seismic assessment of concrete dams using single-valued IMs has been well performed [18][19][20][21], but such study employing vector-valued IMs is very scarce.…”