An Application to the Conditional Mean Spectrum Approach for Seismic Analysis of Coupled Dam–Foundation System

2021 ◽  
pp. 29-40
Author(s):  
Aniket R. Tidke ◽  
Shrabony Adhikary
Keyword(s):  
Seismic Analysis ◽  
Dam Foundation ◽  
Conditional Mean ◽  
Conditional Mean Spectrum

A Generalized Conditional Mean Spectrum and Its Application for Intensity-Based Assessments of Seismic Demands

2017 ◽  
Vol 33 (1) ◽  
pp. 123-143 ◽  
Author(s):  
N. Simon Kwong ◽  
Anil K. Chopra
Keyword(s):  
Computational Effort ◽  
Seismic Demands ◽  
Earthquake Scenario ◽  
Conditional Mean ◽  
Conditional Mean Spectrum ◽  
Accuracy And Precision ◽  
Target Spectrum ◽  
Hazard Level ◽  
Vector Valued

When the response of a structure is influenced significantly by multiple vibration modes, the seismic demands determined by response history analyses with ground motions selected to match a single conditional mean spectrum (CMS) may be unconservative for several response quantities. An existing solution to this problem is to determine the demand as the maximum of mean demands from several CMSs. To reduce the computational effort while maintaining accuracy and precision, we introduce an alternative engineering solution that is based on a simplified version of the generalized CMS, where two specified conditioning spectral accelerations share a common hazard level. vector-valued disaggregation is developed herein to provide a single earthquake scenario for the target spectrum. The results from a realistic case study suggest that the proposed spectrum provides seismic demands that are as accurate and precise as those obtained from analyzing the structure with multiple CMSs while simultaneously reducing the computational effort by a factor of 2 or more.

Seismic Analysis of Concrete Gravity Dams: Nonlinear Fracture Mechanics Models and Size-Scale Effects

2011 ◽  
Vol 82 ◽  
pp. 374-379 ◽  
Author(s):  
Marco Paggi ◽  
Giuseppe Ferro ◽  
Franco Braga
Keyword(s):  
Crack Propagation ◽  
Seismic Analysis ◽  
Scale Effects ◽  
Constitutive Law ◽  
Dam Failure ◽  
Gravity Dams ◽  
Dam Foundation ◽  
Size Scale ◽  
Concrete Gravity Dams ◽  
Nonlinear Dynamic Problem

The phenomenon of interface crack propagation in concrete gravity dams underseismic loading is herein addressed. This problem is particularly important from the engineeringpoint of view. In fact, besides Mixed-Mode crack growth in concrete, dam failure is oftenthe result of crack propagation along the rock-concrete interface at the dam foundation. Toanalyze such a problem, the generalized interface constitutive law recently proposed by the¯rst author is used to proper modelling the phenomenon of crack closing and reopening at theinterface. A damage variable is also introduced in the cohesive zone formulation in order topredict crack propagation under repeated loadings. Special attention is given to the complexityresulting from the solution of the nonlinear dynamic problem and to the choice of the interfaceconstitutive parameters, taking into account the important size-scale e®ects observed in thesecyclopic structures. Numerical examples will show the capabilities of the proposed approachwhen applied to concrete gravity dams.

Seismic Analysis of an Earth-Rock Dam on Thick Alluvial Deposit

2012 ◽  
Vol 594-597 ◽  
pp. 1811-1815
Author(s):  
Wei Jun Cen ◽  
Shuai Wang ◽  
Zhi Xiang Yang ◽  
Hui Sun
Keyword(s):  
Seismic Analysis ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Permanent Deformation ◽  
Dynamic Responses ◽  
Seismic Resistance ◽  
Dam Foundation ◽  
Dynamic Displacement ◽  
Alluvial Deposit

The nonlinear dynamic FEM was applied to analyze the dynamic response of a core-wall earth-rock dam on thick loess alluvial deposit. The dynamic responses of acceleration, dynamic displacement, permanent deformation and the liquefaction state of the dam were obtained. Meanwhile, both dynamic FEM limit equilibrium method and pseudo-static method were used to access the seismic resistance of dam slope stability. The results show that dynamic responses of acceleration and dynamic displacement are reasonable. The permanent deformation is mainly concentrated in the core wall. The downstream dam slope has enough seismic resistance stability. However, there will be big dynamic pore-water pressure in the dam foundation and the loess alluvial deposit will be liquefied during the earthquake. Therefore the resistance method of liquefaction should be adopted for the foundation.

Conditional mean spectrum for Bucharest

2014 ◽  
Vol 7 (2) ◽  
pp. 141-157
Author(s):  
Radu Vacareanu ◽  
Mihail Iancovici ◽  
Florin Pavel
Keyword(s):  
Conditional Mean ◽  
Conditional Mean Spectrum

Combining XFEM and time integration by α-method for seismic analysis of dam-foundation-reservoir

2020 ◽  
Vol 109 ◽  
pp. 102752 ◽  
Author(s):  
M. Haghani ◽  
B. Navayi Neya ◽  
M.T. Ahmadi ◽  
J. Vaseghi Amiri
Keyword(s):  
Seismic Analysis ◽  
Time Integration ◽  
Dam Foundation
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