Robustness of simplified analysis methods for rocking structures on compliant soil


Date

2020-11

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

Recognizing the beneficial effect of nonlinear soil-foundation response has led to a novel design concept, termed 'rocking isolation'. The analysis and design of such rocking structures require nonlinear dynamic time history analyses. Analyzing the entire soil-foundation-structure system is computationally demanding, impeding the application of rocking isolation in practice. Therefore, there is an urgent need to develop efficient simplified analysis methods. This paper assesses the robustness of two simplified analysis methods, using (i) a nonlinear and (ii) a bilinear rocking stiffness combined with linear viscous damping. The robustness of the simplified methods is assessed by (i) one-to-one comparison with a benchmark finite element (FE) analysis using a selection of ground motions and (ii) statistical comparison of probability distributions of response quantities, which characterize the time history response of rocking systems. A bridge pier (assumed rigid) supported on a square foundation, lying on a stiff clay stratum, is used as an illustrative example. Nonlinear dynamic FE time history analysis serves as a benchmark. Both methods yield reasonably accurate predictions of the maximum rotation theta(max). Their stochastic comparison with respect to the empirical cumulative distribution function of theta(max)reveals that the nonlinear and the bilinear methods are not biased. Thus, both can be used to estimate probabilities of exceeding a certain threshold value of theta.Developed in this paper, the bilinear method is much easier to calibrate than the nonlinear, offering similar performance. (© 2020 John Wiley & Sons).

Publication status

published

Editor

Book title

Volume

49 (14)

Pages / Article No.

1388 - 1405

Publisher

Wiley

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Rocking foundations; Rocking structures; Seismic isolation; Simplified analysis methodology; Soil–structure interaction

Organisational unit

09663 - Vassiliou, Michalis (ehemalig) / Vassiliou, Michalis (former) check_circle
09569 - Anastasopoulos, Ioannis / Anastasopoulos, Ioannis check_circle
02607 - Institut für Geotechnik / Institute for Geotechnical Engineering

Notes

Funding

172512 - Overturning probability of uplifting structures under far-field earthquake excitation (SNF)

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