Shake-table response of a bridge-like model with rocking piers and restraining tendons


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Date

2023

Publication Type

Other Conference Item

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yes

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Abstract

Rocking structures are the ones that uplift from their base when they are subjected to sufficiently strong ground motion excitation. Uplift works as a mechanical fuse, limiting the seismic forces transmitted to the structure. Therefore, rocking can be used as a seismic design strategy for buildings and bridges. This study presents the shake-table response of a bridge-like model under 184 ground motion excitations. The model represented a simplified bridge in 1:5 scale. It comprised four cylindrical rocking columns capped with a thick concrete slab. The columns were connected to the concrete slab with steel tendons (one tendon per column). The tendons were fixed at the top of the slab and at the base of the column. The axial stiffness of the tendons provided positive post-uplift stiffness to the system. The columns were allowed to rock and wobble, whereas steel restrainers prevented the columns from sliding out-of-position. After subjected to 170 design-level ground motions, the specimen demonstrated zero damage and minimal residual displacements. The peak displacements were below 250 mm (in model scale), thus compatible to the ones expected in seismically-isolated structures. The maximum force recorded at the tendons was below 70% of their maximum strength. The accelerations transmitted to the superstructure were below 0.2 g. The slab rotations were moderate and below 0.04 rad. The above confirm the efficiency of rocking as a seismic design strategy, especially when combined with steel tendons to provide positive lateral stiffness to the system. The experimental results promote the understanding and designing of rocking systems and provide an extensive dataset for the calibration of numerical models.

Publication status

published

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Editor

Book title

Abstract Volume 21st Swiss Geoscience Meeting

Journal / series

Volume

Pages / Article No.

242 - 243

Publisher

Swiss Academy of Sciences

Event

21st Swiss Geoscience Meeting (SGM 2023)

Edition / version

Methods

Software

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Date collected

Date created

Subject

Modular rocking bridges; Prefabricated concrete bridges; Restrained rocking; Resilient bridge design; Shake table testing; Finite element modeling

Organisational unit

09663 - Vassiliou, Michalis (ehemalig) / Vassiliou, Michalis (former) check_circle

Notes

Presentation held on November 18, 2023

Funding

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