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Seismic Behavior of Earth Dams With Different Reservoir Water Levels Under Near-Field and Far-Field Earthquakes

Asadi Masoud, Soltani Fazlollah, Sinvandi-Pour Abbas, Noroozinejad Farsangi Ehsan

Civil and Environmental Engineering Reports

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2020

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Vol. 30, no. 4

125--141

EN

The height of reservoir water is one of the important factors affecting the seismic behaviour of earth dams. A large number of earth dams have been constructed in different countries that are sometimes located in a high-risk geographical zone. The studies on the seismic behaviour of earth dams have been conducted for several decades. However, this study, considering the importance of the subject, it investigates the seismic behaviour of Sumbar rock-fill embankment dam under near- and far-field earthquakes with variation in the water level behind the dam. The ratio of water height of the dam to dam height is considered as an important indicator to investigate the seismic performance of these structures. The analyses were performed using the ABAQUS finite element platform, under 7 near-field and 7 far-field earthquake records. In this research, the changes in dam stresses, displacements, and failure of the dam have been discussed. The results indicated that the effect of near-field earthquakes on the seismic behaviour of earth dams is more significant than far-field earthquakes.

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Seismic behaviour of cross-shaped steel fibre reinforced concrete columns

Sun Linzhu, Wei Zhengzhen, Li Wei, Xiang Jinhuai

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 4

418--436

EN

This paper proposes a novel cross-shaped column in which steel fibre reinforced concrete (SFRC) is integrated with a high-strength stirrup to enhance its seismic behaviour. An experimental investigation was conducted on eight cross-shaped column specimens subjected to cyclic lateral loading. All of the specimens were evaluated in terms of their cracking patterns, failure modes, hysteresis behaviour, deformation and ductility, strength and stiffness degradation, and energy dissipation performance. The effects of the stirrup strength, stirrup spacing, steel fibre content, and axial load ratio were investigated. The experimental results demonstrated that all of the specimens exhibited flexural failure. The cracked concrete of the specimens with steel fibres could be prevented from spalling. The hysteresis loops of all of the specimens were relatively full without a readily observable pinching phenomenon and the specimens possessed a satisfactory energy dissipation capacity. Compared with the normal specimens, the specimens with high-strength stirrups, close stirrup spacing, and steel fibre exhibited a higher energy dissipation capacity, lateral bearing capacity, displacement ductility, and initial stiffness. However, the ductility rapidly decreased as the axial load ratio increased. Additionally, neither the incorporation of steel fibre nor the reduction of the stirrup spacing or the axial load ratio substantially mitigated the stiffness degradation. Based on the test results, calculation models were proposed for calculating the seismic bending moment capacities of the specimens. The calculated values were in accordance with the test results.

3

Cyclic testing of steel frames infilled with concrete sandwich panels

Hashemi S. J., Razzaghi J., Moghadam A. S., Lourenço P. B.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 2

557--572

EN

In-plane seismic behaviour of concrete sandwich panel-infilled steel frame (CSP-ISF) was experimentally and numerically investigated. Four large-scale, single bay and single story steel frame specimens were tested under reversed cyclic lateral loading. Three infilled frames with different aspect ratios along with one bare frame were considered. It was found that addition of sandwich panels leads to considerable increase in the lateral stiffness and strength, ductility, energy dissipation capacity as well as equivalent viscous damping ratio of the steel frames. Furthermore, the maximum shear capacity of CSP-ISF specimens was validated by analytical approaches which showed good agreement with experimental results. Based on the present experiments, structural performance levels required for Performance-based Analysis are also proposed for concrete sandwich panel used as infill walls. Finally, a numerical model is presented to analyze the nonlinear behaviour of CSP-ISFs.