Inelastic Response of R/C Bridges Under Horizontal and Vertical Earthquake Motions

Saadeghvaziri, M.A.; Foutch, D.A.

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https://hdl.handle.net/2142/14165 Copy

Description

Title

Inelastic Response of R/C Bridges Under Horizontal and Vertical Earthquake Motions

Author(s)

• Saadeghvaziri, M.A.
• Foutch, D.A.

Issue Date

1988-06

Keyword(s)

• earthquake motions
• Elasticity
• Reinforced concrete
• highway bridges

Abstract

The relative importance of the vertical component of ground motion on the inelastic response of R/C highway bridges is investigated. Particular emphasis is placed on modeling of the deck and piers to account for. complex loading histories under combined vertical and horizontal earthquake motions. Analyses of several columns under non-proportional varying axial load indicate the importance of this type of loading on the inelastic behavior of R/C members. Furthermore, the results show that phasing of the axial load significantly affects properties of R/C columns that are very important in seismic design. Analyses of actual bridges indicate that, in general, the vertical motion will increase the level of response and the amount of damage sustained by a highway bridge. Variation in the strength and the stiffness of the columns, caused by varying axial load due to vertical motion, results in an increase in forces and moments in these elements and their foundation. Hysteresis loops are also affected when vertical motion is considered and more damage is sustained by the columns. Tensile axial load caused by the vertical motion reduces the shear capacity of the columns and the possibility of shear failure prevails. Finally, the magnitude and nature of forces induced by the vertical motion on the abutments and foundations are very different compared to cases where vertical motion is not considered. Therefore. it is important to consider this component of ground motion in the design of highway bridges, especially for those located in regions near seismic faults.

Publisher

University of Illinois Engineering Experiment Station. College of Engineering. University of Illinois at Urbana-Champaign.

Series/Report Name or Number

Civil Engineering Studies SRS-540

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/14165

Sponsor(s)/Grant Number(s)

National Science Foundation Grants ECE 85-11315 and ECE 86-10785

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