Details:

Creators:
Dusicka, Peter ; Bazaez, Ramiro ; Knoles, Sarah
Dusicka, Peter ; Bazaez, Ramiro ; Knoles, Sarah Less -
Corporate Creators:
Portland State University. Dept. of Civil & Environmental Engineering
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Bents Braces Bridge Design Earthquake Resistant Design Reinforced Concrete Bridges Retrofitting Structural Analysis
Publication/ Report Number:
FHWA-OR-RD-16-01
Resource Type:
Tech Report
Geographical Coverage:
Oregon
Corporate Publisher:
Oregon. Dept. of Transportation. Research Section
Abstract:
Over the years, earthquakes have exposed the vulnerability of reinforced concrete structures under

seismic loads. The recent occurrence of highly devastating earthquakes near instrumented regions, e.g. 2010 Maule, Chile

and 2011 Tohoku, Japan, has demonstrated the catastrophic impact of such natural force upon reinforced concrete

structures. Research was conducted to investigate the effect of subduction zone earthquakes on structural damage. The

study suggests that large magnitude ground motions of long duration have the potential of significantly increasing the

number of inelastic excursions and consequently incur more extensive structural damage as compared to ground motions

with similar elastic spectral demands but of shorter duration. This increase in demand plays a crucial role in the Pacific

Northwest where a mega subduction zone earthquake is impending.

Typical reinforced concrete bridge bents constructed in the 1950 to mid-1970 in the State of Oregon were designed and

built with minimum seismic considerations. This resulted in inadequate detailing within plastic hinge zones, leaving

numerous RC bents highly susceptible to damage following an earthquake. In this study, the cyclic performance of an as-built RC square column and a reinforced concrete bridge bent retrofitted using buckling restrained braces (BRBs) was

experimentally evaluated using quasi-static cyclic loading protocols aiming to reflect subduction zone earthquake

demands up to displacement ductility. The buckling restrained braces were designed as replaceable elements in order to

take the earthquake-induced energy and dissipate it through nonlinear hysteretic behavior. Two BRB designs were

considered in the study in an effort to assess the influence of BRB stiffness on the overall structural performance. The

results of these large-scale experiments successfully demonstrated the effectiveness of utilizing buckling restrained braces

for achieving high displacement ductility of the retrofitted structure, while also controlling the damage of the existing

vulnerable reinforced concrete bent up to the design performance levels. The potential of improving the overall seismic

behavior and the design performance levels with BRBs offers structural design professionals a viable method for

performance driven retrofit of reinforced concrete bents.


Format:
PDF
Funding:
SPR 741
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:10c2c21bc907d264aa6bdaf23833a7c03e861f843f8ca1308e7024cc88fefb7d
Download URL:
https://rosap.ntl.bts.gov/view/dot/29080/dot_29080_DS1.pdf
File Type:

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