Bridge seismic retrofit measures considering subduction zone earthquakes.

Details

• Creators:
  Dusicka, Peter ; Bazaez, Ramiro ; Knoles, Sarah
• Corporate Creators:
  Portland State University. Department of Civil & Environmental Engineering
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Bridge design
  • Earthquake resistant design
  • Retrofitting
  • Reinforced concrete bridges
  • Bents
  • Braces
  • 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.
  More +
• Format:
  PDF
• Funding:
  SPR 741
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/29080/dot_29080_DS1.pdf
• File Type:
  [PDF - 11.33 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:a88e064df1cb74613b3ea2f44b9b1c4b554e35f7b494758d274ffa14ae7072392e8d47391cb7b43dde8a2d3344adf7677b21aedbf7c645b0beb6727990060671