Impact of cascadia subduction zone earthquake on the seismic evaluation criteria of bridges : technical report : SPR 770.

Details

• Creators:
  Dusicka, Peter ; Lopez, Alvaro
• Corporate Creators:
  Portland State University. Department of Civil & Environmental Engineering
• Corporate Contributors:
  Oregon. Dept. of Transportation. Research Section ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Earthquakes
  • Earthquake resistant design
  • Seismic prospecting
  • Bridges Subduction zone earthquakes
  • seismic hazard analysis
  • reinforced concrete bridge columns
  • shake table test
  • Performance-based seismic design
• Publication/ Report Number:
  FHWA-OR-RD-17-04
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States;Oregon;Pacific States
• Corporate Publisher:
  Oregon. Dept. of Transportation. Research Section
• Abstract:
  A large magnitude long duration subduction earthquake is impending in the Pacific Northwest, which lies near the ; Cascadia Subduction Zone (CSZ). Great subduction zone earthquakes are the largest earthquakes in the world and are the sole source ; zones that can produce earthquakes greater than M8.5. For this reason, structures such as reinforced concrete bridges are facing high ; seismic hazards and risk. The seismic risk used for the bridge design and retrofit is defined by hazard maps of ground acceleration ; values. The maps combine multiple regional sources of ground shaking using a Probabilistic Seismic Hazard Analysis (PSHA). Each ; source has a different intensity, probability of occurrence, and distance to a specific location. One key source of ground shaking in ; PSHA in Oregon is from the Cascadia Subduction Zone; however, a CSZ has several potential scenarios (M8.3 and M9.0) that can have ; significantly different ground motion estimates as a standalone event than what is captured in the values derived from PSHA. In this ; study, a computer model called CSZ14 was developed to obtain the acceleration values expected from a full rupture CSZ event. These ; values were also compared to previous CSZ models as well as to uniform hazard of various return periods from USGS hazard adopted in ; 2002, which continues to be used for the current design of bridges. Also, the increased duration of a CSZ earthquake may result in more ; structural damage than expected. Recent long duration subduction earthquakes occurred in Maule, Chile (Mw 8.8, 2010) and Tohoku, ; Japan (Mw 9.0, 2011) are a reminder of the importance of the effect ground motion duration on structural performance. As part of the ; research on the potential impacts, the dynamic performance of circular reinforced concrete bridge columns was experimentally evaluated ; using shake table tests by comparing the column response from crustal and subduction ground motions. Three continuous reinforced ; columns and three laps-spliced columns were tested using records from 1989 Loma Prieta, 2010 Maule and 2011 Tohoku. The results ; demonstrated that duration of the motion can affect the imposed damage and the displacement capacity of the bridge column.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/31665/dot_31665_DS1.pdf
• File Type:
  [PDF - 13.57 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:bd0c64a0c27a4d69daf7d6a50de174aee0543e47b15d7c5662f3d02e4c7720de6b8288276ee2af859e53010bca958152246c3820ee85d39e66f39fd794cf66bf