- The owner’s proactive measures are designed to keep an estimated 105,00 vehicles per day moving across the nearly 3-mile "critical" crossing in the event of an earthquake
- Haley & Aldrich’s specialized earthquake engineering capabilities supported the structural engineers in the examination of spatial variation in the subsurface conditions along the length of the bridge to generate a holistic, global analysis of bridge performance under 500- and 2500-year earthquake events
- Our understanding of soil dynamics applied to bridge structure interaction, developed over 50+ years of geotechnical engineering practice, gave our clients confidence in their recommendations to the Throgs Neck Bridge owners
- Our earthquake engineering expertise was essential to the comparison of life cycle costs for a rehabilitation option versus a total replacement option
|<< Back to Infrastructure Development
Throgs Neck Bridge Seismic Evaluation
Parsons Corporation and HNTB Corporation
New York, New York
Seismic vulnerability studies are being performed on major bridges throughout New York City’s five boroughs. The first priority is “critical” crossings, bridges which are being evaluated and, if necessary, rehabilitated by their various owners to meet current seismic guidelines.
Haley & Aldrich served as the geotechnical consultant to Parsons Corporation on the main span and to HNTB Corporation on the approaches to the Throgs Neck Bridge, which carries Interstate 295 between the Bronx and Queens across the East River where it meets Long Island Sound. We analyzed soil and rock conditions underlying the bridge and its approaches and applied earthquake engineering modeling under various seismic events using ProShake™ software. We performed ground motion analysis and developed design spectra for the approach regions, as well as acceleration and displacement time histories, for each of the anchorage and tower locations for 500- and 2500-year earthquakes. We provided our soil- structure interaction output to project structural engineers, who were then able to create models that would help the owner in their decision on whether a bridge retrofit would be needed to meet seismic guidelines and, if so, what kind of retrofit would be appropriate.