Henderson Point Connector (US HWY 90): Green Infrastructure Techniques for Coastal Highway Resilience
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields

Dates

to

Document Data
Library
People
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Henderson Point Connector (US HWY 90): Green Infrastructure Techniques for Coastal Highway Resilience

Filetype[PDF-3.70 MB]


English
Details You May Also Like

Details:

  • Creators:
  • Corporate Creators:
  • Corporate Contributors:
    United States. Federal Highway Administration
  • Subject/TRT Terms:
  • Publication/ Report Number:
    FHWA-HEP-18-042
  • Resource Type:
    Tech Report
  • Geographical Coverage:
  • Corporate Publisher:
    United States. Federal Highway Administration
  • Abstract:
    The storm surge and waves generated by Hurricane Katrina caused widespread damage to built infrastructure in coastal Mississippi and neighboring states. A number of coastal bridges and roadways failed during this event. One such bridge in coastal Mississippi was the Henderson Point connector that carries US HWY 90 over railroad tracks and a small tidal creek. One two-lane span was completely displaced from its bent beams while the adjacent span shifted laterally by a few inches. The causes of the failure were not known before this study began. This particular site was chosen for the pilot project in order to address a key knowledge gap regarding the vulnerability of coastal bridges: the approach embankment and approach spans that pass through critical elevations where damage during extreme storms is likely. This green infrastructure pilot project seeks to develop a solution that addresses this vulnerability while increasing the resilience of the built and natural systems. Multiple hydrodynamic models were used to determine the likely causes of failure at the Henderson Point bridge. A number of conventional gray adaptation solutions and green infrastructure adaptation options were considered in this study. A pair of vegetated berms were selected for evaluation as a green infrastructure solution (Figure ES 1). The berms would eliminate or substantially reduce flow velocities near the bridge abutment and low-elevation approach spans by redirecting flood flows away from those vulnerable elements. Even with a relatively low material cost (~$20,000 not including vegetation), the vegetated berms would reduce the likelihood of bridge span failure during its 50-yr design life from 64% to 39%, by protecting the bridge against the 1% annual chance coastal flood event (current protection level is to the 2% event). There were three significant lessons learned in this pilot project. First, this may be the first known coastal bridge that failed as a result of hydrodynamic drag forces due to flowing water during a hurricane. Second, the application of multiple hydrodynamic models at varying spatial scales delivers superior information about damaging coastal hazards near a transportation asset. Third, there may be similar opportunities to improve the resilience of low-elevation bridge spans to similar types of damage in future storm events. For low-elevation bridge spans over land, extending the embankment to higher elevations, or using something similar to the vegetated berms considered here, could potentially reduce their vulnerability to extreme events now and in the future.
  • Format:
    PDF
  • Collection(s):
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

You May Also Like

Checkout today's featured content at rosap.ntl.bts.gov