Bridges & Structures

Geohazards

The geotechnical hazards for transportation applications covered under this technical area include method, procedural and policy guidance for seismic design and retrofit, extreme events, abandoned underground mines, and for evaluating bridges with unknown foundations.

Features

• National Strategy for Landslide Loss Reduction 
  Landslide hazards are present in all 50 States and most U.S. territories, and they affect lives, property, infrastructure, and the environment. Landslides are the downslope movement of earth materials under the force of gravity. They can occur without any obvious trigger. Widespread or severe landslide events are often driven by such hazards as hurricanes, earthquakes, volcanic eruptions, heavy rain events, flooding, and wildfires. Landslides can also cause their own cascading consequences, such as the spread of hazardous materials or the creation of devastating local tsunamis.

  This strategy document, published by the U.S. Geological Survey's Landslide Hazards Program, fulfills the requirements of the National Landslide Preparedness Act (Public Law 116-323) for the publication of a national strategy for landslide hazards, risk reduction, and response. The document was prepared in coordination with a Federal interagency working group that included FHWA. It incorporates input and feedback from a 3-day workshop held virtually on June 22-24, 2021.

  The document presents a vision of how to equitably produce, communicate, and apply landslide data and science to support a broad range of land management, infrastructure, planning, and emergency response decisions.

• Abandoned Underground Mines Resources
• Unknown Foundations

Policy

• Additional Guidance for Assessment of Bridges Over Waterways with Unknown Foundations (10/29/2009)

Guidance

• Eligibility of Activities To Adapt To Climate Change and Extreme Weather Events Under the Federal-Aid and Federal Lands Highway Program (09/24/2012)
• Guidance on Applying Risk Based, Data Driven Decision-Making Process to the FHWA Scour Program (04/09/2012)
• HEC 18 - Evaluating Scour at Bridges (5th edition) (April, 2012)
• Geotechnical Engineering Circular No. 3 - LRFD Seismic Analysis and Design of Transportation Geotechnical Features and Structural Foundations Reference Manual (2011)
• Frequently Asked Questions - Bridges Over Waterways with Unknown Foundations (06/03/2009)
• Checklist and Guidelines for Review of Geotechnical Reports and Preliminary Plans and Specifications (February, 2003)
• Differing Site Conditions (10/09/1996)

Information

• HEC 23 - Bridge Scour and Stream Instability Countermeasures: Experience, Selection, and Design Guidance (3rd edition, Volume 1) (September, 2009)
• HEC 23 - Bridge Scour and Stream Instability Countermeasures: Experience, Selection, and Design Guidance (3rd edition, Volume 2) (September, 2009)

Training & Workshops

• Web-based Resilience Courses
  • FHWA-NHI-142081 Understanding Past, Current and Future Climate Conditions
  • FHWA-NHI-142082 Introduction to Temperature and Precipitation Projections
  • FHWA-NHI-142083 Systems Level Vulnerability Assessments
  • FHWA-NHI-142084 Adaptation Analysis for Project Decision Making
• NHI Geotechnical Courses

Publications

• Manual for Abandoned Underground Mine Inventory and Risk Assessment
• Hazards Publications

Memos

• GT-16 - Unknown Foundations (.pdf, 0.7 mb)