AASHTO GSBSM-1: 2018 [pdf]

AASHTO GSBSM-1: Guide Specifications for Internal Redundancy of Mechanically-Fastened Built-Up Steel Members,

1st Edition with 2022 and 2025 Interim Revisions

Guide Specifications for Evaluating Steel Bridge Member Redundancy enhancing Safety and Inspection Efficiency

What’s Inside?

This guide provides a structured framework to assess the internal redundancy of typical steel bridge members, classifying them as either:

• Fracture Critical Members (FCMs)
• Internally Redundant Members (IRMs)

It outlines a step-by-step procedure for evaluating the internal redundancy of:

• Built-up tension members in flexural and axially loaded tension components.

Research-Backed Methodology

Based on Transportation Pooled Fund Project TPF-5(253), this guide addresses critical issues in performing credible analyses to identify built-up members with adequate internal redundancy. This ensures they can resist complete failure even if one component suddenly fails.

Revolutionizing Inspection Practices

The guide introduces a new methodology for establishing inspection intervals, shifting from traditional calendar-based approaches to a risk-informed, performance-based system. Key features include:

• A special inspection protocol for IRMs, designed to:
  • Detect severed tension components reliably.
  • Ensure inspections are depth and frequency-appropriate for safety.

Latest Updates

Incorporates 2022 and 2025 interim revisions to align with the latest advancements and research.

GSBSM-1-UL, GSBSM-1-I2-UL, 978-1-56051-724-5, 9781560517245