Seismic Vulnerability of the Highway System

Task F3-1(a): Parameters Studies and Design Impacts
Subject Area: NCHRP Project 12-49 Supporting Studies

Principal Investigator(s) and Institution(s)
Ronald Mayes, consultant
Richard V. Nutt, consultant

Objective and Approach
NCHRP Project 12-49 is developing a new seismic design specification and commentary intended as a replacement for the current provisions in the AASHTO LRFD Bridge Design Specifications. Funding for NCHRP Project 12-49 is sufficient to develop the specifications, commentary, and selected design examples but was not intended to support special studies or research that may have been required to address unique or special technical issues. Task F3 is intended to provide technical support during the development of the LRFD specifications, and assist in the development of training materials and workshops following it's conclusion.

Task F3-1(a) will provide support for the conduct of a series of parameter studies required to address the development of design and detailing provisions for various bridge components, including columns, foundations, and abutments. The parameter studies will evaluate the cost impact of different design decisions in a variety of seismic zones of the country. For example, the impact of different R-factors (ranging from 4 to 8) on column design and detailing will be evaluated based on requirements needed to satisfy the demands from different seismic hazard regions. These parametric studies will permit the project team, the NCHRP project panel, and the AASHTO Bridge Committee to make more informed decisions on the impact of alternate design decisions as the specifications are being developed, and will provide documentation regarding these decisions for future specification writers.

Anticipated Start Date and Duration
June 1, 1999 - 24 months