ABSTRACT
Several bridge design specications will be referred to repeatedly herein. In order to simplify the references, the “Standard Specications” means the AASHTO Standard Specifications for Highway Bridges (AASHTO, 2002), the 17th edition will be referenced unless otherwise stated. e “LRFD Specications” means the AASHTO LRFD Bridge Design Specifications (AASHTO, 2012), and the 6th edition will be referenced, unless otherwise stated. e 1st edition of this latter document was developed in the period 1988-1993 when statistically-based probability methods were available, and that became the basis of quantifying safety. Because this is a more modern philosophy than either the load factor design (LFD) method or the allowable stress design (ASD) method, both of which are available in the Standard Specications, and neither of which have a mathematical basis for establishing safety, much of the chapter will deal primarily with the LRFD Specications (AASHTO, 2012).
