Critical Appraisal of Foundation and Substructure Code for Highway Bridges (IRC:78-2014)

Abstract

Harmonization of structural design codes in Europe has been successfully done, where the process culminated in 2010 after 25 years of long and dedicated effort by a group of experts from EU commission. Similar philosophical changes in American codes occurred in the late 1990s and early 2000s through a completely different process. Indian Roads Congress (IRC) is working for more than 15 years now to harmonize the IRC codes pertaining to highway bridge design to limit state philosophy. Significant progress has already been made in this regard. The code on Foundation and Substructure (IRC:78-2014) is, however, still maintaining the working stress philosophy of design and yet to fall in line with the rest of the suite of codes. The philosophical difference between limit state version and working stress version presents a great challenge as well as some confusion in this transition phase. In this paper, a critical appraisal of the current provisions of IRC:78-2014 is highlighted. Inconsistencies between this code and other published codes of IRC are brought out. Some of the contentious provisions in the code which quite often creates confusion to structural and geotechnical engineers in the design of bridge foundations are also highlighted.