Source: ASTM International, West Conshohocken, Pa.
The American Association of State Highway and Transportation Officials’ load and resistance factor design (LRFD) methodology plays a key role in the proposed ASTM WK38166, Specification for Manufacture of Precast Reinforced Concrete Three-Sided Structures for Culverts and Storm Drains.
The standard is being developed by ASTM Subcommittee C13.07 on Acceptance Specification and Precast Concrete Box Sections, part of Committee C13 on Concrete Pipe. In 1988, AASHTO launched a project to develop a modern and comprehensive bridge specification. The resulting document utilized LRFD and incorporated elements of working stress and load factor design. These elements were familiar to bridge engineers addressing events such as earthquakes, floods and ship collisions that could have catastrophic effects on bridges.
According to Michigan Department of Transportation Special Structures Engineer Balaram Singh, chairman of Subcommittee C13.01 on Non-Reinforced Concrete Sewer, Drain and Irrigation Pipe, ASTM WK38166 will be a comprehensive, well-organized and practical specification providing background on designing culverts and storm drains in accordance with the AASHTO LRFD standard. “Culverts and storm drains designed according to LRFD have the inherent advantage of a more uniform level of safety, resulting in low life-cycle cost,” he says. “LRFD allows the use of advanced methods in design and analysis. It provides flexibility for maintaining good and successful engineering practices or customizing load and resistance factors to meet the demands of a project. There will be many good reasons to use the LRFD methodology-based specification once it has been approved.”
Singh notes that C13.07 is interested in developing a real time testing protocol for the proposed standard. All stakeholders in engineering, production and construction are invited to contribute to the ongoing development of ASTM WK38166. — www.astm.org