introduCtion Standard installation Direct Design (SIDD) Design Specification ConCrete pipe The design is based on the American Society of Civil Engineers (ASCE) publication 15-98, “Standard Practice for Direct Design of Buried Precast Concrete Pipe Using Standard Installations (SIDD)”. From the Abstract — “It is based on research and testing over the past twenty years to develop a more rational design procedure for the direct design of buried concrete pipe based on engineering principles followed for the direct design of other reinforced concrete members.” stormwater treatment teChnologies Manufacturing Specification This specification provides the same level of quality and tolerances as the ASTM C76 standard for Class II through V pipe. Beneficial Characteristics Conservative — Analyses are based on the worst case (embankment) loadings, voids in the haunch zone, the greatest predicted loads, and measurable requirements that more accurately assess long-term performance of the system. Versatile — The designer can choose between installation types to suit specific site conditions and budgetary constraints. The four standard installations can be used to optimize the total installed cost by evaluation of the relative pipe cost and backfill material supply and compaction cost. Quantifiable — Definite and measurable levels of acceptance are prescribed, which provides better direction for the designer and contractor. lnstallation/Bedding Specification This is the same installation standard used for ASTM C76 (Class) pipe (see page 35). box seCtions Drawbacks The drawbacks to SIDD relate to the inflexibility of the final product. While SIDD pipe can be designed to meet the needs of a specific project exactly, additional fill cannot be accommodated should site conditions change unless the steel reinforcement was over-designed. Additionally, as SIDD pipe is designed for a specific project, the pipe must be manufactured upon order, which may result in project delays and/or added costs. Please check with your local manufacturer for lead times and pricing. manhole and CatCh basin material LAFARGE PIPE eMANUAL PAGE 27