StormTech chambers are designed in accordance with Section 12.12 of the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications. This document establishes requirements for design of profile wall thermoplastic structures for both live loads and permanent earth loads. Proper use of the AASHTO design method requires that load multipliers for impact and multiple presences are applied to the AASHTO design truck (HS20) live load. Additional factors are applied to the load and earth loads to provide the full safety factors for both live and earth loads.
When installed in accordance with the minimum requirements specified in the StormTech installation instructions, StormTech chambers meet or exceed the AASHTO requirements for both live load and earth load design. StormTech chambers are also designed in accordance with ASTM F2787 “Standard Practice for Structural Design of Thermoplastic Corrugated Wall Stormwater Collection Chambers.” This standard practice relates the AASHTO design methodology for thermoplastic pipe and applies it to buried stormwater chambers.
Note that proper design for permanent earth loads, although often ignored by producers of other buried plastic structures, governs safe product design and is the basis for the service life of the system. StormTech's cutting edge materials research program and extensive product testing has established StormTech as the leader on thermoplastic chamber design for safe, long service life installations.
StormTech chambers are produced to the requirements of the American Society of Testing Materials (ASTM) F2418 “Standard Specification for Polypropylene (PP) Corrugated Stormwater Collection Chambers” and ASTM F2922 “Standard Specification for Polyethylene (PE) Corrugated Stormwater Collection Chambers.” ASTM standards play an important role in establishing strict product requirements that engineers and owners can rely upon for a high quality product on every project.
StormTech's commitment to these two standards ensures consistent high quality products, safe structural design, and a service life in the 100-year range.