Design Development of Large Thermoplastic Chambers for Stormwater Retention

Abstract

Abstract Thermoplastic chambers for stormwater retention applications have been in use for many years. One design, an arch-shaped chamber with a 51 in. nominal width and a 30 in. nominal height, has seen widespread acceptance. This paper reports on the development of a structural design for a similar chamber with a 76 in. nominal width and 45 in. nominal height. Development tasks included evaluation of stiffened corrugation designs to permit the use of larger corrugations, evaluation of arch stiffness and stub compression capacity of the chambers, and full-scale field tests of both welded prototype chambers and production chambers. The development program was focused on demonstrating that the chambers met the target safety levels of AASHTO specifications for shallow burial depths with live loads and for deep conditions.