Structured Wall Non-Pressure Pipes
Plastic Pipes Conference Association # 2004 Milan
Beaver, McGrath, Scharff
Plastic pipe has been used for many years in applications to control surface water runoff by detention, retention, and infiltration. Review of deficiencies with available pipe geometries resulted in creation of a new ‘pipe’ product, termed chambers. Stormwater chambers are arch-shaped, open bottom, polypropylene structures with unlined corrugated wall crosssection used in buried applications with cover between 450 mm (18 in.) to 2438 mm (8 ft). Chambers are manufactured by injection molding. This paper reports on chamber design in accordance with newly accepted thermoplastic profile pipe design theories incorporated into the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor (LRFD) Bridge Design Specifications in 2001, analysis by accepted pipe-soil interaction finite-element analysis procedures, and in-ground testing by accepted pipe qualification testing procedures. The chamber described herein has span (including turned-out foot widths) of 1270 mm (50 in.) and rise of 762 mm (30 in.). This study compares the new thermoplastic pipe profile design methods with comprehensive in-ground testing. The American Society for Testing and Materials (ASTM) is balloting a new standard specification for polypropylene chambers based on the work described herein.
Author(s) : Jesse L. Beaver
The design of corrugated wall thermoplastic pipes requires evaluation of loads applied to the pipe upon installation and those applied to the pipe throughout its service life. For loadings that are characterized as dead loads, the thermoplastic pipe will experience creep and/or relaxation for the duration of the...
Author(s) : McGrath
Gravity flow thermoplastic pipes use profile wall geometries to provide maximum wall stiffness with minimum wall area. This practice minimizes the material used in manufacture, and thus the product cost. In the case of some thermoplastic pipe, polyethylene in particular, this practice has led to a need for design...
Author(s) : Hsuan, McGrath
In past ten years, there is a significant growth in the use of high density polyethylene (HDPE) corrugated pipes in transportation related applications in the United States. At the same time, the evaluation of stress crack resistance (SCR) of the HDPE corrugated pipes has also gone through many changes. A...