No-Dig Winners

Structural Design Methodology for Spray-Applied Pipe Liners in Gravity Storm Water Conveyance Conduit

Structurally spray-applied pipe lining (SAPL) is a technology that has found wide acceptance as a way to inhibit further deterioration and provide structural support for damaged culverts and drainage structures. This technology can take two broad forms: cementitious (geopolymers) and polymeric materials (polyurethanes, polyureas, etc.). While applications can take a wide variety of forms, industry members, state departments of transportation, municipalities, design and consulting engineers, manufacturers and others have not found a single, systematic way to design and implement SAPL applications.

A technical committee of the National Transportation Product Evaluation Program (NTPEP), as a function of the American Association of State Highway Transportation Officials (AASHTO), sought ways to conduct such standard methodology for design and installation. They commissioned the CUIRE group at the University of Texas at Arlington as the investigative body for such research.

The specific objective of this three-year research project is to develop design methodologies and equations for the structural renewal of gravity storm water conveyance culverts using both resin-based and cementitious SAPL applications for large (more than 36 inches) circular and arch-shape storm sewers. This research plan consists of a compilation and review of previous studies, review of existing design equations, soil box testing setup with actuator to duplicate actual field conditions, field data collection, life-cycle cost analysis, finite element modeling to simulate different applications, and other aspects with a thorough and organized research effort into the use of SAPL. One expected result will be development of a structural design standard for SAPL through AASHTO.