Technical Manual: Conduits through Embankment Dams (FEMA 484)

Conduits through Embankment Damsthat has been removed as part of outlet works renovation involving sliplining. Forguidance on the design and construction of entrance and terminal structures, seesection 3.4. Specially fabricated steel transitions are sometimes used at the criticalupstream end of a conduit being sliplined with HDPE pipe. The transition andHDPE pipe are connected using a flanged joint.12.1.1.2 Construction considerationsThe designer must evaluate a number of construction parameters when consideringHDPE pipe for use in sliplining. A few of the most significant parameters include:• Sample testing and certification• Handling and storage• Installation• Repairs to the HDPE slipliner prior to or during the insertion process• Grouting• Postinspection and acceptance• Maintenance and repair of the completed HDPE slipliner• Alternatives to sliplining existing conduits with solid walled HDPE pipeThese parameters are further discussed in the following paragraphs. On a case-bycasebasis, the designer may need to consider additional parameters, depending onthe construction requirements of the specific application.Sample testing and certification.— Manufacturer’s certification should befurnished prior to any shipment of HDPE pipe to the worksite. The certificationprovides proof that the HDPE pipe was manufactured, sampled, tested, andinspected in accordance with ASTM F 714 and meets the requirements. More detailscan be obtained by requesting the actual test data from the manufacturer. Not allHDPE pipe is tested; manufacturers may only test certain lots of pipe or performtesting at regular, scheduled intervals.Handling and storage.—HDPE pipe is much lighter than steel or concrete pipeand generally does not require heavy lifting equipment. HDPE pipe is shipped inlonger lengths than steel or reinforced concrete pipe due to its lighter weight.304