Technical Manual: Conduits through Embankment Dams (FEMA 484)

Conduits through Embankment DamsFigure 77.—A poorly secured waterstop moved during concrete placement.Figure 78.—Waterstop held firmly in place by use of a specially cut slot inthe form.of the joint is fabricated to contain a rectangular recess that holds a continuous solidrubber ring of circular cross section. The rubber gasket is compressed when thespigot is pushed into the bell end of the joint. Figure 79 shows an example of arubber gasket being installed on a precast pipe. The gasket and steel rings, if used,are manufactured to high tolerances to ensure a reliable high pressure seal.Lubricating the gasket and inside face of the bell with vegetable soap can easeassembly. In embankment dams, a mastic sealing compound (figures 66-69) andmetal or geotextile bands are typically placed around the outside length of the jointto prevent any movement of soil backfill into the joint space that might interferewith future joint movement.110