Construction: Lewisville Spillway

Scope Summary: Measures to address the structural stability concerns associated with post-tensioned anchors installed through the ogee weir, and an upstream geomembrane blanket. The design will continue to be refined in FY20, but at this time consists of 99 anchors installed to a depth of 70 ft. A work platform or rail system will be required to install the anchors along the downstream slope of the monoliths. The upstream geomembrane blanket will be installed in the approach channel of the spillway below the current grade and attached to the ogee monoliths. The membrane will extend upstream and be covered with the material removed for its installation. The apron slab overlay will install apron slabs over the existing apron slabs to address uplift and sliding concerns. Each overlay slap will have anchors installed, however the number of anchors varies depending on the distance from the ogee weir.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.