SOL1194705 - Del Mar Bluffs Stabilization Project 5 (DMB5)

The Del Mar Bluffs Stabilization 5 (DMB5) is a maintenance of way project, to maintain the existing track and protect it from erosion, seismic events, and wave action. The project site is located along a 1.6-mile portion of the existing NCTD railroad ROW in the City of Del Mar that extends from rail Milepost (MP) 244.1 near Coast Boulevard south to MP 245.7 at Torrey Pines State Beach. Generally, construction will consist of installation of new trackbed stabilization improvements, including installation of up to 180 new CIDH soldier piles, a 5ft deep continuous concrete grade beam between the piles, and tieback anchors. Retrofit of existing solider piles with 5ft deep continuous concrete grade beams, and addition of tiebacks if necessary. Installation of approximately 2098 LF of new seawalls at the toe of the bluff consisting of CIDH piles with exposed steel members above the surface and wood lagging in between. Additionally, select areas behind the seawalls will be filled at a 2:1 slope to catch mid-bluff, with some areas requiring a full regrading of the slope at 1.5:1 with surface stabilization. Revegetation of fill slopes and regraded slopes will be required. The project also includes installation of drainage improvements including new storm drain pipelines and outlets to the beach, concrete-lined trackside ditches, underdrains, new and modified inlets to existing storm drain systems, concrete channels, splash walls, new channel aprons, and new and modified drainage structures. Installation of supporting structures for select drainage improvements will be required including installation of a soil nail wall adjacent to a new concrete-line trackside ditch, and a solider pile wall to support portions of a concrete channel that runs along the eastern upper bluff. Installation of access road improvements including re-grading of the existing access road and addition of stabilizing material to surface the road. For the SWPPP, this project is a Risk Level 2. The Engineer's Estimate for this project is $45,050,394.00. There is a 17.16% DBE Goal.