Pile drilling and installation to stabilize Del Mar bluffs completed
Construction crews have finished all pile drilling and installation associated with a $4.8 million effort to stabilize the coastal bluffs along the railroad track in Del Mar. This milestone means that the most significant construction activity in the stabilization effort is complete. Remaining work is expected to wrap up within weeks.
The 1.6-mile segment of track along the Del Mar bluffs is an integral part of the 351-mile San Luis Obispo - Los Angeles - San Diego (LOSSAN) rail corridor, which provides a vital link for regional, national, and international movement of passengers and freight. The North County Transit District (NCTD) COASTER and Metrolink commuter rail services, Amtrak Pacific Surfliner intercity service, and BNSF Railway freight service all rely on this segment of track to serve their customers.
SANDAG has led the construction effort in collaboration with NCTD and the City of Del Mar. The work is expected to be complete before the Christmas holiday, within the originally estimated five-month timeline.
Periodic stabilization of the bluffs is necessary to help preserve trackbed support to ensure uninterrupted passenger and freight rail service along the nation’s second busiest passenger rail corridor. With more than 50 trains per day operating on the San Diego segment, construction work must be performed at night.
Working Sunday through Thursday nights, construction crews installed 92, three-foot-wide soldier piles in seven different areas, totaling approximately 900 linear feet. The piles were placed in vertically drilled shafts into the bluffs to depths ranging from 45 to 60 feet and are designed to help secure sections of the bluffs for approximately 20 years.
Coastal erosion has been an ongoing challenge since the rail line was built more than a century ago. SANDAG and NCTD conducted stabilization efforts most recently in 2002 and 2007 at various locations along the Del Mar bluffs.
The last major stabilization effort occurred over a period of about nine months from June 2007 to March 2008. During that time, SANDAG placed 136 soldier piles in areas spanning a combined length of about 1,300 feet.
NCTD will continue to monitor the stability of the bluffs to ensure continued safe rail operations. Additional stabilization efforts are anticipated in the future and will be conducted based on need and funding.
The $4.8 million project was funded predominantly by Caltrans through the State Transportation Improvement Program, with $224,000 from the U.S. Department of Transportation Federal Transit Administration.
West Coast General Corp. and Condon-Johnson & Associates, Inc. served jointly as general contractors for the project. CALTROP provided construction management services. The project was engineered by David Evans and Associates, Inc. Other subconsultants included HELIX Environmental Planning, Inc., Leighton Group for geotechnical services, and Everest International for hydrology.
Additional information about the project is available online at sandag.org/delmarbluffs.
— Submitted by SANDAG