ATSF 1980 El Dorado Line Change Failure/Rehabilitation

Track support failure and rehabilitation of 14 km of railway mainline built in 1980 over a compacted clay (liquid limit 50‐70) is presented. The failed construction substituted a 300‐mm thick 5% lime stabilized layer for subballast. Ballast, 300‐mm thick below the tie base, supported prestressed concrete ties of similar design to those used in the Northeast Corridor reconstruction. Rehabilitation addressed the problems associated with subgrade pumping, track stiffness/softness, internal and external drainage, equivalent granular cover (total depth), and the compatibility of the ballast's toughness and mineral hardness in relation to the aggregate in the concrete ties. Reconstruction used inexpensive, locally available sand‐sized material for the subballast. A custom made geotextile was incorporated for extra safety. The rehabilitated track, carried out in 1984, has performed excellently.