Work at the Columbia University project continues in earnest as the E.E. Cruz team nears completion. Remaining work at grade has been reduced to grade beam waterproofing and backfill and restoration for the West end of the Phase 1 top-down construction area. Site dewatering, in support of the top-down excavation, continues with three shifts running 7 days a week. Ground water elevations have been successfully maintained and the operation will continue through February until construction of the basement structural slab is complete. The Phase 2 scope of work has been completed.
Excavation of the top-down SC2 level (Stages 5 & 6) is complete as is the structural slab and waterproofing for this level. As of mid-January 2014, mass excavation of the top-down SC4 level (Stage 7) was 93% complete.
Currently, the main focus of work is the placement of structural concrete for the SC-4 foundation slab. Of the seven slab sections that make up SC-4, one is fully complete with the second scheduled to be complete within the next week. To achieve each pour, subgrade must be prepared, column over pour chipped, mud mat placed, waterproofing installed, reinforcing steel placed and bulkhead/formwork installed.
The air monitoring and ventilation plan continue to be a success.
Looking forward, construction of the structural Shear Wall and foundation drainage system will follow as the SC-4 slab progresses. The Shear Wall will be constructed on both the SC-2 and SC-4 levels. Formwork for the upper (SC-2) level is approximately 50% complete at this time.