U.S. Navy CVN Drydock Dewatering
The Navy’s CVN Drydock No. 6 had been experiencing settlement for over 40 years. Cracks in the floor slab raised concerns over its structural integrity. Geotechnical investigations indicated loose fill materials and a damaged relief drain system underlying the slab. Compaction grouting was conducted to increase the density of underlying materials at select locations. Additional relief wells were constructed to aid the original relief drain system surrounding the ground improvement modifications. Temporary dewatering wells were also installed to facilitate compaction grouting and relief well construction.
Cornforth Consultants Inc. (CCI) was retained by Jensen Drilling Company; who as a subcontractor to NOVA Group Inc., was charged with the construction of 10 temporary dewatering wells and 18 permanent relief wells. CCI work tasks and responsibilities included: field supervision and inspection, observation and documentation with quality control reports for drilling, temporary dewatering well and permanent relief well installations, well developments, pump and discharge piping, and well capacity tests. Dewatering wells successfully lowered the artesian pressures under the dry dock and allowed the structure repairs to proceed in the dry.