A newly-constructed, tan-colored, box-like building stands 46-ft high in the southwest quadrant of the Naval Support Facility (NSF) in Dahlgren, Va. Blending well with its surroundings, the unassuming structure disguises the highly-technical operations taking place within. Through integrated design-build (IDB) delivery, the multi-story Surface Sensors & Combat Systems Facility (SSCSF) was designed and constructed to merge and accommodate two functions that were relocated to the Naval Surface Warfare Center at Dahlgren as a result of 2005 Base Realignment and Closure (BRAC).
The innovative building design, which will improve the quality and affordability of shipboard software testing and advanced antenna production, successfully integrated electronic equipment, laboratories, computing areas, open and hard-walled office spaces, conference rooms, control rooms and a specialized anechoic chamber. The anechoic chamber will test communications antennas used by U.S. and allied fleets in an electromagnetically-shielded environment.
Accommodating Complex Requirements
Project delivery methods range from basic to complex, and each method has its own advantages and disadvantages. While some methods may be better suited for certain kinds of projects, complex internal components along with diverse users and uses made the SSCSF project ideal for an IDB approach.
Through the design-build approach, a single entity performs both design and construction. In a "traditional" contracting approach, the client chooses an architect or engineer to prepare drawings and specifications and separately selects a contractor through negotiation or competitive bidding. This arrangement tends to pit the designers against the constructors, creating an adversarial environment for the client.
A design-build team, conversely, has designers and a constructor jointly involved in delivering a facility. Collaboration of designers and builders is the foundation of design-build. Benefits of design-build project delivery include a single point responsibility, early knowledge of actual costs, potential schedule reductions and cost savings. The SSCSF facility’s design-builder took the design-build delivery approach one step further by utilizing a fully-integrated design-build model.
The fully-integrated design-build delivery team was composed of in-house architects, engineers and construction professionals, all working side by side on a daily basis. The design and construction personnel remained fully engaged throughout the design and construction of the facility. Tight collaboration between the government clients and the IDB team from early design through project turnover was key to the project’s success. All participants shared and applied common values and goals, reducing waste and optimizing efficiency through all phases of design and construction.
IDB delivery allowed for efficient incorporation of owner-requested modifications throughout the construction process. The complexity of the facility almost guaranteed that modifications and additions would arise as construction progressed and systems integration was contemplated. As unforeseen items arose, the delivery team was able to react quickly and adapt to meet the requirements without adverse schedule impacts. Many significant and critical modifications were quickly incorporated into the design and delivered within the required project timeline.
The project goal was to design and construct a facility that could house different departments with different agendas, while providing flexibility for future growth and evolving usage. Flexibility and adaptability of raised access flooring systems and open office spaces and workstations were incorporated into the design, while ensuring that exterior features conformed to base architectural requirements and force protection criteria. The users had strict time constraints, resulting in a rigid completion date and a substantial liquidated damages clause in the contract.
Numerous challenges arose throughout the project that were successfully overcome because of the IDB process. An integrated team of architects, engineers and construction professionals provided critical evaluation of each of these issues at various stages during the delivery process and successfully implemented timely changes where appropriate.
One challenge was the building site location, which was constrained by four existing streets and one building, none of which provided the required set-back distances required by anti-terrorism and force protection (ATFP) guidance. Because some of the work to be done in the facility is classified as open-secret-storage while other work is classified as controlled access, another challenge was to design the facility with different levels of security in different areas all under one roof. The diverse intended users of the facility had distinct individual requirements for usage of their systems and equipment. Designing mechanical and electrical systems that could function independently but be integrated into and support the overall building system was also challenging.
Perhaps the most challenging issue, however, was an unforeseen constraint running directly under the project site. A sensitive fiber optic cable used to transmit combat systems test data was discovered under the proposed foundation footprint. When it was determined that the mission-critical line could not be moved, the entire building foundation system had to be redesigned to avoid deep piers which could have damaged this line. Only with the collaboration of a fully-integrated design-build team could each of these challenges have been resolved without impacting the schedule.
Benefitting Project Requirements
To get a head start on the critical schedule requirements, an early civil package was pursued that would allow construction activities to begin before winter. This early start on the sitework and concrete tilt-up exterior wall panels would have created an opportunity to continue other interior construction activities during the winter months, improving on the overall schedule. However, when numerous unforeseen utility lines were discovered, construction could not commence. After the government relocated the unforeseen lines, foundation work commenced just as the weather turned significantly worse, which caused the existing soil to lose its bearing capacity. In lieu of further delaying the project while waiting for better weather, the IDB team worked with the government to re-sequence construction. The entire foundation system was over-excavated by 5-ft, allowing the foundations to bear on a more suitable soil layer. Then, the walls were erected prior to slab placement keeping the project on schedule.
Another non-negotiable aspect of the project was the ATFP requirements. “The exterior of the building proved to be a challenge because it had to transition such unique spaces, conform to the base architecture and image, and meet the ATFP requirements,” said Larry Willis, Integrated Design-Build Team Leader. Working together through all the requirements, the IDB team recommended a tilt-up concrete and steel structure which would provide the required hardening for blast protection while meeting user requirements and conforming to base standards.
A final project requirement that benefited from the IDB approach was delivering a Leadership in Energy and Environmental Design (LEED) Silver-certifiable facility. While the facility was built to comply with these stringent energy savings requirements, the government removed the U.S. Green Building Council’s formal certification requirement from the contract due to budget constraints. At project end, however, through the efficiency of the IDB process and creative value engineering, the design-builder was able to offer the USGBC formal certification process to the government and still remain within their budget.
The IDB approach ensured the government received a quality facility, which was safely delivered six months ahead of schedule. The new lab will be linked to other key U.S. Navy research labs and will be the Navy's lead technical center for testing ship combat systems and producing Link 16 Maritime antennas. The nearly 59,000-ft2 building will employ about 130 people. Work currently being done at Navy sites in San Diego, Calif., and Charleston, S.C., will be moved to the Dahlgren site. The facility will be an exceptional resource for Navy scientists and engineers well into the future.