This ongoing project is for the selective demolition of platforms along several Washington Metro. Area Transit Authority platforms. Every platform includes the demolition of the tile and concrete surfaces of the platforms themselves as well as surrounding walkways and curbs plus removal and storage of amenities like signage, lighting fixtures, and handrails. Each individual platform also presents its own unique challenges. Several platforms are in built-up areas with overhead cover and adjacent structures that require substantial logistical planning to move equipment, personnel, and waste onto and off-site. Additionally, because of differences in construction and location many platforms had significant sewage and utilities sections directly beneath areas requiring excavation. This created an additional layer of care and precision at every stage of work.

ACECO’s scope included large-scale demolition of the VA Tunnel owned by CSX Transportation, Inc. This incorporated a section of the rail line covering approximately 7,000 linear feet divided into fifteen sections, each having different requirements. Several sections required the existing North wall of the tunnel to remain intact to prepare for new construction, while others included the entire tunnel (walls, roof, and track foundations) to be demolished. This necessitated a complex system of shoring and bracing to protect existing structure and ensure safety during the demolition, and a carefully-designed demolition plan to be followed meticulously throughout the 17-month project.

This job entailed the demolition of Building J, a part of the Alexandria Renew Enterprises complex, as well as selective demolition of specific areas of adjacent buildings G/1 and G/2. Included in the scope of work was a significant asbestos abatement requirement, which was fulfilled through subcontractor Progress Environmental, LLC, a long-time working partner of ACECO. The project presented unique challenges, as Building J was to be razed down to an elevation of 17.33’ with all deck slab and structural columns left intact. There were also strict vibration limits which could not be exceeded, necessitating the use of hydraulic processors and a crushing plant mobilized to the site by ACECO. 

ACECO was contracted to perform the design and installation of the structural support, demolition of the foundation wall, interior demolition, and excavation, all while protecting the historic facade above. To support the existing building wall and facade, a detailed steel support system was installed utilizing the existing interior building columns as the main load bearing elements. Beams, tube steel, needle beams, diagonal braces, and knife plates were installed to support the building wall and exterior facade. This complex support allowed the foundation wall to be demolished under strict vibration and movement thresholds, creating the illusion of a “floating” building until the new addition is constructed, while meeting the aggressive project schedule.

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The UMD – Chemistry Wing 1 Replacement Project included demolition of the existing Wing 1 and construction of a new chemistry research laboratory facility including new research centers, offices, administrative, spaces, and a conference center. ACECO was contracted to demolish the existing 1950’s Chemistry Wing 1 building, slab, and foundations while meeting an aggressive project schedule as well as being constrained by tight pathways and occupied adjacent walkways and structures.