Retail

Midtown Center/Fannie Mae HQ

SK&A provided structural engineering services for a new headquarters building for the Federal National Mortgage Association (FNMA), commonly known as Fannie Mae.  The new 875,000 sf Midtown Center office complex is comprised of two 14-story towers, East and West.  The structure features 45,000 sf of retail space, multiple three-story atria, three levels of below-grade parking, as well as a fitness center, rooftop terrace, and private alley.  The project also includes a 15,000 sf public courtyard surrounded by the buildings on three sides and is activated by ground floor retail.

A unique and distinct design feature within the complex are its three interconnecting “tunnel” bridges which span more than 110 feet across the site’s courtyard, connecting the east and west towers at levels 9 through 14.  The bridges feature interior walkways (inside of the bridges) and exterior walkways (on top of the bridges, open to the air).  The bridges were typically designed as “king-post” trusses utilizing heavy W36 section for top chord, eight-inch square tube steel section for bottom chord, and two (2) three-inch diameter high-strength tension rods by “Macalloy” as diagonal members connecting to an eight-inch square tube section vertical steel post, at the center of the bridge.

The three-story, below-grade parking deck uses conventionally reinforced concrete flat slab construction.  The courtyard slab and private alley above the top garage level is designed for landscape and fire truck loads.  The office level structural framing consists of eight-inch, post-tensioned concrete slab with eight-inch-thick drop panels over columns.  This efficient framing system allowed sufficient plenum space for the installation of MEP systems within the ceiling as well as the curtainwall anchors.  The project will pursue LEED Gold certification.  

View photos from a 2017 Site Visit.

The Liz | Whitman-Walker Health

SK&A provided structural engineering services for the redevelopment of the Whitman-Walker Health Clinic site into “The Liz”, a mixed-use development incorporating new residential, retail, and office spaces.  The project also entailed the renovation and repurposing of the clinic’s existing historic structures located at 1701 and 1711 14th Street, NW.

The preservation of the two historic buildings required significant underpinning and other below-grade modifications to the existing basements.  The new structures are seven stories above-grade with two new below-grade levels.  The residential areas occupy approximately 80,000 gsf (78 luxury apartments) and retail and office spaces are 80,000 gsf.   Retail tenants include Sephora, Bluestone Lane, Amazon and Parachute Home.  The office space houses Whitman-Walker’s new headquarters, encompassing their administrative, legal, public benefits and research departments, as well as offices for Fivesquares Development and the Goethe Institute, a German language school.

The development also includes a 2,800 sf cultural space for community events and art exhibitions focused on the LGBTQ community.  The remaining square footage (approximately 60,000 gsf) consist sof areas for parking, loading and other back-of-house functions.

The Yards, Parcel O

Situated in Washington, DC’s Capitol Riverfront neighborhood, The Yards is a 42-acre, 5.5 million sf mixed-use redevelopment featuring residential, office, and retail spaces as well as restaurants and a public park.  SK&A is providing structural engineering services for two residential buildings being constructed simultaneously on Parcel O of the development.

The Bower, on Parcel O-1, is a 154,400 gsf, 10-story residential building with 138 condominium units.  Parcel O-2 is a 208,700 gsf, 10-story residential building with 198 units.  Both buildings feature ground floor retail, indoor amenity spaces, lobbies, green roofs, a public courtyard, and a shared two-level, underground parking garage with a flood-resistant design.

The buildings are being constructed over WMATA’s Green Line tunnels, which required that structural analyses be performed to demonstrate the tunnels’ capacity and stability to resist the forces imposed by the unloaded condition during construction and the final condition when the buildings are complete.  

The Watergate Complex Plaza Repairs

The Watergate Complex in Washington, DC includes a hotel, office building, condominiums, and retail.  SK&A’s Repair & Restoration Division provided repairs to the office building’s B-2 level retail plaza area and B-3 level parking garage directly beneath the plaza.  The B-2 level retail plaza area is leased by Penzance and the B-3 level below is owned by Watergate East, Inc. and consists of residential parking, tenant storage rooms, various hallways, and mechanical rooms.

The original waterproofing on the structural slab located below the exterior plaza topping slab is a continuous coal tar fluid-applied waterproofing system, which at the time of the repair was approximately 43 years in age.  Over the years, the original waterproofing has been exposed in isolated areas throughout the plaza, and removed and replaced with either sheet membranes or hot fluid-applied rubberized asphalt systems.

In 2012, SK&A provided construction documents and specifications related to the concrete repairs and waterproofing design for the B-2 level retail plaza and B-3 level garage.  The work was performed from December 2012 to May of 2013 and consisted of the removal and replacement of the exposed aggregate topping slab located throughout the B-2 level plaza within the retail mall area.  Once the topping was removed, the existing waterproofing was removed and replaced and concrete repairs were also performed to the underlying waffle slab.  An existing two to four inch thick decorative concrete topping was replaced in the center of the plaza with a new black, gray, and white alternating colored Miracote coating.  New waterproofing details were provided at drains and along the plaza perimeter in order to provide tie-ins and terminations, as well as to aide in drainage of the plaza.  The repairs involved daily coordination between the contractor and management in order to complete the work and maintain daily access to each individual retail store impacted by the work.
 

Atlantic Plumbing, 8th and V Streets, NW

The former Atlantic Plumbing site, located along 8th and V Streets near Florida Avenue, NW, includes three separate parcels A, B and C.  SK&A provided structural engineering services for the development of Parcels A and B which include two new, luxury, urban high-design residential buildings with ground-level retail spaces and underground parking for 190 cars.  Parcel C, which is currently under design, includes a nine-story hotel and a 10-story residential building connected together by a bridge spanning W Street, NW.  

The first building at 2112 8th Street, NW (Parcel A) is a 10-story, cast-in-place concrete building with 339 units and two levels of below-grade parking.  Building amenities include a rooftop pool, bar, kitchenettes, movie screening area, vegetable garden plots, a business center, communal lounge area with theater, a fitness center, and bicycle storage rooms.  To give the building an edgy, industrial look, the exterior exo-skeleton frame of the building is comprised of Corten weathering steel.  The design and detail of the steel frame exo-skeleton is designed to resist both lateral and thermal loads.

2030 8th Street, NW (Parcel B) includes a second building with six stories and 71 condominium units.  This smaller building is a cast-in-place concrete structure with one level of below-grade parking.  The building features 10’ ceilings, rooftop terraces, a business center, as well as fitness and bicycle storage rooms.

In addition to traditional retail, the project includes 1,500 sf of artist studios occupied by the Washington Project for the Arts as well as a 10,000 sf Landmark movie theater.

The Calvert Apartments

SK&A provided comprehensive structural engineering services for the renovation and reconfiguration of The Calvert Apartments from a dated high-rise building, into a contemporary, mixed-use residential complex. The development features a central 16-story modernized tower with two new apartment buildings on each side as well as underground parking.

The new apartment buildings consist of four levels of post-tensioned concrete over a reinforced concrete retail level.  The first level above the retail floor is an 18” thick transfer slab.  The buildings also feature green roofs, amenities, and three levels of parking below ground.

The project totals 114,000 sf of residential space amongst the two new apartment buildings, 14,200 sf of retail space, 205,000 sf of underground parking for 522 cars and 193,000 sf of renovated residential space within the existing high-rise apartment building. The revitalization of the high-rise portion of the project was extensive and required multiple improvements, including:

  • Replacement of the building’s exterior skin 
  • Addition of a new roof parapet wall 
  • Design of a new building entrance canopy 
  • Enclosure of the existing ground level drive-through at the building entry and addition of four new units within that space
  • Underpinning of the existing building foundations along the new garage 
  • Replacement of the wall assembly with new curtain wall and arched roof profile 
  • Configuration of a new pool
  • Expansion of the existing penthouse levels
  • Modification of two existing elevators 
  • Addition of a new freight elevator and two new elevators to serve the low-rise residential
  • Demolishment of the first floor slab within the hi-rise; the floor was reconstructed to match the first floor level of the new low-rise 
  • Addition of new connection corridors between the new buildings, the hi-rise tower, and new loading dock areas

L’Enfant Plaza East & West Retail Renovations

Located in Washington, DC’s southwest quadrant across from the National Mall and Smithsonian Museums, L’Enfant Plaza is a massive mixed-use, commercial complex of multiple mid-century buildings originally constructed in the 1960’s.  The complex features office/commercial and governmental buildings, a hotel, an underground shopping mall and parking, as well as a major subway station.  The overall complex has been undergoing an extensive renovation and redesign, including the redevelopment of the retail mall as well as the existing L’Enfant Plaza hotel and an office building.  A new 600,000 sf office building will also be constructed in the center of the plaza. 

The retail renovation projects included modernization of the existing underground retail mall, the development of a new glass atrium providing access to the underground retail corridor, and structural strengthening at the promenade and plaza levels to accommodate the future nine-story office building.  The strengthening work for the office building was conducted concurrently with the retail renovation to allow retail operations to continue uninterrupted during construction.

For the strengthening portion of the project, a cost-effective demolition concept was devised involving almost no re-shoring of the existing slab.  New concrete framing was constructed over an existing auditorium occupied by the National Transportation Safety Board (NTSB).  To construct the framing, SK&A assisted the contractor in developing a steel formwork system using new and existing columns for support.  A grid of compression beams was also designed to support the plaza layout and future office building concept.  

The large glass atrium portion of the project is composed of a series of steel moment frames.  Slip-critical bolts at the column-to-beam connection were used to accommodate the contractor’s preference for steel erection.  Additionally, the east stair spans between the promenade and plaza levels, with no posts beneath the landings.

The East and West portions of the renovation were designed and constructed as two separate projects.  The West project received an SEA-MW award in the $15-40 Million Renovation category in February 2015. 

Liberty Center (Ballston Metro Station)

This 5.35 acre mixed-use development includes two office buildings, a residential tower with retail, and structured below-grade parking. Located at 675 Randolph Street in Arlington, VA, the first 13-story, 350,000 sf office building was completed in 2012 and includes a 250,000 sf structured parking garage for 600 cars that resides underneath.  The building is designed to meet Anti-Terrorism Force Protection (ATFP) standards for occupancy by a government agency.  

The 17-story residential tower was completed in 2014.  The 238,000 sf building has 256 units, 9,000 sf of retail, and a 120,000 sf structured parking garage for 272 cars. 

To be completed in 2016, the third building is an additional 20-story, 400,000 sf Class “A” office building.  Located at 4040 Wilson Boulevard, the structure will be the tallest office building in the Arlington corridor.  The development is certified at the Gold level under the LEED-ND (Neighborhood Development) pilot program.

City Vista (Wax Museum Site), 5th & K Streets, NW

Located on the former Old Wax Museum site and in walking distance to the Washington Convention Center, this mixed-use residential/retail development on the 3.2 acre site contains a total of 685 condominium and apartment units, a 55,000 sf Safeway grocery store, 65,000 sf of additional retail space, and 830 below-ground parking spaces.  The project’s residential units were divided among two condo buildings, “The K” and “The L”, both 12 stories, and one rental apartment building standing nine stories tall, “The V.”  Additional amenities for the residents include a rooftop pool, a large third floor courtyard landscaped with tree pits, a large truck loading dock serving the residential units and the retail rooftop terraces, and a second floor fitness center.

The design of the buildings entailed several structurally challenging features including the vertical transition of the building’s columns and walls from garage to retail and then to residential-architectural floor layouts.  A large amount of transfer girders and sloped columns were introduced on different levels of the structures to accommodate the transitions.  The Safeway grocery store beneath the residential building required 55,000 sf of two-story open space.  This necessitated 30-foot tall unbraced columns that support the residential building above.

Woodland Park Crossing

A very successful, open town center-style, mixed-use development on eight acres with residences, retail spaces, and multiple parking areas located on Sunrise Valley Drive in Herndon, VA.  Building #1 (355,000 sf) is a ground-level Harris Teeter grocery store with two levels of parking above and one level below the store.

Buildings #2 (13,200 sf) and #3 (34,600 sf) are two-story retail buildings.  Building #4 has 14,700 sf of ground floor retail with three levels of stick building residential above (50,000 sf).  Buildings 5A and 5B are both residential wood-framed residential buildings totaling 168,000 sf.

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