Virginia Tech Moss Arts Center

Designed by international architecture firm Snøhetta, the LEED Gold-certified Moss Arts Center is the multi-cultural nexus of VT’s campus. Completed in 2013, the $100 million complex houses a 1,300-seat performance hall, a performance lab known as the Cube, a visual arts gallery, research studios and support spaces. The project program encompassed 91,992 square feet of new construction and 55,390 square feet of renovations to Shultz Hall.

The new building structure is a combination of cast-in-place concrete and steel. Due to the high variability of rock depths and quality, and the presence of very soft soil and high groundwater conditions, Schnabel recommended supporting the major structural columns on drilled shafts socketed into the brecciated and hard rock beneath the site.

In response to the presence of relatively shallow groundwater in the area of the 40-foot deep orchestra pit, we consulted on the selection of a ground improvement method for limiting groundwater infiltration into the excavation. Deep soil mixing was ultimately used to control the groundwater flow. Earth pressures for below-grade walls and permanent sub-drainage were among the other geotechnical challenges we encountered and addressed.

During construction, we provided special inspections per state building code requirements, including evaluation of drilled shaft lengths; observation and testing of concrete, structural steel, and masonry elements; and observation of sprayed-on fireproofing, roofing, and exterior insulation finishing system components.

For more information about this project visit the Arts Center website here.

Elizabeth River Tunnels

The Elizabeth River Tunnels (ERT) project is the recipient of a 2017 Grand Award for Engineering Excellence from ACEC. This $1.5 billion transportation infrastructure initiative has four major components:  a new two-lane tunnel adjacent to the existing Midtown Tunnel under the Elizabeth River; maintenance and safety improvements to the Midtown and Downtown tunnels; extending the Martin Luther King Expressway from London Boulevard to Interstate 264; and interchange modifications at Brambleton Avenue and Hampton Boulevard.  Construction began in 2012 and is expected to conclude in early 2018.

Elizabeth River Crossings OpCo, LLC, is the private partner of the Virginia Department of Transportation (VDOT) for the design, construction, finance, operations and maintenance of the ERT project. WSP|Parsons Brinckerhoff led the design team and SKW Constructors, JV (a Skanska, Kiewit, Weeks Marine Joint Venture) is the design-build contractor.

Schnabel provided geotechnical engineering and construction consultation services on the MLK Expressway portion of the project. Our work encompassed subsurface exploration, soil laboratory testing, and geotechnical engineering analysis. The exploration program included 206 test borings, 55 cone penetrometer soundings, and 48 dilatometer soundings. Based on test results we also made recommendations for embankments constructed using different fill materials as well as pile-supported embankments.

The MLK Expressway features nine new or reconfigured ramps, and about a mile of the new roadway is elevated.  Construction began in November 2013 and the MLK opened on November 30, 2016. For more information, go to www.driveert.com .

Photo courtesy of SKW Constructors JV

Children’s Hospital of Richmond Pavilion

The new Children’s Hospital of Richmond Pavilion is the largest, most advanced outpatient facility dedicated to children in the region. This $200 million investment by VCU Health has served to improve the historic and vital Broad Street corridor of downtown Richmond and creates a gateway to the urban medical campus.

Constructing a 640,000 square foot building four stories below grade and 11 stories above grade in a dense and congested urban environment required creative engineering.  Schnabel provided geotechnical services during the early planning stages of the project, as well as supplemental subsurface exploration. The resulting data allowed for a more economical design of the foundations and support of the 55-foot-deep excavation.  We were also responsible for geostructural design of the underpinning and support of excavation.

As an advisor to the owner’s representative throughout design and construction of the Pavilion, we helped solve various unanticipated issues. Among them were revising the underpinning design to compensate for degradation of the adjacent building footings, and environmental concerns with disposal of the soils excavated from the site.

Children’s Hospital of Richmond Pavilion received the 2017 Pinnacle Award from ACEC Virginia.  The organization’s highest honor recognizes projects demonstrating innovation, complexity, achievement and value to the industry.  Read all about it here.

Main Street Train Station

Richmond’s Main Street Train Station is envisioned as a major regional multi-modal transportation hub. Renovation of its historic train shed is the third phase of a $92 million investment to make this dream come true for the city and the landmark building. The 1901 structure is reimagined as an urban resident, traveler and tourist destination featuring an indoor marketplace, a welcome center and event space. Completion is anticipated by summer 2017 at a cost of nearly $50 million.

As the geotechnical engineer of record, Schnabel performed multiple studies to support the planning and design phases. During construction we provided a full range of special inspections as well as a variety of construction materials testing services, including a comprehensive survey of the condition of the original steel frame.  We also fulfilled the role of special inspector for the city.

Photo credit: Richard MacDonald
Renderings courtesy of SMBW

Poe Dam Gate Dewatering Bulkheads

Poe Dam is a concrete gravity structure located in the Plumas National Forest. Completed in 1958, the dam diverts water to penstocks for power generation. The gated main spillway includes four, 50-ft wide by 41-ft high radial gates which required rehabilitation and trunnion pin replacement.

To complete these repairs, temporary bulkheads were required to dewater each bay. Schnabel’s dewatering system design includes a patented floating reverse needle beam system as the upstream cofferdam, and a non-floating modular design for the downstream cofferdam. Gate rehabilitation and trunnion pin replacement was completed over four construction seasons using the moveable upstream and downstream cofferdams on each bay in turn.