City: East Lansing
Owner: Michigan State University
General Contractor: Barton MalowRondout West Branch Bypass Tunnel Shaft
City: Wappinger Falls
State: New York
Owner: New York City of Environmental Protection
General Contractor: Schiavone Construction Co, LLC
One of the main sources of water for New York City are reservoirs in the Catskill Region of upstate New York. This water flows to New York City through a system of tunnels. One of these tunnels that runs under the Hudson River has begun to leak as a result of it’s age. A new tunnel was proposed to allow the existing leaky tunnel to be bypassed. To construct the bypass tunnel, shafts were constructed on both sides of the Hudson to launch and receive the tunnel equipment. Schnabel constructed the secant piles for the shaft on the east bank of the Hudson to support the earth above the rock, and prevent water infiltration.
Owner: Partners Health Care/Brigham & Womens Hospital
General Contractor: Walsh Brothers
Secant piles were used as a permanent water cutoff wall and foundation wall for the proposed underground parking garage at the Brigham Green Hospital in Boston, Massachusetts. Temporary tiebacks were installed for lateral support during construction. Once the garage slabs were placed the temporary tiebacks were detensioned and the slabs served as the permanent lateral support.
Owner: City of Reno
General Contractor: Granite Construction
City: Washington, D.C. (suburbs)
Owner: Virginia Department of Transportation
General Contractor: Flour Lane Construction
Schnabel was hired to design and install permanent walls along a fourteen mile stretch of the I-495 as part of a public/private partnership (P3) to widen the highway and reduce congestion. Schnabel constructed seven tieback walls, twenty two cantilever walls, and one secant pile wall. Seventeen of the walls also had sound barriers above the retaining walls.
Owner: Museum of Fine Artso
General Contractor: John Moriaty & Associatesn
To increase exhibit and storage space, an addition was constructed at the Museum of Fine Arts located on Boylston Street in Boston, Massachusetts. The addition was located along the east side of the existing museum within an existing courtyard in the area of a recently demolished structure. The basement for the new addition extended up to 30 feet below the floor slabs of the adjacent buildings which were supported on a variety of foundations including; shallow spread footing in alluvial sand deposits, low capacity piles bearing in the alluvial sands and clay below, and caissons bearing on the alluvial sands and desiccated Boston Blue Clay crust. Groundwater was less 5 foot below existing slab grade.
To provide excavation support and limit the lowering the groundwater table outside the excavation, Schnabel installed a 66,000 square foot cement deep soil mixed (CDSM). The CDSM wall was selected to control deep seated ground movements, limit movements of adjacent structures, and inhibit groundwater flow into the excavation. Braces and a continuous wale were used to support the CDSM wall where it was located adjacent to structures. Tiebacks were used where there were no structures.
Other geotechnical construction at the site included:
Jet grouting (JG) was used to improve the ground and provide an impervious subgrade layer at the west end of the addition. Concrete pier underpinning was used to support an existing structure on the west end of the site. A secant pile wall using alternating drilled concrete piles and JG columns was used for earth support and a barrier to groundwater for the installation of a storage tank at the south end of the site.
Inclinometers, total station surveying, vibrating wire strain gauges and tieback load cells were used to monitor performance of the excavation support system. Movement of the the shoring were all kept well below tolerable limits.
Owner: Museum of Science and Industry
General Contractor: W.E. O’Neil Construction Company
The Museum of Science and Industry U-505 Submarine Relocation project required the construction of an underground reinforced concrete vault shoring (37 ft deep) and underpinning of the existing museum footings for construction of a new elevator and stairwell area.
State: District of Columbia
Owner: American Trucking Associationn
General Contractor: Forrester Construction
The renovation of historical protected structures usually presents the architect with an array of unusual problems. Complicate a project with height limitations, footprint limitations and the need for additional parking, and the solution will usually require that the site be fully developed below grade. Add to this the need to undermine and support buildings constructed in 1893, 1910 and 1972 and you now have an outline of challenges RTKL faced in adding 25,000 sf of office and parking space to the American Trucking Association building in Washington, DC.
Forrester Construction Company selected Schnabel to design and build a system to extend the foundations of the existing structures to a deeper elevation, prior to excavating the site below the existing buildings and from property line to property line. The approach was a design that focused primarily on traditional pit underpinning to pick up the axial loads from the shear walls that were supposed to be supporting the structures. As the architect supplied plan revisions for the new construction, it became clear that the original concept would impede the construction of new shear walls that would provide the permanent foundations for the renovated buildings.
Schnabel designed a micropile support system that penetrated the footings and transferred the loads to the columns and walls above the footings. This enabled the construction of future foundation structure under the existing footers.
Owner: Ivy Tower Minneapolis, LLC
General Contractor: BOR-SON Construction, Inc.
Owner: Arena Development, LLC
General Contractor: Perini Building Company
Owner: Avenue Communities, LLC
General Contractor: Avenue Communities, LLC