Project Updates: Bradshaw Construction Projects in MD, CT, NC and VA

CONNECTICUT

Wethersfield

Goff Brook Overflow Closure
Bradshaw Construction Corporation
Bradshaw is currently constructing a 60-in. microtunneling/conventional TBM project in Wethersfield for 30- and 48-in. FRP sanitary sewer installations. The fourth (152 ft) and fifth (450 ft) tunnels were recently completed behind a Herrenknecht AVN 1200, following the completion of two prior microtunnels (420 and 855 ft). The first tunnel (650 ft) was installed by an Akkerman WM480. An additional drive of 48-in. RCP has been recently added to the project by change order, and mining has recently started on this final crossing. This newly added 510-ft drive will be installed on an 1,168-ft radius curve. Ground conditions for microtunneling operations have predominantly been siltstone, with occasional decomposed rock and dense alluvium. The project members include the Metropolitan District Commission (Owner), Jacobs (Engineer) and Baltazar Contractors Inc. (General Contractor), with Bradshaw Construction performing as tunneling subcontractor. Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.

MARYLAND

Baltimore

Camden Street Drain Replacement
radshaw Construction Corp.
Bradshaw finished work on a project in a high-profile area of downtown Baltimore as the tunnel contractor working with Clark Construction’s design-build team. An existing storm drain is currently located in the invert of the CSX Transportation Howard Street Tunnel and is the cause of frequent flooding. This project replaces that 48-in. storm with a larger, deeper siphon drain that will eliminate the flooding and eventually allow for CSX to increase the size of the existing tunnel to gain freight capacity through the area. A total of three tunnels were mined out of a 55-ft deep shaft at the intersection of Camden Street and Howard Street, in the shadow of Oriole Park at Camden Yards.

From the 26-ft diameter shaft, three tunnels were completed, all starting at different elevations. The first is the Upper Adit Tunnel, 32 ft of 66-in. liner plate, hand-mined tunnel for a 48-in. FRP storm drain. The Upper Adit connects to the existing storm drain being replaced, bring those flows back to the Camden Street Shaft.

The second tunnel is 68 ft of 48-in. liner plate, hand-mined tunnel for 18-in. PVC pipe, which will ultimately serve as the drain for the Howard Street Tunnel. A reinforced concrete intake structure was poured into place at the far end of the tunnel, which will ultimately be exposed from inside the CSX Transportation Howard Street Tunnel. The Lower Tunnel consisted of a two-pass microtunnel of 73.5-in. steel casing for a 60-in. FRP storm drain. The tunnel spanned 122 ft under Howard Street which finished at the footing of the Convention Center and will be the siphon that reconnects to the existing storm network. The subsurface conditions consisted of poorly graded sand with silt and gravel, which required extensive grouting prior to tunnel excavation.

Information: Todd Brown, Project Manager; tbrown@bradshawcc.com.

NORTH CAROLINA

Durham

Eno River Outfall
Bradshaw Construction Corp.
Bradshaw has been contracted to do the tunneling on a project in Durham. The project consists of a 260-lf microtunnel of 75.4-in. OD steel casing. Subsurface conditions are expected to range from silty sand to competent rock. Information: Mike Wanhatalo, Project Manager; mwanhatalo@bradshawcc.com.

Raleigh

Lower Walnut Creek
Bradshaw Construction Corp.
Bradshaw recently completed tunneling on a project in Raleigh consisting of a 460-lf microtunnel with 75.4-in. OD Hobas jacking pipe. Subsurface conditions were primarily silty sand and partially weathered rock. Information: Mike Wanhatalo, Project Manager; mwanhatalo@bradshawcc.com.

VIRGINIA

Fredericksburg

Claiborne Run Sewer
Bradshaw Construction Corporation
Bradshaw recently completed microtunneling 190 ft of 60-in. steel casing under CSX tracks in Fredericksburg for a 42-in. DIP gravity sewer. The Stafford County DPU (Owner) contracted Timmons Group (Engineer) and W.C. Spratt Inc. (General Contractor) to construct the project, with Bradshaw being selected as microtunneling subcontractor. The 60-in. MTBM used was an AVN-1200 model developed by Herrenknecht. Tunnel depths ranged from 18 to 35 ft below the surface, with the alignment passing beneath the water table through clayey sands, silty sands and poorly graded sands. The tunnel was completed in December 2018. Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.

Richmond

Western Area Trunk Sewer
Bradshaw Construction Corporation
Bradshaw recently completed microtunneling 530 ft of 60-in. steel casing under I-64 in Richmond for a 30-in. DIP gravity sewer. Henrico County (Owner) contracted AECOM (Engineer) and Gaston Brothers Utilities LLC (General Contractor) to construct the project, with Bradshaw being selected as microtunneling subcontractor. The 60-in. MTBM used was a model AVN-1200 manufactured by Herrenknecht. Tunnel depths ranged from 12 to 32 ft below the surface, with the alignment passing beneath the water table through a full face of sandstone, transitioning to clayey sand and gravel. The tunnel and pipe installation was completed in October 2018. Project Information: Doug Piper – Chief Estimator; dpiper@bradshawcc.com.