Microtunneling Bradshaw Company Maryland TUNNELING SPECIALISTS SINCE 1963      
 

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  546 - Myrtle / Morehead Storm Drainage Improvements, Phase 1

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DIMENSIONS
Hand Tunneling NATM/SEM Charlotte, NC City of Charlotte Mixed Face 150' x 13" Ø
SUMMARY: Bradshaw constructed a 13’ horseshoe shaped tunnel 20’ under Morehead Street in downtown Charlotte, NC. The 150’ long was tunnel part of a storm drainage improvement project. The tunnel was designed & constructed using the sequential excavation method (SEM), a hand mine technique using reinforced shotcrete for initial tunnel support. Portions of the tunnel were in mixed face conditions... Complete Project Profile

  539 - Liberty Heights Handmine

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Hand Tunneling Steel/Wood Baltimore, MD City of Baltimore Rock 16' x 48" x 48"
SUMMARY: Bradshaw installed 16 linear feet of a 48 inch woodbox tunnel in rock under Hilton Street. The tunnel accommodated a new sewer line in a residential area of the City of Baltimore. Tunneling was preferred over open cut by both the owner and the general contractor due to the disturbance associated with open cut rock excavation. Complete Project Profile

  538 - Service Customer Built - DC-3rd & H Street, NW

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Hand Tunneling Steel/Wood Washington, D.C. District of Columbia Soft Ground 16' x 48" x 48"
SUMMARY: Bradshaw installed approximately 16 feet of 48 inch woodbox tunnel and ductbank to connect an existing basement to an electrical vault in downtown Washington, DC. Tunneling was deemed a more suitable alternative to traditional trenching methods, because tunneling avoided disruption to road and pedestrian traffic, and eliminated the need to demolish and replace existing surface improvements. Complete Project Profile

  537 - Johns Hopkins Hospital Nelson Harvey Extension Enhancements, Wolfe Street

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Hand Tunneling Steel/Wood Baltimore, MD Johns Hopkins Hospital Mixed Face 85' x 48" x 48"
SUMMARY: Bradshaw Construction was contracted to hand mine a 48 inch by 48 inch wood box tunnel to house a 10 inch polyvinyl chloride pipe and an 18 inch ductile iron pipe. Unanticipated rock was encountered during mining and was removed with pneumatic chisels and hammers. The tunnel was performed due to the close proximity of existing buildings and structures which did not allow for open cut... Complete Project Profile

  536 - Emergency Generator Replacement John Adams Building

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Hand Tunneling Steel/Wood Washington D.C., The Architect of the Capitol Soft Ground 12' x 60" Ø
SUMMARY: Bradshaw installed 12 linear feet of a 60 inch liner plate tunnel in sandy material under a security wall footing at the John Adams Building in downtown Washington, DC. The tunnel allowed for the connection of a new stormwater management structure to an existing manhole, without disruption to surface features or pedestrian traffic. Complete Project Profile

  529 - McMillian Stormwater Storage

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GEOLOGY

DIMENSIONS
Hand Tunneling Steel/Wood Washington D.C., DCW Soft Ground 35' x 72"Ø
SUMMARY: Bradshaw Construction completed two shafts and a hand mine liner plate tunnel as part of a storm water overflow project in northwest Washington DC. As a result of flooding in the area, DC Water decided to convert a more than 100 year old sand filtration chamber into a storm water overflow basin. Bradshaw was subcontracted to install 28 vertical feet of 25 foot diameter shaft while working from... Complete Project Profile

  528 - Children's Hospital of Richmond Pavilion

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Hand Tunneling Steel/Wood Richmond, VA VCU-CHoRP Soft Ground 180' x 96"-132" Ø
SUMMARY: As part of a design/build project, Bradshaw Construction constructed two utility tunnels for the extension to the Children's Hospital of Richmond. Excavation for the first tunnel consisted of 132 inch diameter liner plate with 96 inch reinforced concrete pipe as final lining. The ground conditions were lean clays overlaid with gravely sand in the crown. The second tunnel was for 96 inch liner... Complete Project Profile

  522 - Holy Cross Hospital-Silver Spring-Phase 1B

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GEOLOGY

DIMENSIONS
Hand Tunneling Steel/Wood Silver Spring, MD Holy Cross Hospital Rock 40' x 48" x 48"
SUMMARY: Bradshaw constructed a 48 inch by 48 inch (ID) wood box tunnel under the loading dock for the Holy Cross Hospital in Silver Spring. MD. The over all project was to expand the campus to include a new patient tower for 150 new private patient rooms, a four-level parking garage expansion to accommodate an additional 300 parking spaces, and the central utility plant serving the existing campus... Complete Project Profile

  518 - New Ragged Mountain Dam

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DIMENSIONS
Hand Tunneling Drill and Blast Charlottesville, VA RWSA Rock 482' x 114"Ø
SUMMARY: As part of improvements to increase the capacity of the Ragged Mountain Dam in Charlottesville, VA a tunnel was built to convey primary spillway discharges and house the 36 inch diameter raw water intake pipe which will convey water from the reservoir to the existing treatment facilities near the University of Virginia campus. The 10-foot horseshoe shaped tunnel was 482-feet long. It was... Complete Project Profile

  498 - Lafayette Street Pedestrian Tunnel

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Hand Tunneling Steel/Wood Tallahassee, FL FDOT Soft Ground 55' x 144 " Ø
SUMMARY: Bradshaw Construction built a 55' long hand mine liner plate tunnel for Florida State University to prevent pedestrian overflow onto Lafayette Street after FSU football games. Bradshaw has a long history of building liner plate tunnels; what made this project unique was the active CSX railroad tracks only 6.5' overhead. Trains traveled over the tunnel many times per day during construction... Complete Project Profile

  490 - Little Patuxent Sewer Phase 3

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Hand Tunneling Drill and Blast Savage, MD Howard County Rock 355' x 96" Ø
SUMMARY: Bradshaw Construction hand drilled and blasted a 96 inch tunnel, 355 linear feet in length, to accommodate a 42 inch FRP sanitary sewer. A combination of 96" horseshoe ribs and wood lagging, as well as rock bolts and wire mesh were used to support the seamy and blocky rock patterns. Rock samples showed rock with unconfined compressive strength greater than 55 KSI. There were noise... Complete Project Profile

  486 - Kennesaw Pedestrian Tunnel

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Hand Tunneling Steel/Wood Kennesaw, GA Kennesaw Pedestrian Tunnel Soft Ground 115' x 13' Ø
SUMMARY: Bradshaw hand tunneled 7 feet under a busy CSX Railroad serving Atlanta, GA to install 115 feet of 13 foot diameter tunnel with only 7' of cover between the tunnel and the tracks. The tunnel supports were steel liner plate lined with epoxy paint. It was part of a new park celebrating railroad history and provided a much needed pedestrian underpass. Compensation grouting and real-time monitoring... Complete Project Profile

  476 - Kirkwood Road Tunnels

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Hand Tunneling Steel/Wood Arlington, VA Dominion Power Mixed Face 276' x 48" x 48"
SUMMARY: Bradshaw Construction completed 276' of 48" x 48" hand-mined wood box tunnels for electrical conduit. The main challenges of the project were not known when the project began. The tunnels were supposed to be in soft ground, but partially complete with the first tunnel our crew encountered some hard rock. There was great difficulty in removing the rock for 25' of the tunnel without blasting or... Complete Project Profile

  471 - Suwanee Pedestrian Tunnel

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Hand Tunneling Steel/Wood Suwanee, GA City of Suwanee Soft Ground 62' x 156 " Ø
SUMMARY: Bradshaw Construction installed 62' of 156" steel liner plate tunnel by conventional hand mine methods through a railroad embankment for a pedestrian tunnel. Hand mine techniques were utilized to install the liner plate tunnel under an active Norfolk Southern Railroad with only 7' of cover. Mining took six days to complete, working around the clock. After completion of the excavation, a shotcrete... Complete Project Profile

  459 - Knight Theater Tunnels

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Hand Tunneling NATM/SEM Charlotte, NC Wachovia Bank Mixed Face 160' x 13' x 16.5'
SUMMARY: Bradshaw Construction designed and built two 13' tall by 16.5' wide shotcrete horseshoe-shaped tunnels, totaling 160', for the city of Charlotte, NC. The tunnels were designed as initial/final shotcrete linings, with a sprayed water barrier between shotcrete layers. In addition, the mix design was supplemented with a cementitious admixture to develop internal water resistant properties in the... Complete Project Profile

  457 - Battery Park Trunk Sewer Tunnel

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Hand Tunneling Steel/Wood Richmond, VA City of Richmond Soft Ground 200' x 96" Ø
SUMMARY: As part of a new 3,400' by-pass sewer tunnel, Bradshaw also hand tunneled a total of 200’ of 96” liner plate for a 72” fiberglass storm sewer pipe. Each hand tunnel intersected the 144" rib and board tunnel for underground Y connections or was combined in three way manholes at the shafts. Just as for the primary by-pass tunnel, other major challenges were the extremely accelerated... Complete Project Profile

  443 - Route 262 CSX Crossing

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Hand Tunneling Steel/Wood Staunton, VA VDOT Rock 75' x 120" Ø
SUMMARY: Bradshaw Construction installed a 10'Ø Hand Mined Liner Plate tunnel under CSX Railroad in Staunton, Virginia. The tunnel was excavated from a portal through Boulder Fill in the embankment of the railroad. Due to the voids in the fill, a cementitious grout curtain was pumped over the tunnel alignment before mining. In order to mitigate the risks settlement and the danger of mining through... Complete Project Profile

  430 - Deep River Outfall Sewer

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LOCATION

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GEOLOGY

DIMENSIONS
Hand Tunneling Drill and Blast High Point, NC City of High Point Rock 1,400' x 82" - 96" Ø
SUMMARY: This project involved the utilization of two tunneling methods: hand mine drill & blast, and a TBM capable of mining through hard rock conditions. For the most part the 1,000' TBM run was self-supporting, but some of the weaker zones required rock bolts, roof channels, and even liner-plates for a short reach. Two drill and blast road crossings totaling 400' were completed on this job. Both drill... Complete Project Profile

  412 - Hillen/Ashburton Plant Bypass Pipeline

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LOCATION

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Hand Tunneling Steel/Wood Baltimore, MD Baltimore City DPW Soft Ground 50' x 108" Ø
SUMMARY: Bradshaw hand mined 50 feet of 108 inch liner plate for a 66 inch PCCP sewer and an 8 inch DIP water main under the CSX Railroad. Ground conditions were residual soils of silts, sands and boulders and required hand mining techniques of face breasting and crown fore poling. Bradshaw also installed a 12’ x 24’ mining shaft. The key challenges were the boulder ground conditions, proximity to... Complete Project Profile

  361 - Orme Street Combined Trunk Relief Sewer - Phase 3

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DIMENSIONS
Hand Tunneling NATM/SEM Atlanta, GA City of Atlanta Mixed Face 2,300' x 14' x 16'
SUMMARY: Bradshaw Construction Corporation built the first ever NATM tunnel that utilized compressed air in North America. The project involved the connection of two existing 7' diameter combined sewers to a new 12' diameter relief sewer. Connections were made at seven locations, along a 2,300' alignment in downtown Atlanta. The alignment was enveloped by adjacent structures and utilities. The project was... Complete Project Profile

  348 - R.M. Clayton WRC Plant Expansion - Phase 3

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LOCATION

OWNER

GEOLOGY

DIMENSIONS
Hand Tunneling NATM/SEM Atlanta, GA City of Atlanta Rock 1000' x 16 ' x 16 '
SUMMARY: Bradshaw Construction Corporation drilled and blasted 1000' of rock, and partially weathered rock, in order to install a 12' diameter wastewater pipeline for the City of Atlanta. In order to complete this project in the most expedient manner, a "no blasting" clause in the contract was waived. With the utilization of blasting, we successfully mined through ground conditions that included coming... Complete Project Profile