Tunnel Updates – June 2023

Three times per year, TBM: Tunnel Business Magazine recaps the status of major tunneling projects underway in the United States and Canada. Below is the Tunnel Update that appeared in the June 2023 issue of the print edition.


Carson, Los Angeles and Rancho Palos Verdes

Joint Water Pollution Control Plant Effluent Outfall Tunnel
Dragados USA

The Los Angeles County Sanitation Districts (Sanitation Districts) are undertaking the $630.5 million Joint Water Pollution Control Plant Effluent Outfall Tunnel project. NTP was issued April 8, 2019 with 1953 working days to complete the work and an estimated completion date of mid-2027.

The tunnel is approximately 7 miles long and 21.5 feet in excavated diameter (18 feet in internal diameter). The tunnel alignment varies in depth from approximately 50-feet to 450-feet below the ground surface. The entire tunnel alignment will be below the groundwater table with pressures ranging from 1 to 9 bar.

Work at the JWPCP Shaft Site started in the summer of 2019. Construction of the access shaft slurry wall excavation support system was completed in December 2019. Excavation of the shaft in dry and wet conditions, which was followed by shaft tremie slab construction and dewatering, was completed August 2020. Open-cut construction of the 14-foot diameter cast-in-place concrete Connection A from the proposed Junction Structure No. 1 to the JWPCP Shaft was substantially completed in October 2020. Jet grouting activities for the tail tunnel, starter tunnel, and three safe havens were completed in May 2021. Excavation of the starter and tail tunnels was completed in May 2021. The contractor is using a Herrenknecht slurry TBM, which arrived onsite in late 2020. Fabrication of test precast concrete segments at the Traylor Bros., Inc. Littlerock, California facility began in April 2021. Tunnel machine launch began in the Fall of 2021, with production mining beginning in early-2022. Tunnel mining is anticipated to be completed by early-2025. Multiple hyperbaric interventions for TBM cutterhead inspection and maintenance have been successfully completed to date. Three planned maintenance stops at Safe Havens 1, 2 and 3 were also completed. Approximately 13,000-feet of tunnel lining has been installed to date.

Lead Design Consultant: Parsons; Tunnel Design Consultant: Delve Underground; Tunnel Consultant: Mott MacDonald/BabEng. Listed Major Subcontractors for Dragados – Excavation and Structures: W.A. Rasic Construction Company, Inc.; Jet Grouting and Support of Excavation: Malcolm Drilling Company, Inc.

Personnel: Los Angeles County Sanitation Districts – Construction Management Section: Matthew Palma, Section Head; Russell Vakharia, Resident Engineer/Construction Manager; Sewer Design Section: Anthony Howard, Section Head; Oscar Morales, Supervising Engineer; Yoonkee Min, Senior Engineer; Parsons – Danson Kelii, Project Manager; Delve Underground – John Stolz, Lead Tunnel Design Consultant; Mott MacDonald – Daniel McMaster, Lead Tunnel Consultant; Chris Peiler, Lead Tunnel Engineer; Dragados – Matt Kendall, Project Manager; John Truong, Deputy Project Manager; Nicholas Karlin, Project Engineer.

Los Angeles

Westside Purple Line Extension Section 1
Skanska/Traylor/Shea JV

The Westside Purple Line Extension Project is a 9-mile long project that consists of three Sections. Section 1 is a 3.92-mile long subway alignment with three stations being constructed under Wilshire Boulevard in gassy ground and tar sands with prehistoric fossil deposits.
NTP for the $1.636 million design-build contract was issued on Jan. 12, 2015, with service expected in 2024. The twin Herrenknecht EPB TBMs completed tunneling between 2018 and 2021.
The scope of work includes 17,900 ft of twin-bore tunnel: Reach 1 is 9,600 lf between Wilshire/La Brea Station and Wilshire/Western TBM retrieval shaft; Reach 2 is 4,400 lf between Wilshire/La Brea and Wilshire/Fairfax Stations; and Reach 3 is 3,300 lf between Wilshire/Fairfax and Wilshire/La Cienega Stations. There is also 600 lf of tail track at Wilshire/La Cienega Station.
The tunnel is 18-ft, 10-in. in diameter with 12-in. thick precast concrete lining. Depth varies from 40 ft and 100 ft. The alignment includes three stations and the western retrieval shaft and 23 SEM cross passages. Cross-passages are planned to be mined by the sequential excavation method using variety of localized ground support systems.

Tunnel Designer: PTG/CH2M; Construction Manager: WEST JV (Stantec/Jacobs Engineering/AECOM); Major Subcontractors – TBM Manufacturer: Herrenknecht; Precast: Traylor Precast; Support of Excavation/Piles: Condon Johnson; Jet Grouting: Malcolm Drilling; Geotechnical instrumentation: Group Delta; Dewatering: Moretrench; Standpipe: Link Nielsen.

Los Angeles

Westside Purple Line Extension Section 2
Tutor Perini/O&G

This is a $1.37 billion project for LA Metro that includes 2.6 miles of twin bore tunnel and two new stations (Wilshire/Rodeo and Century City/Constellation). Major construction began in spring 2019, with completion expected in 2025.
Metro reported that the Herrenknecht TBMs completed tunneling. Final project completion is expected in 2025.

Los Angeles

Westside Purple Line Extension Section 3
Frontier-Kemper/Tutor Perini JV

The $410 million project for LA Metro is a 2.6-mile extension from Century City to VA Hospital in Westwood. In contrast to previous recent Metro underground contracts, Section 3 splits out tunnel and stations contracts. The tunnels are being built by EPB TBM. Completion is expected by 2027.
The stations contract was awarded to Tutor Perini/O&G Joint Venture for $1.4 billion. Stations will be located at Westwood/VA Hospital and Westwood/UCLA, with scheduled completion by 2027.

San Jose

BART Silicon Valley Extension
Kiewit Shea Traylor (KST) JV

The $6.9 billion, 6-mile BART Silicon Valley Phase II Extension includes 5 miles tunnel constructed by a single, large-bore TBM on the order of 45-ft in diameter. The extension includes four stations (three underground). The overall project is a 16-mile extension of the Bay Area Rapid Transit system in the San Francisco Bay area. A joint venture of HNTB and WSP agreed to a four-year, $88.3 million program management contract with the owner, Santa Clara Valley Transportation Authority (VTA). Mott MacDonald/PGH Wong was awarded a general engineering consultant contract in January 2019.

At its May 5, 2022, regular board meeting, the VTA Board of Directors voted unanimously to authorize the General Manager/CEO to execute the first in a series of construction contracts for the BART Silicon Valley Phase II (BSVII) Project. This first Contract Package for the Tunnel and Trackwork (CP2) is a Progressive Design Build Contract with Kiewit Shea Traylor (KST), a Joint Venture, in the amount of $235,000,000.

Contract Package (CP2) will be carried out in stages with Stage 1 activities including investigation of innovations, engineering and design, open book cost estimates, and the work schedule. Stage 1 activities are anticipated to occur from May 2022 through approximately December 2023, setting the stage for major construction (Stage 2) which includes boring the tunnel under downtown San Jose.



PAR 1232 Second Creek Interceptor
Bradshaw Construction Corporation

Bradshaw Construction Corporation is currently performing work on the PAR 1232 Second Creek Interceptor project in Denver. The wastewater interceptor will include a number of trenchless crossings, of which Bradshaw Construction Corporation will be installing eight trenchless crossings, totaling over 4,100 lf, by the microtunneling method. Tunnel crossings range from 48-in. steel casing to 73.5-in. steel casing, with drive lengths reaching 1,500 lf on the longest crossing. FRP from 30- to 60-in. is being installed and backfilled once tunneling operations are completed. The tunnels will be installed out of steel sheeted shafts, installed by Lawrence Construction Company. The challenging project geology will consist of multiple mix face conditions with claystone overlaid by coarse and fine alluvium, underneath the water table. Tunnels pass underneath roads, highways, UPRR and BNSF tracks. To date, Bradshaw Construction Corporation has successfully seven of the eight drives, including the 1,500-lf crossing, and is currently installing the final tunnel.

The project members include the Metro Wastewater Reclamation District (Owner), HDR Engineering, Inc. (Engineer), Garney Construction (CMAR), and Bradshaw Construction Corporation working as tunneling subcontractor.

Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.


West Gates DIW Pond Expansiont
Southland Contracting Inc.

This unique $69.9 million project addresses Denver International Airport’s (DEN) most significant environmental risk, the discharge of aircraft deicing fluid to receiving waters. Southland Contracting (SCI) will construct critically needed DIW infrastructure to allow the airport and their airline partners to continue operating during winter weather in compliance with environmental regulations. The new construction will provide volume for the current DIW storage deficit, and the ongoing 39-gate Concourse Expansion Program. Additionally, this project provides for future Deice Pads Delta Sierra (DS) West, DS East Deice Pads Delta (D), and apron expansion DIW runoff and collection storage.

The overall purpose of this project is to replace the existing DIW Pond 002. The tunnel scope of work consists of six bores totaling 5,179 linear feet. Each drive varies by length and diameter to accommodate the active runway, taxiways, and maintenance roads they cross. Based on geotechnical reporting by Lithos Engineering, SCI anticipates claystone and sandstone bedrock to be encountered in shaft and tunnel excavations along with cohesive soils consisting of lean clay with varying amounts of sand and clayey sand.

Additional scopes of work include: Four (4) 5.4-million-gallon pond cells (total of 21.6 MG of storage) located on the West Airfield; 4,400 lf of 90-in. FRP pipe to interconnect between existing Pond 002 and proposed Pond 002R; Diversion structures with gate valves; Pump Station with 4 pumps; 1-million-gallon DIW storage tank; 14-in. DIW force main to move collected DIW waters to the WADS Ponds or Lift Station No. 1 sanitary sewer system; and Control facilities, along with needed infrastructure.

Southland Contracting will first launch beneath Taxiway Whiskey Alpha (WA) to cross Deicing Pad WA and Taxiway Bravo 4 (B4). This 1,465 lf, two-pass installation, will be excavated using a manned 60-in. diameter, Single Shield Tunnel Boring Machine (TBM). This tunnel will be supported with steel casing and utilize one intermediate jacking station. Given the shallow depth at this location, trench boxes will be used for both launch and reception pits.

Following Taxiway Whiskey Alpha, SCI will excavate a 43-ft deep launch shaft supported by steel rib and wood lagging for a single-pass installation. This 550 lf drive, northwest of Taxiway Charlie November (CN), will be excavated using a manned 96-inch diameter Single Shield TBM. The single-pass installation will be completed with direct jacked FRP pipe. A common reception shaft will be installed and supported with steel beam and wood lagging. The common reception shaft will connect waste flow from the 550 lf, single-pass installation, to the downstream 2,051 lf drive crossing beneath Runway 16 Lima / 34 Romeo (16L/34R).

The 2,051 lf drive will be excavated using a manned 132-in. diameter, Single Shield TBM, for two-pass installation. The 132-in. diameter tunnel will carry a 90-in. DIW drain line, 24-in. DIW High Concentrate drain line, 8-in. Glycol Supply line, two 14-in. conveyance pipe, electrical and communication lines. This excavation will be supported with steel ribs and channel. The common reception shaft depth will be 50 feet deep. Given the shallow depth at the launch location, trench boxes will be used for the launch pit.

The three remaining bores have been subcontracted to a local firm, Underground Infrastructure Technology (UIT). These bores range from 30 to 48 in. in diameter and total 1,113 lf.

Lead Designer: Burns & McDonnel Inc.; Tunnel Designer: Lithos Engineering Inc.; TBM Manufacturer: Southland Contracting Inc.; Contractor: Southland Contracting Inc.; Subcontractor: Underground Infrastructure Technology LLC. (UIT); Contractor Design Engineer: Kilduff Underground Engineering Inc.

Personnel: VP of Operations: Kent Vest; Area Manager: Nick Jencopale; Project Manager: Maxwell Pauley; General Superintendent: Joe Vera.



South Hartford Conveyance and Storage Tunnel
Kenny/Obayashi IV, JV

Kenny/Obayashi received NTP on this $279.4 million project for the Hartford Metropolitan District (MDC) on Aug. 1, 2016. The scope of works includes a 4 -mile long tunnel, 21-ft OD and 200 ft deep, along with a 74-ft diameter by 240-ft deep pump station shaft; a 39-ft diameter by 205-ft deep TBM launch shaft; a 32-ft diameter by 216-ft deep retrieval shaft and eight vortex drop shafts.

The tunnel geology includes red siltstone with basalt encountered at fault zones during TBM excavation. After TBM extraction, an Odor Control Building will be constructed at the Retrieval Shaft Site. MDC announced on Jan. 6, 2022, that the TBM reached the arrival shaft. A Herrenknecht Single Shield Rock TBM was used to mine through siltstone, sandstone, and shale of the Portland and East Berlin Formations and the Hampden and Holyoke Basalts. The tunnel alignment was complicated by the presence of numerous faults. Final completion was expected for 2023.



Northeast Boundary Tunnel (NEBT)
Salini Impregilo Healy JV (SIH JV)

The $579.9 million Design & Build project for DC Water involves the design and construction of Division J of the DC Clean Rivers Project called Northeast Boundary Tunnel (NEBT). The project includes the construction of 26,700 ft of tunnel with 23 ft inner diameter from 60 to 140 ft below grade. The tunnel is excavated using an Herrenknecht EPB TBM (Earth Pressure Balance Tunnel Boring Machine). The first section of the NEBT is excavated in a clay soil and the second part of the tunnel is in a sandy layer. Mix face conditions were expected for most of the tunnel alignment.

The project also includes the construction of 7 shafts, ranging from 20 feet to 55 ft diameter, and supported by unreinforced slurry walls or secant piles and lined using Cast in Place concrete. There are also 6 adits to be excavated using the Sequential Excavation Method (SEM) in ground previously improved through either jet grouting or ground freezing techniques. Finally, a 700 ft length of Diversion Sewer with 10 ft of internal finished diameter will be constructed using an EPB (Earth Pressure Balance) TBM (Tunnel Boring Machine) in clay soil which it will be lined with HOBAS pipes installed using the pipe jacking tunneling method.

As of April 2023, 97% of the works are completed. The tunnel excavation was completed in April 2021, the TBM disassembly in June 2021. The tunnel cleanup operations have been completed and the tunnel segment final repairs works are planned to be finalized in May 2023. All the seven drop shafts are already completed except for 3 shaft cover slabs that will be constructed in the upcoming months. All the adits have been built and finally connected to the main tunnel. Regarding the diversion facilities on the surface (Near Surface Structures), all the permanent structures have been constructed and the punch lists and final testing activities are currently ongoing. Site restorations works are currently ongoing in most of the construction sites. The 10-ft diameter TBM drive was completed at the end of October 2021 and a total of 38 HOBAS pipes 20-ft long have been used to construct this tunnel. The NEBT is expected to be connected to the previous DCCR tunnels and enter in service by July 2023, while the rest of decommissioning and surface restoration works are planned to be completed by November 2023.

Unique aspects of the project include: Ground improvement using freezing technique to allow adit excavation in a very dense urban area of Washington, D.C.; Ground improvement under existing utilities using Jet Grout Elliptical columns; Hybrid ground improvement system using freezing and jet grouting method to allow the Adit construction in one of the construction site; Final TBM breakthrough into shaft filled with water; and Unreinforced slurry walls used as support of excavation for the drop shaft construction.

Designer: Brierley Associates; Major Subcontractors: Treviicos, Corman Kokosing, Keller-North America, EnTech Engineering; TBM Manufacturer: Herrenknecht

Personnel: Owner – DC Water Clean Rivers Project: Moussa Wone (Vice President), Jeff Peterson (Construction Manager); Designer – Brierley Associates: Jeremiah Jezersky (Design Manager); Contractor – Salini Impregilo Healy Joint Venture (SIH JV): Daniele Nebbia (Vice President of Tunneling Operations); Fabio Ciciotti (Project Director); Andrea Sesenna (Project Manager).



C-51 Reservoir
Bradshaw Construction Corporation

Bradshaw Construction Corporation has recently completed construction on a private job for Palm Beach Aggregates Inc., situated on an active mine. All work was immediately adjacent to both Florida Power and Light Company (FPL) and Gulfstream Natural Gas utility easements. Bradshaw’s scope of work consisted of twin 956 lf tunnels that were mined out of a single 37 ft x 28 ft steel sheeted launch shaft utilizing 96” FRP Jacking Pipe behind an AVND 1800AB MTBM. Ground conditions encountered showed signed of mixed reach/mixed face, which transitioned between sand and limestone throughout both drives, all under the water table. The project was successfully completed in December. Project members include Palm Beach Aggregates (Owner), North Star / Black and Veatch (Design Engineers), Phillips and Jordan (General Contractor) and Bradshaw Construction Corporation working as the tunneling subcontractor.

Project Information: Chris Flanagan – Project Manager; CFlanagan@bradshawcc.com.


Fort Wayne

Three Rivers Protection and Overflow Reduction Tunnel Project (3RPORT)
Salini Impregilo Lane JV

The $188 million Design-Bid-Build project for Fort Wayne City Utilities consists of approximately 24,500 lf of tunnel, 200 to 240 ft deep, excavated by a Herrenknecht slurry TBM, segmentally lined with a 16-ft finished inside diameter. There are three large diameter shafts, ranging from 29 to 69 ft diameter supported through the overburden with a slurry wall, with drill-and-blast excavation through rock. There are 13 small diameter drop and vent shafts, ranging from 2 to 8 ft, excavated by blind-bore drilling, and lined with ductile iron and centrifugally cast fiberglass reinforced polymer mortar pipe. Approximately 720 lf of adits will be driven using drill-and-blast method to connect the TBM tunnel to the drop and vent shafts. The TBM tunnel and adits will be excavated primarily through limestone of the Wabash Formation with anticipated high groundwater inflow in the range of 5,000 gpm to 10,000 gpm at 6.5 bar pressure.
TBM excavation was completed in 2022. As of February 2023, cleaning of the tunnel was underway and was the only activity for completion of the Project.

Tunnel Designer: Black & Veatch; Construction Manager: Jacobs; Major Subcontractors: CSI Tunnel Systems, Keller – North America, Hardman Construction, Bunn Inc., F.A. Wilhelm Construction, Service Electric. TBM Manufacturer: Herrenknecht.

Personnel: Owner / City of Fort Wayne: Mike Kiester (Manager, City Utilities Engineering); Tunnel Designer / Black & Veatch: Leo Gentile (Senior Project Manager), Matthew Pierce (Project Manager); Construction Manager / Jacobs: Todd Webster (Construction Contract Manager); Contractor / Salini Impregilo Lane JV: Daniele Nebbia (Vice President of Tunneling Operations), Carlos Lang (Project Director), Lance Waddell (Project Manager).


Fall Creek Tunnel
Shea-Kiewit JV

The Fall Creek Tunnel is a 20,244-ft, 20-ft, 2-in diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are ten CSO connecting structures/deaeration chambers and adits. The work is for Citizens Energy Group’s DigIndy project, which is a CSO reduction program including six deep rock tunnels totaling over 28 miles.

Mining commenced in September 2019 and was completed on April 1, 2020. The Fall Creek Tunnel has nine adits totaling over 5,200 feet and adit and deaeration chamber excavation is 100% complete. Adit excavation is complete and chamber build out is ongoing. All drop and vent shaft excavation and lining is complete. Tunnel concrete lining operations and the retrieval shaft concrete lining is 100% complete. Surface connections are ongoing. Based on the terms of a federal consent decree, the Fall Creek Tunnel must be operational by the end of 2025.

Key Project Personnel – Construction PM: Christian Heinz, P.E.; Inspection PM: Sam Cain, P.E. (AECOM); Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Tunnel Construction Supervisor: John Morgan.


Pleasant Run Tunnel
Shea-Kiewit JV

The Pleasant Run Tunnel is a 41,472-ft, 20-ft, 2-in diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are eight CSO connecting structures/deaeration chambers and adits. The work is for Citizens Energy Group’s DigIndy project, which is a CSO reduction program including six deep rock tunnels totaling over 28 miles.

Mining commenced in May 2021 and was completed in August 2022. Drop shaft and vent shaft excavation and lining is ongoing. Adit and deaeration chamber excavation is complete, and crews have commenced lining and buildout. Tunnel concrete lining operations commenced in late April 2023 and is expected to take approximately 16 months to complete. Surface connections are ongoing. Based on the terms of a federal consent decree, the Pleasant Run Tunnel must be operational by the end of 2025.

Key Project Personnel – Construction PM: Christian Heinz, P.E.; Inspection PM: Sam Cain, P.E. (AECOM); Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Tunnel Construction Supervisor: John Morgan.


Ellicott City

Extended North Tunnel
Kiewit-Traylor JV

The project, known as the Extended North Tunnel, will be about 5,000 ft long, 18 ft in diameter and run up to 100 ft underground, just north of Main Street. Kiewit-Traylor was awarded a construction manager at risk contract to build the tunnel.

Howard County has already broken ground on two other major flood mitigation projects – the H7 and Quaker Mill ponds. Both projects are expected to retain nearly 7.5 million gallons of storm water combined.

The cost for the tunnel is approximately $50 million. Construction was expected to begin in 2023 with final completion by 2026. The project is a flood control measure to combat recent major flooding events in the city, with 1,000-year floods occurring along the Patapsco River in 2016 and 2018.


St. Louis

Jefferson Barracks Tunnel
SAK Construction, LLC

The $63.3 million project for the Metropolitan St. Louis Sewer District includes approximately 17,800 lineal feet of TBM bored tunnel, and installation of a 7-ft diameter fiberglass reinforced polymer mortar carrier pipe and fiber optic conduits in the tunnel.

The tunnel is located adjacent to the Mississippi River, extending southwardly from the Lemay Wastewater Treatment Plant, and is intended to replace an aging system of pump stations, force mains and shallow sewers that convey wastewater to the treatment plant. The tunnel is excavated through limestone bedrock at depths ranging from 140 to 215 ft below the ground surface.

Construction was by a main beam TBM launched from an 88-ft diameter shaft which will serve as a pump station to be constructed under a separate contract. A pre-excavation grouting program was conducted at the launch shaft to minimize inflow from any karstic features that could have been encountered during shaft excavation. The TBM was removed via the finished 18-ft diameter, concrete lined shaft at the upstream terminus of the tunnel. Fourteen bored shafts for drop pipes, vent pipes, and fiber optic conduits were also drilled along the tunnel alignment from the surface to the tunnel depth and passed through karstic zones above the tunnel alignment.

The project is about 89 percent complete with excavation of the tunnel using a 13.5-foot diameter TBM being completed in December 2022. Carrier pipe installation began in February 2023. About 5,160 feet of carrier pipe and connection of the carrier pipe with two of the drop chambers were completed by the end of April 2023. Placement of cellular grout backfill for the carrier pipe is scheduled to start in June 2023. Construction of the last intake structure along the tunnel alignment is also in progress and should be completed in early spring 2023. Final Completion is expected in April 2024.

Tunnel Designer: Jacobs Engineering Group; Construction Manager: Shannon & Wilson; Major Construction Subcontractors: Case Foundation (shafts), ACT (pre-excavation grouting), Williams Tunneling (tunnel construction and carrier pipe installation), Goodwin Brothers Construction (intake construction); TBM Refurbishment: Robbins.

Personnel: Patricia Pride, Project Manager, Metropolitan St. Louis Sewer District; Kent Kotthoff, CM Program Manager, Metropolitan St. Louis Sewer District; Ray Scherrer, Division Inspector, Metropolitan St. Louis Sewer District; William Haag, Design Project Manager, Jacobs Engineering Group; Andrew Bursey, Lead Tunnel Designer, Jacobs Engineering Group; Tom Abkemeier, CM Project Manager, Shannon & Wilson, Inc.; David Donovan, Resident Project Representative, Shannon & Wilson, Inc.; Dan Swidrak, Project Manager, SAK Construction; Terry Beesley, General Project Supt.; Jack Bragg, Project Superintendent, SAK Construction; Jack Lynch, Tunnel Division Safety Manager, SAK Construction; Zach Meyer, Safety Manager, SAK Construction.

St. Louis

Lower Meramec Tunnel (11746)
SAK Construction LLC

This is a $174 million project for the Metropolitan St. Louis Sewer District (MSD) comprising 35,903 ft (6.8 miles) of 11-ft excavated diameter, 8-ft inside diameter, 78 to 286 ft deep sanitary sewer tunnel which is expected to be mined utilizing a TBM entirely within limestone, shale and dolomite rock with two required construction shafts and six drop structures. The project is approximately 24% complete.

The Contractor has completed drilling the drop and vent shafts, installed secant piles at the termination TBM retrieval shaft and completed excavation of the termination shaft, tail tunnel, starter tunnel, and the adit to the Fenton dropshaft. The Contractor has completed installation of the upper portion of the concrete lining at the starter shaft. The TBM has been assembled in the starter tunnel and is currently undergoing site acceptance testing.

This project is an extension of the previously constructed Baumgartner Tunnel Project which was 20,200 ft long with an excavated 12.5-ft diameter. Bedrock conditions anticipated to be encountered consist of the Warsaw Formation and the Burlington-Keokuk Limestone. The Warsaw Formation is composed primarily of limestone and shale with small amounts of chert whereas the Burlington-Keokuk Limestone includes limestone and abrasive chert which, in places, composes up to 40% to 60% of the rock mass.

Tunnel Designer is WSP as a subconsultant to HDR Engineering, Inc. The Construction Manager for the project is Black & Veatch.

Personnel: Metropolitan St. Louis Sewer District – Design Project Manager: Jerry Jung; Construction Project Manager: Ray Scherrer. Tunnel Design Engineer: Everett Litton, WSP. Construction Manager: John Deeken, Black & Veatch. SAK – Project Manager; Jim Buckley. Project Engineer; Patrick Niemuth. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Matt Muscarella. General Project Supt.; Terry Beesley. Project Superintendent; Steffan Peck.



Dairy Branch Tributary
Bradshaw Construction Corporation

Bradshaw Construction Corporation continues construction on sanitary sewer tunnels in Charlotte, NC. The 2,399 ft by 60-in. steel casing tunnel will be installed behind a Herrenknecht AVN-1200 MTBM for a 36-in. PVC sanitary sewer. Subsurface conditions consist of granitic rock ranging from 25 kpsi to 38 kpsi and alluvial deposits. Construction started in November 2020 and has completed the 2,399 ft of total tunnel. The project members include the Charlotte Water (Owner), STV Engineers, Inc. (Engineer) B.R.S., Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor.

Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.


Little Sugar Creek Tributary to Central Business District
Bradshaw Construction Corporation

Bradshaw Construction Corporation has started construction on one pass sanitary sewer tunnels in Charlotte, NC. The 3,587-ft by 48-in. reinforced concrete pipe tunnel will be installed behind a Herrenknecht AVN-1200 MTBM. Subsurface conditions consist of granitic rock ranging from 9 kpsi to 30 kpsi and alluvial deposits. Construction began in September 2020 and has completed the 3,587 ft of tunnel. The curved tunnels are the first planned direct jack curved sanitary sewer in North Carolina. The project members include the Charlotte Water (Owner), WSP USA (Engineer) Sanders Utility Construction Co., Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor.

Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.


Upper Little Sugar Creek Trunk Sewer Improvements
Bradshaw Construction Corporation

Bradshaw Construction Corporation has started construction on one pass sanitary sewer tunnels in Charlotte. The 2,272-ft by 72-in. reinforced concrete pipe tunnel will be installed behind a Herrenknecht AVN-1800 MTBM along curved alignments. Subsurface conditions consist of partially weathered rock and alluvial deposits. Construction began in November 2021 and has completed 1,177 ft of the 2,272 ft for the project. The project members include Charlotte Water (Owner), Kimley & Horn (Engineer) Sanders Utility Construction Co., Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor.

Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.


West Neuse Interceptor Improvements
Bradshaw Construction Corporation

Bradshaw Construction Corporation has started construction on two pass sanitary sewer tunnels in Raleigh. The 580-ft by 87.5-in. steel casing to allow for the installation of proposed 66-in. sanitary sewer will be installed behind a Herrenknecht AVN-1800 MTBM. Subsurface conditions consist of granitic rock. Construction began March 2023. The project members include Raleigh Water (Owner), Black & Veatch (Engineer) JF Wilkerson Contracting Co. Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor.

Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.



Shoreline Storage Tunnel
Shoreline Storage Tunnel JV (McNally/Kiewit)

The Shoreline Storage Tunnel (SST) Project is part of Project Clean Lake, a $3 billion, 25-year program. NEORSD began the program in 2011 to meet the Clean Water Act standards and address water quality issues. Project Clean Lake will eliminate 4 billion gallons of wet weather combined sewer overflows (CSOs). Every year this waste releases into Lake Erie and its tributaries in the Greater Cleveland area.

The $201 million Shoreline Storage Tunnel Project is a 23-ft diameter storage tunnel approximately 14,100 ft long. It is also the first phase of CSO control measures required at this location under Consent Decree Control Measure 7. DLZ led the CCTV inspection and condition assessment of 2,500 feet of sewer. That included repair recommendations for circular, egg, arch, and rectangular sewers ranging from 15- to 120-inches in diameter. Design: Delve Underground.

Nicholson was awarded a contract that includes construction of three diaphragm wall access shafts at three different locations along the tunnel alignment to launch and retrieve the Herrenknecht tunnel boring machine. The contract also includes three cement bentonite mass treatment break in/break out blocks for the tunnel boring machine and two soldier pile reinforced cement bentonite walls to be used as support of excavation systems for two near-surface structures.


Shoreline Consolidation Tunnel
Turn – Key Tunneling Inc.

The Shoreline Consolidation Sewer Project (SCS) is part of the Northeast Ohio Regional Sewer District’s Project Clean Lake, a $3 billion, 25-year program NEORSD began in 2011 designed to meet the Clean Water Act standards and address water quality issues. The SCS Project will highlight a 5,100 lf soft ground microtunnel that will connect into the previously constructed Shoreline Storage Tunnel.
Turn – Key Tunneling Inc. (TKT) was contracted by Kokosing Construction Company (KCC) to perform specialized shaft and trenchless construction including 6 tunnels and two vertical shafts.

Completed to date:

20-ft diameter shaft at structure E -12 A
The first tunnel, a 90-in. drift-and-bench, four-flange tunnel liner structure has been completed with 60-in. RCP threaded to connect the E-18A Diversion Structure to the E-18A Junction Structure.
A 78-in. tunnel liner plate structure for 48-in. Hobas sewer to connect Structure E-13A with an underground intercept into the Easterly Interceptor

Up next is a 16-ft diameter vertical shaft at Structure E-10 that will be 38 ft in depth to launch a 96-in. drift-and-bench tunnel that is scheduled to start in July. The contract is expected to be complete by July 2024.

Personnel: Elliott Baum, Project Manager; Gary Ison – Superintendent; Tim Branham – Foreman.


Rickenbacker Intermodal Sanitary Sewer Extension
Turn – Key Tunneling Inc.

The Rickenbacker Intermodal Sanitary Sewer Extension (RISSE) project for the City of Columbus is a new sewer designed to replace an existing pump station and force main along the Northwestern edge of Rickenbacker International Airport. The RISSE Project will involve a total of 6,100 lf of sanitary sewer installation and 1,525 lf of trenchless crossings in five locations.

Turn – Key Tunneling Inc. (TKT) was contracted by Kokosing Construction Company (KCC) to perform three of the five trenchless crossings for a total of 970 Lin. Ft.

Crews utilized an Akkerman pilot tube/guided boring system to install the first crossing of Rickenbacker Road with a total length of 283 lf. The drive was completed successfully through various compositions of glacial till. Crews are currently threading the carrier pipe and grouting the annular space before moving onto the next tunnel – a 310-lf drive through anticipated tough geology.

Personnel: Chris Leonard, Project Manager; Gary Ison – Superintendent; Tim Branham – Foreman.



Arcadia Intake
Southland Contracting / Oscar Renda Contracting JV

This $68 million project for the City of Edmond consists of a single shaft from which three tunnels will be launched. The shaft is 54-ft ID and 80 ft deep. Shoring consists of secant piles, 80EA, 1-m diameter. There are three wet retrieval type tunnels, which will serve as the intakes for the new City water supply system.
The Upper Intake is 150 ft long, 16 ft below lake normal pool elevation. The Middle Intake is 250 ft long, 30 ft below lake normal pool elevation. The Lower Intake is 450 ft long, 40 ft below lake normal pool elevation. MTBM entry seals will be cast in 2-ft thick final concrete liner. Entry seals have 72-in. flanges, on which slide gates will be installed once tunneling is complete. Crews are using 60-in. HOBAS jacking pipe. Tee screens with airburst system will be installed on the end of the HOBAS pipe.

The shaft has been excavated to depth with concrete lining 20% complete. Tunneling and wet retrievals will commence once concrete lining is complete. Marine Dredging has commenced.

This will mark the first lake tap wet retrieval in the United States using FRP pipe. A Herrenknecht AVN1200 machine will be used with an upskin kit with subsea recovery can and hard rock cutterwheel.
Excavated material will consist of sandstone, claystone and mudstone in undisturbed earth, and alluvial fill with lakebed.

Owner: City of Edmond Public Works Authority; Owners’ CM / Engineering Manager: Carollo Engineers; Engineer of Record: Schnabel Engineering; General Contractor: Oscar Renda Contracting; Tunnel Contractor: Southland Contracting Inc.; TBM Manufacturer: Herrenknecht, Southland Contracting.

Personnel: SCI VP of Underground: Kent Vest; SCI Project Manager: Elliott Fuller; SCI Survey Manager: Fareed Imoro; SCI Field Engineer: Kash Sisk; SRJV Senior Project Engineer: Kyle Crawford; SRJV Superintendents: Homero Lugo, Shane Sorteber.


Pawtucket/East Providence

Pawtucket Tunnel

The Narragansett Bay Commission is building the third and final phase of its Combined Sewer Overflow Program. Phase III includes the Pawtucket Tunnel, NBC’s second CSO storage tunnel.

The $245 million Pawtucket Tunnel will be approximately 11,600 ft long, 30 ft in diameter and located in bedrock about 200 ft below the ground surface. The project includes the launch and recovery shafts (which will become permanent access shafts), four drop shafts with connecting adits at existing outfall locations, and an underground shaft- or cavern-style tunnel pump station.

The launch shaft and tunnel pump station will be located at NBC’s Bucklin Point Wastewater Treatment Facility in East Providence. The alignment will be parallel to the Seekonk River and Blackstone River, and end near the border of Pawtucket and Central Falls, Rhode Island. An 8,800-ft long, 10-ft diameter conveyance tunnel, which will connect to the Pawtucket Tunnel, is planned to begin after the Pawtucket Tunnel is completed.

The design-build contractor consists of a joint venture of CBNA and Barletta (CBNA-Barletta JV); also known as CB3A. The prime designer is AECOM. GEI Consultants is assisting AECOM with geotechnical engineering and field support. Design subconsultants include Gall Zeidler Consultants, Mueser Rutledge Consulting Engineers and BETA Group. The program/construction manager for Phase III is Stantec and its teaming partner Pare Corporation. Herrenknecht is supplying the hybrid TBM.

Tunneling was started in September 2022 and due to be completed by the end of 2023. Final project completion was expected by 2027.



Mill Creek/Peaks Branch/State Thomas Drainage Relief Tunnel Project
Southland/Mole Joint Venture

This $206 million project for the City of Dallas comprises 26,385 lf of tunnel (32 ft, 6 in. excavated diameter, 30 ft finished diameter), eight intake shafts (ranging from 120 to 200 ft in depth), 6 lateral tunnels excavated by roadheader or excavators/breakers. The geology is Austin Chalk. Crews are using a Main Beam Robbins TBM.

TBM mining, which included a diameter change from 37 ft 7 in. to 32 ft, 6 in., was completed in July 2022. Crews are currently demobilizing TBM from the tunnel and mobilizing equipment for cast-in-place tunnel concrete lining operation. CIP Lining lois ngoing at multiple lateral and shaft locations. Project completion is anticipated by August 2025.

Owner: City of Dallas; Lead Designer: HALFF; Tunnel Designer: COWI; CM: Black and Veatch; TBM Manufacturer: The Robbins Company; Contractor: Southland Mole JV (Southland Contracting & Mole Constructors); Subcontractor: Oscar Renda Contracting Inc.; Contractor Design Engineer: Aldea Services.

Personnel: SMJV Operations Manager: Kent Vest; SMJV Senior Project Manager: Quang D. Tran, P.E.; SMJV Senior Project Manager: Nick Jencopale; SMJV Surface PM: Caesar Ramirez; SMJV Safety Manager: Stephen Jones; SMJV Assistant Project Manager: Jose Ortiz, P.E.; SMJV Senior Project Engineer: Matt Jackson; SMJV General Superintendent: Mike Clingon; SMJV Project Engineers: Jason Lipp/Liany Marino.

Lake Travis

Brushy Creek Regional Utility Authority (BCRUA) Phase 2 Raw Water Delivery System
Thalle/SAK Construction

The Brushy Creek Regional Utility Authority (BCRUA) was formed in 2006 to withdraw, treat, and deliver water to the cities of Cedar Park, Round Rock, and Leander, Texas. Phase 1 of the system consists of a 32.5 MGD floating pump station and a water treatment plant. The Phase 2 Raw Water Delivery System consists of a new deep water intake and conveyance system at Lake Travis. The Phase 2 system will have an ultimate capacity of 145 MGD and will provide a reliable long term water supply system for the continued growth of the three partner cities while reducing vulnerability to prolonged droughts.

The $225 million project includes two blind-bored lake intake shafts; an 8,800 LF gravity intake tunnel; an underground suction chamber; a 35-ft diameter, 300-ft deep access shaft; 6 raise-bored pump well shafts, a 2,600 LF transmission pipeline tunnel; a blind-bored shaft for the transmission pipeline at the end of the transmission tunnel; a 145 MGD pump station; and a maintenance building. The tunnels are being excavated using an 11.5-ft diameter TBM. A roadheader is being used for the suction chamber and starter and tail tunnels for the TBM launch. The underground work is in limestone of the Glen Rose formation. Significant planning and staging are required due to the limited site area, marine work for the lake taps, and the need to TBM mine and walk back the TBM for two dead-end tunnels at the intake and transmission shafts.

The access shaft excavation is near completion and the suction chamber excavation top heading and first bench are complete. The mining of the transmission tunnel will begin late spring following completion of the suction chamber. The mining of the intake tunnel will begin after completion of the transmission tunnel, anticipated to begin late summer, early fall. Blind-boring of the transmission shaft is completed, blind-boring of the intake shafts will start in May. NTP was issued in June 2022 with completion estimated for April 2027.

The design was developed by a JV of Walker Partners and Freese and Nichols (WP/FNI), with Schnabel Engineering leading the shaft and tunnel design. Construction is being performed by a JV of Thalle and SAK Construction, with SAK performing the underground work. Construction management is being performed by the WP/FNI and Schnabel team.

Personnel – BCRUA General Manager: Karen Bondy; Resident Engineer: Joerg Moser (Walker Partners), Tunnel and Shaft Resident Geotechnical Engineer: Matt Koziol (Schnabel); Design Managers/leads: Aaron Archer (Walker Partners), Jason Christenson (Walker Partners), Erin Flanagan (FNI), Jason Bybel (Walker Partners); Tunnel design lead: James Parkes (Schnabel); Project Manager: Ross Webb (SAK/Affholder), Project Engineer: Kenny Knollmeyer (SAK/Affholder).


DWU Elm Fork 72” Water Main
Southland Contracting / Oscar Renda Contracting JV

This is a $44 million project for Dallas Water Utilities comprising 8,600 lf of 10-ft OD tunnel total including 3 reaches. The TBM, manufactured by Southland Contracting, is a double shielded, open faced, gripper type machine with articulated steering using rib-and-board tunnel support. The carrier pipe is 72-in. steel.

There are 5 shafts ranging from 18 to 35 ft in diameter and depths from 75 to 96 ft built with ring beams and liner plate for support and rock bolts and shotcrete within the Eagle Ford shale.

All shafts and tunnels have been excavated. 5,000 ft of carrier pipe has been installed and backfill grouted with 3,600 ft remaining. Two shafts have been backfilled with manholes and pipe installed. Anticipated completion is January 2024.

The project was re-designed post-bid by Southland Contracting team. The original design required open-cut pipeline installation with invert depths ranging from 18 to 30 vf where overburden material was primarily small-particle sand with groundwater. The original design required 2,000 ft curved microtunnel drive along railroad. Through coordination with Dallas Water Utilities and AECOM, pipeline elevation was lowered, and access manways and appurtenances were added for its installation in a deep tunnel. Two of five shafts are within Railroad ROW. Special design and coordination were required pre-construction. Settlement monitoring is required daily.

Owner: Dallas Water Utilities; Engineer & CM: AECOM; Tunnel Designer: Brierley and Associates; General Contractor/Program Manager: Oscar Renda Contracting; Tunnel Contractor: Southland Contracting Inc.; TBM Manufacturer: Southland Contracting.

Personnel: SRJV Operations Manager: Kent Vest; SRJV Project Manager: Elliott Fuller; SRJV Construction Manager: Clay Griffith; SRJV Senior Project Engineer: Fareed Imoro; SRJV Superintendent: Otillio Ramos.


IPL-19 Long Tunnel Crossings
Bradshaw Construction Corporation

Bradshaw Construction Corporation has begun work on 84-in. steel water line project in Frankston, which consists of two tunnels, spanning 1,712 lf. The tunnels are split up into a 903 lf drive, and 809 lf drive, which will both be mined utilizing 99.5-in. steel casing behind a Herreknecht AVND 1800AB MTBM. Bradshaw is currently 600 lf mined into the longer of the two tunnels, which has encountered layers of clayey queens city sand that has since transitioned into sandy queens city sand. The tunnel is being mined out of a 38-ft rib-and-liner plate shaft with little evidence of ground water. The second of the two tunnels is 50 miles South West of Frankston, and will be launched out of a secant pile shaft and mine under the Union Pacific railroad. The majority of the tunnel geology is classified as the Clayey Wilcox Group, but it is expected to transition late in the drive to a sandy fluviatile deposit. The anticipated completion date for both tunnels is September 2023. Project members include Tarrant Regional Water District (Owner), Brierley Associates (Engineer) and Traylor-Sundt Joint Venture (General Contractor), with Bradshaw Construction performing as the microtunneling subcontractor.

Project Information: Chris Flanagan – Project Manager; CFlanagan@bradshawcc.com.

New Braunfels

SWTP Discharge Water Line
Bradshaw Construction Corporation

Bradshaw Construction Corporation recently completed a tunnel installation on the SWTP Discharge Line Project for New Braunfels Utilities in New Braunfels. This discharge line included one microtunnel crossing with 48-in. RCP totaling 413 ft, jacked out of a 30-ft launch shaft. The crossing was constructed almost entirely on a 620-ft radius vertical curve, wherein VMT guidance technology and JackControl hydraulic joints were utilized. The crossing passed underneath the Guadalupe River, through lean clay, claystone, and clayey-gravel beneath the water table. The project members include, New Braunfels Utilities (Owner), Plummer Associates Inc. (Engineer), Pesado Construction (GC), and Bradshaw Construction Corporation working as the tunneling subcontractor.

Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.



RiverRenew Tunnel

The RiverRenew Tunnel System Project includes a 2-mile-long, 12-ft-wide tunnel, shafts, and other sewer infrastructure that will help prevent about 130 million gallons of sewage from polluting the Potomac River, Hunting Creek, and Hooffs Run each year. Traylor-Shea was awarded a $454.4 million contract to complete the final design and construct the Tunnel System Project. The Traylor-Shea design-build team consists of Traylor Bros, Inc., and J.F. Shea Co., a joint venture, with support from Jacobs Engineering and Corman Kokosing Construction Co.

The Herrenknecht tunnel boring machine (TBM) achieved completion of the factory acceptance test on April 29, 2022. It arrived onsite in July 2022, with assembly starting in August, and boring beginning on Nov. 1. Boring of the Waterfront Tunnel is expected to continue through December 2023. The project also includes the Hoofs Run Interceptor, that will be excavating using a Herrenknecht 76-in. MTBM.

As of March 2023, RiverRenew crews have finished excavation on all four of the project’s shafts: the pumping and screening shafts at AlexRenew and the diversion facility shafts at the Pendleton and Royal Street sites.

The Pendleton and Royal Street shafts help connect existing sewer infrastructure to the 150-foot-deep Waterfront Tunnel and the AlexRenew shafts will screen and lift the combined sewage from the tunnel and direct it to AlexRenew’s Water Resource Recovery Facility for treatment.
Project completion is expected by July 2025.

Designer: Jacobs Engineering; Construction Manager: Brown & Caldwell, JCK Underground, EPC; Major Subcontractors: Kokosing Industrial, Keller North America; TBM Manufacturer: Herrenknecht AG.


Hampton Roads Bridge-Tunnel
Hampton Roads Connector Partners

With a budget of more than $3.8 billion, the Hampton Roads Bridge-Tunnel (HRBT) Expansion project for the Virginia Department of Transportation is the largest highway construction project in the state’s history. The project involves widening the current four-lane segments along nearly 10 miles of the I-64 corridor in Norfolk and Hampton, with new twin tunnels across the harbor. The expansion will increase capacity, ease major congestion and enhance travel time reliability.

The new tunnels will be bored with a 46-ft diameter variable-density Herrenknecht TBM, 50 ft deeper than the existing tunnels. The project represents only the fourth TBM-bored highway tunnel in the United States (Port of Miami Tunnel, Seattle SR 99 Tunnel and the Parallel Thimble Shoal Tunnel in Virginia are the others), and the second largest TBM used in the country (behind SR 99).

In addition to new tunnel construction, the project involves replacing/building bridge structures (five bridges to be replaced, 23 to be widened), replacing marine trestles and widening of the roadway from two to three lanes in each direction.

In early 2019, VDOT entered into a P3 design-build contract with Hampton Roads Connector Partners to build the project. Hampton Roads Connector Partners includes Dragados USA (lead contractor) and HDR and Mott MacDonald (lead designers). Also on the joint venture team are Flatiron Constructors, Vinci Construction and Dodin Campenon Bernard. It was anticipated that the machine will begin its subaqueous journey in late March/early April.

The segments are being cast in Cape Charles, Virginia, on the eastern shore of the Chesapeake Bay, and will arrive to the project site by barge. Approximately 50 percent of the total 21,000 segments needed for the project have been cast as of January 2023.

Project completion is expected in 2025.


Parallel Thimble Shoal Tunnel
Dragados USA/Schiavone Construction

The $756 million project entails the construction of a 5,700-ft bored tunnel connecting two southbound trestles of the existing Chesapeake Bay Bridge and Tunnel, a 17.6-mile structure connecting the Norfolk/Virginia Beach areas to Virginia’s eastern shore which first opened to traffic on April 15, 1964. When complete, the new tunnel will carry two lanes of traffic southbound and the existing tunnel will carry two lanes of traffic northbound.

On Feb. 21, 2023, the 43.5-ft diameter TBM began its initial excavation at the tunnel’s headwall, marking the official start of tunneling for the Parallel Thimble Shoal Channel Tunnel. Tunneling is expected to take 12 to 14 months.

Newport News

Jefferson Avenue Interceptor Force Main Replacement Phase III
Bradshaw Construction Corporation

Bradshaw Construction Corporation will soon begin work on a tunnel installation for the Jefferson Avenue Interceptor Force Main Replacement project in Newport News, VA. The force main will include a 60-in. steel casing tunnel, 540-ft long, passing underneath of I-64 and a canal. The tunnel will be launched out of and recovered into steel sheet shafts installed by the General Contractor. Ground conditions include predominantly clay with sand, beneath the water table. The project members include the Hampton Roads Sanitation District (HRSD) (Owner), RK&K (Engineer), Bridgeman Civil Inc. (GC), and Bradshaw Construction Corporation working as the tunneling subcontractor.

Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.


Chimborazo Drop Shaft and Sanitary Sewer Replacement
Bradshaw Construction Corporation

Bradshaw Construction Corporation has begun work on a sanitary sewer replacement project in downtown Richmond, which consists of four shafts and two tunnels. The four shafts are comprised of two 33 ft x 21 ft ellipse liner plate launch shafts and two 23-ft diameter recovery shafts, the deepest of which is 104 ft. Currently, Bradshaw has completed 3 of 4 shafts (176 vf of 200 vf), and has successfully mined the longer, 331 lf, of the two tunnels. The tunnel was mined utilizing 78-in. Permalok steel casing behind a skinned-up Herrenknect AVN-1500, which Bradshaw opted to equip with a rock cutter head due to unforeseen boulders during the shaft construction. The remainder of the tunnel geology consisted of clayey sand, with sections of elastic silt. Bradshaw is currently mining the second tunnel, which is expected to be completed by the end of May. Tunnel geology expected to be consistent with the first tunnel. The project members include the City of Richmond (Owner), Greeley and Hansen (Engineer) and Southwood Building Constructors(General Contractor), with Bradshaw Construction performing as the shaft and tunneling subcontractor.

Project Information: Chris Flanagan – Project Manager; CFlanagan@bradshawcc.com.



Ship Canal Water Quality project LANE Construction

The $255 million Ship Canal Water Quality Project (SCWQP) Storage Tunnel Contract for Seattle Public Utilities (SPU) is comprised of 13,939 lf of 18-ft, 10-in. ID segmentally lined tunnel using a 21.5-ft diameter pressurized face tunnel boring machine (TBM) with tunnel depths ranging from 35 to 85 ft to top of tunnel, and a conveyance pipe casing under the Ship Canal installed via a curved microtunnel drive, 646 lf and 94-in. diameter.

There are five shaft sites: one slurry wall shaft at the West Shaft site in Ballard (tunnel launch site); three secant pile shafts at the Fremont site, Queen Anne site, and East Shaft site in Wallingford (tunnel exit shaft); and one drilled shaft using a steel casing at the East Ballard site. Anticipated ground conditions along the tunnel alignment consist of a highly variable mix of glacially over-consolidated soils.

When completed, the tunnel will capture and temporarily store more than 29 million gallons of untreated stormwater and sewage until the treatment plant is ready for it. The tunnel will improve water quality regionally by keeping more than 75 million gallons of polluted stormwater (from rain) and sewage each year from flowing into the Lake Washington Ship Canal, Salmon Bay, and Lake Union.

The project is a joint effort between two agencies: Seattle Public Utilities (Lead) and King County Wastewater Treatment Division. Both Agencies are under Consent Decree with the US EPA and DOJ, and the Washington State Department of Ecology to have the SCWQP in service by the end of 2025. The Storage Tunnel is the second of four projects in the SCWQP. There are two subsequent projects to connect the new storage facility to the local sewer systems to complete the SCWQP.

The construction project is 69% complete (as of the end of December 2022). All five shafts are complete and both tunnel boring machines have launched. The 21.5-ft diameter TBM, (“Mudhoney”), has completed approximately 9,000 ft (65%) of the tunnel drive that begins at the Ballard neighborhood eastward along the north side of the Ship Canal toward the Wallingford neighborhood. The 10-ft diameter MTBM was scheduled to complete its journey from Fremont southward under the Ship Canal toward the Queen Anne neighborhood by February 2023. After this period crews will install conveyance pipe and below grade vaults.

The Herrenknecht EPB TBM has performed well through very variable ground conditions with minimal surface settlement, including passing directly underneath the footings of the approach span to Ballard Bridge.

In mid January 2023 the machine reached the second safe haven location where the ground had been improved by jet grouting last year, and further cutting tool replacement and repair works are under way with access to the cutterhead under free air. The team is looking forward to improving upon current production achievements – 90 ft in one day, 367 ft in a week and 1,245 ft in a month.

Tunnel Designer: Delve Underground (formerly McMillen Jacobs Associates); Construction Manager: Jacobs Engineering; TBM Manufacturer: Herrenknecht. Major Subcontractors: Shaft Construction – Malcolm Drilling Co.; Microtunneling – Northwest Boring Co. Inc..; Mechanical and Concrete Structures – Prospect Construction Inc.; Electrical – Chau Electric; Trucking – Grady Excavating Inc.; Segments: CSI.

Personnel: Owner (SPU): Keith Ward: SCWQP Executive; Cynthia Blazina: SCWQP Construction Manager; Stephanie Secord: SCWQP Project Manager; Roger Mitchell: SCWQP Supervising Resident Engineer. Lane Construction: Daniele Nebbia: Vice President of Tunneling Operations; Project Director: Fabrizio Fara; Project Manager: Gianluca Pianezze; Technical Manager: Basilio Giurgola.




Dow’s Lake Tunnel Rehabilitation

Dow’s Lake Tunnel is being rehabilitated as part of the Stage 2 O-Train South Extension. Located under Dow’s Lake, the tunnel is 578 m long and first opened in 1967.

The tunnel is reinforced with 23 concrete box segments separated by 22 expansion joints. The height of the tunnel is approximately 6.7 m from the top of the rail. The width of the tunnel is approximately 5.1 m.
In January 2023, the physical works in the tunnel were approximately 58% completed. This number is expected to reach 100% by Q3 2023, after which works in the tunnel will shift to the testing and commissioning of the new passenger rail system.

Work is currently underway to upgrade the drainage system and modernize the tunnel ventilation system, standpipe system, communication systems, and emergency walkway to align with National Fire Protection Association (NFPA) -130 standards.

Work that has been complete so far is the repairs of expansion joints and areas of cracks that evidenced water infiltration in the tunnel by sealing the expansion joints and injecting existing cracks. Mechanical systems in the tunnel including the installation of 18 jet fans for ventilation, and 22 expansion joint drip pans to channel water infiltration to the trench have been completed. The tunnel standpipe system has been partially upgraded and will be ready for testing by Q3.

Late last year, concrete ties and brand-new rail were installed in the tunnel, replacing the old timber ties. This marked the culmination of a significant revamp of the track infrastructure in the tunnel. The track bed was refurbished with new materials and checked every step of the way with conformance to current track design standards. This has allowed the tunnel to be used for rail-mounted vehicles to pass through and access areas on either side of the portal for snow removal and construction.

Some of the remaining works include cable pulling for communication systems, testing and commissioning of communications systems, train testing within the tunnel, emergency scenario testing, ventilation system testing, installation of emergency stairs, and reinstallation of the walkways.

Fiber optic cable will be installed early in 2023 to provide cellular service in the tunnel. The cable is a 1.25-in. radiating cable, optimized for 4G cellular technology and capable of providing 5G service.

There are some interesting safety features about the tunnel, including three safety bays, which are cut outs within the tunnel walls that have emergency telephones directly linked to Ottawa Fire Services. The bays are designed for people to enter in case of an emergency in the tunnel. Concrete curbs run on either side of the rails the length of the tunnel and house a heat trace to help deal with Ottawa’s harsh winter conditions. One side of the curb is wider than the other, which allows for a dedicated emergency egress route.


Stage 2 LRT Project – Confederation Line East and West Extension Project
East-West Connectors (EWC)

The Stage 2 Confederation Line East and West Extension project is a $2.57 billion (CAD) design-build-finance project for the City of Ottawa being built by East-West Connectors (EWC), a joint venture comprised of Kiewit, Eurovia and VINCI (KEV).

The west extension includes two cut-and-cover tunnels:

The 3-km Parkway Tunnel will travel between Kìchì Sìbì and Lincoln Fields stations traveling underneath the Sir John A. Macdonald Parkway, Richmond Road, and Byron Linear Park.

The 270-m Connaught Tunnel will link Lincoln Fields Station with Queensview Station by traveling underneath Connaught Avenue and connecting with the Pinecrest trench.

Construction of the Parkway Tunnel began in 2020, and at the end of March 2023 it was 58% complete. Construction of the Connaught Tunnel began in 2021, and at the end of March 2023 it was 46% complete. Both tunnels are expected to be fully completed at the end of 2024. The O-Train West extension is expected to begin revenue service at the end of 2026. The Parkway Tunnel will travel through federal lands and a City of Ottawa linear park to preserve recreational opportunities and community linkages. When construction is complete on the Parkway Tunnel, Byron Linear Park will be enhanced to include more trees, less pavement, more public art, and additional plaza space for local events. The Connaught tunnel will travel through a residential neighbourhood.

Overall, the Stage 2 O-Train East and West extensions are a signature project in Canada’s national capital, funded by three levels of government. There is a strong focus to ensure that the project is delivered with minimal impact on the community. This requires close, on-going engagement with stakeholders and the public, as building a large infrastructure project in an urban environment will be disruptive.

To optimize the building sequence, the structures team is utilizing three Everest Traveler formwork systems to pour the three walls of the tunnel and roof together on the Parkway Tunnel. This is a hydraulic system that allows the team to pour 250 cubic metres of concrete every 10 days. The Everest needs to be modified at certain points due to the variability of the cut and cover tunnel.

The team is also using two Peri Travelling Formwork systems, which perform the same functions but in less uniform spaces.

Design engineering services are being provided by WSP Canada and Hatch Ltd. Personnel: Alex Saltarelli, Project Director, East-West Connectors GP.


Ashbridges Bay Treatment Plant Outfall
Southland | Astaldi Joint Venture

This $300 million project for the City of Toronto includes: 16 m diameter shaft, 85 m deep; 3.5 km of 8 m diameter TBM excavated tunnel; 7m ID precast concrete segmental lining; 50 of 1 m diameter risers from tunnel (marine work); and CIP structure at top of shaft. Ground expected was Georgian Bay shale.

The project is 80 percent complete. Shaft excavation is complete for tunnel activities. The 8-m diameter segmental tunnel is complete and TBM demobilized. Offshore risers installations are complete and riser connections in tunnel are 70 percent complete. The effluent conduit structure is underway. The estimated date of completion is September 2024.

Consultant & Designer: Hatch with Jacob & Baird; Major Subcontractors: Johnson Bros. Corp (Off-shore work including Riser installation).

Personnel: Contractor: Southland | Astaldi JV; Project Executive (Kent Vest); Project Director (Joe Savage); Project Manager (Pouya Mirhashemian); Deputy Project Manager (Francisco Urrutia); General Superintendent (Curtis Bahten); Underground Superintendent (Jeff Reagan).

Comments are closed here.