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 2021 issue of the print edition.

Joint Water Pollution Control Plant Effluent Outfall Tunnel Dragados USA

This is a $630.5 million project for the Los Angeles County Sanitation Districts. NTP was issued April 8, 2019, with 1,953 working days to complete the work and an estimated completion date of March 2027.

As part of the implementation of the Clearwater Program, the Sanitation Districts will construct a tunnel approximately 7 miles long and 21.5 ft in excavated diameter (18 ft in internal diameter) to convey disinfected, secondary-treated effluent from the Sanitation Districts’ Joint Water Pollution Control Plant (JWPCP) located in the City of Carson to an existing ocean discharge system at Royal Palms Beach in San Pedro in the City of Los Angeles. The tunnel will be constructed by a single-pass, pressurized face TBM beginning at the JWPCP Shaft Site (entry shaft) and ending at Royal Palms Beach (exit shaft). The tunnel alignment will vary in depth from approximately 50- to 450-ft 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 summer 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-ft 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 was completed in May 2021. Excavation of the starter and tail tunnels was completed in May 2021. The contractor will use a Herrenknecht slurry TBM. Fabrication of test precast concrete segments at the Traylor Bros., Inc. Littlerock, California, facility began in April 2021 with full production anticipated for June 2021. Tunnel construction is anticipated to begin this summer.

Lead Design Consultant: Parsons; Tunnel Design Consultant: McMillan Jacobs Associates; Tunnel Construction Management Consultant: Mott MacDonald. Dragados’ Major Subcontractors – 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: Ignacio Murillo, 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. McMillan Jacobs Associates – John Stolz, Lead Tunnel Design Consultant. Mott MacDonald – Daniel McMaster, Lead Tunnel Construction Management Consultant. BabEng – Allen Jensson, Lead Tunnel Engineer. Dragados – John Kennedy, Vice President of Southern California Operations; Claudio Cimiotti, Project Manager; John Truong, Deputy Project Manager; Nicholas Karlin, Project Engineer.

Mountain Tunnel Improvements Michels Tunneling

The Mountain Tunnel for the San Francisco Public Utilities Commission is a critical lifeline asset through which the SFPUC conveys 85% of its water from the Hetch Hetchy Reservoir to 2.7 million customers in the San Francisco Bay Area. The existing tunnel is 18.9 miles long, including 11.5 miles of 12.5-ft diameter concrete lined section and 7.4 miles of unlined, approximately 14-ft diameter section in granitic rock. The objectives of the Mountain Tunnel Improvements are to rehabilitate the tunnel and make improvements to extend the useful life of this asset for the next 100 years. NTP was issued on Jan. 29, 2021, and submittals, mobilization, staging area/office trailer set ups, access road improvements, rock slope stabilization are in progress. Preparations are also underway for excavations of the new tunnel portal and adit, and the Flow Control Facility deep shaft at Priest Reservoir, and the shaft and bypass tunnel at South Fork. Completion is expected by December 2026.

This project will require five winter season tunnel outages of 60 to 100 days duration each in order to do the repairs and other work inside the tunnel, and to construct the tie-ins connections between the existing tunnel and the new improvements. The new tunnel adit and new shaft housing the flow control valves at Priest Portal, and the new siphon extension at South Fork will require tie-ins.

Tunnel Design: McMillan Jacobs Associates; SFPUC’s Construction Management Bureau is the construction manager; Supplemental RE/CM/Inspection: AECOM. Subcontractors: Apex Rockfall Mitigation, Kroner Environmental, Schrader Mechanical, Cody Builders Supply, Geostructural Engineering Inc., Renesco Inc.

Project Personnel: SFPUC – Regional Project Manager: David Tsztoo, PE; Regional Project Engineer: Tedman Lee, PE ; Project Engineer: Joseph Buitrago, PE (acting); Regional Construction Manager: Jerry Malone. McMillen Jacobs – Project Manager: Jennifer Sketchley, PE; Tunnel Engineer: Glenn Boyce, Principal, PE, GE; AECOM – Contract Manager: Steven Tidwell, Vice President; Resident Engineer: Bob Mues; Lead Inspector: Thomas (Bud) DeGrio.

Regional Connector Transit Project Regional Connector Constructors (Skanska-Traylor JV)

The tunneling portion of the $1.8 billion project for LA Metro involved 5,795 feet of 21 ft diameter twin tunnels. The ground conditions range from alluvium soils to clayey siltstone of the Fernando formation with the groundwater table generally above the tunnel alignment. Tunneling using an EPB TBM was required, along with precast concrete segments with double gaskets as the tunnel lining system. The tunnel depth ranges from 25 ft to approximately 120 ft and crosses below the existing Metro Red Line heavy rail tunnels with less than 7 ft of clearance. The Regional Connector includes approximately 2,100 ft of cut-and-cover and retained cut guideway, a 300 ft crossover cavern excavated by Sequential Excavation Method (SEM) techniques, and three cut-and-cover subway stations. The bored tunnels were excavated by one TBM concurrently with the construction of the three stations, requiring coordination between the cut-and-cover operations and TBM tunnel excavation. The bored tunnels were successfully completed on time in January 2018 with the SEM cavern excavation completed in March 2019.

Structural concrete at the three underground stations and cut-and-cover guideways throughout the project is significantly advanced and will be completed during Q2 2021. Provisions were incorporated into the Historic Broadway Station to accommodate the overbuild of a mid-rise commercial structure. Historic Broadway Station construction will extend through the end of 2021. Backfilling of the 1,400 ft of the cut-and-cover tunnel structure along Flower Street is advancing in preparation for street reconstruction which will extend through the end of 2021.

Presently, the focus throughout the alignment continues to be on the installation of trackwork. The project recently reached two milestones by completing the rail tie-in with the existing Metro A (Blue) and E (Expo) lines, and the installation of the first crossover in the SEM cavern. The second crossover in the Wye structure, where the project connects to the existing L (Gold) Line is scheduled to continue through Q3 2021. While the connection to the existing L Line is under construction, transit passengers are being shuttled around the construction area by Metro buses. As trackwork installation advances, emphasis will turn to systems installation, vertical circulation and architectural finishes. As station finishes are completed, the project will begin the installation of artwork through each of the three stations.

The Contractor has recently begun Overhead Contact Rail (OCR) installation throughout the project alignment and is focused on train systems installation at each station. The completion of the Regional Connector will require significant changes in how LA Metro operates its light rail system as three existing lines are integrated into two systems. Overall, the project is progressing on schedule and is scheduled to begin revenue operations during the third quarter of 2022.

Designer for the Contractor: Mott MacDonald; Preliminary design: CPJV (AECOM/ WSP), which is also performing design services during construction; Metro’s Construction Management Consultant: Arcadis.

Key Project Personnel – Metro Project Executives: Mat Antonelli, Project Manager; Michael Harrington, Engineering Manager; Sy Morales, Construction Manager; Metro Design Consultants: (AECOM/WSP), William Hansmire, Tunnel Design Manger; Metro Construction Management Consultants: (Arcadis), Jaydeep Pendse, CMSS Manager; Contractor Project Executives (Regional Connector Contractors RCC): (Skanska) Mike Aparicio, Greg Zwiep, Justin Waguespack; (Traylor), Christophe Bragard.

Silicon Valley Clean Water Gravity Pipeline Barnard Bessac JV

The $206.7 million project for Silicon Valley Clean Water (SVCW) comprises 17,400 linear ft of tunnel with two independent tunnel drives with four shafts (1 Launch Shaft, 1 Retrieval Shaft,1 Retrieval/Tie-In Shaft, and 1 Tie-In Shaft). The tunnel diameter is 16.2-ft OD with depths ranging from 30-ft to 60-ft. The geology comprises medium to stiff clay with layers of sand and silty sand geology. Crews are using EPB tunneling and will install a second pass liner with 10-ft and 11-ft GFRP pipe.

The project is 75% percent complete, including completion of the first tunnel drive (5,200 ft) and 11,000-ft of the second tunnel drive (12,300 ft total). The remaining tunneling for the second tunnel drive includes several challenges, including mining between and beneath two residential properties and mining directly beneath the existing, failing sanitary sewer force main before making a final sweeping 800-ft radius turn through a jet grout block and ultimately into the surge flow splitter (SFS) retrieval shaft.

Jet grouting was completed at the SFS retrieval shaft and slurry wall demolition of the soft eye will be performed by a roadheader in advance of the TBM breakthrough. Other progress includes completion of the San Carlos shaft excavation and installation of the GFRP pipe in the first tunnel drive. The remaining work includes construction of the ~20-ft long San Carlos adit via pipe jacking methods combined with localized grouting from within the shaft and TAM grouting from the surface. The San Carlos adit ultimately will connect the San Carlos shaft to the recently completed Bair Island tunnel (tunnel no. 1), creating a pathway to convey wastewater from neighboring pump stations to the gravity pipeline tunnel prior to treatment at the SVCW treatment plant.

Engineer: Arup; Construction Manager: Tanner Pacific; Major Subcontractors: Drill Tech; Blue Iron Shoring; Malcolm Drilling; Schnabel; TBM: Herrenknecht; Precast Segment Supplier: Traylor Shea Precast; FRP Supplier: Future Pipe Industries; FRP logistics company: Infrastructure Solutions LLC.; Specialty Equipment Manufacture: Kelley Engineered Equipment LLC.

Key Project Personnel: Project Manager: Jack Sucilsky; General Superintendent: Mike Hanley; Assistant Project Manager: Glenn Strid; Superintendent: Mike Gilbertson.

North East 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. It includes the construction of 26,700 ft of 23-ft ID tunnel from 60 to 140 ft below grade. The tunnel is excavated using an Herrenknecht EPB TBM. 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 alignment.

The project also includes the construction of 7 shafts, ranging from 20 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 TBM in clay soil which will be lined with HOBAS pipes installed using the pipe jacking tunneling method.

NTP was issued Sept. 15, 2017, with an estimated completion date of March 19, 2023. As of April 2021, 73% of the works were completed. The tunnel excavation was completed in April 2021 and currently the TBM disassembly operations are ongoing. All the drop shafts have been already excavated. 30% of the adit construction works have been completed. Regarding the diversion facilities to be constructed on the surface (Near Surface Structures), the support of excavation system and the ground improvement have been fully completed while the excavation and the permanent structures construction are ongoing in most of the construction sites. The 10-ft diameter TBM is expected to be delivered on site by June 2021 to start the excavation of the 700-ft Diversion Sewer.

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

Project Personnel: Owner – DC Water Clean Rivers Project: Carlton Ray (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); Flaviano Solesin (Tunnel Construction Manager); Gianluca Pianezze (Sites Construction Manager); Pietro Banov (Design-Build Coordinator).

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

The $188 million design-bid-build project 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. About 720 lf of adits will be driven using drill-blast to connect the TBM tunnel to the drop and vent shafts. The TBM tunnel and adits will be excavated through limestone of the Wabash Formation with anticipated high groundwater inflow in the range of 5,000 to 10,000 gpm at 6.5 bar pressure.

Through the end of April 2021, the project is 69% complete. TBM excavation is approximately 92% complete, and is scheduled to finish in June 2021. Cast in place concrete lining of the Upflow and Pump Station Shafts will then commence along with the excavation and lining of the adit and deaeration chambers from within the TBM tunnel. Overall project completion is expected by April 2023.

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

Personnel – Owner/City of Ft Wayne: Mike Kiester (Manager, City Utilities Engineering), TJ Short (Senior Program Manager, Sewer 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), Lance Waddell (Project Manager), Brad Krumel (Construction Manager), Francesco Chiappalone (Technical Manager). Information: Lance Waddell at lwaddell@laneconstruct.com.

White River Tunnel, Lower Pogues Run Tunnel Shea-Kiewit JV

The White River Tunnel is a 30,600-ft, 20-ft, 2-in diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are two bifurcations in the final alignment and seven CSO connecting structures/deaeration chambers and adits. The Lower Pogues Run Tunnel is a 10,200-ft, 20-ft, 2-in bored tunnel with an 18-ft finished concrete lining, which bifurcates from the White River Tunnel alignment, and includes two 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 2016 from a 35-ft diameter shaft that was previously constructed as the retrieval shaft for the Deep Rock Tunnel Connector alignment. After successfully mining the Lower Pogues Run Tunnel, the TBM was backed up and successfully relaunched within the White River Tunnel. The TBM holed through at the White River Tunnel Retrieval Shaft on April 10th, 2019, completing close to 41,000 feet of mining. As of May 2021, all adits and deaeration chambers have been drilled and shot, for a total of approximately 2,000 feet of excavation. Additionally, concrete lining operations are complete in the Lower Pogues Run Tunnel and will be completed in the White River Tunnel in May 2021. Based on the terms of a federal consent decree, the White River and Lower Pogues Run Tunnels must be operational by the end of 2021.

Key Project Personnel – Construction PM: Christian Heinz, P.E.; Assistant Project Manager/ Project Engineer: Percy Townsend; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Zack Heinrich, Kendall Gadd, Chris Monahan, Max Engen. Inspection PM: Sam Cain, P.E. (AECOM). Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Construction Supervisor: John Morgan.

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 from a 30-ft diameter shaft that was previously constructed as the retrieval shaft for the White River Tunnel alignment. After successfully mining the White River Tunnel, the TBM mined through the shaft and underwent a minor refurbishment. Mining was completed on April 1, 2020. The tunnel terminated approximately 2,400 feet past the retrieval shaft location. The TBM was backed up and parked downstream of the shaft, and the remainder of the shaft was shot down to the invert. The TBM has been retrieved and transported to the site of the Pleasant Run Tunnel launch shaft. The Fall Creek Tunnel has over 5,200 feet of adits, and adit excavation is approximately 70% complete. Tunnel concrete lining operations are anticipated to commence in June 2021. 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.; Assistant Project Manager/ Project Engineer: Percy Townsend; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Zack Heinrich, Kendall Gadd, Chris Monahan, Max Engen. Inspection PM: Sam Cain, P.E. (AECOM). Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; 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.

Slurry wall installation for the launch shaft occurred in the Summer 2019. The launch shaft and starter tunnel are complete. The TBM completed mining the Fall Creek Tunnel in April 2020 and was delivered to the Pleasant Run launch shaft site where was refurbished, and the TBM is now fully assembled underground. Mining began in May 2021. Once complete, the entire 28-mile DigIndy system will have utilized a single Robbins main beam TBM. In addition to 28 miles of hard rock mining, the TBM will have been backed up over nine miles allowing the elimination of multiple launch and retrieval shafts. 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.; Assistant Project Manager/ Project Engineer: Percy Townsend; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Zack Heinrich, Kendall Gadd, Chris Monahan, Max Engen. Inspection PM: Sam Cain, P.E. (AECOM). Owner: Citizens Energy Group – Manager, DigIndy Capital Program: Mike Miller, P.E.; Construction Supervisor: John Morgan.

Ohio River Tunnel Shea-Traylor JV

The Ohio River Tunnel for the Louisville and Jefferson County Metropolitan Sewer District (MSD) was issued NTP Nov. 8, 2017, and is scheduled to reach Final Completion around Spring 2022. The tunnel length is 21,300 ft; Diameter: 22 ft excavated; 20 ft finished; Tunnel depth – 200 ft; Number of shafts – 6. Ground conditions include limestone and dolomite rock, potential fault zones, and potential natural gas zones in the rock.

TBM excavation of the entire tunnel has been completed, with a hole-through date of Sept. 22, 2020. The TBM along with all its trailing decks and appurtenances have been removed from the Retrieval Shaft/Drop Shaft DS06. Gas was encountered only once during tunnel excavation. No groundwater inflow nor any fault zones were encountered during tunnel excavation. Concrete lining of the Tunnel Bifurcation and tail tunnel is complete. S-T JV has completed construction of the Drop Shaft DS01 surface structure, shaft, and adit connection to the main tunnel. Drop Shaft DS02 is also complete. Along the mainline tunnel, 2,800 ft of the 20,400 ft has been concrete lined. Currently, S-T JV is working on concrete lining the mainline tunnel and construction of the surface structure at Drop Shaft DS04. Concurrently construction of the adits for Drop Shafts DS03 and DS05 is ongoing.

Tunnel Designer: Black & Veatch; Construction Manager: Black & Veatch; Major Subcontractors: Platt Construction, Steppo Supply, T.E.M., CTL Engineering, Harmon Steel; TBM Manufacturer: Robbins.

Key Project Personnel: Greg Powell: MSD Construction Manager; Jacob Mathis: MSD Project Manager; Jonathan Steflik: Black & Veatch Design Project Manager; Mark Bradford: Black & Veatch Design Tunnel Lead; Pete Boysen: Black & Veatch Sr. Construction Manager; Alston Noronha: Black & Veatch Construction Manager; Shemek Oginski: S-T JV Project Manager; Jesse Salai: S-T JV Operations Manager.

Deer Creek Sanitary Tunnel (Clayton Road to RDP) (11731-015.1)

This is a $147.8 million project for the Metropolitan St. Louis Sewer District located in the cities of Shrewsbury, Maplewood, Brentwood, Richmond Heights, Webster Groves, Ladue within St. Louis County. NTP given on Sept. 4, 2017. Substantial completion of the tunnel is scheduled for Nov. 30, 2021, and final completion of the tunnel and dewatering pump station is scheduled for Sept. 9, 2022.

The project includes 22,800 lf of 19-ft diameter tunnel with 5 drop shafts. The average depth is 120 ft. The project is 95% complete. Excavation of the 40-ft diameter pump station wet well shaft, two 40-ft diameter pump station dry well shafts, and one 35-ft diameter retrieval shaft have been completed. The tunnel excavation was completed on Jan. 28, 2020. The 12-in. thick cast-in-place concrete liner has been completed in the tunnel. Excavation has been completed at each of the five drop shafts and construction of the diversion structures and deaeration chambers are in various stages of completion at each of the five sites.

Design: PARSONS Water and Infrastructure, Inc.; CM: Black & Veatch Corp.; Contractor: SAK Construction, LLC; Subcontractor: Goodwin Brothers Construction Co. (Near Surface and Surface Construction); TBM: Robbins.

Project Personnel: SAK – Project Manager; Brent Duncan. Project Engineer; Dan Swidrak. Tunnel Engineer; Heath Groom. Project Controls; Tom O’Sullivan. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Cedric Bransford. General Project Supt.; Terry Beesley. Project Superintendent; Frank Lynch. Concrete Superintendent; Shayne Peck. Design Project Manager – Nancy Matteoni, Black & Veatch; Construction Manager – Clay Haynes; Metropolitan St. Louis Sewer District – Design Project Manager – Jeff Smith; Metropolitan St. Louis Sewer District- Construction Project Manager – Dan Nichols.

Jefferson Barracks Tunnel. SAK Construction LLC

This $63.3 million project for the Metropolitan St. Louis Sewer District consists of the construction of approximately 17,800 lf of 11-ft excavated diameter tunnel, and the installation of a 7-ft diameter FRP carrier pipe and fiber optic conduits in the tunnel. NTP was issued March 1, 2017. Estimated completion is early 2023.

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 located approximately 140 to 215 ft below the ground surface in limestone bedrock. Construction is by a main beam TBM launched from an 88-ft diameter shaft. This shaft will serve as the location for 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 which might be encountered during shaft excavation. The TBM will be removed via a 22-ft diameter shaft at the upstream terminus of the tunnel. In addition to the launch and retrieval shaft, there are 14 bored shafts for drop pipes, vent pipes, and fiber optic conduits from the surface to tunnel depth. These shafts pass through a karstic zone located below the level of the Mississippi River. Consequently, these shafts were blind bored.

As of December 2019, excavation of the launch and retrieval shafts has been completed, and 7,100 ft of the tunnel had been mined. Tunneling work was suspended in December of 2019 following the TBM encountering a karst feature while mining. In July 2020 after additional investigation the contractor constructed a 205-ft deep recovery shaft and began excavating through the karst feature. It is anticipated that the contractor will have completed the excavation through the karst feature by July 2021. Completion of the entire project is anticipated to be in early 2023.

Karst was the most important geotechnical issue for the project as the bluffs along the Mississippi River are riddled with caves and karstic crevices. The presence of karst influenced the vertical alignment of the tunnel and impacted the design and construction of shafts that pass through the karstic zone.

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

Project Personnel: Patricia Pride, Project Manager, Metropolitan St. Louis Sewer District; Ray Scherrer, CM Program Manager, Metropolitan St. Louis Sewer District; William Haag, Design Project Manager, Jacobs Engineering Group; Andrew Bursey, Lead Tunnel Designer, Jacobs Engineering Group; Thomas Abkemeier, Vice President, Shannon & Wilson, Inc. SAK – PM; KC Hildenbrand. PM Dan Swidrak. General Project Supt.; Terry Beesley. Project Superintendent; Jeff Belt. Tunnel Superintendent; Jackie Bragg. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Ken Vandergeest.

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 14.5-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 5% complete and the contractor is currently performing shaft excavation.

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.

Key Project Personnel: Metropolitan St. Louis Sewer District – Design Project Manager: Jerry Jung; Construction Project Manager: Ray Scherrer. Design Project Manager: Doug Hickey, HDR. Tunnel Design Engineer: Everett Litton, WSP. Construction Manager: John Deeken, Black & Veatch. SAK – Project Manager; Brent Duncan. Project Engineer; Heath Groom. Project Controls; Tom O’Sullivan. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Cedric Bransford. General Project Supt.; Terry Beesley. Project Superintendent; Shayne Peck.

Schoharie Reservoir Low Level Outlet Southland/Renda JV

Southland/Renda is building this $142.6 million project for the New York City DEP. NTP was issued in June 2015. It has an estimated completion date of April 2022.

Both 9.5-ft microtunnels are complete; the 1,225-ft land leg drive and the 950-ft water leg drive with wet retrieval from the bottom of reservoir at a depth of 160-ft. An unplanned extensive rebuild of the machine was required between the two drives due to significant wear of both internal and external parts. Both line and grade were within tolerance for both tunnel drives. Wet retrieval required an adjustment to the original planned operation necessitating field adjustments to the means and methods.

The shaft has been concrete lined to near the top and the wheel mounted roller gate frames installed and dry fit. The concrete gate guides that extend from the bottom of the shaft to the maintenance floor 140-ft above are complete. Shoring has been installed and the maintenance and hoist floor will soon be cast followed by the remainder of the circular building aboveground. The concrete for electrical enclosure adjacent to the gate shaft is complete and the masonry block is complete.

After retrieval, the adaptor was cut off the Permalok pipe by divers and the 90-degree elbow and intake set and welded onto the tunnel pipe by way of a buttstrap connection. The underwater cofferdam was then filled with tremie concrete to just below the bellmouth and a plug installed so that the tunnel could be dewatered. A 25-ft tall 12-sided inlet screen made of 316 stainless steel was then positioned over the intake with one foot below the top of the bellmouth and tremie concrete placed to lock it in place. A hatch at the top will allow for removal of the plug at the end of the project and also allow for installation of the plug in the future for maintenance and inspection. All marine equipment has been removed from the reservoir and demobilized.

After removal of the marine equipment from the reservoir, the temporary sheeting for the marine staging area was removed and stacked rip rap placed along the bank leading up to the East Overlook area. The East Overlook will be a visitor center open to the public for viewing and history of the dam. All concrete has been placed for the retaining walls, the interpretive center, and the walking bridge. Masonry work is underway. Civil work including two bio-retention cells, storm drains and other permanent erosion control have been installed. Bridge erection has begun with sidewalks and paving to follow.

Other Major Parties Affiliated with the Project: DEP AM, Emory Chase; Project Designer (Gannett Fleming/Hazen Sawyer), Everette Knight; Resident Engineer (AECOM), Patrick Hoosier; MTBM Manufacturer, Herrenknecht

Personnel: SRJV Operations Manager, Kent Vent, SRJV Project Manager, Chris Davis; Project Engineers, Tim Bray, Joe Janke, Ammar Fallaha, Christy Ellis; Superintendent, Douglass Somers; Safety Manager, Jose Perdomo; Office Manager Martina Keeler.

Doan Valley Storage Tunnel Project McNally/Kiewit DVT JV

The $142.3 million project for the Northeast Ohio Regional Sewer District includes two conveyance tunnels (WCT and MLKCT), 8.5-ft finished diameter for a total length of 9,400 lf mined with a 12-ft dia. Robbins Main Beam TBM. It is a two-pass tunneling using rib and lagging as initial support and precast concrete pipe as final liner. Tunnel depth ranges between 30 and 100 ft below grade.

The main Doan Valley Tunnel (DVT) is 18-ft finished diameter for 10,000 lf mined with a 20.75-ft dia. Herrenknecht Single Shield Hard Rock TBM in one pass using universal ring, 5+1 segments (fiber reinforced). Tunnel invert depth is between 50 and 100 ft below grade with ntercepting pre-existing brick sewers up to 3 ft above the tunnel crown.

Also included are seven shafts between 23 and 55 ft diameter, 30 to 100 ft in depth.

The geology is primarily Chagrin shale bedrock for all three tunnels, except for a short reach at the very end of the WCT drive, in Cleveland shale. Both Chagrin and Cleveland shales rock masses are characterized by low UCS (up to 2,800), clay-filled bedding joints, weathered interbeds, and tendency for slaking.

The WCT 12-ft dia. tunnel drive was completed on Dec. 12, 2018. Pipe installation and cellular grout backfill were completed on July 30, 2019. The DVT tunnel drive was completed on Sept. 7, 2019. The DVT Starter Tunnel (18-ft diameter, 300 lf of synthetic fiber cast-on-place concrete. Operations Completed on April 17, 2020.

The MLKCT 12-ft dia. tunnel drive was completed on Jan. 15, 2020, and pipe installation operations completed on April 8, 2020. Cellular grout backfill was completed Aug. 28, 2020.

The DVT-2 Shaft (main mining shaft) cast-in-place final lining was completed on March 19, 2021.

Remaining work includes final testing and commissioning for automated hydraulic sluice gate tunnel flow control system. Removing temporary flow maintenance/control devices, introducing flow into tunnel, and final restoration of sites. Overall project progress is 98%.

Designer: McMillen/Jacobs Associates – Wade Trim; Construction Manager (NEORSD): Bob Auber; Construction Supervisor (NEORSD): Karrie Buxton. Major Subcontracts: CSI-Forterra (18 ft ID precast concrete segments); Northstar (Concrete Structures); BASF (DVT annular grout and ground conditioning); PIG (cellular grout); Jennmar (steel ribs); Northern Concrete Pipe (8.5 ft ID precast pipes).

Personnel – McNally/Kiewit DVT JV: Chris Lynagh – Project Manager; Joe Teter – General Superintendent; Collin Schroeder – Shaft/Structures Engineer; Adam Hornbeck – Superintendent/Walker; Lance Jackson – Project Engineer; Brian Negrea – Tunnel Engineer; Mark Kaletta – Equipment Superintendent; Jeff Acor – Chief Surveyor; Travis Dyer – Project Surveyor; Matt Szaraz – QHSE Manager.

Westerly Storage Tunnel Jay Dee/Obayashi JV

Jay Dee/Obayashi JV is approximately 88% complete with this $135 million project for the Northeast Ohio Regional Sewer District. At Site WST-1, the cast-in-place shaft liner and baffles are finished and the site turned over to follow-on contractor in October 2020. At Site WST-2, the cast-in-place shaft liner and baffles are finished, and site restoration, including landscaping and hardscaping, are finished.

TBM tunneling was completed in January 2021. Crew are approximately 95% complete with TBM disassembly. Excavation and support of excavation has started at the WST-3 Gate Structure.

Tunnel Designer: Stantec Mott MacDonald Westerly JV; Construction Manager: Owner managed (NEORSD); Major Subcontractors: DiGioia-Suburban Excavating (open cut and misc. site work), Nicholson Construction Company (Shaft SOE), Marra Services Inc (shaft excavation at two sites), Northstar Contracting Inc. (concrete structures); TBM Manufacturer: Lovsuns.

Personnel – Project Sponsor (Jay Dee Obayashi JV): Brian Hagan; Project Manager (Jay Dee Obayashi JV): Nate Long; Project Engineer (Jay Dee Obayashi JV): Lisa Smiley; General Superintendent (Jay Dee Obayashi JV): Jerry Pordon; Deputy Director of Engineering & Construction (NEORSD): Doug Gabriel; Construction Manager (NEORSD): Robert Auber; Senior Construction Supervisor (NEORSD): Ryan Sullivan.

Integrated Pipeline Project – Sections 19-1 and 19-2 IPL Partners

Integrated Pipeline Sections 19-1 and 19-2 project is a $21 million project comprising 2,000 lf of 10-ft excavated diameter tunnel. There are 10 different tunnels crossing TXDOT roads each with launch and receiving shafts (20 shafts) Depths are shallow, under 40 ft, through sands and clays using a boom-in-shield tunneling machine.

Crews are approximately 20% complete, and have completed two of the 10 tunnel crossings. The Estimated Date of Completion is March 21, 2022.

Owner: Tarrant Regional Water District; Designers: HDR Engineering and BGE Inc.; CM: Caledonia Construction Management; TBM Manufacturer: Custom fabricated machine by Southland Contracting, Inc.

Personnel: IPL Partners Operations Manager: Kent Vest; IPL Partners Project Manager: Jose Jimenez; IPL Partners Project Engineer: Hossein Mirenayat; IPL Partners Superintendents: Rod Fisher and Rick Leever.

DWU Elm Fork 72-in. Water Main Oscar Renda Contracting

This $43.186 million project for Dallas Water Utilities comprises 8,600 lf of tunneling in three reaches. Oscar Renda crew is building the 10-ft excavated diameter tunnel using rib-and-board support. A final liner of 72-in. steel carrier pipe will be installed. There are 5 shafts ranging from 18 to 35 ft in diameter, and ranging in depth from 75 to 96 vf – all 4-flange liner plate in overburden and rock bolts and shotcrete within the Eagle Ford Shale. Crews are using a double-shielded, open-faced machine with tailcan and articulated steering. Crews have completed excavation of Shafts 4 and 5 (both shafts which the TBM will launch). The tail and starter tunnel were expected to be complete by the end of May, with the first TBM launch (Reach 3) scheduled for June 2021.

The project was re-designed post-bid by Southland Contracting team. The contractors’ opportunity for re-design was described in original contract documents. 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 also required a 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.

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

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

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

This is a $206.7 million project for the City of Dallas that involves 26,385 lf of tunnel (32-ft, 6-in. excavated diameter, 30-ft finished diameter) with 8 Intake Shafts (ranging from 120 to 200 vf depth) and 6 lateral tunnels excavated by roadheader or excavators/breakers. The tunnel will be driven through Austin chalk with a Main Beam TBM.

To date, crews have completed excavation of 7 shafts with currently 1 shaft remaining ranging from 22 to 35 ft diameter and 110 to 190 ft deep. Total of 8 Shafts on project (5 Intake Shafts, 1 Outfall Shaft, 1 Dewatering Station Shaft, and 1 Access Shaft).

10,500lf of tunnel excavation has been completed with the Robbins Main Beam TBM (10,000 lf at 37-ft, 7-in. diameter. Crews have started TBM mining at 32-ft, 6-in. diameter, with approximately 16,500 lf of TBM tunnel excavation remaining.

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 Project Manager: Nick Jencopale; SMJV QC Manager: Matt Jackson; SMJV General Superintendent: Mike Clingon; SMJV Senior Project Engineer: Jose Ortiz, P.E.; SMJV Field Engineers: Jason Lipp/Kade Conner.

Integrated Pipeline Project 108” Pipeline – Trinity River Tunnel IPL Partners

This is a $48.5 million project for the Tarrant Regional Water District involving 4,400 lf of 15-ft, 7-in. excavated diameter (13-ft, 10-in. finished diameter) tunnel, as well as three shafts ((ranging from 60 to 150 vf). The ground consists mainly of weathered mudstone and will be excavated using an open-face TBM with hydraulic jacks and concrete segmental lining.

The project is currently 94% completed, with all tunnel excavation complete. Crews are currently grouting the annulus. Project completion is expected by August. Concrete segments were cast on site using the contractor’s segment forms. Tunneling included a river crossing of approximately 700 ft underneath the Trinity River with 50 ft or less of ground cover. Tunneling was completed at a grade of 6.6% through the highly weathered mudstone with various faults.

Owner: Tarrant Regional Water District; Lead Designer: Parsons; Tunnel Designer: Parsons/Stiver Engineering; CM: Freese and Nichols, Inc.; TBM Manufacturer: Custom fabricated machine by Southland Contracting, Inc.

Personnel: IPL Partners Operations Manager: Kent Vest; IPL Partners Project Manager: Jose Jimenez; IPL Partners Project Engineer: Hossein Mirenayat; IPL Partners Superintendents: Otilio Ramos.

Bois D’Arc Treated Water Pipeline Segment E Tunnel Southland Contracting / Oscar Renda Contracting JV (SRJV)

This $12.4 million project for the North Texas Municipal Water District involves the construction of 2,534 lf of 10-ft excavated diameter tunnel using 4-flange liner plate and lined with 84-in. steel carrier pipe. There are two shafts: a 30-ft ID Launch Shaft with 4-flange liner plate and ring beams in overburden; and a 25-ft, 9-in. ID Receiving Shaft with 4-flange liner plate and ring beams in overburden. The tunnel is being driven through Austin Chalk with a double shielded, open-faced, gripper type machine with articulated steering. Both shafts have been excavated and tunneling is complete. All carrier pipe has been installed and grouted within tunnel. Crews are currently installing vertical pipe and backfilling shafts.

Owner: North Texas Municipal Water District; Lead Designer: HDR; Tunnel Designer: Stiver Engineering; CM: Freese & Nichols; GC/PM: Garney Construction Inc. TBM Manufacturer: Southland Contracting Inc.; Tunnel Contractor: Southland Contracting Inc.

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

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 consist of a highly variable mix of glacially over-consolidated soils. The construction project is 33% complete. Four of the five shafts are complete and both tunnel crews are preparing their launch shafts. Over the next six months, the TBM will begin its journey, and the 8-ft diameter MTBM will complete its drive southward under the Ship Canal. NTP was issued Dec 26, 2019. Completion is expected by Aug. 2023.

Designer: McMillen Jacobs Associates; CM: Jacobs Engineering; TBM: Herrenknecht. Subcontractors: Shaft Construction – Malcolm Drilling Co.; Microtunneling – Northwest Boring; Mechanical and Concrete Structures – Prospect Construction; Electrical – Chau Electric; Trucking – Grady Excavating; 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; Technical manager (Tunnel): Eren Kursdogan; Construction Managers: Raffaele Aliberti, Alessandro Marini.

Kemano T2 Tunnel Project – Upstream Works Barnard Constructors of Canada, LP

The Kemano T2 tunnel is for Rio Tinto located 74 km southwest of Kitmat, BC. The project involves the construction of the 16-km long KT2 which began in the early 1990s. The project is currently in its final phase, which involves excavation of 7.6 km of new tunnel and refurbishment of an 8.4 km portion of the second tunnel that was constructed in the 1990s. In July 2020, Barnard Constructors of Canada, LP was awarded the Upstream Works portion of the Kemano T2 Tunnel Project to construct the remaining approximately 4 km of the 7.6 km new tunnel. The tunnel is being excavated by a 6.56-m diameter Herrenknecht single-shield hard rock TBM and includes installation of precast concrete tunnel lining.

The Barnard team has excavated over 1.6 km since restarting TBM operations on Sept. 3, 2020. The entire site is maintaining a 0.00 AIFR (All Injury Frequency Rate) for 2021 and achieved a safety milestone of one year free of Lost Time Injury. Barnard is doing their part by maintaining a 0.00 recordable frequency rate project to date.

This remote camp is located on the traditional territory of the Haisla First Nation and is accessible from Kitimat by boat, barge, and helicopter only. All materials, personnel, and pieces of equipment are barged in and out.

Engineer – Hatch Ltd.; TBM manufacturer – Herrenknecht.

Personnel: Owner: Rio Tinto: Alex Jones – Project Manager, Gregory “Alf” Garnett – Underground Area Manager. EPCM: Hatch: Riley McMillan – Lead Field Engineer, Luis Corgo – Deputy Underground Area Manager, Shawn Tucker – Deputy Underground Area Manager, Daniel Jezek – Lead Underground Engineer and Engineer of Record, Gary Kramer – Engineer of Record. Barnard: Project Managers: Jimmy McGauley, Ryan Eitutis; General Superintendents – Patrick Finn, Tommy McDowell; Lead Engineers: Matthew Whittle, Michael Zenker; Construction Superintendents – Matthew Ulizio, Ross McLean, Craig Arnes; Field Engineers – Brett Campbell, Michael Delaney, Guillermo Charles-Barrera, Michael Karl.

Second Narrows Water Supply Tunnel, Burrard Inlet Crossing Traylor-Aecon General Partnership

The Second Narrows Water Supply Tunnel for the Greater Vancouver Water District (Metro Vancouver) is a $286 million project that will improve reliability and increase capacity for Metro Vancouver to deliver drinking water throughout the Vancouver area. Notice to Proceed was issued Jan. 15, 2019 and final completion is expected in the summer of 2023.

The project consists of two shafts (18mØ x 68m and 10mØ x 110m) on either side of the Burrard Inlet that are connected by 1,100 m of 5.8-m ID, 6.7-m excavated diameter segmentally lined tunnel that will be constructed with a mix shield TBM. Ground improvement includes a safe haven constructed using ground freezing 425 m into the drive. Three permanent water mains (2 @ 2.438m, 1 @ 1.524 m) will be installed within the tunnel, up both shafts and into large underground valve chambers atop each shaft.

Geology consists of permeable and variable soft ground containing a high percentage of cobbles and boulders with a transition to weak rock over the final 300 m of the drive. Face pressures of up to 7 bar are anticipated and hyperbaric intervention via saturation diving is planned.

The South shaft is now 101 m deep and excavation is scheduled to be complete in Q2 2021. The TBM is fully assembled after previously completing installation transitions from short mode (shield only) to partial assembly (through deck 3) and has advanced 425 m into the frozen safe haven. A free air intervention is planned in the coming weeks after which tunnel advance will continue through Q3 2021.

Owner: Metro Vancouver (PM: Allen Mitchell, DPM: Mark Qian); Tunnel Designer: McMillen Jacobs (Andrew McGlenn); Construction Manager: Mott MacDonald (CM: Richard Brydon, DCM: Ian Whitehead); Contractor: Matt Burdick, Andrew Rule, Erica Bailey, Bill Crider.

Major Subcontractors: Herrenknecht (TBM); Schauenburg (slurry treatment plant provider); Malcolm-Petrifond JV (slurry wall); Keller North America (ground freezing); Ballard Marine Construction (hyperbaric services); Northwest Pipe (pipe); MSE Precast (precast segments).

Stage 2 LRT Project – O-Train South Extension Project TransitNEXT

This $1.6 billion project for the City of Ottawa is being built by TransitNEXT, a wholly-owned subsidiary of SNC-Lavalin, which is the prime contractor. The Dows Lake Tunnel is a critical piece of infrastructure providing a north-south connection along the former Trillium Line. Originally built and owned by Canadian Pacific Railway (CPR), it opened for operation in 1964 as a rail tunnel to accommodate freight trains. The tunnel was converted for use by OC-Transpo in 2001 for the O-Train. As part of the South Extension Project, the TransitNEXT team is working with the City of Ottawa and its partners to address several historical challenges through design and construction of the tunnel’s upgrades: Improving the water infiltration management system at expansion joints by performing joint repairs; Upgrading and providing maintenance of the drainage system including the installation of a new pump system and ensuring the adequacy of the existing drainage system capacity; Upgrades and modernization of the tunnel ventilation system, trackwork, standpipe system, communication systems, and emergency walkway to align with NFPA – 130 standards. The length of tunnel is 578 m with 23 reinforced concrete box segments separated by expansion joints. It is approximately 6.7 m high from the top of the rail and 5.1 m wide.

Rehabilitation of the Dow’s Lake Tunnel is nearing completion as crews conclude waterproofing of tunnel expansion joints, concrete repair and additional steel reinforcement. Work is currently underway to upgrade the drainage system and modernize the tunnel ventilation system, trackwork, standpipe system, communication systems, and emergency walkway to align with NFPA -130 standards.

Stage 2 LRT Project – O-Train West Extension Project East-West Connectors (EWC)

This is a $2.57 billion (CAD) design-build-finance project for the City of Ottawa being built by East-West Connectors (EWC), a JV comprising Kiewit, Eurovia and VINCI (KEV). Estimated date of completion is 2025.

The west extension includes two cut-and-cover tunnels. The 3-km Parkway tunnel will travel between Dominion Station and Lincoln Fields Station traveling underneath the Sir John A. Macdonald Parkway and Byron Linear Park. The 270-m Connaught tunnel will link Lincoln Fields Station with Queensview Station by traveling underneath Connaught Avenue.

The Parkway cut-and-cover construction began in 2020. Excavation began at the top surface level, and support walls are being installed as the tunnel gets deeper. Once excavation and construction of the concrete tunnel structure is complete, localized backfill and restoration of the surface will begin. As of spring 2021, excavation of the Parkway tunnel is progressing well. Approximately 35,000 cubic meters or 12% of the total quantity, has been excavated, and 46% of the pile drilling has been completed.

The Parkway tunnel will travel under federally owned lands and a City of Ottawa park in order 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 under a residential neighborhood. Overall, the Stage 2 LRT O-Train East and West extensions is a signature project in Canada’s national capital, funded by three levels of government. There is close, ongoing collaboration with all stakeholders and the public, as building a large infrastructure project in an urban environment can be disruptive.

Excavation is facilitated by the various use of support of excavation (SOE) depending on the ground conditions encountered. Types of SOE include slurry walls, secant pile walls and soldier piling and lagging.

Design/Engineering Services: WSP Canada, Hatch Ltd.

Personnel: Chris Loeffler, Senior Vice President and Project Director, Kiewit Infrastructure Corporation; Gwyon Nelson, Project Director, Kiewit Eurovia Vinci.

Ashbridges Bay Treatment Plant Outfall Project Southland/Astaldi JV

NTP for this $300 million project for the City of Toronto was issued in January 2019 and has an estimated date of completion of January 2024. The job comprises a 16-m diameter shaft, 85 m deep; 3.5 km of 8-m diameter TBM excavated tunnel; 7m ID Precast Concrete segmental lining; and 50 each of 1-m diameter risers from tunnel (marine work). Georgian Bay shale is the expected ground condition.

The project is currently 35% complete. Shaft excavation is complete and the 107-m long starter has been excavated. The TBM was assembled and launched, and tunnel excavation is ongoing. Riser installation is also ongoing.

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

Personnel: Contractor: Southland | Astaldi JV – Operations Manager (Kent Vest); Project Manager (Joe Savage); Deputy Project Manager (Francisco Urrutia); Technical Manager (Khaled El-Kalawi); General Superintendent (Curtis Bahten).