Tunnel Updates – October 2021

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 October 2021 issue of the print edition.

CALIFORNIA

Carson/Los Angeles/Rancho Palos Verdes

Joint Water Pollution Control Plant Effluent Outfall Tunnel
Dragados USA

NTP on this $630.5 million project for Los Angeles County Sanitation Districts was issued April 8, 2019, with 1,953 working days to complete the work and an estimated completion date of May 2027. The project will serve the sanitation needs of approximately 5 million people in 73 cities and unincorporated areas of Los Angeles County.

The project is part of the Sanitation Districts’ Clearwater Program, which evaluates infrastructure and facilities needs through the year 2050 and makes recommendations on how to maintain a reliable and cost-effective wastewater management system.

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 provide better seismic resiliency, provide additional capacity for population growth and storm events, and will provide redundancy for the two existing tunnels that were constructed in 1937 and 1958, which have not been inspected in nearly 60 years. The tunnel will be constructed by an EPB or slurry 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. As part of the scope, a 14-ft diameter cast-in-place concrete connection will be constructed to convey the treated effluent from an existing force main to the proposed JWPCP Shaft. Other notable project features include an approximately 60-ft diameter and 113-ft deep drop shaft, a junction structure and two valve structures at the JWPCP and a manifold structure at Royal Palms Beach.

Tunneling will go through two very distinct ground conditions. The first half of the tunnel will be through soft ground with depths up to 110 ft. The second half of the tunnel will be through hard rock with depths up to 450 ft where the tunnel will be subjected to intense ground squeezing conditions due to the overburden pressure.

The tunnel lining will consist of bolted and gasketed precast concrete segments. Tunneling will go through splays of the Palos Verdes Fault Zone where 16-ft diameter steel liner will be used within the 18-ft diameter concrete segments to accommodate displacement from seismic events at two locations. When in operation, the tunnel will be under hydrostatic pressure. In the first half of the alignment, internal pressure will exceed the external pressure and post-tensioning of the concrete segmental liner will be necessary. To offset the “hoop stress” developed from internal pressure, a post-tensioning system consisting of internal steel tendons along the circumference of the concrete liner was specified. This post tensioning design is unique and has only been used a few times in the world, but never before in North America. In the second half of the alignment, the hard rock around the tunnel will offset the internal pressure, and post-tensioning will not be required.

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 dontractor will be using a Herrenknecht slurry TBM, which arrived onsite in late 2020. The TBM has been named “Rachel” in honor of Rachel Carson, who authored the book Silent Spring which was credited with sparking the global environmental movement. Fabrication of test precast concrete segments at Traylor Bros. Inc.’s Littlerock, California, facility began in April 2021. Tunnel construction is anticipated to begin in September 2021.

Lead Design Consultant: Parsons; Tunnel Design Consultant: McMillan Jacobs Associates; Tunnel Construction Management Consultant: Mott MacDonald. 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: 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.

Los Angeles

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

The Regional Connector Transit Project is in the heart of downtown Los Angeles in a congested urban environment where construction encounters numerous challenges and requires coordination with multiple third parties. The Regional Connector Transit Project will connect three operating rails systems, the Metro A (Blue) and E (Expo) lines on the West, and the L (Gold) line on the East. When complete, transit riders will no longer need multiple transfers and can travel north-south and east-west on the same system. Significant progress is expected in 2021 in anticipation of the construction completion in the summer and opening to the public in the fall of 2022.

The tunneling portion of the $1.8 billion Regional Connector Transit Project for the Los Angeles County Metropolitan Transportation Authority 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. Pressure balance tunneling utilizing an EPB TBM was required, along with precast concrete segments with double gaskets as the tunnel lining system. The tunnel depth (cover) 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 now completed. With provisions being incorporated into the Historic Broadway Station to accommodate the overbuild of a mid-rise commercial structure, the Historic Broadway Station construction will extend through the second quarter of 2022. Backfilling of the 1,400 ft of the cut-and-cover tunnel structure along Flower Street is completed and now the project is in preparation for street restoration which will extend through mid-2022.

Presently, the focus throughout the alignment continues to be on the installation of train systems and station finishes. The project 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 remaining two crossovers near the Wye structure, where the project connects to the existing L Line (Gold) are scheduled to be completed in Fall of 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 winds down in the Wye, 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 completed the majority of the Overhead Contact Rail (OCR) installation throughout the project alignment and is focused on train systems installation at each station. Additionally, the project has now begun Light Rail Vehicle (LRV) clearance testing between 7th St/Metro Center Station and the new Historic Broadway Station with California Public Utilities Commission (CPUC) support. 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. Preparations are already underway in anticipation of these operational changes. Overall, the project is progressing on schedule and is scheduled to begin revenue operations during the third quarter of 2022.

Other parties affiliated with the project – Tunnel Designer for the Contractor: Mott McDonald; Preliminary design was completed by CPJV (AECOM/ WSP), which is also performing design services during construction, and Metro’s Construction Management Consultant is 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.

Tuolumne County

Mountain Tunnel Improvements Project
Michels Tunneling

The project is in the central Sierra Mountain Range near the town of Groveland in Tuolumne County. The existing tunnel begins at Early Intake Reservoir on the Tuolumne River and extends approximately 19 miles west to the Priest Reservoir, near the town of Groveland.

The scope of the work for this $139 million job for the San Francisco Public Utilities Commission (SFPUC) includes: existing tunnel interior repair and modification work within the 19 mile tunnel length which includes concrete lining repairs, contact grouting, pressure grouting, approximately 5,000 linear feet of new concrete invert paving, demolition of existing bulkheads and installation of new bulkheads, bulkhead improvements and debris removal. Construction of new tunnel improvements which includes a new Flow Control Facility (FCF) which is comprised of a 55-ft diameter , 150-ft deep new shaft, bypass tunnels and connections with the existing tunnel; the construction of new portal, 1,000-ft long adit, tie-in of the adit to the existing tunnel, construction of a new access shaft with a new connecting adit, new siphon extension of about 300 ft with an inclined shaft connecting to the existing tunnel and installation of approximately 1,500 ft of steel pipe lining. Other work within the project limits includes construction of permanent spoil fill sites, installation of a water filtration system during the tunnel shutdowns and water treatments plants for construction water discharge, road/slope stabilization for the adit access roads, various types of retaining walls, a micro pile supported concrete deck, environmental permit compliance and other site improvements and restoration.

The 150-ft deep and 55-ft internal diameter FCF shaft will be constructed primarily in a schist formation. The FCF bypass tunnels, which are horseshoe shape with varying dimensions, will also be constructed in schist. The 1,000-ft long horseshoe shape adit will constructed in both diorite and schist. The 100-ft deep and 17-ft internal diameter access shaft and bypass tunnel siphon extensions will be constructed in diorite. It is expected that drill-and-blast will be the construction method for all underground construction.

The project is approximately 10% complete. Mass excavation, retaining wall construction for the FCF site pad is nearly complete with shaft excavation to begin in early fall 2021. The adit portal is under construction with adit excavation to begin the in the fall 2021. Adit access road and slope stabilization are progressing at a good rate. First major milestone will be the 2022 winter outage which allow work to commence inside the existing tunnel while continuing to work on the outside of the tunnel.

The objectives of the Mountain Tunnel Improvements are to rehabilitate the tunnel and to make improvements to extend the useful life of this asset for the next 100 years. This project will require five winter season tunnel outages of 60- to 100-day durations each in order to complete the in-tunnel repairs and other work inside the tunnel and to construct the tie-in connections between the existing tunnel and the new improvements.

NTP was issued January 29, 2021 and the estimated date of completion is December 2026.

Lead Design Consultant is McMillen Jacobs Associates, SFPUC Construction Management Bureau is the construction manager, construction management and construction inspection provided by AECOM; Major coordination with Hetch Hetchy Water and Power, Ted Allen; Major Michels subcontractors include Apex Rockfall Mitigation, Kroner Environmental, Schrader Mechanical, Cody Builders Supply, Renesco Inc. and Mach8Bio.

Personnel: SFPUC – Regional Project Manager: Randy Anderson; Project Engineer: Joseph Buitrago; Regional Construction Manager and Acting Resident Engineer: Jerry Malone; Assistant Resident Engineer: Mike Nessl; Public Outreach: Betsy Lauppe Rhodes.

McMillen Jacobs and Associates – Project Manager: Jennifer Sketchley, Associate; Design Project Manager: Renee Fippin, Principal: Tunnel Engineer: Glenn Boyce, Principal.

AECOM – Contract Manager: Steven Tidwell, Vice President, Lead Inspectors: Thomas (Bud) Degrio and Kevin Bolle, Safety Manager: Rick Cavil.
Michels Tunneling – Project Manager: Ed Whitman; Project Engineer: David McCallum.

DISTRICT OF COLUMBIA

Washington

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 called North East 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. Mixed 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 TBM in clay soil which will be lined with HOBAS pipes installed using the pipe jacking tunneling method.

As of August 2021, 75% of the works were completed. The tunnel excavation was completed in April 2021, the TBM disassembly in June 2021 and currently the tunnel cleanup operations are ongoing. The excavation of all the 7 drop shaft is already completed. 55% 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 arrived on site in June 2021 and started the excavation of the 700-ft Diversion Sewer in August 2021. To date, five HOBAS pipes, 20-ft long, have been installed, which corresponds to the 15% of the tunnel to be constructed.

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 on 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.

NTP was issued on Sept. 15, 2017, with an estimated completion date of March 26, 2023.

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

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).
ILLINOIS

Bedford Park/McCook

McCook Reservoir, Des Plaines Inflow Tunnel
Walsh Construction Company II, LLC

The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is the owner for this $107,770,362 project. NTP was issued July 9, 2016, with estimated date of completion in spring 2022.
The project consists of approximately 5,850 lf of tunnel, 20-ft concrete lined finished diameter, wit an approximate depth of 280 ft. Also included is one 12-ft diameter construction shaft and one 45-ft diameter gate shaft. The tunnel was excavated through bedrock by drill-blast.

The project is approximately 92% complete with major milestones excavation and construction of the gate shaft, excavation and lining of the 20-ft diameter tunnel, and connection to Stage 1 of the McCook Reservoir with subsequent tunnel plug when the reservoir became live in 2017. In addition, the two 22-ft x 21-ft steel gates and hydraulic cylinders to control water within the tunnel when it becomes live have been delivered to the site and are currently installed. Once gates are approved for operation, the contractor will make the connection into the existing live 33-ft tunnel on the north end and remove the plug on the south end (reservoir side). Current construction activities are quality control checks on the two installed gates and field acceptance tests on the mechanical and electrical components in the Gate Control Building before live tunnel connections commence.

Challenges have included the time constraint of having the south end of the tunnel connected to Stage 1 of the reservoir before the reservoir came on-line at the end of 2017. The other unique feature will be connecting the north end of the proposed tunnel to an existing live 33-ft tunnel that collects combined sewage for the Chicagoland area.

Parties affiliated with the project: Black and Veatch Corporation (Tunnel & Gate Designer); Linita Design & Manufacturing Group; Pagoda & Electric Construction Inc.; Truck King Hauling; Terrell Materials Corporation; Atlantic Painting Company; Vulcan Materials; and Steppo Supply & Construction Inc.

Key Project Personnel – MWRDGC: Kevin Fitzpatrick (Design Project Manager), Patrick Jensen (Design Engineer), Carmen Scalise (Construction Project Manager), Tim Nolan (Resident Engineer). Black and Veatch: Faruk Oksuz (Project Director), Cary Hirner (Project Manager) and Mark White (Engineering Manager). Walsh: Mark Fournier (Project Manager), Erik Schneider (Technical Engineer).

INDIANA

Fort Wayne, IN

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 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.

Through the end of July 2021, the project is 70% complete. The TBM drive completed on July 1, 2020, when MaMaJo intersected the Retrieval Shaft. TBM mining continued through the bottom of the shaft and out the other side, mining an additional 60 ft to its final position where the cutterhead and shields will be abandoned in place. Removal of the gantry systems is underway along with the pre-excavation grouting for the underground adit and deaeration chambers which will later be excavated through drill and blast operations and receive a final lining to tie into the main tunnel. The Pump Station and Upflow Shaft cast-in-place concrete liners are due to begin in the next few months.

NTP was issued May 1, 2017, with an estimated completion date of June 20, 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 Fort 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).

Indianapolis

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.

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. Final preparations are underway to commission both tunnels and comply with the consent decree deadline. Ongoing activities include installation of mechanical equipment and instrumentation at each of the drop shaft sites, as well as final grouting of the drop and vent shafts. Contact grouting is also ongoing within the adits and mainline tunnel. In addition, the contractor is installing a fiber optic network within the tunnel that connects each of the drop shaft sites to both of Citizens’ advanced wastewater treatment plants. Plant personnel can remotely monitor conditions in the tunnel system and operate mechanical gates at each of the drop shaft sites to control tunnel filling.

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.; Tunnel Construction Supervisor: John Morgan.

Indianapolis

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 ft 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 nine adits totaling over 5,200 ft. Adit excavation is 80% complete, with crews working to finish the last adit that is over 1,600 ft long. Tunnel concrete lining operations are anticipated to commence in September 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.; Tunnel Construction Supervisor: John Morgan.

Indianapolis

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 the TBM has excavated over 12,000 ft of tunnel as of late August. Crews are also constructing a 30-ft diameter intermediate shaft approximately 20,000 ft into the alignment. Due to the number of curves in the tunnel alignment, tunneling and muck handling operations will be relocated to the intermediate shaft in order to maximize efficiency of the horizontal conveyor belt system. 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.; Tunnel Construction Supervisor: John Morgan.

KENTUCKY

Louisville

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 summer 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, 7,700 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. Construction of Drop Shaft DS03 adit is ongoing and construction of Drop Shaft DS05 adit is complete. S-T JV has started concrete lining operations for the Working Shaft.

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.

MISSOURI

St. Louis

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

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 was 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 tunnel dewatering pump station is currently being constructed under a separate contract.

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.
The contractor utilized a horizontal conveyor to convey muck from the TBM heading to the working shaft, a vertical conveyor to convey material from the shaft to grade, and a stacker conveyor to convey the material into a stockpile for removal by truck. Two-pass construction is utilized, with rock dowels and mesh placed as initial support until the excavation was completed, followed by installation of the 12-in. thick cast-in-place concrete liner.

Parties Affiliated with the Project: PARSONS Water and Infrastructure, Inc. (Tunnel Designer); Black & Veatch Corporation (Construction Manager); SAK Construction LLC (Contractor); Goodwin Brothers Construction Co. (Subcontractor – Near Surface and Surface Construction); Robbins (TBM Manufacturer).

Key Project Personnel: SAK – Project Manager; Brent Duncan. Project Engineer; Project Controls; Tom O’Sullivan. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Cedric Bransford. General Project Supt.; Terry Beesley. 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.

St. Louis

Jefferson Barracks Tunnel
SAK Construction

The Metropolitan St. Louis Sewer District is building this $63.3 million project. NTP was issued March 1, 2017. Completion is expected by October 2023. The project comprises approximately 17,800 lf of 11-ft excavated diameter 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 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.
In May 2019, a karst feature was encountered that caused tunneling work to be suspended after mining about 7,100 ft of tunnel with the 11-ft diameter TBM. In July 2020 after additional investigations, SAK began work to recover the 11-ft diameter TBM. Construction of a 205-ft deep recovery shaft about 200 ft in front of the TBM followed by excavating a tunnel back to the TBM which required hand mining through the karst feature in front of the TBM was completed. The TBM was recovered in late July 2021.

A larger, 13.5-ft diameter TBM with the capability of probing and grouting through its face is currently being refurbished by Robbins. The new TBM will be launched from the recovery shaft with tunneling anticipated resuming in January 2022. Completion of the entire project is currently anticipated to be in fall 2023.
Karst was identified at 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 construction and carrier pipe installation), Goodwin Brothers Construction (intake construction). TBM Refurbishment: Robbins.

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, CM Project Manager, Shannon & Wilson, Inc.; Scott Garbs, 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; Ken Vadergeest, Safety Manager, SAK Construction.

St. Louis

Lower Meramec Tunnel (11746)
SAK Construction

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 excavating the starter tunnel; drilling the drop and vent shafts; and installing the secant pile excavation support system for the TBM retrieval shaft.

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; Spencer Miller. Project Controls; Tom O’Sullivan. Tunnel Division Safety Manager; Jack Lynch. Safety Manager; Cedric Bransford. General Project Supt.; Terry Beesley; Project Superintendent; Shayne Peck.

NORTH CAROLINA

Monroe

Yadkin River Water Supply Project
CDM Constructors, Inc./Turn – Key Tunneling, Inc.

This is a $1.5 million project for Union County North Carolina Public Works that involves the installation of seven jack-and-bore runs for a total of 734 lf of 54- and 36-in. pipe, as well as construction of seven bore pits and seven receiving pits.

Three bore pits and three receiving pits and 377 ft of the 54-in. are done. Three runs have been completed to date. Turn – Key Tunneling was able to provide extensive equipment to run multiple sites at a time. Multiple specialized cutting heads have been supplied to cut through the various densities of rock encountered on the project. Crews are using a Robbins SBU on the project.

Project Personnel: Nathaniel Grove, PE, MPP, CDM Constructors, Inc. ; Brian Froehlich, President, PE, Turn – Key Tunneling Inc.; Chris Allen, Chief Estimator, Turn – Key Tunneling Inc.; Chris Leonard, Senior Project Manager: Turn – Key Tunneling Inc.; James Froehlich, Superintendent: Turn – Key Tunneling Inc.

Winston-Salem

North Mill Creek Outfall Replacement
Zachry Construction Corp./ Turn – Key Tunneling Inc.

This is a $2 million project for the City of Winston-Salem consisting of the installation of 400 lf of 60-in. steel casing by trenchless methods in three locations. Installation is being performed by hand mining and auger boring in mixed face conditions. Once the casings are installed, the Hobas carrier pipe is pushed into place and grouted. One run is beneath an active CSX railroad and two others are under live roadways.

Two of the three runs have been completed to date, including threading and backfilling. Run 3 is currently in process and was nearing the 75% mark for completion at press time. The team is splitting work between day and night shifts to deliver the project on-time and in-full.

Despite terrible ground on the first bore, the team has successfully completed the scope of work on an 83-ft bore within 0.01 ft of grade. The ground has been a soupy mix of sand and silt with large boulders mixed in. Undeterred by heavy rains impacting the work, the team has continued the project on-schedule.

Engineer: Gavel & Dorn Engineering, PLLC. Project Personnel: Ron Ward, Project Engineer, Zachry Construction Corporation; Brian Froehlich, President, PE, Turn – Key Tunneling, Inc.; Chris Allen, Chief Estimator, Turn – Key Tunneling, Inc.; Chris Leonard, Senior Project Manager, Turn – Key Tunneling, Inc.; David Ratliff, Superintendent: Turn – Key Tunneling, Inc.

OHIO

Cleveland

Westerly Storage Tunnel
Jay Dee Obayashi JV

The Westerly Storage Tunnel is a $135 million combined sewer overflow project for the Northeast Ohio Regional Sewer District (NEORSD) as part of its Project Clean Lake. The project is approximately 90% complete.

Recent activities include:

Site WST-1: Site turned over to follow-on contractor in October 2020.
Site WST-2: Site restoration, including landscaping and hardscaping, finished.
Site turned over to City of Cleveland.
Tunnel: Tunnel excavation has finished in January 2021.
TBM disassembly within tunnel has been completed in June 2021.
Starter tunnel cast-in-place concrete lining is in progress (15% done).
WST-3 Gate Structure: Excavation and support of excavation is in progress (85% done).
WST-3 Shaft: Cast-in-place mass concrete slab installation is in progress (20% done).
Cast-in-place shaft lining and baffles will be installed after the shaft slab is finished.

Parties Affiliated with the Project: 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.

Project Personnel: Project Sponsor (Jay Dee Obayashi JV): John T. DiPonio; Project Manager (Jay Dee Obayashi JV): Nate Long; Project Engineer (Jay Dee Obayashi JV): Lisa Smiley; General Superintendent (Jay Dee Obayashi JV): Phil Rhodes; Deputy Director of Engineering & Construction (NEORSD): Doug Gabriel; Construction Manager (NEORSD): Robert Auber; Senior Construction Supervisor (NEORSD): Richard Depew.

TENNESSEE

Nashville

Davidson Branch Pump Station
JSJ Construction LLC/ Turn – Key Tunneling

This is a $1 million sanitary sewer project for the Metropolitan Government of Nashville and Davidson County that involves the installation of 350 lf of 60-in. steel casting and 245 lf of 36-in. steel casing.

The 350=ft casing was installed using a Robbins Small Boring Unit (SBU). According to Robbins, this shatters the previous world record of 280 lf of 60-in. rock boring with an SBU. Threading is underway and grouting of the annular space will follow before moving on to the 245-ft run.

Challenges existed on-site because of a river running through the project. Turn – Key would have to not only jack and bore 350 lf of 60-in. steel casing but would have to work around the challenges the river could pose to the tunnel.

Turn – Key Tunneling installed a 250-ft long pilot tube to verify the rock competency, especially beneath the river. This was attempted with a laser-guided pilot tube. However, rock in excess of 19,000 PSI was encountered. So, the project team utilized an 8-in. tri-cone head. They then probed from inside the casing, through the face, to ensure the 60-in. bore would not encounter a cavity or porous rock that would allow the river to free-flow into the casing.

Project Personnel: Gregory Wallace, Project Manager, JSJ Construction, LLC; Brian Froehlich, President, PE, Turn – Key Tunneling Inc.; Chris Allen, Chief Estimator, Turn – Key Tunneling Inc.; Chris Leonard, Senior Project Manager: Turn – Key Tunneling Inc.; James Froehlich, Superintendent: Turn – Key Tunneling Inc.

TEXAS

Athens

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

IPL Partners is building this $21 million project for the Tarrant Regional Water District. Estimated completion date is Aug. 19, 2022. The job includes 2,000 lf of 10-ft excavated diameter tunnel, with 10 different tunnels crossing TXDOT roads each with launch and receiving shafts (20 shafts). Depths are shallow at under 40 ft. Expected ground conditions include sands and clays. Crews will use a boom-in-shield tunneling machine.

The schedule update shows 63% complete because it considers various tasks including submittals, but crews have completed only 30% of tunnel footage. Currently, four of the 10 tunnel crossings are complete.

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.

Dallas

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

This is a $206.7 million project for the City of Dallas that includes: 26,385 lf of tunnel at 32-ft, 6-in. OD and 30-ft ID; 8 Intake Shafts (ranging from 120 to 200 vf in depth); a dewatering station, and 6 lateral tunnels excavated by roadheader or excavators/breakers. The tunnel traverses Austin chalk and is mined with a Robbins Main Beam TBM.

Crews have completed excavation of 7 shafts and currently with 1 shaft remaining. Shafts range from 22 to 35 ft in diameter and 110 to 190 ft deep. There are 5 Intake Shafts, 1 Outfall Shaft, 1 Dewatering Station Shaft, and 1 Access Shaft. Crews completed mining an approximately 10,000-ft section of 37 ft, 7 in. tunnel and completed converting the TBM diameter from 37 ft, 7 in. to 32 ft, 6 in. completely within the confines of the tunnel. The JV has completed 5,000 ft of the smaller diameter tunnel with 11,000 ft remaining.

The liner is a 15-in. thick cast-in-place final concrete liner. The project has crews working in 6 working sites within the city environment, and tunneling under city infrastructure, including state highways, light rail tunnels and surface tracks, and railroads.

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.

WASHINGTON

Seattle

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 38% complete (as of the end of August 2021). All five shafts are complete and both tunnel boring machines launched. The 21.5-ft diameter TBM, (names “Mudhoney”), has begun its journey from the Ballard neighborhood eastward along the north side of the Ship Canal toward the Wallingford neighborhood, and the 10-ft diameter MTBM will complete its journey from Fremont, southward under the Ship Canal toward the Queen Anne neighborhood by end of September. Also, during this period crews will install conveyance pipe and below grade vaults.

The TBM has successfully launched using ‘steel bell’ structure to create a regular EPB TBM tunneling conditions at the face and around the entire tunneling envelop before breaking out of slurry wall and into glacial deposited ground, instead of any soil improvement at the launch shaft.

TBM launch drive is longer than usual launches using umbilicials. The launch set up also includes temporary gantries and conveyor belt. Once it is completed the whole machine will be assembled in the tunnel. Muck cars, rotary dump, car passer and car mover will be used for the mucking operations for the final set up.

Tunnel Designer: 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; Technical manager (Tunnel): Eren Kusdogan; Construction Managers: Raffaele Aliberti, Alessandro Marini.

CANADA

BRITISH COLUMBIA

Delta

Annacis Island Outfall Tunnel
Pomerleau Inc. in partnership with Bessac CANADA

This $184 million (CAD) project for Metro Vancouver consists of the construction of a new outfall pipeline from the Annacis Island Wastewater Treatment Plant (WTP) to the Fraser River including:
Two shafts with 40 m deep slurry walls

Two segmental lining tunnels 4.20 m ID (200 m and 580 m long) excavated with a slurry TBM. A second short steel liner is partially placed after tunneling.

One river riser and 2 x 110 m long 2.5 m ID diffuser pipe buried in the Fraser River bottom.
A new water control structure in the water treatment plant.

NTP was provided in July 2019. The construction started in fall 2019 and is expected to last until 2024.
After construction of the 15 m ID launch shaft, the TBM shield was assembled and placed in a steel bell for a safe TBM launch in a reduced jet grout plug. The excavation of the fist tunnel drive began at beginning of March. The first drive was completed on the first week of August when the shield broke into the 9 m ID effluent shaft

The whole production of the concrete segments was completed in June. On the marine works side, the installation of the sheet pipes for the cofferdam and its excavation were achieved on time before the beginning of the fishing season. The large steel riser, and the seismic diffuser pipes are now ready for installation.

In a complex sensitive geology, the project short tunnel drives requires a stringent attention as the project is always in a launching mode. The final retrieval of the TBM at the end of the second drive in the cofferdam will also be a one-of-a-kind operation.

Parties Affiliated with the Project: CDM Smith, led by Ed Kennedy, is the project designer; Hatch, led by Tim Langmaid, is the construction manager; Bessac is the TBM manufacturer. MS is the STP supplier; MSE is the segment precaster.

Personnel: Glenn Holloway is the PM; Guillaume Roux is the operation manager; Rick Brazier is the general superintendent.

Kemano

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

Construction for the 16-km long KT2 for Rio Tinto 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-diameter Herrenknecht single-shield hard rock TBM and includes installation of precast concrete tunnel lining.
Overall tunnel excavation is more than 95% complete. August proved to be an outstanding month for the Kemano T2 Tunnel Upstream Works Project with 559.5 m of new tunnel constructed. This impressively surpassed the month’s target as well as the previous record for monthly production of 483 m set in July. Despite challenges, the team has been able to safely continue strong production and has extended its 300-plus day Lost Time Incident (LTI) free streak. Currently, the planning focus is set on post-breakthrough readiness. Planning and procurement are well underway to ensure the success continues through the post TBM breakthrough phase of the project, which is expected to begin in October.

The 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 brought in and out via barge or boat.

Engineer – Hatch Ltd.; TBM manufacturer and Technicians – 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, Tom McDowell. Lead Engineers: Matthew Whittle, Michael Zenker. Construction Superintendents – Matthew Ulizio, Ross McLean, Craig Arnes, Mike Gilbertson, Govar Hayder, Chad Mac Donnell, Maurizio Matta. Field Engineers – Brett Campbell, Michael Delaney, Guillermo Charles-Barrera, Michael Karl, Josh Richard, Andrew Rafuse, John Doerr, Brent Chalker.

North Vancouver, BC

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

The Second Narrows Water Supply Tunnel is a $286 million project for the Greater Vancouver Water District (Metro Vancouver) 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 fall 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 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 @ 2.438 m, 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 complete at 110 meters deep and is ready to receive the TBM. Initial excavation, shoring and concrete work for the south valve chamber electrical vault is underway with work on the full south valve chamber slated to being in Q4 2021.

Two interventions were performed on the TBM – brief hyperbaric inspection (6.1 bar) 425 m in the drive and a nearly complete tool change in free at 690 m. TBM is approximately 150 m from the south shaft with hole through anticipated in September. Tunneling equipment demobilization will be followed by tunnel pipe installation through Q1 2022.

Personnel – Owner: Metro Vancouver (PM: Mark Qian); Tunnel Designer: McMillen Jacobs (Andrew McGlenn); Construction Manager: Mott MacDonald/Jacobs (CM: Ian Whitehead, DCM: Ken Rosenberg); Contractor: Matt Burdick, Andrew Rule, Erica Bailey, Bill Crider

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

ONTARIO

Ottawa

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

The Stage 2 Confederation Line east and west extensions project is a $2.57 billion (CAD) design-build-finance project for the City of Ottawa being built by East-West Connectors (EWC), 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 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 tunnel construction began in 2020. Before it could begin, traffic was shifted, and underground utilities were relocated. Work was staged to minimize impacts on pedestrians, cyclists, and local traffic.

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 August 2021, excavation of the Parkway tunnel is progressing well. Approximately 218,000 cubic meters or 44% of the total quantity, has been excavated, and 80% of the pile drilling has been completed, as well as 59% of slurry wall installed along the Sir John A. Macdonald Parkway. Seventy-six percent of support of excavation (SOE) piles have been installed at Pinecrest/Connaught.

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 SOE, depending on the ground conditions encountered. Types of SOE include slurry walls, secant pile walls and soldier piling and lagging.
The estimated date of completion is 2025.

Design engineering services are being provided by WSP Canada and Hatch Ltd.

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

Ottawa

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

The $1.6 billion Stage 2 Trillium Line extension is being built by TransitNEXT, a wholly owned subsidiary of SNC-Lavalin, for the City of Ottawa.

The Dows Lake Tunnel is a critical piece of infrastructure along the Trillium Line alignment. 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, TransitNEXT will address several historical challenges through design and construction of the tunnel’s upgrades, including:

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; and,
Upgrades and modernization of the tunnel ventilation system, trackwork, standpipe system, communication systems, and emergency walkway to align with National Fire Protection Association (NFPA)-130 standards.

The length of the tunnel is 578 m with 23 reinforced concrete box segments separated by 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

Prior to construction, detailed inspections of the Dows Lake Tunnel were conducted. A virtual 3D Building Information Model (BIM) of the entire tunnel including the pump house was created to ensure a well-coordinated design and avoid issues during construction.

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 National Fire Protection Association (NFPA) -130 standards. TransitNEXT is currently installing brackets for the power supply to the tunnel ventilation system.

Estimated completion date is 2022.

Toronto

Ashbridges Bay Treatment Plant Outfall
Southland | Astaldi Joint Venture

This $300 million project for the City of Toronto includes a 16-meter diameter shaft, 85 m deep; 3.5 km of 8-m diameter TBM excavated tunnel; 7 m ID Precast Concrete segmental lining; and 50 each 1-m diameter risers from the tunnel. Crews expect most of the alignment to be within Georgian Bay shale.
To date, the project is approximately 50% percent. Shaft excavation is complete for tunnel activities. The 8-m diameter segmental tunnel is over 50% complete, while Offshore Riser installation is nearing completion.

Consultant & Designer: Hatch with Jacob & Baird; Subcontractor: Johnson Bros. Corp. (Offshore work including Riser installation).

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

Toronto

Coxwell Bypass Tunnel Project
North Tunnel Constructors ULC (Jay Dee Canada, Michels Canada, C&M McNally Tunnel Constructors Joint Venture)

The scope of the Coxwell Bypass Tunnel for the City of Toronto includes construction of approximately 10.5 km of 6.3 m finished diameter rock tunnel, five (4@20, 1@22 m diameter) storage shafts that are 50-56 m deep and 11 tunnel connection drop shafts, along with associated deaeration and adit tunnels. NTP for this $378.3 million project was issued on Aug. 7, 2018, with an estimated completion date of April 29, 2024.
The CBT is anticipated to be excavated entirely through shale bedrock of the Georgian Bay formation, at approximately 50 m deep. Most of the tunnel alignment runs parallel to a buried bedrock valley. The CBT crosses this valley in two locations with the bedrock cover less than 6 m. The contract required a TBM capable of operation in both open and closed mode due to concerns in a 1.1 km length of tunnel with reduced rock cover above the crown of the tunnel with potential to encounter mixed face conditions with saturated, unconsolidated soils in the crown of the tunnel in this stretch. A dual mode TBM (Open and EPB capable of operating with active pressure of 6 bar) was designed and manufactured by Lovsuns for the excavation of CBT tunnel.

The project is approximately 55% complete, with 65% of the tunnel excavated. Five out of 5 large shafts have been excavated. Ten out of 11 drop shafts/air shafts have been excavated and lined. One out of 11 Adits has been excavated.

Unique aspects of the project include tunneling with a dual mode TBM through a buried valley, utilization of precast segments with two component grouting in swelling shale of the Georgian Bay formation, re-use of rock excavated in the tunnel as lakefill for future owner WWTP expansion project, significant volume of contaminated and deleterious material in shaft and site work, shaft drilling and site work in crowded, congested and high-profile neighborhoods.

Parties Affiliated with the Project: Engineering Design and Construction Management: Black & Veatch Canada in association with R.V. Anderson Associates Limited. Major Subcontractors: GFL Infrastructure Group Inc., York Environmental Solutions LTD., D’Orazio Infrastructure Group. TBM Manufacturer: Lovsuns.

Personnel: City of Toronto: Manager: Jackie Kennedy/ Project Lead: Robert Mayberry; Designer/Construction Management: Lead Tunnel Engineer: David Day; Construction Manager: Daniel Cressman; Resident Engineer: Vireak Hinh. Contractor/North Tunnel Constructors ULC: Project Sponsor: Abdul-Ghani “AG” Mekkaoui/ Project Manager: Ehsan Alavi.