Tunnel Updates – February 2020

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 February 2020 issue of the print edition.


Los Angeles

Joint Water Pollution Control Plant Effluent Outfall Tunnel
Dragados USA
This is a $630.5 million outfall tunnel for the Los Angeles County Sanitation Districts being built in the cities of Carson, Los Angeles and Rancho Palos Verdes. NTP was issued April 8, 2019, with 1,900 working days to complete the work and an estimated completion date of October 2026.

The Joint Water Pollution Control Plant Effluent Outfall Tunnel project will serve the sanitation needs of approximately 5 million people in 73 cities and unincorporated areas of Los Angeles County.

The tunnel will be approximately 7 miles long and 18 ft ID to convey disinfected, secondary-treated effluent from the Sanitation Districts’ Joint Water Pollution Control Plant (JWPCP) located in 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 either a slurry or EPB single pass 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-foot 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 began in the summer of 2019. Construction of the slurry wall for the JWPCP Shaft Site is ongoing with excavation of the shaft expected to begin the first half of 2020. The contractor has proposed using a Herrenknecht slurry TBM, which is anticipated to arrive onsite in late 2020. Tunnel construction is anticipated to begin in the first half of 2021.

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

Key Project Personnel: Los Angeles County Sanitation Districts – Construction Management Section: Ignacio Murillo, Section Head; Russell Vakharia, Resident Engineer; 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 Manager; 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
Regional Connector Constructors
Regional Connector Constructors (RCC), a joint venture between Skanska and Traylor, continues to make progress on the 1.9-mile underground light rail tunnels and stations. Crews have begun installation of approximately 2,000 ft of floating slab track (1,000 ft in each tunnel) underneath the rails in the sections under the Walt Disney Concert Flak and Colburn School of Music to prevent vibrations from being transferred outside the tunnel.

In the SEM cavern, crews finished pouring concrete for the external walls. A section of intermediate wall and plenum slab have been poured and the arch forms have been installed on the slab. Close planning on the interfaces with the tunnel and the station are under way. The bulk of the work is still centered on completing the build-out of the three stations. Due to their large size and weight, the electrical transformers have been delivered and staged in every station prior to building the room around them.

Flower Street is in full concrete production mode, taking advantage of the linear aspect of the works (1,350-ft long cut and cover). Two roof pours have already taken place on the east end and the invert is almost complete. The team at Hope Station has placed concrete for the third mezzanine and is working on the fourth. Tunnel eye seals have been installed on both ends of the station. At Broadway Station, crews finished the invert pour leading to the cavern and are working on the mezzanine and concourse walls. At 1st and Central, the concrete in the wye has been completed in preparation for the closure of Alameda and the joint venture will start backfilling and removing pin piles early next year. Each station is gearing up to provide access for track installation, which is scheduled to begin in February.

Other parties affiliated with the project – Tunnel Designer for the Contractor: Mott McDonald; TBM Manufacturer: Herrenkecht. 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: Gary Baker, Project Manager; Michael Harrington, Engineering Manager; Mat Antonelli, Construction Manager; Metro Design Consultants: (AECOM/WSP), Bill Hansmire, Tunnel Design Manger; Metro Construction Manger Consultants: (Arcadis), Jaydeep Pendse, Resident Engineer; Contractor Project Executives (Regional Connector Contractors RCC): (Skanska) Mike Aparicio, Mike Smithson, Greg Zwiep, Justin Waguespack; (Traylor) John McDonald, Richard McLane, Christophe Bragard.

Los Angeles

Westside Purple Line Extension Section 1
Skanska/Traylor/Shea JV
The Westside Purple Line Extension Project is a 9-mile long project that consists of three Sections. Section 1 is a 3.92-mile long subway alignment with three stations being constructed under Wilshire Boulevard in gassy ground and tar sands with prehistoric fossil deposits.

NTP for the $1.636 million design-build contract was issued on Jan. 12, 2015, with service expected in 2023. The twin Herrenknecht EPB TBMs have completed the first stretch of tunneling from Wilshire/La Brea to Wilshire/Western Station. The second breakthrough occurred June 27. The TBMs were dis-assembled, trucked back to Wilshire/La Brea to begin digging the next section to Wilshire/La Cienega. Elsie and Soyeon, the Section 1 TBMs, are currently tunneling to the west under Wilshire Boulevard and should be arriving at Wilshire/Fairfax Station in February.

The scope of work includes 17,900 ft of twin-bore tunnel: Reach 1 is 9,600 lf between Wilshire/La Brea Station and Wilshire/Western TBM retrieval shaft; Reach 2 is 4,400 lf between Wilshire/La Brea and Wilshire/Fairfax Stations; and Reach 3 is 3,300 lf between Wilshire/Fairfax and Wilshire/La Cienega Stations. There is also 600 lf of tail track at Wilshire/La Cienega Station.

The tunnel is 18-ft, 10-in. in diameter with 12-in. thick precast concrete lining. Depth varies from 40 ft and 100 ft. The alignment includes three stations and the western retrieval shaft and 23 cross passages. Cross-passages are planned to be mined by the sequential excavation method using variety of localized ground support systems.

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

Los Angeles

Westside Purple Line Extension Section 2
Tutor Perini-O&G JV
Section 2 includes 2.59 miles of new alignment and stations at Wilshire/Rodeo and Century City/Constellation. The JV was awarded a $1.37 million contract in 2017.

As of mid-June, the Herrenknecht TBMs were on site at the Century City construction yard, where they will be assembled and begin mining east to Wilshire/La Cienege. Mining is expected to take two years. Construction at the Wilshire/Rodeo station in Beverly Hills ramped up with piling to create the supports for the underground station box. The TBMs are being assembled underground in a TBM launch box in Century City on Constellation Boulevard.

STV is the engineer of record and principal designer for the JV.

Los Angeles

Westside Purple Line Extension Section 3-Tunnels
Tutor Perini/Frontier-Kemper
The $410 million project involves the design and construction of twin bored tunnels spanning 2.6 miles between Century City and the VA Hospital in Westwood. Substantial completion is anticipated in summer 2022, with revenue service in 2027.

In Westwood, work to map and relocate underground utilities took place in 2019. Metro and the FTA are finalizing a grant and groundbreaking for major construction should be soon.

Los Angeles

Westside Purple Line Extension Section 3-Stations
Tutor Perini/O&G
Tutor Perini/O&G JV has received notice of intent to award a contract from the Los Angeles County Metropolitan Transportation Authority The contract value is anticipated to be approximately $1.4 billion. The work entails the design and construction of two new subway stations at Westwood/UCLA and Westwood/Veteran Administration Hospital. Tutor Perini is currently performing initial design work on the companion Purple Line Extension Section 3 Tunnels project, awarded last year, which will build the tunnels and related systems that connect with the new stations.



MGUH Surgical Pavilion
Clark Construction Group LLC
This project for MedStar Health Inc. started on June 24, 2019, and was scheduled for completion on Jan. 22, 2020. It consists of 275 lf of 75.4-in. Permalok spiral welded steel casing and 40-vf, 16-ft diameter liner plate obstruction removal shaft. Crews placed 16- and 24-in. DIP within the Ground conditions were weathered rock, sandy clay and clayey sand were the anticipated ground conditions. Crews removed steel cased foundation piles in the tunnel profile prior to the commencement of tunneling activities. Tunneling was completed by Bradshaw Construction Corp. under a subcontract using a Herrenknecht AVN1500. Project Manager: Matthew Webb.


Northeast Boundary Tunnel Project
Salini Impregilo Healy
This $579.9 million job for DC Water involves a combined sewer overflow (CSO) tunnel 26,737 ft long x 23 ft finish diameter (Excavated diameter: 26 ft 3 in.). Crews are using an EPB TBM in heavy clay and water bearing clayey sands at water pressures up to 3 bar. The project includes seven slurry wall shafts up to 130 ft deep in a dense urban environment. Ground freezing is being used at two shafts to connect the shaft to the tunnel. Jet grouting is being used at other shafts to connect shafts to the tunnel. The tunnel connects underground to an existing 21-ft. diameter live sewer. Extensive instrumentation to track performance of TBM with regards to settlement is being employed.

The project is approximately 40% complete. As of mid-December 2019, the TBM has advanced 12,400 ft out of 26,737. The TBM will break into the only shaft along the tunnel alignment at 15,750 ft about March 2020 and then will proceed another 10,900 ft to the extraction shaft. Work is proceeding at numerous shaft sites for all the ground support of shafts and interceptor structures. Slurry walls at W Street, Mount Olivet Road, Rhode Island Avenue, and 4th Street are complete. One slurry wall shaft left to go at R Street. Secant pile shaft with piles 4-ft. diameter x 93-ft long completed at Florida Avenue. Extensive jet grouting done to install plugs done at two shafts with a third underway and one more to go. Jet grouting is also done to improve ground at adit locations for Mount Olivet. Ground freeze pipe installation for adit at bottom of 4th Street shaft is underway. Extensive cement bentonite walls placed for near surface structures at W Street and 4th Street. Shaft lining to start soon at W Street.

The tunnel is a challenging alignment with 15 curves, shaft entry and exit, and only one shaft online in 26,737 ft to check alignment. TBM muck removal by conveyor belt in the tunnel and by a 17 cy clamshell at the shaft. Tunnel and all associated structures have a 100-year design life. The work environment for the shaft construction along Rhode Island Avenue is challenging with small shaft sites combined with urban residential neighborhoods and a high traffic corridor. DC Water and SIH are making extensive community outreach efforts. The tunnel and all shaft support are designed by SIH while the remaining permanent structures are designed by DC Water. NTP was issued Sept. 15, 2018. Completion is expected by Jan. 27, 2023.

Designer: Brierley Associates; TBM: Herrenknecht; Slurry Walls, Jet Grout, Secant Piles, Solider Piles: Treviicos; Dewatering: Moretrench; Segmental Tunnel Liner: ConSeg JV; Muck Hauling: Bulldog Construction; Instrumentation: Entech; Traffic Engineering and Instrumentation Installation: EBA; Construction Manager: EPC Consultants; DC Clean Rivers Program Manager: McMillen Jacobs/Greeley & Hansen.

Key Project Personnel: Project Director: Shane Yanagisawa; Project Manager: Daniele Nebbia; Construction Manager: Flaviano Solesin; Safety Manager: Tim Jones; QC/QA Manager: Rick Munzer; Engineering Manager: Pietro Banov; Business Manager: Stefano Cadoni; Plant & Equipment Manager: Mauro Pizzaia; Design Manager: Pietro Banov; Brierley Associates Design Manager: Jeremiah Jezerski;
Resident Engineer: Scott Shylanski.



Niles Avenue Sewer Improvements
Bradshaw Construction Corporation
Bradshaw Construction Corporation recently broke ground on a project, contracted under Garney Construction, in the suburbs of Northwest Atlanta for the Department of Watershed Management. The purpose of the work is to realign an existing 15-in. sewer that has been constantly overflowing due to excessive concrete/rock debris build up within the line. BCC is expected to install 1,760 lf of 18-in. ductile iron sewer pipe by trenchless means in difficult geotechnical conditions that warrant both the use of a Robbins Rockhead Double Shielded TBM and a Herrenknecht MTBM.

The project consists of four shafts, connected by three tunnel drives spanning 1,760 lf. The longest of the tunnels, 713 lf, will be installed using Robbins 72-in. Rockhead Double Shielded TBM. The other two drives will span distances of 346 and 701 lf, where two-pass microtunneling will be used to install the 18-in. DIP inside 48-in. RCP jacking pipe. Project duration is 8 months.

Project Manager: Mike Wanhatalo.



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 the DigIndy project, 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. The TBM was pulled through the shaft, and immediately began mining the Fall Creek Tunnel. As of December 2019, approximately 12,000 feet of concrete liner has been placed in the White River Tunnel, and lining activities in Lower Pogues Run Tunnel are anticipated to begin in February 2020. 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 17,850-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 the DigIndy CSO reduction program.

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. As of December 2019, the TBM has mined approximately 11,000 ft, and hole through is anticipated in February. Per the 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.



I-64 & Grinstead CSO Trenchless Installation
Bradshaw Construction Corporation
Bradshaw Construction Corporation recently completed constructing a CSO interceptor tunnel. The 1,252-lf rib-and-board tunnel was installed behind a 102.5-in. LOVAT ME-99RL Series 11700 TBM. Mining progressed through an S-curve on twin 2,300-ft radius curves through 900 ft of sticky clay and 350 ft of weathered limestone, and 81-in. FRP was installed and backfilled. Bradshaw also constructed two 24-ft ID shafts, one with liner plate and one with rib-and-board. The project members included the Louisville and Jefferson County Metropolitan Sewer District (Owner), Qk4 (Engineer) and Bradshaw Construction performing as the General Contractor. Project Manager: Jordan Bradshaw.


Ohio River Tunnel (ORT)
Shea-Traylor JV (S-T JV)
The $106.6 million Ohio River Tunnel for the Louisville and Jefferson County Metropolitan Sewer District (MSD) was issued NTP Nov. 8, 2017, and is scheduled to reach Substantial Completion by Dec. 31, 2020 (Final Completion: March 31, 2021). The tunnel length is 21,300 ft; Diameter: 22 ft excavated, 20 ft finished; Depth – 200 ft; Shafts – 6. Ground conditions include limestone and dolomite rock, potential fault zones, and potential natural gas zones in the rock.

Tunneling is being done by a main beam TBM. Large diameter shafts are built using secant piles through overburden, and drill-and-blast through rock. The small diameter shafts are built using steel can through overburden, raise-bore through rock.

Excavation of the three large diameter shafts is complete: Working Shaft, Pump Station Shaft, and TBM Retrieval Shaft. Adit excavation for Drop Shaft DS01 is complete. TBM excavation is 40% complete. Due to stakeholder requirements, the design consisted of a 1,100 ft tunnel bifurcation section, which branched off the main tunnel alignment. After TBM excavation of the bifurcation, the entire TBM had to be backed up through the 1,100 ft section, then reset to resume excavation.

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.


Montgomery County/Prince George’s County

Purple Line Light Rail Project
Purple Line Transit Partners (PLTP)
The Purple Line is a 16.2-mile light rail transit line extending from Bethesda in Montgomery County to New Carrollton in Prince George’s County. It is being delivered via a $5.6 billion P3 contract that includes a $2.1 billion design-build construction contract. The line connects major activity centers located inside the heavily congested Capital Beltway, and will provide direct connections to four branches of the WMATA Metrorail system (both branches of the Red Line at Bethesda and Silver Spring, the Green Line at College Park, and the Orange Line at New Carrollton), as well as all three MARC commuter rail lines (linking Washington, Baltimore, and Frederick, Maryland) and Amtrak’s Northeast Corridor. NTP was received on June 17, 2016. The revenue Service Availability (RSA) date is March 11, 2022.

The scope of work includes a twin-track light rail system operating mainly at grade in dedicated or exclusive lanes and 21 stations. The route includes 0.7 miles of elevated guideway and 1,020 lf of tunnel excavated by SEM. There is also a shaft and cavern to be constructed in bedrock in Bethesda that will serve as interface between the future Purple Line and the existing underground WMATA station. SEM Tunnel excavation was completed in March and installation of waterproofing and the secondary liner in November 2019. Work on the cut-and-cover tunnel concrete structure is currently ongoing. Sinking of the shaft in Bethesda by drill-and-blast is in progress as well. Current depth is approximately 90 feet measured from grade. Crews are currently placing the cast-in-place liner required to be installed before cavern excavation can commence.

The ground conditions at tunnel horizon encompass mixed face conditions varying from slightly weathered metamorphic rock to completely decomposed rock known as saprolite. Most of the tunnel runs below the groundwater table.

Design-Build Contractor: Purple Line Transit Constructors (PLTC), an LLC comprised of Fluor, Lane, and Traylor Bros. Tunnel Designer: Mott MacDonald.

Project Personnel – MTA Project Director: Jeff Ensor; Concessionaire’s Project Manager: Peter Van der Waart; PLTC: Project Manager Scott Risley; Construction Manager: Ken Prince; Underground Construction Manager: Jean-Marc Wehrli.



10th Avenue WM River Crossing
Bradshaw Construction Corp.
Bradshaw is constructing an 896-ft microtunnel under the Mississippi River, jacking 60-in. steel casing that will house a 48-in. water main. Subsurface conditions are baselined to be weak sandstone. Project Manager: Mike Wanhatalo.


St. Louis

Deer Creek Sanitary Tunne
SAK Construction LLC
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 $147.7 million job for the Metropolitan St. Louis Sewer District comprises 22,800 lf of tunnel, 19 ft diameter, with an average depth of 120 ft. There are 5 drop shafts. The alignment traverses the cities of Shrewsbury, Maplewood, Brentwood, Richmond Heights, Webster Groves and Ladue within St. Louis County.

The project is 63% complete. Excavation of the 40-ft diameter pump station dry well shaft and two 40-ft diameter wet well shafts have been completed. The starter and tail tunnel have been excavated, and the TBM has excavated approximately 18,500 ft of the tunnel. Work has been performed at each of the five drop structure sites. Excavation has been completed on the 35-ft diameter retrieval shaft.

The contractor is utilizing 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, 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 Corp. (Construction Manager); SAK Construction LLC (Contractor); Goodwin Brothers Construction Co. (Subcontractor – Near Surface and Surface Construction); Robbins (TBM Manufacturer).

Key Project Personnel: SAK – Construction Project Manager – Brent Duncan; SAK – Construction Superintendent – Frank Lynch; Parsons – 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 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. 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 has been mined.

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.

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; K.C. Hildenbrand, Project Manager, SAK; Thomas Abkemeier, Vice President, Shannon & Wilson, Inc.; Patrick Kinsella, Resident Project Representative, Shannon & Wilson, Inc.

St. Louis

Maline Creek CSO Storage Facility
SAK/Goodwin JV
This $82.8 million project consists of the construction of a 28-ft finished diameter concrete-lined cavern, approximately 2,700 ft long, and a 40-ft diameter, 12.5 mgd submersible pump station. The purpose of the cavern is to store wet weather flows from combined sewers that otherwise would have overflowed to Maline Creek. The stored flow will be pumped from the cavern back to the sewer system and treatment plant when capacity becomes available after the storm. Besides the pump station shaft, which served as the access shaft during cavern mining, there are eight bored shafts associated with drop and vent pipes. The cavern was constructed by drill-blast and is located approximately 140 ft below grade in limestone bedrock.

As of December 2019, project construction is approximately 90 percent complete. The lining of the cavern and the pump station shaft are complete. Construction of one of the three intakes is complete with the other two intakes nearing completion. Construction of the pump station building foundation is 90% complete. Below grade piping and conduits for the pump station are in place. Substantial completion of the pump station is expected in August 2020 and final completion of the project in October 2020.

The project is located close to the floodwall, which provides flood protection to the City of St. Louis. A 6-ft adit from the main cavern crosses beneath the floodwall. Construction of the cavern and adit near and under the floodwall required close coordination with the U.S. Army Corps of Engineers and special monitoring of the floodwall.

Owner: Metropolitan St. Louis Sewer District. Tunnel Designer: Jacobs Engineering Group. Construction Manager: Black & Veatch Corporation. Major Construction Subcontractors: Williams Tunneling (tunnel and shaft construction), XL Contracting (near surface sewers).

Personnel: Patricia Pride, Project Manager, Metropolitan St. Louis Sewer District; Ray Scherrer, CM Program Manager, Metropolitan St. Louis Sewer District; David Ahlemeyer, Design Project Manager, Jacobs Engineering Group; Andrew Bursey, Lead Tunnel Designer, Jacobs Engineering Group; Colin Sessions, Designer – Lining and Intake Design, Jacobs Engineering Group; Jon Reader, Project Manager, SAK/Goodwin JV; Doug Wachsnicht, Project Executive, SAK/Goodwin JV; Kevin Nelson, Construction Manager, Black & Veatch Corporation; John Deeken, Resident Project Representative, Black & Veatch Corporation.


Las Vegas

Lake Mead Low Lake Level Pumping Station (L3PS) Project
Barnard of Nevada Inc.
In May 2015, Barnard entered into a Construction Manager at Risk (CMAR) contract for the $440 million L3PS Project for the Southern Nevada Water Authority. As of December 2018 all of the underground excavation and construction has been completed. Additionally, the steel bulkhead dome has been removed which now connects the Pumping Station to the previously construction Intake No. 3 Tunnel filling the underground forebay with water from Lake Mead. Concurrent with the underground construction, the Above-ground Pumping Station work continues with the Discharge piping installation, Valve Vaults, Electrical/Maintenance Building construction, installation of 32 of 34 each submersible pumps, and start-up and commissioning activities. All work is scheduled to be completed in 2020.

Underground work includes: 525-ft deep x 26-ft diameter Access Shaft; bulkhead to allow for future expansion; 80-ft deep x 26-ft diameter Riser Shaft to connect to existing Intake No. 3 connector tunnel; 33-ft wide x 36-ft high x 400-ft long horseshoe-shaped Forebay Cavern; Forebay Connector Tunnel; and 34 drilled 8-ft diameter x 500-ft deep pump well shafts with steel-lined 6-ft diameter casings. The Above-ground Pumping Station and appurtenances include: 34-each 30 MGD submersible pumps; valves and discharge header piping; surge tank, concrete valve vaults, electrical controls and starting equipment for the pumps; electrical control building; electrical feed from an onsite substation; and 144-in. discharge aqueducts.

Design Engineer: MW/Hill A Joint Venture; Construction Manager: Parsons Corp.

Key Project Personnel: SNWA: Peter Jauch, Director of Engineering; Erika Moonin, Project Manager; Parsons: Kevin Ulrey, Construction Manager; MW/HILL: Ted Davis and Steve Hunt, Lead Engineers; Barnard: Operations Manager, Dan Schall; Project Manager, Jordan Hoover; Project Superintendent, Andy Granger; Superintendents, Engineers, and Safety: Marc MeieSalgado, Dave Miller, Joerg Moser, Scott Evans, Kyle Simmons, Craig Arnes, Troy Gates, and Matthew Johnson.



Doan Valley Relief and Consolidation Sewer
Triad Engineering and Contracting Co.
This $13 million project for the Northeast Ohio Regional Sewer District includes the construction of 3,137 lf of 72-in. diameter sewer via trenchless methods. The tunnel will be 2,007 lf by conventional two-pass methods, 1,130 lf by microtunneling; 1,475 lf of 48-in. sewer by open-cut methods, three flow control structures, eight manholes, one cast-in-place manhole and modification of one regulator structure. Ground conditions vary from shale bedrock to clay till, sandy clay and some sand seams with water.

The microtunnel is complete by Super Excavators. The two-stage tunnel is complete by Triad. Shaft 2 and S-1 structures are complete. Shaft 1 and connector structure DV 25 are underway. The upstream open-cut connector piping is nearly complete.

NTP was issued July 9, 2018 with completion expected within 900 days.

Personnel: NEORSD manager: A.J. Smith; NEORSD resident engineer: Matt Waite; Tunnel Designer: AECOM: Dave Mast, P.E.; Contractor Project Manager: Philip Kassouf; Project Superintendent: Rick Chipka Jr.; Tunnel Superintendent/Engineer: Brad Kassouf; Assistant Project Engineer: Art Hanus.


Doan Valley Tunnel
McNally/Kiewit DVT JV
NTP for this $142.3 million project for the Northeast Ohio Regional Sewer District was issued July 10, 2017, with substantial completion set for November 2021. The job 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 diameter Robbins Main Beam TBM. The tunnel will be two-pass with rib and lagging as initial support and precast concrete pipe as final liner. Tunnel depth: between 30 and 100 ft below grade.

The main tunnel (DVT) is 18-ft finished diameter for 10,000 lf mined with a 20.75-ft diameter Herrenknecht Single Shield Hard Rock TBM. It is one pass using a universal ring, 5+1 segments (fiber reinforced). Tunnel invert depth: between 50 and 100 ft below grade. The tunnel intercepts pre-existing brick sewers up to 3 ft above the tunnel crown. There are seven shafts between 23 and 55 ft diameter; 30 to 100 ft 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 tunnel drive completed on Dec. 12, 2018. Pipe installation and cellular grout backfill completed on July 30, 2019. The DVT tunnel drive completed on Sept. 7, 2019. MLKCT tunnel drive started on Oct. 22, 2019, and is 60% completed. The overall project is 60% complete.

Special/unique Features of the Job: Urban context with pre-existing utilities to be consolidated and/or diverted before establishing shaft/tunnel jobsites; Tunnel drives intercepting pre-existing utility lines, culverts and brick sewers only a few feet above the tunnel crown; TBM tendency to dive into the soft and weak rock mass, with constant mitigation measures against cutterhead clogging; Logistics challenges at the main site with concurrent operations in the process of building three tunnels from two adjacent shafts (e.g. DVT TBM receiving and assembly at the same time as WCT TBM mining; WCT pipe installation at the same time as DVT TBM mining).

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 Pipes (8.5-ft ID precast pipes).

Key Project Personnel: Joe Teter – General Superintended McNally/Kiewit DVT JV; Mark Kaletta – Equipment Superintendent McNally/Kiewit DVT JV; Martino Scialpi – Tunnel Manager McNally/Kiewit DVT JV; Lance Jackson – Project Engineer McNally/Kiewit DVT JV; Brian Negrea – Tunnel Engineer McNally/Kiewit DVT JV; Collin Schroeder – Shaft/Structures Engineer McNally / Kiewit DVT JV; Chris Lynagh – Project Manager McNally/Kiewit DVT JV.


East 140th Consolidation and Relief Sewer
Triad Engineering and Contracting Co./C&M McNally Tunnel Constructors JV
NTP for this $69.4 million project for the Northeast Ohio Regional Sewer District was issued August 2016. The project includes 14,000 lf of 60- to 84-in. tunnel, 8 access shafts, 6800 lf of 12- to 54-in. diameter consolidation and relief sewers, three detention basins, 12,000 ft of 12- to 54-in. storm sewers, regulator improvements, and junction chambers.

All tunnels are completed and lined. Junction chambers and connecting structures are complete. The remaining live sewer connections, several regulators and final surface restoration that were delayed by the Dugway Storage Tunnel will begin in the first quarter 2020.

NEORSD manager: A.J. Smith; NEORSD resident engineer: Tony Vitale; Tunnel Designer: DLZ: Tom Hessler; Key Project Personnel: JV Manager: Cliff Kassouf; Assistant JV Manager: John Teahen; Project Manager: Phil Kassouf; Equipment Manager: Rick Chipka; Tunnel Superintendent: James Lowery; Project Engineers: Matt Bennett, Brad Kassouf.


London Road Relief Sewer
Triad Engineering and Contracting Co./C&M McNally Tunnel Constructors JV
NTP for this $39.6 million job for the Northeast Ohio Regional Sewer District was issue July 31,2018, with substantial completion expected within 730 days (Final Completion: 850 days). It involves 10,700 lf of bored tunnel between 7 and 9.5 ft diameter, 6 shafts, 8 diversion structures, junctions and manholes, modifications to six regulators, and 870 lf of sewers by open-cut methods.

Reach 2 tunnel is complete. Reach 1 tunnel excavation is nearly complete. Reach 3 tunnel will begin 1st Q 2020. Reach 4 sewer installation is complete. Reach 5 structure work is complete. Reach 6 structure work and open-cut sewer installation is underway. Shaft 3 and 6 concrete structures are underway.

NEORSD manager: Robert Auber; NEORSD resident engineer: Matthew Waite; Tunnel Designer: Ben DiFiore, Mott MacDonald. TBMs: Two refurbished Lovsuns. M 112 and RM 83. Personnel: Project Manager: Philip Kassouf, P.E.; Tunnel Superintendent: James Lowery; Project Engineer: Matthew Bennett, Brad Kassouf.


Westerly Storage Tunnel
Jay Dee Obayashi JV
The Westerly Storage Tunnel is a $135 million project for the Northeast Ohio Regional Sewer District. It is approximately 46% complete. Recent activities include:

  • Shaft final concrete structure at site WST-1: approximately 2,500 cy of cast-in-place concrete placed (approximately 120 vf of shaft lining). Overall shaft final concrete currently 40% done.
  • Shaft excavation at site WST-2: approximately 1,900 cy of soil excavated to a final soil depth of 165 ft; approximately 1,900 cy of rock excavated to a final rock depth of 267 ft; Overall shaft excavation 100% done.
  • Near surface structure SOE, excavation, and final structures at site WST-2: Support of excavation 100% installed; Excavation 100% done. Final structure installation currently 60% done.
  • Tunnel excavation with tunnel boring machine at WST-3: TBM arrived on site and was assembled. On-site commissioning in process.

Tunnel Designer: Stantec Mott MacDonald Westerly JV; Construction Manager: Owner managed (NEORSD); Major Subcontractors: DiGioia-Suburban Excavating (open cut and miscellaneous 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/Project Manager (Jay Dee Obayashi JV): Tim Backers; Deputy 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.


Oklahoma City

OKC Sanitary Sewer Relief Interceptor SC-0950
Bradshaw Construction Corporation
Bradshaw Construction Corporation will soon begin construction on three tunnels as part of a sanitary sewer installation in Oklahoma City. The three drives totaling 902 lf of 90-in. welded steel casing tunnel will be installed behind a RASA DH-1900 MTBM. Mining conditions will vary between sands, silts and clays of various stiffness and density, all under the water table. Drives will range from 540 to 167 lf, traversing under I-35 and railroad crossings. Soldier pile and steel plate launch and recovery shafts and 72-in. FRP will be installed by the general contractor. Construction was scheduled to begin in late January. The project members include the Oklahoma City Water Utilities Trust (Owner), Cabbiness Engineering (Engineer), McKee Utility Contractors Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Manager: Jordan Bradshaw.



Hilltop Energy Center LLC Water Intake Tunnel
Bradshaw Construction Corporation
Bradshaw Construction Corporation will soon begin construction on a raw water intake tunnel in Nemacolin. The 330-ft by 60-in. welded steel casing tunnel will be installed behind a Herrenknecht AVN-1200 MTBM. Mining will begin in 25 ksi limestone and progress into dense river alluvium before the drive is terminated once the MTBM daylights. After MTBM recovery, Bradshaw will install a 24-in. HDPE carrier pipe, three 2-in. stainless steel air discharge lines, and backfill grout the tunnel. Construction was scheduled to begin in late January. The project members include Kiewit Power (Owner), Hilltop Energy Center LLC (Engineer), Garney Companies Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Manager: Jordan Bradshaw.



Reedy River Basin Sewer Tunnel
Super Excavators Inc./Cooperatia Muratori Cementisti, a Joint Venture
This $39,4 million project for Renewable Water Resources (RE-WA) comprises 6,000 lf of 130-in. ID rock tunnel with 84-in. carrier pipe (Hobas CCFRPM Pipe) grouted in place. Tunnel depth ranges from 40 to 130 ft below ground surface. 40-ft ID by 40p-ft deep launch shaft and 30-ft ID by 130-ft deep receiving shaft. Tunnel is to be mined in intact Gneiss bedrock using a double shielded rock gripper TBM. Shaft construction is to consist of liner plate and rock dowels with wire mesh. The project also includes 1,600 lf of 60-in. and 42-in. upstream and downstream connecting sewer as well as several junction chambers, screening/diversions structures and with odor control facilities.

The project is on schedule. Work on the Junction Chamber, Diversion Structure and Drop Structure is complete. Crews have finished the starter tunnel. The TBM was being placed in the launch shaft on Dec. 4 with mining to begin in January 2020.

Tunnel Designer/Construction Manager – Black & Veatch; TBM Manufacturer – Komatsu/Terratech/Robbins ; Subcontractors and Suppliers – Pacific International Grout (Cellular Grout), Tunnel Carrier Pipe (Hobas Pipe).

Personnel: Justin Kolster – Senior Project Manager, Super Excavators / CMCRA Joint Venture; Stephen O’Connell – Construction Manager, Black & Veatch; Jason Gillespie – Senior Project Manager, Renewable Water Resources.



Mill Creek/Peaks Branch/State Thomas Drainage Relief Tunnel Project
Southland/Mole Joint Venture
This is a $206 million project for the City of Dallas with a scheduled completion date of March 4, 2023. The project includes 26,385 lf of 32.5-ft excavated diameter (30-ft ID) tunnel and seven shafts (ranging in depth from 120 to 200 vf). The alignment mostly comprises Austin chalk and will be excavated by a Main Beam TBM and roadheader.

The project is 35% completed by duration. Crews completed excavation of 2 intake shafts and currently excavating 2 intake shafts ranging from 22 to 25 ft diameter and 110 to 190 ft deep. There is a total of 6 intake shafts on project. Testing and commissioning of TBM on surface is complete.

Owner: City of Dallas; Lead Designer: HALFF; Tunnel Designer: COWI; CM: Black and Veatch; TBM Manufacturer: Robbins; Subcontractor: Oscar Renda Constructing Inc.

Key Project 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.



Hampton Roads Bridge Tunnel
Hampton Roads Connector Partners
The Hampton Roads Bridge Tunnel is a $3.3 billion project for the Virginia Department of Transportation. It will ease this congestion along I-64 across Hampton Roads with the addition of twin two-lane bored tunnels just west of the existing eastbound tunnel.

Hampton Roads Connector Partners is a joint venture consisting of multiple partners, with Dragados USA serving as lead contractor and HDR and Mott MacDonald as lead designers. The team also includes Flatiron Constructors, Vinci Construction, and Dodin Campenon Bernard.

The project is expected to be completed by November 2025. The majority of construction will take place between 2020 and 2025. In October, crews began collecting offshore soil borings along the alignment.

Hampton Roads

Parallel Thimble Shoal Tunnel
The $755.9 million Parallel Thimble Shoal Tunnel project entails the construction of a 5,700-ft bored tunnel connecting two southbound trestles of the existing Chesapeake Bay Bridge and Tunnel, a 17.6-mile structure connecting the Norfolk/Virginia Beach areas to Virginia’s eastern shore. The design-build contractor was selected July 2016. Estimated project completion is 2023.

The owner and contractor continue to work together to complete the project design. All critical path design work is complete. The final design packages pertaining to the new ventilation buildings, the fishing pier, the replacement of three trestles at One and Two Islands, internal tunnel work and the island surfaces remain open.

As of October, CTJV completed more than 55 of the slurry wall panels on One Island. CTJV is also performing jet grout work on the island. At Concrete Systems Inc. (CSI) in Chesapeake, Virginia, production was in full swing. Precast tunnel liner segments are being produced and stored on site while they wait for Chessie, the 42-ft TBM manufactured by Herrenknecht, to begin digging.

Virginia Beach

PRS Reliability Upgrades – Providence Rd.
Bradshaw Construction Corporation
Bradshaw Construction Corporation recently completed a 182-ft tunnel in Virginia Beach for a 42-in. FRP sewer installation. The 60-in. Permalok steel casing tunnel was installed behind a Herrenknect AVN-1200. Ground conditions encountered were poorly graded sand beneath the water table. The 42-in. FRP was installed on casing spacers provided by APS and backfill grouted with cellular grout provided by CJGeo. The project members included the Hampton Roads Sanitation District (Owner), RK&K (Engineer) and Ulliman Schutte Construction (Construction Manager), with Bradshaw Construction performing as tunneling subcontractor. Project Manager: Jordan Bradshaw.

Virginia Beach

Virginia Beach Blvd. Force Main Phase VI
Bradshaw Construction Corporation
Bradshaw Construction Corporation will soon begin construction on a series of force main tunnels in Virginia Beach. Five drives totaling 1,730 lf of 60-in. Permalok steel casing tunnel will be installed behind a Herrenknecht AVN-1200 MTBM. Mining conditions will vary between sands, silts and clays, all under the water table. Drives will range from 730 to 158 lf, up to 40 ft deep. Steel sheeted launch and recovery shafts and 48-in. HDPE will be installed by others. Construction is scheduled to begin in early March, 2020. The project members include Hampton Roads Sanitation District (HRSD) (Owner), Kimley Horn LLP (Engineer), Bridgeman Civil Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Manager: Jordan Bradshaw.



North Vancouver

Second Narrows Water Supply Tunnel, Burrard Inlet Crossing
Traylor-Aecon General Partnership
The Second Narrows Water Supply Tunnel is a $286 million project for Greater Vancouver Water District 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 May 2023.

Project consists of two shafts (18 m OD x 68 m and 10 m OD x 110 m) 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 mixshield TBM. Ground improvement includes a safe haven constructed using ground freezing 400 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.

Slurry wall installation and excavation of the North shaft are complete, and excavation of the South shaft is just getting started. Tunneling equipment is slated for delivery in January 2020 with assembly and launch planned for Q2 2020.

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.

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).



Combined Sewage Storage Tunnel (CSST)
Dragados-Tomlinson Joint-Venture (DTJV)
Construction for this $146 million project for the City of Ottawa commenced in summer 2016, and the CSST will be in operation in 2020.

The project includes the construction of two inter-connected tunnels: an east-west tunnel (EWT) through the downtown core from LeBreton Flats to New Edinburgh Park, and a north-south tunnel (NST) along Kent St. from Chamberlain Ave. to the Ottawa River, just behind the Supreme Court. The total length is 6.2 km, with an inside diameter of 3 m. Depth is 10 to 31 m. The project includes the construction of 15 major access shafts, as well as support buildings such as odor control facilities.

A double-shield TBM from Herrenknecht was used to construct the tunnel. Tunneling also made use of a locomotive and tracks for the transport of muck cars, pre-cast concrete liner segments and personnel. A gantry crane was used at the surface to support tunneling operations.

The full length of the tunnels were excavated in bedrock. Bedrock formations encountered included the Veralum, Lindsay and Billings formations, which generally consist of limestone and shale.

Currently, construction is taking place at 10 of the 11 surface locations across the City. These include, shaft and chamber construction, existing infrastructure connections, construction and pre-commissioning of odor control facilities, tunneling support operations, outfall chamber construction, and preparation for receiving of the TBM at the bottom of a 19 m deep shaft. All tunneling for the project is now complete.
In constructing the CSST, Ottawa will provie CSO reduction, basement flooding control and critical system resiliency.

Stantec and Jacobs are the administrators of the construction contract to ensure the CSST Project is built in accordance with the City’s design with geotechnical support from Golder. Stantec completed the Environmental Assessment and functional design. Stantec and Jacobs completed the preliminary and detailed design and are now both providing contract administration and inspection services through the construction phase.

Owner (City of Ottawa): Manager – Ziad Ghadban, Program Manager – Steven Courtland, Program Manager Stakeholder Engagement – Jennifer Carreira; Contract Administrator: Project Manager – Adrien Comeau (Stantec), Contract Administrator – Steve Rowe (Jacobs), formerly Clare Humphrey (Jacobs), Assistant Contract Administrator – Colin Goodwin (Stantec), Construction Director – Gerald Bauer (Stantec), Jacobs Project Manager – Pascal Pitre (Jacobs); Contractor (Dragados-Tomlinson Joint Venture): Project Manager – Fernando Triana (Dragados), Civil Construction Manager – Bert Hendriks (Tomlinson), Project Engineer – Surface Works – Richard Poulin (Tomlinson).


Ashbridges Bay Treatment Plant Outfall
Southland Astaldi JV
This is a $300 million (CAN) project for the City of Toronto. NTP was issued January 2019 and estimated date of completion is January 2024. The project comprises 3,500 m of 7-m ID tunnel, 85 m deep, and one shaft.

Onshore at the shaft location, overburden materials up to 20 m in thickness are anticipated to be encountered consisting of sand, silt and clays overlain by landfill material associated with a historic reclamation area. Offshore at the riser locations, overburden material consisting of silts and sands overlain by recent sediments comprised of under-consolidated materials are anticipated to be encountered.
The alignment is within the Georgian Bay Formation Shale, which is described as a greenish to bluish grey non-calcareous shale. The shale is a fissile rock with widely spaced vertical or inclined jointing and closely spaced sub-horizontal bedding planes interbedded with limestone, siltstone and sandstone.

Anticipated construction methods include: Shaft SOE: Secant Piles and Rock bolts with Wire Mesh and Shotcrete. Tunnel: Shielded Tunnel Boring Machine with single pass precast concrete tunnel lining (PCTL) system.

The project commenced in January 2019 and is about 15% complete. Shaft construction and offshore marine work is currently underway. TBM tunneling is set to begin in summer 2020.

The offshore marine work includes fifty 1,000 mm diameter risers with ports installed in line with the tunnel extending from the tunnel horizon to the lakebed.

Tunnel Designer: Hatch with Jacobs & Baird; Construction Manager: Hatch with Jacobs & Baird; Subcontractors: Johnson Bros.; Suppliers: CSI (PCTL Segments); TBM Manufacturer: Robbins.

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