Tunnel Updates – June 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 June 2020 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 the Los Angeles County Sanitation Districts was issued on April 8, 2019, with 1,900 working days to complete the work and an estimated completion date of October 2026. The project will serve the sanitation needs of approximately 5 million people in 73 cities and unincorporated areas of Los Angeles County. It 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.

The tunnel will be approximately 7 miles long and 18 ft in internal diameter to convey disinfected, secondary-treated effluent from the Sanitation Districts’ Joint Water Pollution Control Plant (JWPCP) located in the Carson, California, to an existing ocean discharge system at Royal Palms Beach in San Pedro in the City of Los Angeles. The new 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 a slurry, 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-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 the summer of 2019. Construction of the access shaft slurry wall excavation support system was completed in December 2019. Excavation of the shaft in dry and wet conditions is ongoing. This will be followed by shaft tremie slab construction and dewatering, with an anticipated completion of summer 2020. Jet grouting for the tail tunnel, starter tunnel, and three safe havens is ongoing with an anticipated completion date of early 2021. The contractor will be 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: McMillan 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 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 which provides 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.

The tunneling portion of the $1.8 billion Regional Connector Transit Project for the Los Angeles County Metropolitan Transportation Authority involves 5,795 ft of twin tunnels with an excavated diameter of 21 ft. The ground conditions range from alluvium soils to clayey siltstone of the Fernando formation, with the potential for methane, hydrogen sulfide gas, and boulders. The groundwater table is 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.

As of March 2020, construction progress includes:

The bored tunnels were successfully completed on time in January 2018, and the TBM has been demobilized. All three cross passages, tunnel inverts, and walkways are completed.

All three underground stations have been excavated and are currently in the concrete phase, with walls and elevated slabs being constructed at each location, currently each station is 65% complete.

The SEM cavern, located next to the Historic Broadway Station, is a 300 ft long x 58 ft wide and 36 ft high cavern and will be used to provide a future cross over for Metro Operations. The excavation for the cavern was broken into three drifts staggered by 60 ft. The left drift, started on May 31, 2018, and the right drift, started on July 6, 2018. Each were completed in 5 months. The center drift was broken into a top heading and invert heading which were completed in 6 months. The excavation of the cavern was successfully completed in March 2019 with surface settlement matching the predicted values from the design model. The SEM cavern is 100% complete.

The Flower Street cut-and-cover tunnel continues with concrete inverts and is over 70% complete. Backfilling has begun between 3rd and 5th Streets and will continue into 2nd quarter 2021.
Structural concrete for the wye structure leading to the 1st Street and Central station is advancing rapidly with the construction of underground guideway and the demolition of the existing at-grade station scheduled to begin in the 4th quarter 2020. Some sections of backfilling have begun at the intersections of Alameda and First Street.

Many Track activities have begun. Floating Track Slabs are continuing to be installed, additionally LVT Resilient Track has started construction, and CWR sticks have been distributed along the project alignment.
The overall project is progressing on schedule and is anticipating beginning revenue operations during the 4th quarter 2022.

The Regional Connector is a Design/Build Project. Design packages are now complete, with construction approximately 70% complete, as of March 2020.

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; Sy Morales, 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) Chris Hebert, Richard McLane, Christophe Bragard.

Redwood City

Silicon Valley Clean Water (SVCW) Gravity Pipeline Project
Bernard-Bessac JV
This is a $206.7 million progressive design-build project for the Silicon Valley Clean Water, a Joint Powers Authority (JPA). It was issued NTP on Nov. 8, 2018, with an anticipated completion date of July 1, 2022.
It comprises 17,450 lf tunnel of 16-ft, 2-in. OD tunnel and 3 shafts constructed by BBJV (1 launch shaft, 1 retrieval shaft, and 1 tie-in shaft). The geology includes fill material (depth varies, but approximately 5 to 10 ft beneath ground surface), Young Bay Mud (depth varies, but approximately 10 to 25 ft beneath ground surface), , Upper Layered Sediments (tunnel layer, depth varies but approximately 25 to 60 ft beneath ground surface), and Old Bay Mud (depth varies, but approximately 60 ft+ beneath ground surface). Construction methods include: Tunneling = EPB soft ground tunneling; Launch shaft = Slurry Wall SOE with crane/excavator/muck box excavation; Retrieval Shaft = Sheetpile SOE with 4 levels of internal Bracing with crane/excavator/muck box excavation; Tie-In Shaft = Under final design but most likely Liner Plate SOE with partial depth Jet Grout ground improvement. The project includes the installation of 5,100 lf of 10-ft ID FRP pipe and 12,350 lf of 11-ft ID FRP pipe installation within the segmentally lined tunnel.

The Barnard Bessac Joint Venture (“BBJV”) team reached a major project milestone with the successful completion of the first of two tunnel drives. On March 25, the TBM holed through into the Bair Island Retrieval Shaft ahead of schedule.

The first tunnel drive was approximately 5,100 ft in length, or 1/3 of the total tunnel length for the project. The Airport Access Shaft (AAS) was the launch shaft location and from there, the TBM passed beneath the San Carlos Airport taxiway, beneath a shallow cover creek crossing (15 ft cover), and ultimately holed through at the Bair Island Retrieval Shaft with precise alignment, within a couple of inches of the theoretical target both vertically and horizontally. In addition to the precision tunnel alignment over a length of approximately 1 mile, BBJV crews sustained astonishing daily productions and shrunk the project schedule. The success of the first tunnel drive was a result of a multitude of factors including, but not limited to, a thorough pre-construction design preceding equipment selection, exceptional subcontractor relationships, skilled craft workforce, and a united management team.

With the first tunnel drive completed, the next tasks for the tunneling operation are to meticulously disassemble and remove a portion of the TBM from the Bair Island shaft. The Cutterhead, Main Shield, Middle Shield, Tail Shield, Screw Conveyor, and Segment Erector will be disassembled then hoisted from the 32-lf x 52-lf internally braced Bair Island Retrieval shaft. All removed TBM components that exceed on-road width restrictions will be transported back to the AAS via Highway 101 under wide load permits. Extensive coordination with our transporting subcontractor, Bigge, and coordination with Caltrans is underway. Transportation of the wide loads was set for late April 2020.

The balance of the TBM components that will not be hoisted from the Bair Island Retrieval Shaft will be transported back to the AAS via the tunnel. The vent line, utilities and continuous conveyor (muck conveyance system) were removed to allow sufficient space for this operation. BBJV crew are utilizing an Air Tugger to winch the TBM trailing gantries (580 ft long and weighing 546 tons of TBM support gear) back through the tunnel to the AAS. The Air Tugger is mounted atop a flatcar, similar to a flatbed trailer, and is connected to one of the two electric locomotives, which will travel on the locomotive rails. The Air Tugger will winch the trailing gantries in approximate 30-lf intervals while a 2nd electric locomotive will assist in the operation. The 2nd locomotive will be staged within the trailing gantries and will be utilized to leapfrog the 2nd set of rails or jump rails, an elevated rail system that supports the trailing gantries located just outside the locomotive rails, which was used to support the trailing gantries during tunneling operations. Once the trailing gantries are pulled back to the AAS, they will be hoisted from the AAS invert and will be staged on the surface, necessary repairs will be made, and preparation for a re-launch for the second drive (in the opposite direction) will take place. This tedious work will make for a very busy late spring and early summer for BBJV crews.

Concurrent with Tunnel Drive 2 tunneling, the team has planned to start FRP pipe installation in the completed Tunnel Drive 1 (San Carlos Shaft to the Bair Island Retrieval Shaft), which was once thought to be a logistics nightmare if performed concurrent with tunneling activities. Ultimately, this will allow for the team to get a head start on the pipe installation learning curve, which was once on the critical path. Part of this installation will also require the excavation of the San Carlos Shaft within the San Carlos Airport, and connecting adit. This San Carlos shaft is currently in design, getting progressed to 100 percent, and will require utility relocates, potential ground improvement, and challenging SOE installation. Additionally, and due to Federal Aviation Administration constraints, the San Carlos shaft must be constructed with low overhead equipment due to an allowable working height of 21-lf above ground level.

Elsewhere in the world, in Jakarta, Indonesia, fabrication of the second batch of FRP Pipe is complete, has been loaded on to the flat bottom ship, and has departed the port of Merak in route to Stockton, CA. The ship is expected to arrive in mid-May after making the approximate 9,000 mile journey across the Pacific Ocean. After its arrival in Stockton, CA, the FRP pipe will be off-loaded, inspected and delivered to the BBJV temporary pipe storage yard in Sunol, CA. Any necessary repairs will be completed once the pipe arrives at the Sunol yard, then will be stored and covered until needed on the project.

This is a Progressive Design-Build Contract Structure with a multi-phase contract; Stage 1 (10-60% Design with Early Contractor Involvement) and a Stage 2 (Final Design 60-100% with Construction). As of the end of April, the project was 35% complete.

Tunnel and Shaft Designer is Arup, Construction Manager is Tanner Pacific Inc., Major Subcontractors: Malcolm Drilling (Slurry Wall SOE), Drill Tech Drilling and Shoring (Inclined Conveyor Tunnel and Starter Tunnels), Blue Iron Foundations (Sheetpile SOE), Future Pipe Industries (FRP Pipe Supplier), Traylor Shea Precast (Concrete Segments).

Key Project Personnel: Jack Sucilsky (BBJV PM), Mike Hanley (BBJV Gen Superintendent), Olivier Robert (BBJV Deputy PM), Glenn Strid (BBJV Asst PM), Mike Gilbertson (BBJV Superintendent), Richard Ray (BBJV Master Mechanic).

DISTRICT of COLUMBIA

Washington

Northeast Boundary Tunnel Project
Salini Impregilo Healy
This is a $579.9 million combined sewer overflow (CSO) tunnel project for District of Columbia Water and Sewer Authority (DC Water) measuring 26,737 ft long and 23 ft in finished diameter (excavated diameter = 26 ft, 3 in.). The tunnel is driven using EPB TBM in heavy clay and water-bearing clayey sands at water pressures up to 3 bar. In addition to the tunnel, the scope includes construction of seven slurry wall shafts up to 130 ft deep in dense urban environment. Ground freezing was used at two shafts to connect the shaft to tunnel. Jet grouting used at other shafts to connect the shafts to the tunnel. The tunnel connects underground to an existing 21 ft diameter live sewer. Extensive instrumentation is needed to track performance of the TBM with regards to settlement.

The project is approximately 50% complete. On April 10, 2020, the TBM holed through into the W Street Shaft on line and grade after advancing 15,695 ft. This is the only shaft directly on the tunnel alignment. The TBM cutterhead is being rebuilt and the TBM is scheduled to resume advancing on May 11. It will then proceed another 10,900 ft to the R Street extraction shaft. Work is proceeding at numerous shaft sites for all the ground support of shafts and interceptor structures. Shaft lining at W Street was done just in time for the TBM breakthrough. The last shaft slurry wall at R Street is complete. Crews are proceeding at multiple locations installing jet grout plugs in secant pile structures and also jet grouting safe havens for the TBM. The ground freeze has been turned on at 4th Street shaft for the first adit excavation. Shaft lining is proceeding at the 4th Street and Mount Olivet Road shafts. Extensive cement bentonite walls are being placed at R Street.

The Northeast Boundary Tunnel is part of a $2.7 billion program by DC Water to mitigate CSO discharges into the Anacostia and Potomac Rivers and bring flood relief to NE Washington, D.C. 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 is 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 Sept. 15, 2018, with final completion set for Jan. 27, 2023.

Designer: Brierley Associates; TBM Supplier: Herrenknecht; Slurry Walls, Jet Grout, Secant Piles, Solider Piles: Treviicos; Dewatering: Moretrench; Segmental Tunnel Liner Supplier: 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 and Greeley & Hansen.

Key Project Personnel – Project Director: Shane Yanagisawa; Project Manager: Fabio Ciciotti; 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. For enquiries contact Shane Yanagisawa at 360-606-4375.

FLORIDA

Tampa

Tampa Waterfront District
Bradshaw Construction Corp.
Bradshaw Construction will be starting construction on a water main tunnel in Tampa. The 176-lf by 30-in. steel casing tunnel will be installed behind a Herrenknecht AVN-800 MTBM for a 12-in. water main. Subsurface conditions are baselined to be poorly graded sand. Construction is scheduled to be completed by the end of July 2020. The project members include the City of Tampa (Owner), Stantec (Engineer) Kimmins Contracting Corp. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.

GEORGIA

Athens

Upper North Oconee – Phase 2B Trunk Sewer Replacement
Bradshaw Construction Corp.
Bradshaw Construction will soon begin construction on two tunnels in Athens-Clarke County for re-alignment of the gravity sewer line. The first drive will utilize 60-in. steel casing jacked behind a Herrenknecht AVN 1200 MTBM to tunnel directly under the Athens Line railroad spanning approximately 110 ft. The second tunnel will require two separate tunneling methods due to a transition in ground conditions. A NATM starter tunnel will be excavated out of the shaft until it becomes too difficult to proceed, where a rock head TBM manufactured by Robbins will take over and mine approximately 1,100 ft through competent rock. The rock TBM will curve under a busy section of Georgia State Route 10, and be recovered in a liner plate recovery tunnel and walked into the receiving pit. After both tunnels are complete, 36-in. ductile iron gravity sewer pipe will be installed and backfilled. Ground conditions are anticipated to transition between partially weather rock and granite. The project is scheduled to begin in late May 2020. Project members include Athens-Clarke County (Owner), Garney Construction (General Contractor) and Bradshaw Construction working as the tunneling subcontractor. Project Information: Chris Flanagan – Project Manager; CFlanagan@bradshawcc.com.

Atlanta

Niles Avenue Sewer Improvements
Bradshaw Construction Corp.
Bradshaw Construction Corp. is currently working on a project, contracted under Garney Construction, in the suburbs of NW Atlanta for the Department of Watershed Management to realign an existing 15-in. sewer line. Bradshaw 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.

Bradshaw has completed the installation of four liner plate shafts ranging in size and geology, and has started mining utilizing both the TBM and MTBM simultaneously. Currently, the Robbins TBM is mining through a 1,000-ft radius curve in a bald rock tunnel spanning a total distance of 713 lf. Bradshaw has also started mining the first of two MTBM drives, spanning distances of 346 and 701 lf. Both drives will be installed as a two-pass system, with 48-in. RCP jacking pipe used as the casing. After the completion of all three tunnels, 18-in. DI pipe will be installed and backfilled. Construction is expected to be completed late July 2020.

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

INDIANA

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.

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 April 2020, approximately 22,000 feet of concrete liner has been placed, as lining operations are ongoing in both tunnels. Based on the terms of a federal consent decree, the White River and Lower Pogues Run Tunnels must be operational by the end of 2021.

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

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

Mining commenced in September 2019 from a 30-ft diameter shaft that was previously constructed as the retrieval shaft for the White River Tunnel alignment. After successfully mining the White River Tunnel, the TBM mined through the shaft and underwent a minor refurbishment. Mining was completed on April 1, 2020. The tunnel terminates approximately 2,400 feet past the retrieval shaft location. The TBM will be backed up and parked downstream of the shaft, and the remainder of the shaft will be shot down to the invert. The TBM will then be retrieved and transported to the site of the Pleasant Run Tunnel launch shaft, where it will undergo a full refurbishment before mining the final leg of the DigIndy system. Based on the terms of a federal consent decree, the Fall Creek Tunnel must be operational by the end of 2025.

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

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

Slurry wall installation for the launch shaft occurred in the Summer 2019. The contractor remobilized to the site in February 2020 and launch shaft excavation is ongoing. The TBM completed mining the Fall Creek Tunnel in April 2020 and will be delivered to the Pleasant Run launch shaft site where it will be refurbished prior to reassembly underground. Mining is anticipated to commence in Fall 2020. Once complete, the entire 28-mile DigIndy system will have utilized a single Robbins main beam TBM. In addition to 28 miles of hard rock mining, the TBM will have been backed up over nine miles allowing the elimination of multiple launch and retrieval shafts. Based on the terms of a federal consent decree, the Pleasant Run Tunnel must be operational by the end of 2025.

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

KENTUCKY

Louisville

Ohio River Tunnel (ORT)
Shea-Traylor JV (S-T 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 Substantial Completion by February 2021 (Final Completion: May 2021). 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

Tunneling is being done by a main beam tunnel boring machine (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. Tunnel excavation is 77% complete, with the TBM less than 5,000 ft from hole-through at the retrieval shaft as of mid-May. Excavation of Drop Shaft DS04 is complete. Drop and vent pipe construction within the shaft is complete at Drop Shafts DS01 and DS02.

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, and then reset to resume excavation of the main tunnel. The revised project cost, with change orders, is approximately $150 million.

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.

MARYLAND

Baltimore

Jones Falls Sewershed – SC 941
Bradshaw Construction Corp.
Bradshaw Construction will soon begin constructing twin liner plate tunnels for a siphon installation by hand mining. The 48- and 72-in. liner plate tunnels will extend approximately 24 ft each, passing directly underneath an existing precast 66-in. x 84-in. twin storm drain with minimal clearance. After the tunnels are installed, 18- and 54-in. DIP will be installed and backfilled in the liner plate tunnels. Ground conditions are anticipated to be sand with rock fragments and decomposed rock in the invert. The project is scheduled to begin in late May 2020. The project members include the City of Baltimore (Owner), Anchor Construction (General Contractor) and Bradshaw Construction working as tunneling subcontractor. Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.

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.

MISSOURI

St. Louis

Deer Creek Sanitary Tunnel
SAK Construction
The Deer Creek Sanitary Tunnel comprises 21,000 ft of 19-ft diameter bored tunnel. The ground cover over the tunnel alignment will vary in depth between approximately 85 and 170 ft. In general, the tunnel alignment will pass through limestone/dolomite of the St. Louis and Salem Formations. The tunnel’s final liner will be unreinforced cast in–place (CIP) concrete at least 1-ft thick. The $147 million project for the Metropolitan St. Louis Sewer District First is about 73% complete with concrete lining work just underway. The subcontractor, Goodwin Brothers, has continued work on all of the drop shafts, and SAK is currently working on the Black Creek adit in addition to the tunnel lining work.

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 March 1, 2020, project construction was approximately 90 percent complete. Construction of the pump station is 85% complete. Construction will continue through fall 2020.

Shaft drilling work for all of the intake structures was completed in spring 2017. Construction of the Chain of Rocks Drive intake is 99% complete. Minor work will continue at the site through spring 2020. Construction of the CSO 052 intake is 95% complete and work will be completed when river levels drop. The Church Drive site will continue to be active through summer 2020. Construction of the Church Drive intake is currently 59% complete.

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.

NEVADA

Las Vegas

Barnard of Nevada, Inc. (Barnard)
Lake Mead Low Lake Level Pumping Station (L3PS) Project
In May 2015, Barnard entered into a $440 million Construction Manager at Risk (CMAR) contract for the L3PS Project for the Southern Nevada Water Authority. As of December 2018 all of the underground excavation and construction has been completed. As of April 2020 all Aboveground Construction including startup, commissioning, and performance testing of the Pumping Station has been completed and the Project has achieved Substantial and Final Completion. All work was successfully completed on time and under SNWA’s Project Budget.

The 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 accompanying appurtenances includes: 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-inch discharge aqueducts.

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

Key Project Personnel: SNWA: Peter Jauch, Director of Engineering; Adriana Ventimiglia, 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, Matthew Johnson, and Sabestian Trevino.

NEW YORK

Newburgh

Delaware Aqueduct Bypass Tunnel
Kiewit-Shea JV
The $707 million project for the New York City Department of Environmental Protection involves building a 2.5-mile long tunnel 600 ft under the Hudson River from Newburgh to Wappinger. Once finished, the bypass tunnel will convey water around a leaking section of the Delaware Aqueduct. The leaking section will be plugged and taken out of service permanently.

At 85 miles long, the Delaware Aqueduct is the longest tunnel in the world. It conveys about half of New York City’s drinking water from reservoirs in the Catskills Mountains. The project is the largest repair in the 178-year history of New York City’s water supply.

The finished bypass tunnel will be 14 ft in diameter. The initial excavation by a tunnel boring machine, completed in August 2019, was 21.6 ft to accommodate 9,200 ft of 16-ft diameter steel interliner with a final cast-in-place concrete liner.

The existing Delaware Aqueduct will be unwatered when the bypass is finished so that it can be connected to structurally sound portions of the existing aqueduct. During this unwatering a tunnel condition survey will be made and a smaller leak to the northwest will be sealed by grouting.

With the tunnel excavation complete, workers have been installing the steel liner segments. As of May, the team had installed more than 165 sections of steel liner; 230 will be installed altogether. Workers have also completed approximately 45% mark of placing cellular grout behind the liner. Concrete lining operations will continue through 2021, and the team is also planning for the final connection. The project, which began in July 2015, has a completion date of March 2022.

Special/unique Features of the Job:

• Delaware Aqueduct is the longest tunnel in the world
• Largest repair in the 178-year history of New York City’s water supply – the largest municipal water supply in the United States
• Project includes an 890-ft deep shaft
• High pressure, pre-excavation grouting
• 12,500 lf of hard-rock excavation with a tunnel boring machine
• Triple-pass liner system

Design: New York City DEP In-House Design with support from McMillan Jacobs Associates; Construction Manager: Parsons; TBM: Robbins.

NORTH CAROLINA

Charlotte

Dairy Branch Tributary
Bradshaw Construction Corp.
Bradshaw Construction will be starting construction on sanitary sewer tunnels in Charlotte. The 2,399-lf by 60-in. steel casing tunnel will be installed behind a Herrenknecht AVN-1200 MTBM for a 36” sanitary sewer. Subsurface conditions consist of granitic rock ranging from 25 kpsi to 38 kpsi and alluvial deposits. Construction is scheduled to be begin June 2020. The project members include the Charlotte Water (Owner), STV Engineers Inc. (Engineer) B.R.S. Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.

Charlotte

Little Sugar Creek Tributary to Central Business District
Bradshaw Construction Corp.
Bradshaw Construction will be starting construction on one-pass sanitary sewer tunnels in Charlotte. The 3,587-lf by 48-in. reinforced concrete pipe tunnel will be installed behind a Herrenknecht AVN-1200 MTBM. Subsurface conditions consist of granitic rock ranging from 9 kpsi to 30 kpsi and alluvial deposits. Construction is scheduled to be begin June 2020. The project members include the Charlotte Water (Owner), WSP USA (Engineer), Sanders Utility Construction Co. Inc. (General Contractor) and Bradshaw Construction performing as tunneling subcontractor. Project Information: Matthew Webb – Project Manager; mwebb@bradshawcc.com.

OHIO

Cleveland

Doan Valley Tunnel Project
McNally/Kiewit DVT JV
The Doan Valley Tunnel project is a $142.3 million project as part of the Northeast Ohio Regional Sewer District’s Project Clean Lake. It comprises 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. It is a two-pass tunnel with rib and lagging as initial support and precast concrete pipe as final liner. Tunnel depth ranges from 30 to 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 a one pass with a universal ring (5+1 segments, fiber reinforced). Tunnel invert depth ranges from 50 to 100 ft below grade. DVT intercepts pre-existing brick sewers up to 3 ft above the tunnel crown.

The project also includes seven shafts between 23 and 55 ft diameter and 30 to 100 ft deep.
The geology consists primarily of 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 12-ft diameter WCT tunnel drive was completed on Dec. 12, 2018. Pipe installation and cellular grout backfill completed on July 30, 2019.

The DVT tunnel drive was completed on Sept. 7, 2019. The DVT Starter Tunnel, 18-ft diameter and 300 lf, comprised of Synthetic Fiber Cast In Place Concrete, was completed on April 17, 2020.

The MLKCT 12-ft diameter tunnel drive was completed on Jan. 15, 2020, and pipe installation operations completed on April 8, 2020.

Remaining Work includes Near Surface Structure work – final shaft concrete work along with restoration of sites. Overall project progress is 87% complete.

Special/unique features of the job include: 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 with softer shales; 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); and several large sewers to tie into and divert flow to tunnel.

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); Nothern Concrete Pipe (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; Jeff Acor – Chief Surveyor McNally/Kiewit DVT JV; Matt Szaraz – QHSE Manager McNally/Kiewit DVT JV; Lance Jackson – Project Engineer McNally/Kiewit DVT JV; Ian Danielson – Tunnel 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.

Cleveland

Westerly Storage Tunnel
Jay Dee Obayashi JV
This is a $135 million project for Northeast Ohio Regional Sewer District’s (NEORSD) Project Clean Lake comprises 2 miles of 25-ft diameter tunnel approximately 200-250 ft underground. The job is approximately 57% complete.

Recent activities:

• Shaft final concrete structure at site WST-1: Approx. 5,500 cy of cast-in-place concrete placed (approx. 215 vertical ft of shaft lining).
• Overall shaft final concrete currently 70% done.
• Shaft final concrete structure at site WST-2: Approx. 1,500 cy of cast-in-place concrete placed (approx. 200 vertical ft of shaft lining).
• Overall shaft final concrete currently 75% done.
• Near surface structures at site WST-2: Final structure installation currently 100% done.
• Tunnel excavation with Tunnel Boring Machine (TBM) at WST-3: Mining currently 5% done.

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.

Key Project 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.

Independence

Cuyahoga Valley Interceptor – Walton Hills Trunk Sewer Repair
Turn-Key Tunneling Inc.
Turn-Key Tunneling is building this project for the Northeast Ohio Regional Sewer District. NTP was issued March 9, 2020, with completion scheduled for September 2020.

A previous project had geotechnical exploration performed and accidentally punched a hole into a live sanitary sewer nearly 40 ft deep in the middle of a wetlands. This project called for Turn-Key Tunneling to locate the damaged section on the Cuyahoga Valley Interceptor-Walton Hills Trunk Sewer; size and design the shaft support of excavation; perform shaft excavation and sewer repair; and site restoration.

Turn-Key Tunneling first will locate the damaged point on the CVI-WHT sewer and establish the center of failure. Turn-Key will then excavate and install a 12-ft shaft liner and attempt to seal off the water because this installation is under the water table. Vertical caisson(s) will likely be needed inside the liner plate shaft and will extend down to the damaged sewer pipe.

Turn-Key will pour CDF inside a 96-in. caisson and pull up the casing as the hole is filled with CDF. The liner plate shaft will be removed as well while pouring CDF. Turn-Key will then break out concrete “starter” ring to be below grade level and place 3 ft of 2-in. stone to match the rest of the existing roadway.

Key Project Personnel: Brian Froehlich, Project Engineer – Turn-Key Tunneling; Gary Ison, Project Superintendent – Turn-Key Tunneling; Brian Daugherty – Construction Supervisor II with Northeast Ohio Regional Sewer District.

OKLAHOMA

Oklahoma City

OKC Sanitary Sewer Relief Interceptor SC-0950
Bradshaw Construction Corp.
Bradshaw Construction is in the process of constructing three tunnels as part of a sanitary sewer installation in Oklahoma City. The three drives, totaling 902 lf of 90-in. welded steel casing, 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 BNSF railroad crossings. Soldier pile and steel plate launch and recovery shafts and 72-in. FRP will be installed by the General Contractor. Construction began in February 2020 and is scheduled to be completed by the end of May 2020. 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 Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.

PENNSYLVANIA

Nemacolin

Hilltop Energy Center LLC Water Intake Tunnel
Bradshaw Construction Corp.
Bradshaw Construction Corporation recently completed construction on this raw water intake tunnel. The 330-ft by 60-in. welded steel casing tunnel was installed behind a Herrenknecht AVN-1200 MTBM. Mining began in 25 ksi limestone and progressed into dense river alluvium before the drive was terminated in the Monongahela River. Following MTBM recovery, Bradshaw is currently installing a 24-in. HDPE carrier pipe, three 2-in. stainless steel air discharge lines, and will backfill grout the tunnel once complete. Construction was scheduled to be completed by the end of May, 2020. 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 Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com

SOUTH CAROLINA

Greenville

Reedy River Basin Sewer Tunnel
Super Excavators Inc./Cooperatia Muratori Cementisti, a Joint Venture
The $39.47 million Reedy River Basin Sewer Tunnel project for Renewable Water Resources (RE-WA) involves 6,000 lf of 130-in. ID rock tunnel with 84-in. carrier pipe (Hobas CCFRPM Pipe) grouted in place, ranging from 40 to 130 ft below ground surface. The project includes a 40-ft ID by 40-ft deep launch shaft, and a 30-ft ID by 130-ft deep receiving shaft. The 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- and 42-in. upstream and downstream connecting sewer, as well as several junction chambers, screening/diversions structures and odor control facilities.

NTP was issues March 5, 2018, with final completion scheduled for May 28, 2021. The project is on schedule. Tunneling is over half way completed. The upstream sewer and downstream open-cut sewers are substantially completed. Elastomeric lining of the CIP structure has begun.

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

Key Project 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.

TEXAS

Dallas

Mill Creek/Peaks Branch/State Thomas Drainage Relief Tunnel Project
Southland/Mole JV
Southland/Mole is constructing this $206 million project for the City of Dallas. It consists of 26,385 lf of 32-ft, 6-in. OD tunnel (30-ft ID); 8 shafts (ranging from 120 to 200 ft in depth); 6 lateral tunnels excavated by roadheader or excavators/breakers. The majority of the tunnel is through Austin chalk excavated by a Main Beam TBM.

The project is 40% complete by duration. Crews have completed excavation of 5 shafts and are currently excavating 2 shafts ranging from 22 to 35 ft diameter and 110 to 190 ft deep. Testing and commissioning of TBM underground is complete and TBM mining was scheduled to commence April 24. Upon completion, a 15-in. thick cast-in-place final concrete liner will be installed.

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.

VIRGINIA

Virginia Beach

Virginia Beach Blvd Force Main Phase VI
Bradshaw Construction Corp.
Bradshaw is beginning construction on a series of force main tunnels comprising three drives totaling 1,360 lf of 60-in. Permalok steel casing 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 260 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 be completed by August 2020. The project members include Hampton Roads Sanitation District (HRSD) (Owner), Kimley Horn LLP (Engineer) Bridgeman Civil Inc. (General Contractor) and Bradshaw Construction as tunneling subcontractor. Project Information: Jordan Bradshaw – Project Manager; Jordan.bradshaw@bradshawcc.com.

WEST VIRGINIA

Beckley

WV Turnpike Culvert Repair Retrofit, Project IC-20
Turn-Key Tunneling Inc.
Wiseman Construction Co. Inc. is the general contractor working for the West Virginia Parkways Authority on this $249,000 project. NTP was issued April 27, 2020, with completion set for May 25, 2020. The scope of work involves the retrofit of various culverts in Mercer, Raleigh, Fayette, and Kanawha Counties, WV. Turn-Key Tunneling will provide and install 100 ft of 54-in. diameter tunnel liner plate through a mixed face of shot rock and fill. The final liner is to be 42-in. with the annular space filled with cellular grout.
Turn-Key Tunneling will set up the tunnel to meet the existing failed 42-in. CMP center line to center line, remove any temporary shoring provided at the face of the working pit from inside the tunnel, and commence a drift and bench tunnel installation. This method involves excavating enough room for a partial ring of liner plates and hanging those plates before excavating for the remaining portion of the ring. This will progress like a moving slope which will keep the ground supported as the tunnel is advanced. The existing 42-in. CMP will be removed from inside this 48-in. tunnel as part of the tunnel excavation process. Our plan is to over-excavate as little as possible to allow for the new tunnel structure. Any over-excavation will be filled with a lean grout mix.

Engineer: HNTB Corporation.

Key Project Personnel: Chris Leonard, Project Engineer – Turn-Key Tunneling; Gary Ison, Project Superintendent – Turn-Key Tunneling; James Linkinogger, Vice President – Wiseman Construction Co.

CANADA

BRITISH COLUMBIA

Delta

Annacis Island Outfall Tunnel
Pomerleau Inc. in partnership with Bessac CANADA
NTP for this is $184 million (CAN) project for Metro Vancouver was provided July 19, 2019, construction started in fall 2019 and will last until 2024. The project consists of the construction of a new outfall pipeline from the Annacis Island Wastewater Treatment Plant (WTP) to the Fraser River.

It includes the following key components:

• two 15 and 10 m diameter 40 m deep shafts inside the plant;
• two segmental lining tunnels 4.20 m internal diameter (200 m and 580 m long) with a slurry TBM,
• one riser in the Fraser River;
• a 2 x 110 meter long 2.5 m diameter diffuser buried in the Fraser River bottom;
• a new water control structure connected to the existing one.

The project has maintained activity during the pandemic crisis. The slurry walls are now completed for both shafts, and the ground treatment by jet grouting is ongoing. The project is unusual due to the short length of both drives and the absence of final retrieval shaft under the river bed.
CDM Smith is the project designer, Hatch the construction manager, the slurry walls were built by Keller, the TBM manufacturer is Bessac. ARUP is the contractor engineer for the tunnel section

Key Project Personnel: Glenn Holloway is the PM, Guillaume Roux, the deputy project manager acting as the operation manager, Rick Brazier is the general superintendent.

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 (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 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.

Shaft preparatory concrete work in complete at the North (launch) shaft, and excavation of the South shaft continues. The TBM was received in February 2020, and the shields were set in the shaft and mated as of late April. Preparations continue for a Q2 2020 launch.

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).

ONTARIO

Ottawa

Combined Sewage Storage Tunnel (CSST)
Dragados-Tomlinson Joint-Venture (DTJV)
City of Ottawa
This $146 million project for the City of Ottawa 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 Street from Chamberlain Avenue to the Ottawa River, just behind the Supreme Court of Canada. The tunnels are a total length of 6.2 km, with an inside diameter of 3 m, and are 10-31 m below ground level. The CSST project also includes the construction of 15 major access shafts, as well as support buildings such as odor control facilities. Construction commenced in the summer of 2016, and the CSST will be in operation in 2020.

A double-shield tunnel boring machine (TBM) was used to construct the tunnel. The fully assembled TBM was approximately 250 m long. 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 surface to support tunneling operations, including removing and dumping muck cars and lowering liner segments for tunnel assembly.

The full length of the CSST tunnels were excavated in bedrock. The bedrock formations encountered by the CSST tunnels and shaft excavations include the Veralum, Lindsay and Billings formations, which generally consist of limestone and shale.

All tunneling for the project is complete. However, construction continues at 10 of the 11 surface locations across the City. This includes chamber construction, existing infrastructure connections, system pre-commissioning and site reinstatement.

In constructing the CSST, Ottawa will achieve, by 2020, a level of performance that meets and potentially exceeds current combined sewer overflow (CSO) regulations and guidelines – putting the City of Ottawa at the forefront of Canada’s leaders in meeting industry regulations and guidelines for CSO controls. Project infrastructure has been constructed to be multi-purpose: providing 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. R.W. Tomlinson, Marathon, Talco and, Black and MacDonald are major subcontractors. The TBM was manufactured by Herrenknecht.

Key Project Personnel – Owner (City of Ottawa): Manager – Ziad Ghadban; Program Manager – Steven Courtland; Program Manager Stakeholder Engagement – Jenn Carreira.

Contract Administrator: Project Manager – Adrien Comeau (Stantec); Contract Administrator – Colin Goodwin (Stantec) – formerly Clare Humphrey (Jacobs); Assistant Contract Administrator – Shawn Ireland (Stantec); Construction Director – Gerald Bauer (Stantec); Jacobs Project Manager – Genevieve Roy (Jacobs); Lead Construction Inspector – Dmitriy Kryukov.

Contractor (Dragados-Tomlinson Joint Venture): Project Director – Fernando Triana (Dragados); Civil Works Manager – Bert Hendriks (Tomlinson); Tunnel Manager – Juan Luis Martinez (Dragados); Shaft Manager – Richard Poulin (Tomlinson).