Tunnel Updates – October 2020

0

Three times per year, TBM: Tunnel Business Magazine recaps the status of major tunneling projects underway in the United States and Canada. Below is the Tunnel Update that appeared in the October 2020 issue of the print edition.

CALIFORNIA

Carson/Los Angeles/Rancho Palos Verdes

Joint Water Pollution Control Plant Effluent Outfall Tunnel
Dragados USA

The Los Angeles County Sanitation Districts (Sanitation Districts) are undertaking the $630.5 million Joint Water Pollution Control Plant Effluent Outfall Tunnel project, which includes a tunnel 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 located in the City of Carson, California, to an existing ocean discharge system at Royal Palms Beach in San Pedro in the City of Los Angeles. The tunnel will be constructed by a pressurized face, single-pass TBM.

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

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

Work at the JWPCP Shaft Site started in summer 2019. Construction of the access shaft slurry wall excavation support system was completed in December 2019. Excavation of the shaft in dry and wet conditions, which was followed by shaft tremie slab construction and dewatering, was completed August 2020. Jet grouting activities 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;

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.

Groveland

Mountain Tunnel Improvements
Michels

Bids on this project for the San Francisco Public Utilities Commission (SFPUC) were opened on Aug. 27, 2020, with Michels Tunneling as the apparent low bidder at $138,965,566. NTP is anticipated by Jan. 4, 2021, with estimated construction final completion in December 2026
The Mountain Tunnel is a critical lifeline asset through which the SFPUC conveys 85% of its water from the Hetch Hetchy Reservoir within Yosemite National Park in the Sierra Mountains to 2.7 million wholesale and retail customers in the San Francisco Bay Area. The objectives of the Mountain Tunnel Improvements are to rehabilitate the tunnel and make improvements to extend the useful life of this asset for the next 100 years. The scope of work includes: concrete lining repairs, contact grouting, approximately 5,000 lf of concrete invert paving, a new tunnel portal and 1,000 lf by 14-ft diameter adit tunnel at Priest Portal, two new shafts of 100-ft and 150-ft depth and connector tunnel sections to the existing tunnel, two 72-in. control valves plus four 72-in. insolation valves, an approximately 700-ft by 14-ft diameter bypass tunnel extension of South Fork Siphon below the Tuolumne River, approximately 1,500 lf of steel pipe tunnel lining, adit bulkhead improvements at Early Intake, construction staging areas for spoils fill sites and office trailers, access road/slope stabilization for safer access, water treatment plants for construction water discharge, environmental permit compliance, and other site improvements and site restoration.

Design was completed and the project was put out to bid in November 2019. However, due to the COVID-19 pandemic, bidding was extended to Aug. 27, 2020, to avoid the spring 2020 adverse pandemic impacts and to develop appropriate specifications for safe construction practices.

McMillan Jacobs Associates was the tunnel designer of record. The construction manager will be the SFPUC’s Construction Management Bureau with supplemental resident engineer, construction management and inspection staffing provided by AECOM. Major Michels subcontractors include Apex Rockfall Mitigation, Kroner Environmental, Schrader Mechanical, Cody Builders Supply, Geostructural Engineering, Inc., and Renesco, Inc.

Key Project Personnel: SFPUC – Regional Project Manager: David Tsztoo, PE; Regional Project Engineer: Lawrence Soe, PE (past); Joseph Buitrago, PE (acting); Regional Construction Manager: Jerry Malone. McMillan Jacobs – Project Manager: Rene Fippin, Principal, PE, GE; Project Engineer: Jennifer Sketchley, Associate, PE; Tunnel Engineer: Glenn Boyce, Principal, PE, GE; AECOM – Contract Officer: Eric Zagol, Vice President; Resident Engineer: Bob Mues; Lead Inspector: Thomas (Bud) DeGrio.

DISTRICT OF COLUMBIA

Washington

Northeast Boundary Tunnel Project
Salini Impregilo Healy

This $579.9 combined sewer overflow (CSO) tunnel for DC Water is 26,737 ft long with a 23-ft finish diameter (26 ft, 3 in. excavated diameter). The tunnel is driven using an EPB TBM in heavy clay and water bearing clayey sands at water pressures up to 3 bar. The job includes construction of seven slurry wall shafts up to 130 ft. deep in a dense urban environment. Ground freezing was used at two shafts to connect the shafts to the tunnel. Jet grouting was used at other shafts for connections. The tunnel connects underground to an existing 21-ft diameter live sewer. Extensive instrumentation was included to track the performance of the TBM with regards to settlement.

As of Sept. 1, the project was approximately 57% complete. The TBM has resumed advancing after a breakthrough and cutterhead rebuild at the W Street Shaft during April and May. The TBM will pass under the WMATA Red Line Metro Station on Rhode Island Avenue in October. It will then proceed another 7,747 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 will top out in September. The R Street shaft was completed and the rock interface at the shaft bottom grouted. Crews are proceeding at multiple locations installing jet grout plugs in secant pile structures and also jet grouting safe havens for the TBM, as well as excavating the connecting adit at the 4th Street shaft in frozen ground and starting structural concrete work for sewer diversion at 4th Street. Finishing work is underway for the cement-bentonite soldier pile walls at Mount Olivet Road.

The Northeast Boundary Tunnel is part of an overall $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. The 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. Final Completion is scheduled 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; 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 Fabio Ciciotti at 202-615-0652.

GEORGIA

Athens

Upper North Oconee – Phase 2B Trunk Sewer Replacement
Bradshaw Construction Corp.

Bradshaw Construction has begun construction in Athens-Clarke County for re-alignment of a gravity sewer line. Bradshaw has just completed the first tunnel drive spanning 116 ft under the Athens Line Railroad, in which 60-in. steel casing was jacked behind an AVN 1200 MTBM. 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 maneuvered 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 be completed in March 2021. Project members include Athens-Clarke County (Owner), Garney Construction (General Contractor) and Bradshaw Construction working as the tunneling subcontractor.

/**** Advertisement ****/

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

Atlanta

Niles Avenue Sewer Improvements
Bradshaw Construction Corp.

Bradshaw Construction 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 on three separate tunnels utilizing both the TBM and MTBM. The Robbins TBM has finished mining through a 1,000-ft radius curve in a bald rock tunnel spanning a total distance of 713 lf. Bradshaw also completed mining with the MTBM simultaneously, which spanned a distance of 346 lf in mixed ground conditions. The last tunnel, 701 lf, combines the use of both tunnel boring machines. The MTBM was launched 415 lf one direction into wet silty clay, while the Robbins TBM launched in the opposite direction to receive the MTBM within the rock portion of the drive. The Robbins machine will be backed up into the shaft and the MTBM will be jacked the remainder of the way. Once complete, 18-in. DI pipe will be installed and backfilled. Construction is expected to be completed October 2020.

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

ILLINOIS

Bedford Park/McCook

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

The McCook Reservoir, Des Plaines Inflow Tunnel project is a $107.7 million project for the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC). NTP was July 9, 2016, with estimated date of completion on Nov. 19, 2021

The project comprises approximately one 5,850 lf of tunnel (20-ft concrete lined finished diameter), approximately 280 ft deep, one 12-ft diameter construction shaft, and one 45-ft diameter gate shaft. The tunnel was excavated all through bedrock with the use of a drill & blast method.

The job is about 78% complete. Major milestones completed was excavation of construction & gate shaft, excavation and lining of 20-ft diameter tunnel, and connection to Stage 1 of the McCook Reservoir with subsequent tunnel plug when the reservoir became live in 2017. Upcoming milestones will be the delivery of two 22-ft by 21-ft steel gates and hydraulic cylinders to control water within the tunnel when it becomes live. Once gates are installed, the contractor will make the connection into the existing live 33-ft tunnel on the North end and remove the plug on the south end (reservoir side). Current construction activities are lining the 45-ft diameter gate shaft with concrete and constructing the Control Building which will house all of the mechanical equipment for the gates.

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

Tunnel & Gate Designer was Black and Veatch Corporation, Walsh Construction Manager is Mark Fournier, MWRDGC Project Manager is Kevin Fitzpatrick, Mining Company in charge for excavation of Stage 1 of the McCook Reservoir was Vulcan Materials (Vulcan & Walsh needed to coordinate their work when the proposed tunnel was connecting into the reservoir), Major subcontractors were Linita Design & Manufacturing Group, Pagoda & Electric Construction Inc., Truck King Hauling, Terrell Materials Corporation, Atlantic Painting Company and Steppo Supply & Construction Inc.

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

INDIANA

Fort Wayne

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

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

Through the end of August 2020, TBM excavation is approximately 53% complete, and is scheduled to complete in May 2021.

Tunnel Designer: Black & Veatch, Construction Manager: Jacobs, Major Subcontractors: CSI Tunnel Systems, Keller – North America, Kokosing Industrial, Hardman Construction, Bunn, Inc., Shambaugh & Son, LP, TBM Manufacturer: Herrenknecht.

Key Project Personnel: Owner/City of Ft Wayne: Mike Kiester (Manager, City Utilities Engineering), TJ Short (Senior Program Manager, Sewer Engineering); Tunnel Designer/Black & Veatch: Leo Gentile (Senior Project Manager), Matthew Pierce (Project Manager), Construction Manager/Jacobs: Todd Webster (Construction Contract Manager), Contractor/Salini Impregilo Lane JV: Daniele Nebbia (Vice President of Tunneling Operations), Bill Dean (Project Director), Lance Waddell (Project Manager), Brad Krumel (Construction Manager), Francesco Chiappalone (Technical Manager). Information: Lance Waddell at lwaddell@laneconstruct.com.

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 10, 2019, completing close to 41,000 ft of mining. As of September 2020, 1,700 ft of adits have been drilled and shot, including one single run of 1,112 ft. Additionally, concrete 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; Operations Manager: Percy Townsend; Design Engineer: Dr. Ran Chen; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Max Engen, Marvin Ko.

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

Indianapolis

Fall Creek Tunnel
Shea-Kiewit JV

The Fall Creek Tunnel is a 20,244-ft, 20-ft, 2-in. diameter bored tunnel with an 18-ft finished concrete lining (approximately 250 ft deep). There are 10 CSO connecting structures/deaeration chambers and adits. The work is for Citizens Energy Group’s DigIndy project, which is a CSO reduction program including six deep rock tunnels totaling over 28 miles.

Mining commenced in September 2019 from a 30-ft diameter shaft that was previously constructed as the retrieval shaft for the White River Tunnel alignment. After successfully mining the White River Tunnel, the TBM mined through the shaft and underwent a minor refurbishment. Mining was completed on April 1, 2020. The tunnel terminated approximately 2,400 ft past the retrieval shaft location. The TBM was backed up and parked downstream of the shaft, and the remainder of the shaft was shot down to the invert. The TBM has been retrieved and transported to the site of the Pleasant Run Tunnel launch shaft, where it is undergoing a full refurbishment before mining the final leg of the DigIndy system. The Fall Creek Tunnel has over 5,200 ft of adits, and adit excavation is ongoing. Based on the terms of a federal consent decree, the Fall Creek Tunnel must be operational by the end of 2025.

Key Project Personnel – Construction PM: Christian Heinz; Operations Manager: Percy Townsend; Design Engineer: Dr. Ran Chen; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Max Engen, Marvin Ko.

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

Indianapolis

Pleasant Run Tunnel
Shea-Kiewit JV

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

Slurry wall installation for the launch shaft occurred in the Summer 2019. The launch shaft has been excavated to the invert elevation, and the contractor has started excavation of the 610-ft long starter tunnel. The TBM completed mining the Fall Creek Tunnel in April 2020 and was delivered to the Pleasant Run launch shaft site where it is undergoing a full refurbishment prior to reassembly underground. Mining is anticipated to commence by the end of 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 9 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; Operations Manager: Percy Townsend; Design Engineer: Dr. Ran Chen; Safety Manager: Kyle Shickles; Field Engineers: Eric Haacke, Max Engen, Marvin Ko.

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
Shea-Traylor JV

The Ohio River Tunnel for the Louisville and Jefferson County Metropolitan Sewer District (MSD) is 21,300 ft, 22 ft excavated, 20 ft finished diameter, 200 ft deep with 6 shafts. Ground conditions include limestone and dolomite rock, potential fault zones, and potential natural gas zones in the rock.

Natural gas was encountered through probe holes drilled ahead of the TBM on Aug. 26, 2020, when the TBM cutterhead was at STA 195+86. Gas was only detected at the tunnel face. No gas was detected on the TBM trailing decks, rest of the tunnel, or working shaft. It took a few days of continuous tunnel ventilation before the gas levels were below 10% LEL at the tunnel face. S-T JV resumed probing and grouting operations, and the TBM is now past this zone.

TBM excavation is 98% complete. Approximately 300 ft before hole-through at the Retrieval Shaft/DS06. Construction of the adit connecting Drop Shaft DS01 to the main tunnel is complete. S-T JV has started concrete lining the Tunnel Bifurcation section.

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 recently completed constructing twin liner plate tunnels for a siphon installation by hand mining in Baltimore. The 48- and 72-in. liner plate tunnels extended approximately 24 ft each, passing directly underneath an existing precast 66- by 84-in. twin storm drain with no clearance. After the tunnels were completed, 18- and 54-in. DIP lines were installed and backfilled in the liner plate tunnels. Ground conditions were predominantly shot rock and sand fill with decomposed rock in the invert. The project was completed in July 2020. The project members included 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)

SEM Tunnel excavation was completed in March 2019 and installation of water-proofing and the Secondary Liner in November. Construction of the cut-and-cover structure at the east end of the tunnel was completed in June 2020 and concrete work for the approach structure is ongoing.

Sinking of the shaft in Bethesda by drill-and-blast is in progress as well. Current depth is approximately 90 ft. Crews completed placement of the cast-in-place liner required to be installed before cavern excavation can commence in May this year. 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: Vernon Hartsock; Concessionaire’s Project Manager: Peter Van der Waart; PLTC: Project Manager Scott Risley; Construction Manager: Ken Prince; Underground Construction Manager: Jean-Marc Wehrli.

NEW YORK

Gilboa

Schoharie Reservoir Low Level Outlet
Southland/Renda JV

This $142.6 million project for NYC DEP comprises two 9.5-ft microtunnels: a 1,225-ft land leg drive and a 950-ft water leg drive with wet retrieval from the bottom of reservoir at a depth of 160-ft. Both microtunnels are complete. An unplanned extensive rebuild of the machine was required between the two drives due to significant wear of both internal and external parts. Both line and grade were within tolerance for both tunnel drives. Wet retrieval required an adjustment to the original planned operation necessitating field adjustments to the means and methods.

NTP was issued June 29, 2015. The estimated date of completion is December 2021.

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

Key Project Personnel: SRJV Project Manager, John Arciszewski; Field Operations Manager, Chris Davis; Project Engineers, Tim Bray, Joe Janke, Ammar Fallaha, Christy Ellis; Superintendent, Douglass Somers; Safety Manager, Jose Perdomo.

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.

Tunnel excavation is complete. Workers have also completed the steel inter-liner installation. A total of 230 sections of inter-liner have been installed. Workers have also completed placing cellular grout behind the liner. The final cast-in-place lining placement has started and will continue into 2021. Some work remains to complete the shafts, along with the final connection of the new tunnel to the existing Delaware Aqueduct.

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

OHIO

Cleveland

Doan Valley Tunnel Project
McNally/Kiewit DVT JV

The Doan Valley Tunnel is a $142.3 million CSO abatement project for the Northeast Ohio Regional Sewer District (NEORSD) comprising:

  • Two conveyance tunnels (WCT and MLKCT): 8.5-ft finished diameter for a total length of 9,400 lf. Mined with a 12-ft dia. Robbins Main Beam TBM. Two passes: Rib-and-lagging as initial support; Precast concrete pipe as final liner. Tunnel depth: between 30 and 100 ft below grade.
  • One main tunnel (DVT): 18-ft finished diameter for 10,000 lf. Mined with a 20.75-ft dia. Herrenknecht Single Shield Hard Rock TBM. One pass: universal ring, 5+1 segments (fiber reinforced). Tunnel invert depth: between 50 and 100 ft below grade. Intercepting pre-existing brick sewers up to 3 ft above the tunnel crown.
  • Seven shafts between 23 and 55 ft in diameter; 30 to 100 ft in depth.
  • The geology is primarily Chagrin Shale bedrock for all three tunnels, except for a short reach at the very end of the WCT drive, in Cleveland Shale. Both Chagrin and Cleveland shale rock masses are characterized by low UCS (up to 2,800), clay-filled bedding joints, weathered interbeds, and tendency for slaking.
  • The WCT 12-ft diameter tunnel drive was completed on Dec. 12, 2018. Pipe installation and cellular grout backfill were completed on July 30, 2019. The DVT tunnel drive was completed on Sept 7, 2019. The DVT Starter Tunnel, 18-ft diameter with 300 lf of Synthetic Fiber Cast-In-Place Concrete, completed operations on April 17, 2020.
  • The MLKCT 12-ft diameter. tunnel drive was completed on Jan. 15, 2020, and pipe installation operations were completed on April 8, 2020, with cellular grout backfill completed Aug. 28.
  • Remaining work includes near surface structure work, final shaft concrete work; Installation, along with final testing and commissioning, for automated hydraulic sluice gate tunnel flow control system; and Removing temporary flow maintenance/control devices and introducing flow to tunnel along with restoration of sites. The overall project is 93% complete.

Designer: McMillen/Jacobs Associates – Wade Trim; Construction Manager (NEORSD): Bob Auber; Construction Supervisor (NEORSD): Karrie Buxton.

Major Subcontracts: CSI-Forterra (18-ft ID precast concrete segments); Northstar (Concrete Structures); BASF (DVT annular grout and ground conditioning); PIG (cellular grout); Jennmar (steel ribs); Northern Concrete Pipe (8.5-ft ID precast pipes).

Key Project Personnel: Chris Lynagh – Project Manager McNally/Kiewit DVT JV; Joe Teter – General Superintended McNally/Kiewit DVT JV; Collin Schroeder – Shaft/Structures Engineer McNally/Kiewit DVT JV; Adam Hornbeck – Superintendent/Walker McNally/Kiewit DVT JV; Lance Jackson – Project Engineer McNally/Kiewit DVT JV; Brian Negrea – Tunnel Engineer 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.

Cleveland

Westerly Storage Tunnel
Jay Dee Obayashi JV

The Westerly Storage Tunnel is a $135 million project for the Northeast Ohio Regional Sewer District (NEORSD). It is a component of the district’s 25-year Project Clean Lake CSO program. The project is approximately 68% complete.

Recent activities include:

  • Shaft final concrete structure at site WST-1:
  • Approx. 6,700 cy of cast-in-place concrete placed (approx. 215 vertical ft of shaft lining).
  • Overall shaft final concrete currently 85% done.
  • Shaft final concrete structure at site WST-2:
  • Approx. 2,200 cy of cast-in-place concrete placed (approx. 267 vertical ft of shaft lining).
  • Overall shaft final concrete currently 100% done.
  • Restoration of site WST-2:
  • Site restoration is currently 70% done.
  • Tunnel excavation with Tunnel Boring Machine (TBM) at WST-3:
  • Approx. 265,000 tons of rock excavated.
  • Mining currently 52% done.

Tunnel Designer: Stantec Mott MacDonald Westerly JV; Construction Manager: 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.; TBM Manufacturer: Lovsuns.

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

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 was mined in intact gneiss bedrock using a double shielded rock gripper TBM. Shaft construction consists 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.

Tunnel hole through occurred on Sept. 17, 2020. The project is now in the loading of the 84-in. Hobas liner pipe phase, which should be completed by the end of 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), 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

Joes Creek Interceptor
Southland Contracting Inc.

The $15.8 million Joes Creek Interceptor project for the City of Dallas comprises 8,370 lf 60-in. excavated diameter tunnel with 36-in. HOBAS Carrier pipe and 20 shafts (ranging from 21 to 48 vf). Ground conditions change drastically and include sand, sand with gravel, sandstone, sandy clay, shaley clay, and shale (Eagle Ford). Tunneling encompasses three methods: 60-in. Herrenknecht microtunnel boring machine (76% of job), 60-in. double-shield, open-faced, rigid, steering-shoe guided TBM (designed and fabricated by Southland Holdings) (23% of job), and 54-in. casing by jacking and hand mining (1% of job).

Crews have completed excavation of 15 of 21 shafts and 14 of 17 tunnels (73% of tunneling by footage). They are installing carrier pipe and manholes and backfilling shafts as they go. Nineteen of 21 shafts are in high-traffic streets of Dallas. Southland completed a 1,256 lf, 60-in. microtunnel drive within 1/16 in. of centerline.

Owner: City of Dallas; Lead Designer: Hazen and Sawyer; CM: City of Dallas; TBM Manufacturer: Southland Contracting, Herrenknecht.

Key Project Personnel: SCI Operations Manager: Kent Vest; SCI Project Manager: Elliott Fuller; SCI Senior Engineer: Fareed Imoro; SCI General Superintendent: Homero Lugo.

Dallas

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

This $206.7 million project for the City of Dallas includes 26,385 lf of tunnel, 32.5-ft excavated diameter (30-ft ID), 8 Intake Shafts (ranging from 120 to 200 vf), and 6 lateral tunnels excavated by roadheader or excavators/breakers. The tunnel is being excavated by a Main Beam TBM through primarily Austin Chalk.
Crews completed excavation of five shafts and currently excavating two shafts ranging from 22 to 35 ft diameter and 110 to 190 ft deep. Mining with the Main Beam TBM is ongoing and have excavated approximately, 5,000 lf. The estimated date of completion is March 4, 2023.

The TBM is equipped to bore diameters of 37-ft, 7-in. and 32-ft, 6-in. The final liner is a 15-in. thick cast-in-place final concrete liner. There are six working sites within city environment, and tunneling occurs under city infrastructure (including state highways, light rail tunnels/surface tracks, rail roads).

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.

Houston

Northeast Transmission Line
Harper Brothers

The City of Houston, along with four regional water authority partners, is currently designing and constructing the Northeast Transmission Line, the largest water line project in its history. A series of 120-in. and 108-in. water transmission lines, with 96, 84, 66 and 54-in. interconnections, is being built to convey up to 96 million-gallons-per-day (MGD) to the City of Houston and 269 MGD to the regional water authorities. Once built, the waterline will serve approximately 900,000 homes.

The NETL projects are split into 13 contract segments. One of the segments – a 108-in. water line along city easements – required 5 tunnel crossings. The longest tunnel, which passes underneath the TxDOT Highway, Interstate 69, had numerous complications. To start with, it had a length of 1,150 ft with a minimum primary liner diameter of 130-in. The overpass itself contains 15 lanes of traffic, and the frontage roads contain an additional eight lanes. Soil conditions for the tunnel varied from full face of clay to a mixed face consisting of clay and sand, and to a full face of sand. A 400-ft section of the drive showed coarse, non-cohesive soils under the water table. Furthermore, due to the nature of the soil strata, TxDOT required the development of a tunnel excavation strategy that limited the potential for loss of ground and settlement, as well as possible impacts to the bridge. Construction of this tunnel began in December 2019. Despite these challenges, this $11 million tunnel was successfully completed on schedule in May 2020. A 137-in. Herrenknecht Earth Pressure Balance Machine (EPBM) with 135-in. Permalock pipe was used for the installation. Lockwood, Andrews, and Newnam, Inc., (LAN), served as the designer and Harper Brothers Construction, LLC. constructed the project.

Kerens

Integrated Pipeline Project 108-in. Pipeline – Trinity River Tunnel
IPL Partners

This $48.5 million project for the Tarrant Regional Water District comprises 4,400 lf of 15-ft, 7-in. excavated diameter tunnel (13-ft, 10-in. finished diameter) with three shafts (ranging from 60 to 150 vf). Crews are using an open-face TBM with hydraulic jacks and concrete segmental lining to mine through weathered mudstone with various faults.

The project is 86% completed with tunnel excavation complete. Currently crews are installing 108-in. steel pipe in tunnel with a pipe carrier.

Concrete segments were cast on site with the contractor’s segment forms. Tunneling included a river crossing of approximately 700 ft underneath the Trinity River with 50 ft or less of ground cover. Tunneling is at a grade of 6.6%. Completion is anticipated by March 8, 2021.

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

IPL Partners Operations Manager: Kent Vest; IPL Partners Project Manager: Jose Jimenez; IPL Partners Project Engineer: Hossein Mirenayat; IPL Partners Superintendents: Genaro Ramos and Mario Ramos.

McKinney

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

This $12.4 million project for the North Texas Municipal Water District involves the construction of 2,534 lf of 118-in. excavated diameter tunnel using 4-flange liner plate, into which 84-in. steel carrier pipe will be placed. There are two shafts: Launch shaft – 30-ft clear diameter with 4-flange liner plate and ring beams in overburden; Receiving shaft –25-ft, 9-in. clear diameter with 4-flange liner plate and ring beams in overburden. Crews are using a double-shielded, open faced, gripper type machine with articulated steering to mine through Austin chalk.

The main shaft is excavated and the receiving shaft is 50% excavated. Tunnel excavation is 20% complete. Crews will tunnel under the East Fork of Trinity River and BNSF Railroad tracks, and are working in remote area.

Owner: North Texas Municipal Water District; Lead Designer: HDR; Tunnel Designer: Stiver Engineering; CM: Freese & Nichols; General Contractor/Program Manager: Garney Construction Inc.; TBM Manufacturer:Bruce Richardson, Southland Contracting; Tunnel Contractor: Southland Contracting Inc.

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

WASHINGTON

Seattle

Ship Canal Water Quality Project
The Lane Construction Company

The $254.9 million Ship Canal Water Quality Project for Seattle Public Utilities comprises 13,939 ft of 18-ft, 10-in. ID segmentally lined tunnel using a pressurized face TBM. Tunnel depth ranges from 35 to 85 ft below grade to top of tunnel. Also included is conveyance pipe casing under the Ship Canal installed via a curved microtunnel drive, 646 lf and 94-in. diameter.

There are five shaft sites: 1 slurry wall shaft – West Shaft site in Ballard (tunnel launch site); 3 secant pile shafts – Fremont site, Queen Anne site, and East Shaft site in Wallingford (tunnel exit shaft); and 1 drilled shaft using a steel casing – East Ballard site.

Anticipated ground conditions along the tunnel alignment consist of a highly variable mix of glacially over-consolidated soils

The project is currently 10% complete. Crews have mobilized to all 5 shaft sites, and have completed the slurry wall at the West Shaft site. Upcoming work for the next 6 months includes construction of the five shafts.

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

Owner: Seattle Public Utilities: Keith Ward – Project Executive; Cynthia Blazina – Construction Manager; Alan Lord – Program Manager; Eleanor Jackson – Design Manager; Stephanie Secord – Project Manager. Construction Management Firm: Jacobs Engineering: Greg Colzani – Tunnel Construction Management Leader; Roger Mitchell – Supervising Resident Engineer. Design Firm: McMillan Jacobs and Associates: Jeremy Johnson – Design Manager; Dan Dreyfus – Tunnel Design Lead; Contractor: The Lane Construction Company: Daniele Nebbia – Project Director; Fabrizio Fara – Project Manager; Kevin Murray – Construction Manager; , Glen Frank – Technical Manager.


CANADA

BRITISH COLUMBIA

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 that will improve reliability and increase capacity for Metro Vancouver to deliver drinking water throughout the Vancouver area. Project consists of two shafts (18mØ x 68m and 10mØ x 110m) on either side of the Burrard inlet that are connected by 1,100 m of 5.8m ID, 6.7m excavated diameter segmentally lined tunnel that will be constructed with a mix shield TBM. Ground improvement includes a safe haven constructed using ground freezing 400 meters into the drive. Three permanent water mains (2 @ 2.438m, 1 @ 1.524 m) will be installed within the tunnel, up both shafts and into large underground valve chambers atop each shaft.

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

South shaft is now 70 meters and excavation scheduled to be complete in Q1 2021. TBM and supporting infrastructure are assembled and commissioned at the north site with launch slated for late Q3 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, Bill Crider.

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

Vancouver

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

NTP on this $184 million (CAD) project for Metro Vancouver was provided in July 19, the construction started in fall 2019, and tunnel excavation will begin in December 2020. The project 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 including:

  • two 15 and 10 m ID 40 m deep slurry wall shafts
  • two segmental lining tunnels 4.20 m ID (200 m and 580 m long) with a slurry TBM
  • one river riser and 2 x 110 m long 2.5 m ID diffuser pipe buried in the Fraser River bottom;
  • a new water control structure

The 15 m ID launch shaft is excavated and the invert slab is poured. Final lining is under construction. The second inland shaft has been excavated and the base slab will be cast mid September. All jet grouting activities are now complete. The factory acceptance tests of the slurry TBM were completed in France on Aug. 27. Marine work in the Frasier River for the octagonal cofferdam started on July 2 by the installation of the sheetpile template. Sheetpiling with protection against erosion 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, led by Ed Kennedy, is the project designer; Hatch, led by Tim Langmaid, is the construction manager; Bessac is the TBM manufacturer; MS is the slurry treatment plant manufacturer; MSE is the segment precaster; ARUP is the contractor engineer for the tunnel section.

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

ONTARIO

Toronto

Ashbridges Bay Treatment Plant Outfall Project
Southland | Astaldi Joint Venture

A $300 million project located in the east-end of Toronto consists of a 3.5-km long outfall tunnel, an 85-m deep shaft, an effluent conduit structure, and 50 offshore risers. The wastewater treatment plant outfall is the point at which the effluent is discharged back into Lake Ontario. The new outfall tunnel will improve water quality at the city’s shorelines and beaches after completion. The purpose of the new outfall tunnel is to increase its capacity and better convey the effluent from the plant into the lake, as well as to better operate under conditions such as rainstorms.

The 8-m diameter single shield tunnel boring machine will be launched from the 16 meter in diameter shaft located at near the shoreline of Lake Ontario. The 51-m diameter risers will intersect the tunnel along the final kilometer span at 20-m spacing. The tunnel will be lined with precast segments, which will be transported to the TBM using multi-service-vehicles (MSVs).

Secant piles have been installed and 80 m of shaft excavation through soil and Georgian Bay shale has been complete. A 107-m long starter tunnel has been excavated and supported using wire mesh, rock bolts, and shotcrete. The 110-m long TBM will be delivered in September and assembled in the starter tunnel.
The offshore portion of the project is subcontracted out to Johnson Brothers, part of the Southland Holdings family of companies. Thirteen risers have been drilled and installed and pressure tested. The risers are vertical stainless-steel pipes which will diffuse the treated effluent into the lake. As the tunneling work advances, the tunnel-riser connection work will be performed from the tunnel, which includes removing the already installed segments located at and near the crown.

In 2022 construction of cast-in-place concrete conduit structure will also get underway. Intended to direct effluent from the plant to the shaft, it will include two 4-m -high by 4-m wide secondary conduits and two bypass units measuring 7 m wide by 4 m high.

Owner: City of Toronto; Consultant: Hatch with Jacob & Baird; Contractor: Southland | Astaldi JV; Project Manager (Joe Savage); Deputy Project Manager (Francisco Urrutia); Technical Manager (Khaled El-Kalawi); General Superintendent (Curtis Bahten).

Share.

About Author

Comments are closed.