TBM Tunneling under High Water Pressures Rondout West ......Kiewit-Shea Constructors, AJV • Groundwater Head • Ranges from 675 ft to 875 ft • Max. Heading Inflows Ungrouted •

Kiewit-Shea Constructors, AJV

TBM Tunneling under High Water PressuresRondout West Branch Bypass Tunnel

2019 TUNNELING SHORT COURSE12th Annual Breakthroughs in Tunneling Short Course September 9-11, 2019


NYC Water Supply System

• 3 Upland watershed systems• Delaware (50% total supply)• Catskill (40% total supply)• Croton (10% total supply)

• 3 Aqueducts• Delaware• Catskill• New Croton

• 4 Tunnels• City Tunnel No. 1• City Tunnel No. 2• City Tunnel No. 3• Richmond Tunnel

50% 40%

10%

Project Overview – NYC Water Supply

Kiewit-Shea Constructors, AJVProject Overview – RWBT Leaks

Wawarsing Crossing

Roseton Crossing

RWBT Currently leaking between 15 MGD and 35 MGD in 2 locations:• Roseton Crossing

• ~1030 ft in length• Wawarsing Crossing

• ~600 ft in length

• In service since 1944• 13.5’ Finished ID• Depth of 300-2300 ft

below surface• Crosses Hudson ~600 ft

below surface of water• Maximum capacity of 900

MGD• Average yearly utilization

of 600 MGD• 11 shafts along alignment

Kiewit-Shea Constructors, AJVProject Overview – Existing Tunnel


Project: Rondout-West Branch Bypass TunnelContract: BT-2Owner: NYC Department of Environmental ProtectionContract Type: Lump Sum/Unit PriceContract Value: $706.6MBid March 27, 2015Start Work June 2016

Project Overview


Kiewit-Shea Constructors, AJVProject Overview – Bypass Tunnel Layout

Project Plan View


• Structural components– Collar mounted base frame

structure– Muck head frame– Supply head frame– Muck and supply back legs– Twenty-eight person personnel

cage– Muck car bails and muck cars– Movable 140-ton shaft cover

• Structural weight over 625 US tons

8

Shaft 5B Hoist & Headframe


9

Shaft 5B Hoist & Headframe


10

Shaft 5B Site Layout

Kiewit-Shea Constructors, AJVShaft 5B Muck Dump

Kiewit-Shea Constructors, AJVShaft 5B – Drill& Shoot: Bell Out, Starter and Tail Tunnel

Summary of Work:Location Length QtyShaft 43’-10” 50 VF 2,571 CYGantry Chamber 45’ HS 50 LF 2,691 CYTail Tunnel 25’ HS 30 LF 620 CYStarter Tunnel 25’ HS 300 LF 6,120 CYWest Connection 20’ HS 160 LF 2,116 CY

TOTAL: 14,118 CY

Kiewit-Shea Constructors, AJVShaft 5B – Bell Out, Starter and Tail Tunnel


Tunnel Reaches• Reach 1 - 2,560lf – Shale (Normanskill Formation)• Reach 2 - 3,900lf – Limestone & Dolomite (Wappinger Formation)• Reach 3 – 3,500lf – Limestone & Dolomite (Wappinger Formation)• Reach 4 – 2,540lf – Shale (Mount Merino Formation)

Project Overview – TBM Tunnel Geology


• Groundwater Head• Ranges from 675 ft to 875 ft

• Max. Heading InflowsUngrouted

• TBM: 250 – 1300 gpm• D&S: 100 – 500 gpm

• Solution Cavities 3 – 30 lf, 5 – 30 Cy of flowing material

• Reach 2: 3ea• Reach 3: 6ea

Maximum AverageReaches 1 and 4 34,000 10,000Reaches 2 and 3 54,000 35,000

UCS

Project Overview – TBM Tunnel Geology

Kiewit-Shea Constructors, AJVRock Cores


• Robbins Single Shield TBM w/ Precast rebar reinforced 6 pcs segments

TBM Tunnel Quantities:Excavation – 12,419LF Exc. Diam. – 21.7ftReinforced Precast Liner – Width= 5ft; ID/OD=18’-2”/20’-4” Annulus Grout – 20,600NCyMuck –170,000BCy

Robbins Tunnel Boring Machine


• Delivery of Cutterhead Support

TBM Assembly

Kiewit-Shea Constructors, AJVTBM Assembly

Kiewit-Shea Constructors, AJVTBM Carrier

• Moved TBM sections under hoist

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TBM Assembly

Kiewit-Shea Constructors, AJVTBM Assembly

Kiewit-Shea Constructors, AJVProject Overview – Tunnel Segments

Kiewit-Shea Constructors, AJVTBM Tunneling under High Water Pressures

Groundwater Control• Risks

– High Water Pressure – Flush Flows– Water Bearing Feature – Wash Out Annulus

Grout • Tools for two stages of

work– Preemptive Tools – Reactive Tools

Old Faithful

Kiewit-Shea Constructors, AJVPre-emptive Tools

• Original Project Data • Probe Drilling • Geo-physical Look Ahead • Pre-Excavation Grout

Kiewit-Shea Constructors, AJVOriginal Project Data

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Section 31 71 19 TBM Excavation• Probe holes overlapped minimum of 20 feet. • Probe holes outside the tunnel perimeter shall be

backfilled with grout• Probe holes shall be monitored and recorded by the

Contractor

TBM Probeholes

1. Hole ID; 2. Start/end time for each drill rod; 3. Water inflows encountered by hole depth; 4. Rod drop or rapid advancement due to voids or open apertures; 5. Bound or stuck drill steel and depth of occurrence; 6. Plugged steel; 7. Collapsing hole; 8. Flowing ground.

Kiewit-Shea Constructors, AJVProbe Hole Drilling

• 2 each drills capable of drilling through Cutterhead (CHD)

• 8 + 8 drilling ports in CHD

• 1 each drill to drill through front shield

• 14 drilling ports in shield

• Mobile drill for relief holes& cut-off grouting

Kiewit-Shea Constructors, AJVProbe Hole Drilling – cont’d

Specifications state:• Probe holes must overlap 20

feet• 2 probe holes in Reach 1& 4• 4 probe holes in Reach 2 & 3

Drilling Equipment• Down Hole Hammers

– Ideal for drilling in water environment

– Straighter drilling compared to top hammer drilling

• Blowout Preventers • Stand Pipe/Collar Pipe

Kiewit-Shea Constructors, AJVTBM Drilling Positions

Kiewit-Shea Constructors, AJVGeophysics Look Ahead

• Use Ground Penetrating Radar (GPR) through our probe drill holes

Kiewit-Shea Constructors, AJVPre-Excavation Grout (PEG)

Definition: • Grout before excavation of

the ground to control water inflow and solidify the mass

Specifications state:• Trigger:

– 0.3gpm/ft.-probe– 30gpm/feature

Kiewit-Shea Constructors, AJVTBM PEG Equipment

Hany Agitator HRW1200

Hany Grout Pump ZMP 726V

Hany Mixer HCM 610

Kiewit-Shea Constructors, AJVReactive Tools

• TBM Dewatering Equipment• Bullflex Ring / Stage II Grout / Chem Grout• TBM Bulkhead (Sealing Machine)



So How Did We Do?TBM Launch 1/8/2018



TBM Mining Operations







Kiewit-Shea Constructors, AJVPre-Excavation Grout

• First round of PEG Ring 1513• Last round of PEG Ring 1852• PEG 1,700lf/12,500lf or just under 15% of

drive • 16 Rds of PEG Grout • 180,000lbs of Type III cement consumed

Kiewit-Shea Constructors, AJVGrout Packers

Kiewit-Shea Constructors, AJVSingle Use Inflatable Packers



TBM Grouting Operations

Kiewit-Shea Constructors, AJVPEG Grouting Operation

Kiewit-Shea Constructors, AJVTBM Tunnel Dewatering • TBM 800gpm + 1700gpm emergency dewatering• 8”+10” Tunnel discharge lines• Shaft Bottom pumps – 2x800hp -2,500gpm/ea• Max 350gpm during TBM drive – Most of the water inflow from drain

holes thru liner behind the TBM

Kiewit-Shea Constructors, AJVHi-Pressure Water

Kiewit-Shea Constructors, AJVStage II Grout / Chem Grout

Kiewit-Shea Constructors, AJVTBM CarrierTBM Hole Thru 8/13/2019

Kiewit-Shea Constructors, AJVRight Now: TBM DemobeTo help protect your privacy, PowerPoint has blocked automatic download of this picture.

Kiewit-Shea Constructors, AJVSo How Did We Do?

TBM TunnelingSchedule:• TBM Launch 1/8/2018• Hole Thru 8/13/2019

TBM Performance:• Best Shift 35ft• Best Day 90ft• Best Week 360ft

Kiewit-Shea Constructors, AJVRemaining Work

• Welded Steel Pipe Liner 9,200 LF 16-ft. ID x 1-in. thick• Cellular Concrete Backfill between steel liner and

segments• Reinforced Concrete Liner - 14’Ø (finished ID) x

12,500 LF • Tie-in Phase


Questions?

Documents

TBM Tunneling under High Water Pressures Rondout West ......Kiewit-Shea Constructors, AJV • Groundwater Head • Ranges from 675 ft to 875 ft • Max. Heading Inflows Ungrouted •