Neelum Jhelum Hydroelectric Project: Construction of Tunnel System
Robert Magna: Principal Construction Engineer • MWH/Stantec
Peter Dickson: Global Geotechnical Practice Leader • MWH/Stantec
10th Annual Breakthroughs in Tunneling Short Course
CHICAGO | August 14-16, 2017
Outline
1 Introduction: Project Location and Key Features
2 Issues & Challenges
3 Introduction of TBMs 2 years into Project
4 Contractual Issues
5 Lessons Learned
Project Location and Key
Features
1
• Located in Lower Himalaya,
Jammu & Kashmir, Pakistan
• 969 MW run-of-river
hydroelectric project
• Resources – Neelum River,
tributary of Jhelum River
Project Location
• Design Engineering and CM
– also a JV
• MWH (Stantec) /Norplan
/NESPAK /ACE
• Owner – WAPDA (Govt of
Pakistan)
• Construction Contractor is
Chinese Consortium –
CGGC and CMEC
Key Players and Contracts
• Three Construction Lots
• Construction started 2008
• Estimated complete 2018
• Construction Cost - $ 2.75
billion - $5 billion
Tunnel Lengths (km)
Headrace
• Drill-blast 26.1
• TBM 21.5
Tailrace
• Drill-blast 3.5
Access Tunnels
• Powerhouse 2.5
• Construction 10.8
• Surge 3.2
67.6 km
(42 miles)
Essentially this is a
Tunnel Project
The Underground Power Station Complex
– Example of Tunnel Complexity
Tunnel Configurations
• Various tunnel profiles and lining types,
depending on hydraulic and structural
requirements
• Wide range of excavation methods
• Tunnel exc. = 8.00 m – 11.70 m (26’ to 38’)
• Almost exclusively classified as rock tunneling,
except short sections of soft ground (faults,
etc.)
Project Issues & Challenges
Technical & Non-Technical
2
Tunnel Alignment – Technical Challenges
• Complex Himalayan geology
• Weak rock units, severe deformation
• High seismic hazard - Active faulting
• High cover – convergence, rock burst
• Low cover – steel-lining, hydrojacking,
pre-exc grouting
Groundwater Ingress at High P and High Q
• 15 - 20 bars (200-300 psi)
• Potential for erosion of weaker materials
and washout of infills
• Potential to destabilize excavations
• High volume inflows, infinite recharge
• At any one location up to 15,000
l/min (4,000 gpm)
• Pre-excavation grouting required (5 km)
Tunnel Collapses and Major Water Inflow
• Four major incidents involving partial
tunnel collapse
• Major or exceptionally high water inflows
• Collapse remediation involved:
• Temporary concrete and backfill
plugs
• Staged grouting at pressures up to 50
bars
• Grouted pipe umbrellas for support
across areas of chimney failure
• Remote Site – Impact on Logistics
• Third World Location – Influencing:
• Logistics
• Labor
• Social/cultural/political issues
• Multiple languages
• First major tunnel project in country, largest civil works project
• Steep learning curve for Owner and country at large
• Construction Contract let too early, before design complete
• Financial Issues - Payments
Non-Technical Challenges
Introduction of TBMs 2 Years
into Contract:
3
TBM Variation Order
2 Years into Construction……
• Change 22 km of Twin Drill-Blast Tunnels to Twin TBM Tunnels
(72,200 lin ft)
• 8.5 m diameter (27 ft 10 in)
Issues - starters:
• Three different languages
• Three different currencies
• Existing Contract Base Year is 2007
• Work on the Twin Tunnel Change Starts in 2009
• Work on the Contractual Change (Variation
Order) Starts in 2011
• No TBMs planned or ordered
• No Camps to accommodate additional resources
• No Power Supply for TBMs
• No access to Site for TBM Main Bearing and Other Large TBM Components
• No TBM Tunnel Personnel
• No mechanism except the MOU for the Change.
• CGGC (Contractor) the only option
April 2011
• Memorandum of Understanding (MOU) between the Client & Contractor is executed in April of 2011 to recover schedule, “to the whole of the works”, the contractor proposed using 2 TBMs
• What the MOU outlines:
• Advance of funds to the Contractor to purchase the TBMs
• Parties shall negotiate a variation order
• Commercial Considerations
– Establishment of new payment items or adjustment to existing sums, rates, and BOQ quantities shall be agreed to by the Parties
Issues - continued:
Items Already in Progress by June, 2011
• TBM Procurement Bid for the TBMs
• Two Bidders HK & Robbins
• HK wins the TBM supply contract
• HFO Generator Procurement – 16 mw of power
• TBM Route From Docks to Site & Bridge Construction
• Proposal for Jhelum River Crossing
• Contractor initial proposal submitted for the whole
of the works for the Twin TBM Tunnels – Single Source
Next Steps
• Review Contractor proposal
• Review existing contract
• Meet the Client, NJC Staff, and the Contractor
• Begin Organization of the Variation Order• Payment Items
• Existing payment items that will be pertinent to the Variation Order
• New Items to be incorporated into the Variation Order
• Independent Estimate to verify the Contractor’s proposal
• Negotiations with the Contractor’s staff to:– Explain their proposal cost buildup
– Negotiate prices using the independent estimate vs. the Contractor’s proposal
• Develop a Measurement and Payment Section for the Variation Order
Variation Order
• 523 Unit Price Items
• 385 - Unit Price Items are to be escalated by the month and year the work is performed• Units – m, m2, m3, kg, pcs, ton, ls, day, hr, kwh
• Camp Construction
• Water Treatment
• Assembly Chamber Rock Excavation and Rock Support
• TBM Assembly
• TBM Mining
• TBM Mining Rock Support– Initial Rock Support - L1
– Secondary Rock Support – L2
• TBM Disassembly
• 65% paid in Local Currency (PKRs)• 35% paid in USD
• 138 Unit Price Items are paid in 2011 USD – Not
Escalated
• Equipment
– TBMs
– Assembly Chamber Cranes
– Shotcrete Batch Plant
– Electrical Components
– HFO Power Plants ( 4 each, 4 mw Mann generators)
– TBM Consulting
– Recruiting & Medical Expenses
– Additional Design Costs
Variation Order
Examples of Items EscalatedV-2.8 TBM Assembly
V-2.8.01Bridge Crane (TBM #1) (Need to install, and remove, in both the Assembly, and Disassembly Chambers)
each 2.0
V-2.8.02Bridge Crane (TBM #2) (Need to install, and remove, in both the Assembly, and Disassembly Chambers)
each 2.0
V-2.8.03 TBM #1 machine and backup assembly each 1.0
V-2.8.04 TBM #2 machine and backup assembly each 1.0
V-2.8.05 Erection of Stationary Conveyor Belt LS 1.0
V-2.8.06 Track Placement (up to TBM #1 assembly chamber) LS 1.0
V-2.8.07 Track Placement (up to TBM #2 assembly chamber) LS 1.0
V-2.8.08 Track Placement (TBM #1 Mining) m 11,205.0
V-2.8.09 Track Placement (TBM #2 Mining) m 11,205.0
V-4.1 TBM 1# Mining (57 m2) m 11205.0
V-4.1.01 Rock Excavation (Q2) m 672.3
V-4.1.02 Rock Excavation (Q3) m 5,042.3
V-4.1.03 Rock Excavation (Q4) m 4,482.0
V-4.1.04 Rock Excavation (Q5) m 1,008.5
V-4.1.05 Muck Transferring by Stationary Conveyor Belt & Dump Truck m3 638,685.0
V-4.1.06 Geological Forcasting days 890.0
V-4.1.07 Convergence Measurement Station (Max 3 Pins) pcs 28.0
V-4.1.08 Mutilpoint Borehole Extometer pcs 13.0
V-4.2 Initial Rock Support with TBM 1#
V-4.2.01Fully cement-grouted rock bolts, deformed bar. at the face.D=25 mm. Depth in rock 4.0m
pcs 56,709.0
V-4.2.02Fully cement-grouted expansion shell-anchored rock bolts, deformed bar.At the face.D=25 mm. Depth in rock 4.0 m
pcs 11,140.0
V-4.2.03 Welded wire fabric fixed to rock bolts. At the face kg 453,870.0
V-4.2.04 Shotcrete Fibre Reinforced m3 14,348.0
V-4.2.05 Providing and installation of steel ring beam set 1,587.0
Examples of Items Not EscalatedV-1.1 Insurance, Bank Charges, Consultants
V-1.1.1 Insurance
V-1.1.1.01 Contractors All Risk (Check Scope of Risk Insurance) LS 1.0
V-1.1.1.02 Insurance Cost of Equipments LS 1.0
V-1.1.1.03 TBM Insurance LS 1.0
V-1.1.2 Bank Charges for Guarantees
V-1.1.2.01 Bank Charges for Guarantees LS 1.0
V-1.1.3 Cost of Feasilbility Study for Adopting TBM (Provisional Sum)
V-1.1.3.01 Cost of Feasilbility Study for Adopting TBM (Provisional Sum) LS 1.0
V-1.1.4 Cost of TBM Consulting and Related (Provisional Sum)
V-1.1.4.01 Cost of TBM Consulting and Related (Provisional Sum) LS 1.0
V-1.2 Procurement of TBM
V-1.2.01 TBM Purchase (CIF) LS 1.0
V-1.2.02 Custom Clearance Agent Fee LS 1.0
V-1.2.03 Inland Transportation (including access improvements) LS 1.0
V-1.2.04 Custom Clearance Fee LS 1.0
V-1.2.05 Reimbursement of Withholding Tax (6%) LS 1.0
V-1.2.06 Contractor Processing Fee: TBM Purchase Only LS 1.0
As per the MOU of April 2011
• Commercial Considerations• Establishment of new payment items or
adjustment to existing sums, rates and BOQ quantities shall be agreed to by the Parties
• Parties shall negotiate a variation order
• New payment items and a new BOQ for the variation order have been established, now all we have to do is negotiate new rates and sums
Contractual Issues4
The Negotiations
• Many items were negotiated but
there were four major areas that were
a challenge to reach a consensus on:
1. Contractor additional equipment which
was retained by the contractor but
purchased by the Client
2. Number of personnel manning the TBMs
3. TBM advance rates
4. Markup
Contractor Retained Additional Equipment
but purchased by the Client
• Non escalated items such as:– Cranes, ventilation systems, electrical systems
and batch plants
– The Contractor would retain possession but the Client paid for them
– TBMs remained the property of the Client
• Resolution:– A salvage value was applied to each piece
of equipment and the salvage value was deducted from the price in the BOQ
– Region VI - USACE Equipment rates were used to determine the salvage value
Number of Personnel Manning TBMs
• Contractor number and independent estimate number differed by a large amount which greatly affected the TBM mining rates.
– Contractor number was +/- two times the independent estimate.
• Resolution:
– The variation order TBM mining rates included the contractors number of personnel.
– A clause was added into the variation order that after 2,000 m of TBM mining the rates would be reassessed as to the number of personnel required to man the TBMs.
– The TBM mining rates would then be adjusted downward or remain as originally stipulated in the V.O.
TBM Advance Rates
Started:Contractor NJC
Ave Production Ave Production
Rock Classification m/day m/day
Q2 16.7 21.3
Q3 15.0 18.1
Q4 10.0 10.2
Q5 5.0 8.9
Ave. All Rock Class 11.7 14.6
Contractor NJC
Ave Production Ave Production
Rock Classification m/day m/day
Q2 16.8 16.8
Q3 15.0 15.0
Q4 11.0 11.0
Q5 5.0 5.0
Ave. All Rock Class 12.0 12.0
Resolution:
Markup
• Provisions of the main contract documents allow the contractor 41.3% markup
• Since this was a variation order and a unit price BoQwith the Contractor being paid for installed quantities and the client was purchasing equipment, it was determined that the risk factor was less for the Contractor and a lower markup would be applicable
• Resolution:
Contractor and Client agreed on 25% markup
Base Pk Rs to USD
Base Rate of De-escalation to
2006
1 USD – July 2011= 86.0024 Pk Rs.
This allows the de-escalation to 2006 of
all escalatable unit price items to be
brought back to the base year when
the contract was bid.
Variation Order Agreement on Price
2011 – USD $413,117,300.00
Per Agreement on 2012-03-30 Conference Call July 5, 2012
SUBJECTTBM VO - COST COMPARISON: NJC vs CGGC Use June 2011 Benchmarks:
ITEMESCALATABLE & NON-ESCALATABLE ITEMS Avrg Fx Rate per Various Web Sites 86.0024
DATEJuly 5, 2012 De-Escalation Factor per IPC #42 43.80%
Headrace Tunnel Design Change: Tender Contract Drill & Blast Mining to TBM Mining
By NJC By CGGC
Rs (Varies) 2011 US $ Rs (Varies) 2011 US $
Work Added to Original Scope for TBM VO22: Escalatable Items in 2006 Rs: Rs 22,015,791,390 $ 255,990,430 Rs 22,015,791,390 $ 255,990,430
Provisional Sum (For Escalation on Work Added through November 2015): Rs 13,513,287,858 $ 157,126,869 Rs 13,513,287,858 $ 157,126,869
Subtotal of TBM VO22 Escalatable Items Through November 2015: Rs 35,529,079,248 $ 413,117,300 Rs 35,529,079,248 $ 413,117,300
Variation Order Cost to Contract
2015 – USD $335,275,816.00
PROJECTED COST TO CONTRACT FOR TBM VO22: R1
Per Agreement on 2012-03-30 Conference Call July 5, 2012
SUBJECTTBM VO - COST COMPARISON: NJC vs CGGC Use June 2011 Benchmarks:
ITEMESCALATABLE & NON-ESCALATABLE ITEMS Avrg Fx Rate per Various Web Sites 86.0024
DATEJuly 5, 2012 De-Escalation Factor per IPC #42 43.80%
Headrace Tunnel Design Change:
Tender Contract Drill & Blast Mining to TBM Mining
By NJC By CGGC
Rs (Varies) 2011 US $ Rs (Varies) 2011 US $
Work Added to Original Scope for TBM VO22: Escalatable Items in 2006 Rs: Rs 22,015,791,390 $ 255,990,430 Rs 22,015,791,390 $ 255,990,430
Provisional Sum (For Escalation on Work Added through November 2015): Rs 13,513,287,858 $ 157,126,869 Rs 13,513,287,858 $ 157,126,869
Subtotal of TBM VO22 Escalatable Items Through November 2015: Rs 35,529,079,248 $ 413,117,300 Rs 35,529,079,248 $ 413,117,300
Work Added to Original Scope for TBM VO22: Non-Escalatable Items 2011 US$: $ 158,090,290 $ 158,090,290
TOTAL EXPENDITURES for TBM VO22 (Through November 2015): Rs 35,529,079,248 $ 158,090,290 Rs 35,529,079,248 $ 158,090,290
Credit to Contract for Escalatable Work Deducted from Original Scope due to TBM VO22:-Rs 12,495,929,436 ($145,297,450)-Rs 12,495,929,436 ($145,297,450)
Provisional Sum (For Escalation on Deducted Work through November 2015): -Rs 7,794,769,322 ($90,634,323)-Rs 7,794,769,322 ($90,634,323)
Subtotal of Work Deduction Credit to Contract Through November 2015: -Rs 20,290,698,758 ($235,931,774)-Rs 20,290,698,758 ($235,931,774)
PROJECTED NET INCREASE TO CONTRACT FOR TBM VO22 THROUGH NOVEMBER 2015: Rs 15,238,380,490 $ 158,090,290 Rs 15,238,380,490 $ 158,090,290
NOTES: 1) Escalation is based on the factors used in PC-1: 10% pa on the Local Payment Component (65%), and 2.5% on the Foreign Payment Component (35%)
2) Escalation Provisional Sums, additions and deductions, are based on Note #1, and on the TBM Mining durations in the CGGC Schedule dated April 23, 2012
August, 2012
• After three years of discussions, planning, negotiation and surmounting numerous challenges (2009 to 2012) the TBM Variation Order is executed by the Client and the Contractor
• TBM Mining of the Twin Tunnels begins
in February of 2013 and is completed
in May of 2017 - Four years
Six years total from inception to
completion
With the cooperation of all stakeholders,
means and methods of construction for the
twin headrace tunnels were changed to
accelerate the schedule to ensure that the
client could generate power at the earliest
possible date
Nothing is impossible!
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