# Presentation: 597740

## Civil Construction in the US Chris Laughton, Fermilab

## Outline

- Sites Under Consideration
- West Coast
- Midwest
- Scope
- Cost & Schedule
- Contingency
- Next Steps

## Sites Under Consideration

- West Coast
- Diablo Canyon*
- Midwest
- Braidwood*
- Byron ~ overburden requirements would place detector halls in weak sandstone. Dolomite and sandstone tunnels would be below the water table.
- LaSalle ~ similar site conditions to Braidwood.
- Wolf Creek ~ sited in shales and limestones.

- * Scoped and Estimated

- Diablo Canyon-Type
- Portal Entrance

## Scope Underground Construction

- Braidwood
- 2 Vertical Shafts - 10m Ø & 120m deep
- 1 Tunnel - 300m long 8m span horseshoe tunnel. Uniform 1% tunnel gradient to shaft.
- Firewall-Isolated Excavations accessed from the Running Tunnel/Shafts
- 3 Detector Rooms
- 1 x Near Detector Room - 32 m long 12 m span
- 2 x Far Detector Rooms with 8 m span access tunnels - 16 m long x 12 m span
- 1 Underground Emergency Refuge (at end of tunnel)
- 6 m long 4m span
- separately ventilation 2-hour fire rated wall
- Utility/Sump Room 4 m horseshoe
- nominal 8m length

- Diablo Canyon
- 1 Portal Entrance  -10 m long
- 1 Tunnel - 850m long 6m span horseshoe tunnel. Uniform 1% tunnel gradient to portal.
- Firewall-Isolated Excavations accessed from the Running Tunnel
- 2 Detector Rooms
- 2 x 40m long 10m span chambers
- 1 Underground Emergency Refuge
- Nominal 6 m long 4m span
- Equipped with 2-hour fire rated wall and self-rescuers

## Scope“Finish-Out” - Similar for Both Sites

- Single continuous concrete floor
- Hilman roller rails embedded (except in refuge)
- Cable Trays
- Pipe Stands
- Utilities in place at beneficial occupancy at both sites
- light string,
- ventilation ducting and fans
- refuge firewall
- At Braidwood
- Flood barrier at Far Detector site (1 m high concrete blocks)
- Pumps (Goodman quote)
- Elevators (Alimak quote)

- Shotcrete Finish Walls & Crown

## Scope Ground Conditions(assumptions pending site investigation)

- Braidwood
- Soils
- ~ 20 m of saturated soils
- Rock (Various Units)
- Coal measure strata
- Limestone with shale (NuMI - Fort Atkinson)
- Shale (NuMI - Scales)
- Galena Platteville (Dolomitic Limestone or Dolostone)
- Notable question marks relating to:
- Deep water table elevation?
- In situ stress levels?
- Swelling potential of rock units containing clay minerals?
- Etc..

- Diablo Canyon
- Minimal Soil/Weathered Rock
- Rock (Mainly Dolomitic Sandstone)
- Heavily deformed geologic structure (folded/faulted)
- Inter/Intra-bedded volcanic sills (altered basalt, tuffs..)
- Surface rock samples have tested to ~ “high strength”
- Thin chert stringers present (highly abrasive micro-silica)
- Notable question marks relating too:
- Structure at depth- what’s where?
- Abrasive cherts - roadheader impact
- Blocky rock behavior  at depth
- Altered basalt behavior at depth
- Etc..

## ScopeExcavation Methods & Means

- Braidwood
- Drill and Blast appears to be the preferred excavation method - short tunnels of varying cross-sections sited in relatively strong rock units
- Permanent Tunnel/Room Support
- Rock Bolts
- Reinforced Shotcrete
- Permanent Shaft Support provided by cast-in-place concrete lining

- Diablo Canyon
- Drill and Blast used for initial estimate - based on high strengths of surface-gathered samples
- (Viability of mechanical excavation will be reviewed after a modicum of site investigation has been performed)
- Permanent Tunnel/Room Support
- Rock Bolts,
- Lattice Girders
- Reinforced Shotcrete

- Scoop Tram

- Drill Rig

- Shotcrete

## Cost & ScheduleThe Estimating Process

- Proposal should be based on a reliable cost estimate.
- “The only kind of estimate that is worth anything is the one that is clearly defined on paper and bears the signature of the author.” J.S.Redpath, (1980). Theta 13 has underground estimates that are:
- Well-documented and  site-specific - developed “from the bottom up”
- Estimated independently by an experienced, tunneling professional.
- Reviewed independently by experienced, tunneling professionals.
- Underground estimate scopes include:
- Underground Structural Shell and Utilities
- Utilities left in place (power, ventilation, water, air lines, communication..).
- Permanent facilities installed (groundwater pumps, elevators and refuge firewall, surface water treatment facilities).
- Estimates exclude:
- Engineering, Design, Inspection and Administration (EDIA), Surface Buildings, Technical Installations, Life Cycle Costs

## Cost & Schedule Aims of the Estimating Process

- Objectives
- Reduce uncertainty in cost/schedule data collected/reported in early work.
- Deliver a schedule and estimate by Mid-March.
- Outcome
- Consulted directly with tunnel estimators to obtain site-specific products, that met the deadlines at a relatively low unit cost:
- ~ $10k Tunnel Cost Estimating Consultants (Hilton, Sperry & Wightman) vs.
- ~ $15-20k Outside Tunnel Design Companies (CNA, HMM & Jacobs Ass.) &
- ~ $40k In-House Engineering Group
- Established Solid Basis for Future Planning
- Experimental scoping and proposal development
- Reviews (Constructability, Value Engineering, Contract Strategies)
- Site investigation work
- Minimize potential for claims of “low-balling” - that may have surfaced if “ball-park” numbers had been used
- Cost better understood -> Can plan with more confidence

## Cost & Schedule Review of the Unit Cost Data Sets

- Sources: tunnel contractors, designers and consultants
- Re-sorted for sub-horizontal, 4 - 8m span rock tunnels
- Mined in last ten years by TBM, D&B or RH methodology
- Hard abrasive or very soft host rocks eliminated
- Cost “as reported/quoted” as a final cost per linear distance (auxiliary structures included)
- _Wide Range_ of unit costs $3k to $12k/linear foot
- Average of 27 case histories ~ $5k/linear foot
- Lowest unit costs in longer TBM tunnels (uniform mining/ground conditions/”good” TBM-systems, ref. Fermilab-Robbins R&D)
- Highest unit costs in shorter drill and blast/roadheader tunnels (variable mining/ground conditions poor systems)

## Cost & Schedule Need for a Site-Specific Estimate

- Wide range in unit prices underlines need for a site-specific estimate
- Costs ƒ(wage rates, craft skills, craft availability, infrastructure, support services, taxes, climate, local customs and methods, local support/opposition to the project, etc...)
- Costs ƒ(ground conditions....)
- In tunneling a trend noted towards fewer bids/less competition:
- Contractors are leaving the business -> too risky
- Contractors are working at full capacity -> too busy
- Contractors are joint venturing -> too risky
- Nowadays expect fewer bids
- Unit prices are Site-Specific & Time Specific - Braidwood & Diablo Canyon unit pricing can be used for the sites but should not be used on other sites and should be checked periodically.

## Cost & ScheduleBottoms-up Estimates’ Bottom-lines

- Braidwood
- Duration 39 months
- “First” detector site delivered in17 or 20 months (far or near)
- Cost $34.6M
- General Mobilization ~3.3M
- Shafts ~ 15.9M
- Tunnel ~ $9.1M
- Detector Rooms ~ $6.0M
- Refuge ~$0.3M
- 40% contingency.
- Initial  comments: equipment selection, crew sizing and productivity OK. Shorter shafts could use cranes.

- Diablo Canyon
- Duration 24 months
- Cost $23 M
- General Mobilization ~$2.9M
- Portal Cost ~$0.3M
- Tunnel ~ 16.5M
- Detector Rooms ~$3.2M
- Refuge ~$0.1M
- 30% contingency.
- Initial  comments: equipment selection, crew sizing and productivity OK. Some relatively conservative production factors - mucking might be done more quickly.

## ContingencyUnderground Construction

- Many ways for a tunnel project to go wrong (not just a issues of differing conditions!)
- Make sure cost and schedule expectations are realistic at the outset and kept that way for the duration of the project.
- Risks needs to be identified, mitigated and properly documented/communicated.
- Even if the ground is expected to be perfect early construction contingencies need to be at least 25% range.

## ContingencyStatus of the US Proposals

- Rock mass characterization, alignment and estimate assumptions are subject to review after site-specific investigation work is performed
- Localized studies and site-specific investigation is a pre-requisite to support the advancement of the underground design

- Basis of Estimate.
- Guesswork based on limited desk study of regional data sets.

- • We do not know for sure what is there because we haven’t looked yet!
- • Can’t mitigate what has not yet been identified!
- • _Contingency Allocated_

## Next Steps

- Site Investigation
- Engineering Tasking and Organization
- Reviews
- Making contact with design and contracting companies who can support the engineering, reviews - individual consultants will also be of value (notably where contracting rules are challenging!).

- “Man-Made” Tunnels
- (Neutrinos @ Main Injector)

- “Natural” Tunnels
- (Spooner’s Cove)

## Next StepsSite Investigation

- Braidwood (w/Exelon)
- Desk Studies
- ISGS support - others?
- Field Work
-  @ Braidwood
- @ Other local rock/soil sites
- Initial Shaft Site Selection
- Avoid any surface and buried obstructions etc.
- Drilling Campaign
- ~ Coreholes along shaft centerlines

- Diablo Canyon (w/PG&E)
- Desk Studies
- LBL Earth Science Support ~ complete
- Field Work
- @ Diablo Canyon site
- @ Other local rock sites
- Initial Tunnel Site Selection
- Portal Location,
- Tunnel Alignment
- Drilling Campaign
- ~ Directional drilling
- ~ Seismics @ Portal

## Next StepsEngineering Task Definition 

- Initial Organizational Steps
- Site Investigation Work package(s)
- Plan Engineering Tasks (Discipline:Task Matrix)
- Outside Support Scope/Contractor Selection/Contracting
- What  can’t we do in-house?
- Who do we need to help? How do we find them?
- Develop some familiarity with Beavers, Groundhogs and Moles.
- Contracting Strategies (risks allocation/sharing)
- Design-Build (D-B)
- Engineer-Procure-Construct (E-P-C) etc..
- Schedule and WBS Development
- Availability of other Resources

## Next StepsReviews

- Requirements Definition (underground site visits)
- Make sure we are not asking for more than we need
- Define “acceptable conditions” e.g. moisture/floor movement (avoid over-design & specification)
- Constructability Reviews
- Look for easier, practical ways of performing the work
- Value Engineering Reviews
- Once scope, costs and risks are well-defined investigate and estimate alternate ways of achieving the same end

## Next StepsFind Reviewers, Designers & Builders(Beavers, Groundhogs & Moles)

- Tunnel Designers
- CNA*
- Condor Earth Technologies*
- Hatch Mott MacDonald*
- Jacobs Associates*
- Montgomery Watson Harza*
- Parsons Brinckerhoff*
- Parsons Engineering*
- URS*
- etc..

- National Tunnel Contractors
- Affholder, Atkinson, Frontier-Kemper Kenny Construction, Kiewit Construction, Obayashi, Traylor Brothers, etc..
- Local (Ca) Wine Cavers
- Alf Burtleson, California Wine Caves, Magorian, Nordby Wine Caves*, Glen Ragsdale, etc.

- Partial listings                                     * SOQ Provided/Promised