AT/FP Challenges in Renovation of Existing Military Facilities

Presented by: David Dickey, PE

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Anti-Terrorism Standards

 UFC 4-010-01

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Triggers for Compliance

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Is compliance mandatory?

Not all renovations must comply with standards.

Triggers

– Renovation costs > 50% Replacement Cost – Conversion of Use – Glazing Replacement Projects – Building Additions – Leased Buildings

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Information Gathering

Site Investigations

   Need all As-Built drawings – Including previous renovations Budget for Site Visits – Entire design team should attend Reduces RFI’s, Change Orders, and Conservative Bids

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Information Gathering

Unforeseen Conditions

 If no As-built drawings exist – Extensive site investigation required   Unknown materials – Masonry – Unreinforced? – Wood – species, size, spacing?

– Concrete – strength?

– Steel – grade? weldable?

Testing for material properties – X-ray, samples, destructive testing – Will the design contract fund?

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Information Gathering

Unforeseen Conditions

 Many items covered by interior finishes – Asbestos, electrical – Structure for window attachments   Is Selective Demolition possible?

Maintenance funding for patching?

  Increase contingency to cover unforeseen conditions?

Unforeseen conditions can exceed 5% contingency quickly

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Civil / Site

 Force Protection Barriers – Passive • Curbs • Fencing • Hardscapes • Cable Barriers • Planters • Bollards WVARNG - AFRC – Kingwood, WV

Civil / Site

 Barriers – Active • Wedge barriers • Pop-up bollards

Source: www.herculesfencenc.com

Source: www.multi-barrier.com

8 Source: www.herculesfencenc.com

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Architectural

   Eliminate external roof access Main entrance facing installation perim.

– Occupants may use different entrance, or – Screen the front entrance Maintain Aesthetics

Architectural / Civil

 Fencing

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Source: www.ameristarfence.com

Architectural / Civil

 Landscaping

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Command & Control Fac. – Ft. Campbell, KY

Architectural / Civil

 Landscaping

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NOSC – El Paso, TX

Mechanical

 Enclose Units Within 33ft of Building

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NOSC – El Paso, TX

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Mechanical

  Louver locations 10’ above ground – Not mandatory, but desirable – Could duct through roof – Use 2 nd floor space as Mech. Rm.

Bracing of suspended equipment – Difficult to access if ceiling is not being replaced

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Mechanical / Electrical

Mailroom Addition

   Requires dedicated ventilation and exhaust systems Automatic shutoff with low leakage dampers Tie controls into main DDC system

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Architectural / Structural

Mailroom Addition

  Seal Walls and Doors Well Harden Walls for Mail Bomb Threat – Demo existing floor slab – New foundations

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Structural

Prevent Progressive Collapse

 For buildings 3 stories or more

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Civil / Site

Standoff Distance

 Biggest issue with existing facilities

New guidance for New Reserve Facilities ALL standoffs = 148’

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Civil / Site

– Provide access control at conventional standoff distance and restrict parking within Minimum standoff distance

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Civil / Site / Structural

 Parking beneath building or on rooftop – Eliminate – Access Control – Blast analysis for Type II explosive • Beneath – Reflected blast pressures • Rooftop – No standoff distance to roof structure

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Architectural / Structural

 Fragment retention films and blast curtains no longer acceptable Insulated Glazing Units – Laminated Glass

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Architectural / Structural

  If Standoff Distances are met – Glazing, frames, components, anchors, and supporting structure must still meet UFC – Wall is considered conventional construction • No wall retrofit necessary If Standoff Distances are NOT met – Glazing, frames, components, anchors, and supporting structure must be designed for higher blast loads – Wall must be analyzed for blast pressures • Wall/Building retrofit may be necessary

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Architectural / Structural

Window Supporting Structure

  Static Analysis – Extremely Conservative Dynamic Analysis – Less conservative – Qualified blast engineer – Software is becoming easier to use • SBEDS

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Structural

 SBEDS software

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Structural

   Results of Window Jamb Design CASE: Brick wall with metal stud backup, 36”Wx48”H window, 15’ tall jamb – Dynamic Analysis • One 6” deep 12 Gage stud required per jamb – Static Analysis • Four 6” deep 12 Gage studs required per jamb Recommend Using Dynamic Analysis for all projects – New and Existing

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Structural

Retrofit Window Supporting Structure

 Steel Tubes – Inset into building – Anchor to slabs below and above • Difficult with weaker roof or floor system   Unreinforced Masonry Walls – Cut blocks, drill & epoxy rebar, grout solid – Grout solid and reinforce externally Each project is different

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Key Points

         Know Triggers Info: As-built drawings – Site visits Reduce Unforeseen Conditions Site: Barriers, landscaping, aesthetics Parking will be impacted Influence of Standoff Distances Window Replacement Dynamic vs. Static Analysis Each project is different