at/fp challenges in renovation of existing military facilities presented by: david dickey, pe

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

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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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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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

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Civil / Site

Barriers– Active

• Wedge barriers• Pop-up bollards

Source: www.multi-barrier.com

Source: www.herculesfencenc.com

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

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Architectural / Civil

Fencing

Source: www.ameristarfence.com

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Landscaping

Command & Control Fac. – Ft. Campbell, KY

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Landscaping

NOSC – El Paso, TX

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Mechanical

Enclose Units Within 33ft of Building

NOSC – El Paso, TX

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Mechanical

Louver locations 10’ above ground– Not mandatory, but desirable– Could duct through roof– Use 2nd 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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Parking and Roadways– Provide access control at conventional

standoff distance and restrict parking within Minimum standoff distance

Civil / Site

Parking and Roadways– Move parking & roadways

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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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Window Replacement Fragment retention films and blast

curtains no longer acceptable

Window ReplacementWindow Replacement Fragment retention films and blast

curtains no longer acceptable Insulated Glazing Units

– Laminated Glass

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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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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

Dynamic vs. Static Analysis

Window Replacement

Influence of Standoff Distances

Each project is different

at/fp challenges in renovation of existing military facilities presented by: david dickey, pe

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