BUILDING DESIGN FOR HOMELAND SECURITY Unit IX Building Design Guidance Unit Objectives Explain architectural considerations to mitigate impacts from blast effects and transmission of chemical, biological, and radiological agents from exterior and interior incidents. Identify key elements of building structural and non- structural systems for mitigation of blast effects. Compare and contrast the benefit of building envelope, mechanical system, electrical system, fire protection system, and communication system mitigation measures, including synergies and conflicts. Apply these concepts to an existing building or building conceptual design and identify mitigation measures needed to reduce vulnerabilities. Overview Architectural Building Structural and Nonstructural Considerations Building Envelope Considerations Other Building Systems Building Mitigation Measures Activity Architectural Building Configuration Ta ll, S m all Fo ot pri nt Low, Large Footprint Architectural Building Configuration R e c t a n g u l a r v e r s u s " U " , " L " o r " E " Avoid re-entrant corners Flus h face versu s eave s and overh angs Shapes That Accentuate Blast BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-5 Architectural Building Configuration Ground floor elevation 4 feet above grade Orient glazing perpendicular Avoid exposed structural elements Pitched roofs and pitched window sills Architectural Đ Space Design (1) Place unsecured or high risk areas outside building footprint Do not mix high risk and low risk tenants in same building Locate critical assets into interior of building Separate areas of high visitor activity (unsecured) from critical assets Architectural Đ Space Design (2) Architectural Đ Space Design (3) Eliminate hiding places Interior barriers Offset doorways Minimize glazing, particul arly interior glazing near high- risk areas Architectural Đ Other Design Elements Safe havens Office locations Mixed occupancies Public toilets and service areas Retail uses in the lobby Stairwells Mailroom Progressive Collapse Design GSA Progressive Collapse Analysis and Design Guidance for New Federal Office Buildings and Major Modernization Projects DoD Unified Facilities Criteria - Minimum Antiterrorism Standards for Buildings Progressive Collapse Concept below. (Hardening may be an acceptable alternative) BUILDING PLAN BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-12 Structural Systems - Collapse GSA and DoD criteria do not provide specific guidance for an engineering structural response model. Owner and design team should decide how much progressive collapse analysis and mitigation to incorporate into design. Nonstructural Elements Overhead architectural features, utilities, and other fixtures > 14 kilograms (31 pounds) Ą Mount to resist forces 0.5 x W in any directionand 1.5 x W in downward direction (DoD Unified Facilities Criteria) . Ą Plus any seismic requirements BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-14 Good Engineering Guidelines (1) Consider incorporating internal damping into the structural system. Use of symmetric reinforcement. Use wire mesh in plaster. Use multiple barrier materials and construction techniques. Recognize that components might act in opposite directions than designed. Lap splices and other discontinuities should be staggered Good Engineering Guidelines (2) Column spacing should be minimized. Floor to floor heights should be minimized, less than or equal to 16 feet. Use fully grouted and reinforced construction when CMU is selected. Use one-way wall elements spanning from floor-to-floor. Use ductile detailing requirements for seismic design when possible. Use architectural features that provide a minimum of 6 inches from primary vertical load carrying members. Deflections around certain members, such as windows, should be controlled to prevent premature failure. BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-17 Building Materials: General Guidance Generally speaking: All building materials and types acceptable under model building codes are allowed. Special consideration should be given to materials that have inherent flexibility and that are better able to respond to load reversals. Careful detailing is required for material such as prestressed concrete, pre-cast concrete, and masonry to adequately respond to the design loads. The construction type selected must meet all performance criteria of the specified level of protection. Building Envelope During an actual blast or CBR event, the building envelope becomes the first layer of defense to protect the people inside: . Ą Walls . Ą Windows . Ą Doors Ą Roofs Soil can be highly effective in reducing damage during an explosive event Minimize "ornamentation" that may become flying debris in an explosion. Building Envelope- Walls (1) Exterior walls should resist the actual pressures and impulses acting on the exterior wall surfaces from the threats defined for the facility. Exterior walls should be capable of withstanding the dynamic reactions from the windows. Beyond ensuring a flexible failure mode, design the exterior wall to resist the pressure levels of the design threat. As desired Level of Protection increases, additional mass and reinforcement may be required. Building Envelope Đ Windows (1) Balanced Window Design Glass strength Glass connection to window frame (bite) Frame strength Frame anchoring to building Frame and building interaction Building Envelope Đ Windows (2) Glass (weakest to strongest) . Ą Annealed (shards) . Ą Heat Strengthened (shards) . Ą Fully Tempered (pellets) . Ą Laminated (large pieces) . Ą Polycarbonate (bullet- resistant) " B a l a n c e d D e s i g n " GSA Glazing Performance Conditions Window Frames (1) Goal: transfer the load from the glass to the frame and retain glass in the frame W e t G l a z e ( s i l i c o n ) Window Frames (2) Goal: transfer the load to the building structure Balanced strength: glass, frame, and connection of frame to the wall "Balanced Design" Fragment Retention Film (1) Clear tough polyester film attached to the inside of a glass surface with strong pressure-sensitive adhesive. Also known as shatter-resistant film, safety film, or protective film. Relatively low installation costs. Level of protection varies with thickness of film and method of installation. Limited life. Unit IX-26 FRF (2) "Daylight Application " "Wet Glazing" (edge to edge) BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-27 Blast Curtains Invented by the British during WW II Kevlar curtains Allow venting of the blast wave while "catching" fragments May be augmented with FRF Catch Bar Must be centered on window. FRF must be thick enough to hold the fragments (_ 7 mil). Plan View Building Envelope Đ Good Window Practice No windows adjacent to doors. Minimize number and size of windows. DoD requires laminated glass for high- occupancy buildings. Stationary, non-operating windows, but operable window may be needed by code. Building Envelope Đ Doors Balanced strength . Ą Door . Ą Frame . Ą Anchorage to building Hollow steel doors or steel-clad doors Steel door frames Blast-resistant doors available . Ą Generally heavy . Ą Generally expensive Building Envelope Đ Roofs Preferred Đ poured in place reinforced concrete Lower protection Đ steel framing with concrete and metal deck slab Sloped sacrificial roof over protective roof/ceiling Restrict access to roof Functional layout Đ physical separation or hardening Structural layout Đ systems installation Do not mount utility equipment or fixtures on exterior walls or mailrooms Avoid hanging utility roof slab or ceiling Mechanical Systems (2) Restrict Access . Ą Rooms . Ą Closets . Ą Roofs . Ą Building information . Ą Also consider for other systems Ventilation and Filtration Evaluate HVAC Control Options (Building Specific) . Ą System shutdown . Ą Zone pressurization . Ą Air purge (e.g., 100 percent OA if internal release) . Ą Specialized exhaust for some areas . Ą Pressurized egress routes (may already exist) . Ą Procedures and training incorporated into buildingŐs emergency response plan Emergency Plans Site lighting Emergency lighting Duress alarms Redundant communications Maintenance, Administration, and Training (1) HVAC Maintenance Staff Training Ą System upgrades will require new training. Preventive Maintenance and Procedures . Ą Maintenance is critical to keep protective systems operational. . Ą Regularly test strategic equipment. Maintenance, Administration, and Training (2) Emergency response plans, policies, procedures . Ą All buildings should have current emergency plans. . Ą Incorporate CBR scenarios into plans. . Ą Coordinate with local emergency response personnel. . Ą Train and rehearse. .Ą Detail communication capabilities. . Ą Upgrade as necessary. . Ą Will likely need specific instructions for CBR event. Fire Protection Systems Single-point failure Dual pumps Dual pumps at different locations Security locks comply with NFPA code Communications Systems Redundant communications Radio telemetry Alarm and information systems Empty conduits Mass notification Electronic Security Systems The purpose of electronic security is to improve the reliability and effectiveness of life safety systems, security systems, and building functions. Entry Control Stations Holding area for unauthorized vehicles or those needing further inspection. Control measures such as displaying a decal. Proper lighting for entry-control stations that are manned 24 hours each day. Signs should be erected to assist in controlling authorized entry. Entry control stations should be hardened against attacks. Practical Applications What can be done with a reasonable level of effort? End of Chapter 3, FEMA 426 listing of . Ą Less protection, less cost, and less effort . Ą Greater protection, greater cost, at greater effort Desired Building Protection Level Component design based on: Design Basis Threat Threat Independent approach Level of Protection sought Leverage natural hazards design/retrofit Incorporate security design as part of normal capital or O&M program Use existing tools/techniques, but augment with new Summary Building Design Guidance and Mitigation Options Using the FEMA 426 Checklist will help identify vulnerabilities and provide recommended mitigation options. There are many methods to mitigate each vulnerability. Relatively low cost mitigations significantly reduce risk. Unit IX Case Study Activity Building Design Guidance and Mitigation Measures Background Emphasis: . Ą Providing a balanced building envelope that is a defensive layer against the terrorist tactic of interest . Ą Avoiding situations where one incident affects more than one building system FEMA 426, Building Vulnerability Assessment Checklist Requirements Assign sections of the checklist to qualified group members Refer to HIC case study, and answer worksheet questions Review results to identify vulnerabilities and possible mitigation measures BUILDING DESIGN FOR HOMELAND SECURITY Unit IX-47