6.1 SECTION 6 BUILDING DESIGN CRITERIA R. A. LaBoube, P.E. Professor of Civil Engineering, University of Missouri-Rolla, Rolla, Missouri Building designs generally are controlled by local or state building codes. In addition, designs must satisfy owner requirements and specifications. For buildings on sites not covered by building codes, or for conditions not included in building codes or owner specifications, designers must use their own judgment in selecting design criteria. This section has been prepared to provide information that will be helpful for this purpose. It summarizes the requirements of model building codes and standard specifications and calls attention to rec- ommended practices. The American Institute of Steel Construction (AISC) promulgates several standard spec- ifications, but two are of special importance in building design. One is the ‘‘Specification for Structural Steel Buildings—Allowable Stress Design (ASD) and Plastic Design.’’ The second is the ‘‘Load and Resistance Factor Design (LRFD) Specification for Structural Steel Buildings,’’ which takes into account the strength of steel in the plastic range and utilizes the concepts of first-order theory of probability and reliability. The standards for both ASD and LRFD are reviewed in this section. Steels used in structural applications are specified in accordance with the applicable spec- ification of ASTM. Where heavy sections are to be spliced by welding, special material notch-toughness requirements may be applicable, as well as special fabrication details (see Arts. 1.13, 1.14, and 1.21). 6.1 BUILDING CODES A building code is a legal ordinance enacted by public bodies, such as city councils, regional planning commissions, states, or federal agencies, establishing regulations governing building design and construction. Building codes are enacted to protect public health, safety, and welfare. A building code presents minimum requirements to protect the public from harm. It does not necessarily indicate the most efficient or most economical practice. Building codes specify design techniques in accordance with generally accepted theory. They present rules and procedures that represent the current generally accepted engineering practices. A building code is a consensus document that relies on information contained in other recognized codes or standard specifications, e.g., the model building codes promulgated by 6.2 SECTION SIX building officials associations and standards of AISC, ASTM, and the American National Standards Institute (ANSI). Information generally contained in a building code addresses all aspects of building design and construction, e.g., fire protection, mechanical and electrical installations, plumbing installations, design loads and member strengths, types of construc- tion and materials, and safeguards during construction. For its purposes, a building code adopts provisions of other codes or specifications either by direct reference or with modifi- cations. 6.2 APPROVAL OF SPECIAL CONSTRUCTION Increasing use of specialized types of construction not covered by building codes has stim- ulated preparation of special-use permits or approvals. Model codes individually and collec- tively have established formal review procedures that enable manufacturers to attain approval of building products. These code-approval procedures entail a rigorous engineering review of all aspects of product design. 6.3 STANDARD SPECIFICATIONS Standard specifications are consensus documents sponsored by professional or trade asso- ciations to protect the public and to avoid, as much as possible, misuse of a product or method and thus promote the responsible use of the product. Examples of such specifications are the American Institute of Steel Construction (AISC) allowable stress design (ASD) and load and resistance factor design (LRFD) specifications; the American Iron and Steel Insti- tute’s (AISI’s) ‘‘Specification for the Design of Cold-Formed Steel Structural Members,’’the Steel Joist Institute’s ‘‘Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders,’’ and the American Welding Society’s (AWS’s) ‘‘Structural Welding Code—Steel’’ (AWS D1.1). Another important class of standard specifications defines acceptable standards of quality of building materials, standard methods of testing, and required workmanship in fabrication and erection. Many of these widely used specifications are developed by ASTM. As need arises, ASTM specifications are revised to incorporate the latest technological advances. The complete ASTM designation for a specification includes the year in which the latest revision was approved. For example, A588/A588M-97 refers to specification A588, adopted in 1997. The M indicates that it includes alternative metric units. In addition to standards for product design and building materials, there are standard specifications for minimum design loads, e.g., ‘‘Minimum Design Loads for Buildings and Other Structures’’ (ASCE 7-95), American Society of Civil Engineers, and ‘‘Low-Rise Build- ing Systems Manual,’’ Metal Building Manufacturers Association. It is advisable to use the latest editions of standards, recommended practices, and building codes. 6.4 BUILDING OCCUPANCY LOADS Safe yet economical building designs necessitate application of reasonable and prudent de- sign loads. Computation of design loads can require a complex analysis involving such considerations as building end use, location, and geometry. BUILDING DESIGN CRITERIA 6.3 6.4.1 Building Code–Specified Loads Before initiating a design, engineers must become familiar with the load requirements of the local building code. All building codes specify minimum design loads. These include, when applicable, dead, live, wind, earthquake, and impact loads, as well as earth pressures. Dead, floor live, and roof live loads are considered vertical loads and generally are spec- ified as force per unit area, e.g., lb per ft 2 or kPa. These loads are often referred to as gravity loads. In some cases, concentrated dead or live loads also must be considered. Wind loads are assumed to act normal to building surfaces and are expressed as pressures, e.g., psf or kPa. Depending on the direction of the wind and the geometry of the structure, wind loads may exert either a positive or negative pressure on a building surface. All building codes and project specifications require that a building have sufficient strength to resist imposed loads without exceeding the design strength in any element of the structure. Of equal importance to design strength is the design requirement that a building be functional as stipulated by serviceability considerations. Serviceability requirements are generally given as allowable or permissible maximum deflections, either vertical or horizon- tal, or both. 6.4.2 Dead Loads The dead load of a building includes weights of walls, permanent partitions, floors, roofs, framing, fixed service equipment, and all other permanent construction (Table 6.1). The American Society of Civil Engineers (ASCE) standard, ‘‘Minimum Design Loads for Build- ings and Other Structures’’ (ASCE 7-95), gives detailed information regarding computation of dead loads for both normal and special considerations. 6.4.3 Floor Live Loads Typical requirements for live loads on floors for different occupancies are summarized in Table 6.2. These minimum design loads may differ from requirements of local or state building codes or project specifications. The engineer of record for the building to be con- structed is responsible for determining the appropriate load requirements. Temporary or movable partitions should be considered a floor live load. For structures designed for live loads exceeding 80 lb per ft 2 , however, the effect of partitions may be ignored, if permitted by the local building code. Live Load Reduction. Because of the small probability that a member supporting a large floor area will be subjected to full live loading over the entire area, building codes permit a reduced live load based on the areas contributing loads to the member (influence area). Influence area is defined as the floor area over which the influence surface for structural effects on a member is significantly different from zero. Thus the influence area for an interior column comprises the four surrounding bays (four times the conventional tributary area), and the influence area for a corner column is the adjoining corner bay (also four times the tributary area, or area next to the column and enclosed by the bay center lines). Similarly, the influence area for a girder is two times the tributary area and equals the panel area for a two-way slab. The standard, ‘‘Minimum Design Loads for Buildings and Other Structures’’ (ASCE 7- 95), American Society of Civil Engineers, permits a reduced live load L (lb per ft 2 ) computed from Eq. (6.1) for design of members with an influence area of 400 ft 2 or more: L ϭ L (0.25 ϩ 15/͙A ) (6.1) oI 6.4 TABLE 6.1 Minimum Design Dead Loads Component Load, lb/ft 2 Component Load, lb/ft 2 Component Load, lb/ft 2 Ceilings Acoustical fiber tile 1 Gypsum board (per 1 ⁄ 8 -in thickness) 0.55 Mechanical duct allowance 4 Plaster on tile or concrete 5 Plaster on wood lath 8 Suspended steel channel system 2 Suspended metal lath and cement plaster 15 Suspended metal lath and gypsum plaster 10 Wood furring suspension system 2.5 Coverings, roof, and wall Asbestos-cement shingles 4 Asphalt shingles 2 Cement tile 16 Clay tile (for mortar add 10 lb): Book tile, 2-in 12 Book tile, 3-in 20 Ludowici 10 Waterproofing membranes: Bituminous, gravel-covered 5.5 Bituminous, smooth surface 1.5 Liquid applied 1.0 Single-ply, sheet 0.7 Wood sheathing (per inch thickness) 3 Wood shingles 3 Floor fill Cinder concrete, per inch 9 Lightweight concrete, per inch 8 Sand, per inch 8 Stone concrete, per inch 12 Floors and floor finishes Asphalt block (2-in), 1 ⁄ 2 -in mortar 30 Cement finish (1-in) on stone-concrete 32 fill Ceramic or quarry tile ( 3 ⁄ 4 -in) on 1 ⁄ 2 -in 16 mortar bed Ceramic or quarry tile ( 3 ⁄ 4 -in) on 1-in 23 mortar bed Frame partitions Movable steel partitions 4 Wood or steel studs, 1 ⁄ 2 -in gypsum board 8 each side Wood studs, 2 ϫ 4; unplastered 4 Wood studs, 2 ϫ 4, plastered one side 12 Wood studs, 2 ϫ 4, plastered two sides 20 Frame walls Exterior stud walls: 2 ϫ 4@16in, 5 ⁄ 8 -in gypsum, insulated, 11 3 ⁄ 8 -in siding 2 ϫ 6@16in, 5 ⁄ 8 -in gypsum, insulated, 12 3 ⁄ 8 -in siding Exterior stud walls with brick veneer 48 Windows, glass, frame and sash 8 Masonry walls* Clay brick wythes: 4in 39 8in 79 6.5 TABLE 6.1 Minimum Design Dead Loads Component Load, lb/ft 2 Component Load, lb/ft 2 Component Load, lb/ft 2 Roman 12 Spanish 19 Composition: Three-ply ready roofing 1 Four-ply felt and gravel 5.5 Five-ply felt and gravel 6 Copper or tin 1 Deck, metal, 20 ga 2.5 Deck, metal, 18 ga 3 Decking, 2-in wood (Douglas fir) 5 Decking, 3-in wood (Douglas fir) 8 Fiberboard, 1 ⁄ 2 -in 0.75 Gypsum sheathing, 1 ⁄ 2 -in 2 Insulation, roof boards (per inch thickness): Cellular 0.7 Fibrous glass 1.1 Fiberboard 1.5 Perlite 0.8 Polystyrene foam 0.2 Urethane foam with skin 0.5 Plywood (per 1 ⁄ 8 -in thickness) 0.4 Rigid insulation, 1 ⁄ 2 -in 0.75 Skylight, metal frame, 3 ⁄ 8 -in wire glass 8 Slate, 3 ⁄ 16 -in 7 Slate, 1 ⁄ 4 -in 10 Concrete fill finish (per inch thicknes) 12 Hardwood flooring, 7 ⁄ 8 -in 4 Linoleum or asphalt tile, 1 ⁄ 4 -in 1 Marble and mortar on stone-concrete fill 33 Slate (per inch thickness) 15 Solid flat tile on 1-in mortar base 23 Subflooring, 3 ⁄ 4 -in 3 Terrazzo (1 1 ⁄ 2 -in) directly on slab 19 Terrazzo (1-in) on stone-concrete fill 32 Terrazzo (1-in), 2-in stone concrete 32 Wood block (3-in) on mastic, no fill 10 Wood block (3-in) on 1 ⁄ 2 -in mortar base 16 Floors, wood-joist (no plaster) double wood floor Joist sizes, in 2 ϫ 6 2 ϫ 8 2 ϫ 10 2 ϫ 12 12-in spacing, lb/ft 2 6 6 7 8 16-in spacing, lb/ft 2 5 6 6 7 24-in spacing, lb/ft 2 5 5 6 6 12 in 16 in Hollow concrete masonry unit wythes: Wythe thickness (in) Unit percent solid Light weight units (105 pcf): No grout 48 o.c. 40 o.c. 32 o.c. Grout 24 o.c. spacing · 16 o.c. Full grout Normal Weight Units (135 pcf): No grout 48 o.c. 40 o.c. 32 o.c. Grout 24 o.c. spacing · 16 o.c. Solid concrete masonry unit wythes (incl. concrete brick): Wythe thickness, Lightweight units (105 pcf): Normal weight units (135 pcf): 4 70 22 29 4 32 41 6 55 27 31 33 34 37 42 57 35 33 36 38 41 47 64 6 49 63 8 52 35 40 43 45 49 56 77 45 50 53 55 59 66 87 8 67 86 10 50 42 49 53 56 61 70 98 54 61 65 68 73 82 110 10 84 108 115 155 12 48 49 58 63 66 72 84 119 63 72 77 80 86 98 133 12 102 131 *Weights of masonry include mortar but not plaster. For plaster, add 5 lb/ ft 2 for each face plastered. Values given represent averages. In some cases there is a considerable range of weight for the same construction. Coverings, roof, and wall (cont.) Floors and floor finishes (cont.) Masonry walls (cont.) Clay brick wythes: (cont.) Clay tile (cont.) Continued 6.6 SECTION SIX TABLE 6.2 Minimum Design Live Loads a. Uniformly distributed design live loads Occupancy or use Live load, lb/ft 2 Occupancy or use Live load, lb/ft 2 Armories and drill rooms 150 Assembly areas and theaters Fixed sets (fastened to floor) 60 Lobbies 100 Movable seats 100 Platforms (assembly) 100 Stage floors 150 Balconies (exterior) 100 On one- and two-family residences only, and not exceeding 100 ft 2 60 Bowling alleys, poolrooms, and similar recreational areas 75 Corridors First floor 100 Other floors, same as occupancy served except as indicated Dance halls and ballrooms 100 Decks (patio and roof) Same as area served, or for the type of occupancy accommodated Dining rooms and restaurants 100 Fire escapes 100 On single-family dwellings only 40 Garages (see Table 6.2b also) Passenger cars only 50 For trucks and buses use AASHTO a lane loads (see Table 6.2b also) Grandstands c (see Stadium) Gymnasiums, main floors and balconies c 100 Hospitals (see Table 6.2b also) Operating room, laboratories 60 Private rooms 40 Wards 40 Corridors above first floor 80 Libraries (see Table 6.2b also) Reading rooms 60 Stack rooms d 150 Corridors above first floor 80 Manufacturing (see Table 6.2b also) Light 125 Heavy 250 Marquees and canopies 75 Office buildings b (see Table 6.2b also) Lobbies 100 Offices 50 Penal institutions Cell blocks 40 Corridors 100 Residential Dwellings (one- and two- family) Uninhabitable attics without storage 10 Uninhabitable attics with storage 20 Habitable attics and sleeping areas 30 All other areas 40 Hotels and multifamily buildings Private rooms and corridors serving them 40 Public rooms, corridors, and lobbies serving them 100 Schools (see Table 6.2b also) Classrooms 40 Corridors above first floor 80 Sidewalks, vehicular driveways, and yards, subject to trucking a (see Table 6.2b also) 250 Stadium and arenas c 100 Bleachers 100 Fixed seats (fastened to floor) 60 Stairs and exitways (see Table 6.2b also) 100 Storage warehouses Light 125 Heavy 250 Stores Retail First floor 100 Upper floors 75 Wholesale, all floors 125 Walkways and elevated platforms (other than exitways) 60 Yards and terraces (pedestrians) 100 BUILDING DESIGN CRITERIA 6.7 TABLE 6.2 Minimum Design Live Loads (Continued) b. Concentrated live loads e Location Load, lb Elevator machine room grating (on 4-in 2 area) 300 Finish, light floor-plate construction (on 1-in 2 area) 200 Garages: Passenger cars: Manual parking (on 20-in 2 area) 2,000 Mechanical parking (no slab), per wheel 1,500 Trucks, buses (on 20-in 2 area) per wheel 16,000 Hospitals 1000 Libraries 1000 Manufacturing Light 2000 Heavy 3000 Office floors (on area 2.5 ft square) 2,000 Roof-truss panel point over garage, manufacturing, or storage floors 2,000 Schools 1000 Scuttles, skylight ribs, and accessible ceilings (on area 2.5 ft square) 200 Sidewalks (on area 2.5 ft square) 8,000 Stair treads (on 4-in 2 area at center of tread) 300 c. Minimum design loads for materials Material Load, lb/ft 3 Material Load, lb/ft 2 Aluminum, cast 165 Bituminous products: Asphalt 81 Petroleum, gasoline 42 Pitch 69 Tar 75 Brass, cast 534 Bronze, 8 to 14% tin 509 Cement, portland, loose 90 Cement, portland, set 183 Cinders, dry, in bulk 45 Coal, bituminous or lignite, piled 47 Coal, bituminous or lignite, piled 47 Coal, peat, dry, piled 23 Charcoal 12 Copper 556 Earth (not submerged): Clay, dry 63 Clay, damp 110 Clay and gravel, dry 100 Silt, moist, loose 78 Silt, moist, packed 96 Earth (not submerged) (Continued ): Sand and gravel, dry, loose 100 Sand and gravel, dry, packed 120 Sand and gravel, wet 120 Gold, solid 1205 Gravel, dry 104 Gypsum, loose 70 Ice 57.2 Iron, cast 450 Lead 710 Lime, hydrated, loose 32 Lime, hydrated, compacted 45 Magnesium alloys 112 Mortar, hardened: Cement 130 Lime 110 Riprap (not submerged): Limestone 83 Sandstone 90 Sand, clean and dry 90 6.8 SECTION SIX TABLE 6.2 Minimum Design Live Loads (Continued) c. Minimum Design loads for materials (Continued ) Material Load, lb/ft 3 Material Load, lb/ft 2 Sand, river, dry 106 Silver 656 Steel 490 Stone, ashlar: Basalt, granite, gneiss 165 Limestone, marble, quartz 160 Stone, ashlar (Continued ): Sandstone 140 Shale, slate 155 Tin, cast 459 Water, fresh 62.4 Water, sea 64 a American Association of State Highway and Transportation Officials lane loads should also be considered where appropriate. File and computer rooms should be designed for heavier loads; depending on anticipated installations. See also corridors. c For detailed recommendations, see American National Standard for Assembly Seating, Tents, and Air-Supported Structures. ANSI/NFPA 102. d For the weight of books and shelves, assume a density of 65 pcf, convert it to a uniformly distributed area load, and use the result if it exceeds 150 lb/ ft 2 . e Use instead of uniformly distributed live load, except for roof trusses, if concentrated loads produce greater stresses or deflections. Add impact factor for machinery and moving loads: 100% for elevators, 20% for light machines, 50% for reciprocating machines, 33% for floor or balcony hangers. For craneways, add a vertical force equal to 25% of the maximum wheel load; a lateral force equal to 10% of the weight of trolley and lifted load, at the top of each rail; and a longitudinal force equal to 10% of maximum wheel loads, acting at top of rail. where L o ϭ unreduced live load, lb per ft 2 A I ϭ influence area, ft 2 The reduced live load should not be less than 0.5L o for members supporting one floor nor 0.4L o for all other loading situations. If live loads exceed 100 lb per ft 2 , and for garages for passenger cars only, design live loads may be reduced 20% for members supporting more than one floor. For members supporting garage floors, one-way slabs, roofs, or areas used for public assembly, no reduction is permitted if the design live load is 100 lb per ft 2 or less. 6.4.4 Concentrated Loads Some building codes require that members be designed to support a specified concentrated live load in addition to the uniform live load. The concentrated live load may be assumed to be uniformly distributed over an area of 2.5 ft 2 and located to produce the maximum stresses in the members. Table 6.2b lists some typical loads that may be specified in building codes. 6.4.5 Pattern Loading This is an arrangement of live loads that produces maximum possible stresses at a point in a continuous beam. The member carries full dead and live loads, but full live load may occur only in alternating spans or some combination of spans. In a high-rise building frame, maximum positive moments are produced by a checkerboard pattern of live load, i.e., by BUILDING DESIGN CRITERIA 6.9 TABLE 6.3 Roof Live Loads (lb per ft 2 ) of Horizontal Projection* Roof slope Tributary loaded area, ft 2 , for any structural member 0 to 200 201 to 600 Over 600 Flat or rise less than 4:12 Arch or dome with rise less than 1 ⁄ 8 of span 20 16 12 Rise 4:12 to less than 12:12 16 14 12 Arch or dome with rise 1 ⁄ 8 span to less than 3 ⁄ 8 span Rise 12:12 or greater Arch or dome with rise 3 ⁄ 8 of span or greater 12 12 12 *As specified in ‘‘Low-Rise Building Systems Manual,’’ Metal Building Manu- facturers Association, Cleveland, Ohio. full live load on alternate spans horizontally and alternate bays vertically. Maximum negative moments at a joint occur, for most practical purposes, with full live loads only on the spans adjoining the joint. Thus pattern loading may produce critical moments in certain members and should be investigated. 6.5 ROOF LOADS In northern areas, roof loads are determined by the expected maximum snow loads. However, in southern areas, where snow accumulation is not a problem, minimum roof live loads are specified to accommodate the weight of workers, equipment, and materials during mainte- nance and repair. 6.5.1 Roof Live Loads Some building codes specify that design of flat, curved, or pitched roofs should take into account the effects of occupancy and rain loads and be designed for minimum live loads, such as those given in Table 6.3. Other codes require that structural members in flat, pitched, or curved roofs be designed for a live load L r (lb per ft 2 of horizontal projection) computed from L ϭ 20RR Ն 12 (6.2) r 12 where R 1 ϭ reduction factor for size of tributary area ϭ 1 for A t Յ 200 ϭ 1.2 Ϫ 0.001A t for 200 Ͻ A t Ͻ 600 ϭ 0.6 for A t Ն 600 A l ϭ tributary area, or area contributing load to the structural member, ft 2 (Sec. 6.4.3) R 2 ϭ reduction factor for slope of roof ϭ 1 for FՅ 4 6.10 SECTION SIX ϭ 1.2 Ϫ 0.05F for 4 Ͻ F Ͻ 12 ϭ 0.6 for F Ն 12 F ϭ rate of rise for a pitched roof, in/ft ϭ rise-to-span ratio multiplied by 32 for an arch or dome 6.5.2 Snow Loads Determination of design snow loads for roofs is often based on the maximum ground snow load in a 50-year mean recurrence period (2% probability of being exceeded in any year). This load or data for computing it from an extreme-value statistical analysis of weather records of snow on the ground may be obtained from the local building code or the National Weather Service. Maps showing ground snow loads for various regions are presented in model building codes and standards, such as ‘‘Minimum Design Loads for Buildings and Other Structures’’ (ASCE 7-95), American Society of Civil Engineers. The map scales, how- ever, may be too small for use for some regions, especially where the amount of local variation is extreme or high country is involved. Some building codes and ASCE 7-95 specify an equation that takes into account the consequences of a structural failure in view of the end use of the building to be constructed and the wind exposure of the roof: p ϭ 0.7CCIp (6.3) ƒ et g where C e ϭ wind exposure factor (Table 6.4) C t ϭ thermal effects factor (Table 6.6) I ϭ importance factor for end use (Table 6.7) p ƒ ϭ roof snow load, lb per ft 2 p g ϭ ground snow load for 50-year recurrence period, lb per ft 2 The ‘‘Low-Rise Building systems Manual,’’ Metal Building Manufacturers Association, Cleveland, Ohio, based on a modified form of ASCE 7, recommends that the design of roof snow load be determined from p ϭ ICp (6.4) ƒ sg where I s is an importance factor and C reflects the roof type. In their provisions for roof design, codes and standards also allow for the effect of roof slopes, snow drifts, and unbalanced snow loads. The structural members should be investi- gated for the maximum possible stress that the loads might induce. 6.6 WIND LOADS Wind loads are randomly applied dynamic loads. The intensity of the wind pressure on the surface of a structure depends on wind velocity, air density, orientation of the structure, area of contact surface, and shape of the structure. Because of the complexity involved in defining both the dynamic wind load and the behavior of an indeterminate steel structure when sub- jected to wind loads, the design criteria adopted by building codes and standards have been based on the application of an equivalent static wind pressure. This equivalent static design wind pressure p (psf) is defined in a general sense by p ϭ qGC (6.5) p where q ϭ velocity pressure, psf G ϭ gust response factor to account for fluctuations in wind speed [...]... Zone (SF) 85 90 100 110 120 130 140 150 160 170 10 Ϫ59 ϩ16 Ϫ 68 ϩ19 Ϫ77 ϩ21 87 20 ϩ5 Ϫ19 ϩ6 Ϫ22 ϩ7 Ϫ27 8 Ϫ33 ϩ10 Ϫ39 ϩ12 Ϫ46 ϩ13 Ϫ53 ϩ15 Ϫ61 ϩ 18 Ϫ69 ϩ20 Ϫ 78 ϩ4 Ϫ14 ϩ5 Ϫ16 ϩ6 Ϫ19 ϩ7 Ϫ24 8 Ϫ 28 ϩ10 Ϫ33 ϩ11 Ϫ 38 ϩ13 Ϫ44 ϩ15 Ϫ50 ϩ17 Ϫ56 ϩ5 Ϫ33 ϩ6 Ϫ37 ϩ7 Ϫ45 ϩ9 Ϫ55 ϩ11 Ϫ65 ϩ12 Ϫ77 ϩ14 89 ϩ16 Ϫ102 ϩ19 Ϫ116 ϩ21 Ϫ131 20 ϩ5 Ϫ27 ϩ6 Ϫ30 ϩ7 Ϫ37 8 Ϫ45 ϩ10 Ϫ54 ϩ12 Ϫ63 ϩ13 Ϫ73 ϩ15 84 ϩ 18 Ϫ96 ϩ20 Ϫ1 08 ϩ4 Ϫ14 ϩ5... Ϫ52 ϩ22 Ϫ60 ϩ25 Ϫ70 ϩ29 81 ϩ33 Ϫ92 ϩ37 Ϫ103 20 ϩ9 Ϫ24 ϩ10 Ϫ26 ϩ12 Ϫ33 ϩ15 Ϫ39 ϩ 18 Ϫ47 ϩ21 Ϫ55 ϩ24 Ϫ64 ϩ 28 Ϫ73 ϩ32 83 ϩ36 Ϫ94 8 Ϫ 18 ϩ9 Ϫ20 ϩ11 Ϫ25 ϩ14 Ϫ30 ϩ16 Ϫ36 ϩ19 Ϫ42 ϩ22 Ϫ49 ϩ26 Ϫ57 ϩ29 Ϫ64 ϩ33 Ϫ73 ϩ9 Ϫ37 ϩ10 Ϫ41 ϩ13 Ϫ51 ϩ16 Ϫ62 ϩ19 Ϫ73 ϩ22 86 ϩ25 Ϫ100 ϩ29 Ϫ115 ϩ33 Ϫ131 ϩ37 Ϫ147 20 ϩ9 Ϫ31 ϩ10 Ϫ35 ϩ12 Ϫ43 ϩ15 Ϫ52 ϩ 18 Ϫ62 ϩ21 Ϫ73 ϩ24 84 ϩ 28 Ϫ97 ϩ32 Ϫ110 ϩ36 Ϫ125 8 Ϫ 18 ϩ9 Ϫ20 ϩ11 Ϫ25 ϩ14 Ϫ30... 84 ϩ 18 Ϫ96 ϩ20 Ϫ1 08 ϩ4 Ϫ14 ϩ5 Ϫ16 ϩ6 Ϫ19 ϩ7 Ϫ24 8 Ϫ 28 ϩ10 Ϫ33 ϩ11 Ϫ 38 ϩ13 Ϫ44 ϩ15 Ϫ50 ϩ17 Ϫ56 ϩ13 Ϫ14 ϩ15 Ϫ16 ϩ 18 Ϫ19 ϩ22 Ϫ24 ϩ26 Ϫ 28 ϩ30 Ϫ33 ϩ35 Ϫ 38 ϩ40 Ϫ44 ϩ46 Ϫ50 ϩ52 Ϫ56 50 ϩ12 Ϫ13 ϩ13 Ϫ14 ϩ16 Ϫ 18 ϩ19 Ϫ22 ϩ23 Ϫ26 ϩ27 Ϫ30 ϩ31 Ϫ35 ϩ36 Ϫ40 ϩ41 Ϫ46 ϩ46 Ϫ51 ϩ10 Ϫ11 ϩ11 Ϫ12 ϩ13 Ϫ15 ϩ16 Ϫ 18 ϩ19 Ϫ21 ϩ23 Ϫ25 ϩ26 Ϫ29 ϩ30 Ϫ34 ϩ34 Ϫ 38 ϩ39 Ϫ43 ϩ13 Ϫ17 ϩ15 Ϫ19 ϩ 18 Ϫ24 ϩ22 Ϫ29 ϩ26 Ϫ35 ϩ30 Ϫ41 ϩ35 Ϫ47 ϩ40 Ϫ54 ϩ46... ϩ17 Ϫ 18 ϩ19 Ϫ20 ϩ24 Ϫ25 ϩ29 Ϫ30 ϩ34 Ϫ36 ϩ40 Ϫ42 ϩ46 Ϫ49 ϩ53 Ϫ57 ϩ60 Ϫ64 ϩ 68 Ϫ73 50 ϩ16 Ϫ17 ϩ 18 Ϫ19 ϩ22 Ϫ23 ϩ26 Ϫ 28 ϩ31 Ϫ34 ϩ37 Ϫ40 ϩ42 Ϫ46 ϩ49 Ϫ53 ϩ55 Ϫ60 ϩ63 Ϫ 68 500 ϩ14 Ϫ15 ϩ15 Ϫ17 ϩ19 Ϫ21 ϩ23 Ϫ25 ϩ27 Ϫ30 ϩ32 Ϫ35 ϩ37 Ϫ40 ϩ43 Ϫ46 ϩ49 Ϫ53 ϩ55 Ϫ59 10 ϩ17 Ϫ21 ϩ19 Ϫ24 ϩ24 Ϫ30 ϩ29 Ϫ36 ϩ34 Ϫ43 ϩ40 Ϫ50 ϩ46 Ϫ 58 ϩ53 Ϫ67 ϩ60 Ϫ76 ϩ 68 86 50 ϩ16 Ϫ19 ϩ 18 Ϫ21 ϩ22 Ϫ26 ϩ26 Ϫ31 ϩ31 Ϫ37 ϩ37 Ϫ44 ϩ42 Ϫ51 ϩ49 Ϫ 58 ϩ55... wind speed V (mph) Effective wind area Location Zone (SF) 85 90 100 110 120 130 140 150 160 170 10 Ϫ13 ϩ6 Ϫ15 ϩ7 Ϫ 18 ϩ9 Ϫ22 ϩ11 Ϫ26 ϩ12 Ϫ30 ϩ14 Ϫ35 ϩ16 Ϫ40 ϩ19 Ϫ46 ϩ21 Ϫ52 20 ϩ5 Ϫ13 ϩ6 Ϫ14 ϩ7 Ϫ 18 8 Ϫ21 ϩ10 Ϫ25 ϩ12 Ϫ30 ϩ13 Ϫ34 ϩ15 Ϫ39 ϩ 18 Ϫ45 ϩ20 Ϫ51 100 1 ϩ5 ϩ4 Ϫ12 ϩ5 Ϫ13 ϩ6 Ϫ16 ϩ7 Ϫ20 8 Ϫ24 ϩ10 Ϫ 28 ϩ11 Ϫ32 ϩ13 Ϫ37 ϩ15 Ϫ42 ϩ17 Ϫ 48 6.17 6. 18 TABLE 6.11 Design Wind Pressure—Method 1 Components and... ϩ9 Ϫ17 ϩ10 Ϫ19 ϩ12 Ϫ23 ϩ15 Ϫ 28 ϩ 18 Ϫ33 ϩ21 Ϫ39 ϩ24 Ϫ45 ϩ 28 Ϫ52 ϩ32 Ϫ59 ϩ36 Ϫ67 100 Roof ϩ9 8 Ϫ16 ϩ9 Ϫ 18 ϩ11 Ϫ22 ϩ14 Ϫ27 ϩ16 Ϫ32 ϩ19 Ϫ37 ϩ22 Ϫ43 ϩ26 Ϫ50 ϩ29 Ϫ57 ϩ33 Ϫ64 6.19 6.20 TABLE 6.12 Design Wind Pressure—Method 1 Components and Cladding—Partially Enclosed Building (Continued ) DESIGN WIND PRESSURE (PSF) Effective wind area Location Zone (SF) Basic wind speed V (mph) 85 90 100 110 120 130 140 150... Concrete or an Ordinary Moment Frame of Steel Capable of Resisting at Least 25% of Prescribed Seismic Forces Special concentrically-braced frames Concentrically-braced frames Inverted Pendulum Structures-Seismic Force Resisting system Special moment frames of structural steel Ordinary moment frames of structural steel Response modification coefficient,* R 6.5 4 8 7 7 5 6 8 3 8 7 6 6 5 2.5 1.25 * R reduces forces... 380 / ͙Fy , Fv ϭ 0.40Fy (6.25) Fv ϭ FyCv / 2 .89 Յ 0.4Fy (6.26) For h / t Ͼ 380 / ͙Fy , BUILDING DESIGN CRITERIA where Cv ϭ 6.35 45,000kv when Cv Ͻ 0 .8 Fy(h / t)2 ϭ 190 h/t ΊF when C Ͼ 0 .8 kv v y 5.34 kv ϭ 4.00 ϩ when a / h Ͻ 1.00 (a / h)2 4.00 ϭ 5.34 ϩ when a / h Ͼ 1.0 (a / h)2 Alternative rules are given for design on the basis of tension field action 6.14.2 Shear in Bolts For bolts and threaded parts,... Wind-Force Resisting System DESIGN WIND PRESSURE (PSF) Basic Wind Speed V (MPH) Building classification 85 90 100 110 120 130 140 150 160 170 Enclosed Ϫ14 Ϫ16 Ϫ20 Ϫ24 Ϫ29 Ϫ33 Ϫ39 Ϫ45 Ϫ51 Ϫ57 Partially enclosed Location Ϫ19 Ϫ21 Ϫ26 Ϫ31 Ϫ37 Ϫ44 Ϫ51 Ϫ 58 Ϫ66 Ϫ74 Enclosed or partially enclosed 12 14 17 20 24 29 33 38 43 49 Roof Wall 1 Design wind pressures above represent the following: Roof—Net pressure (sum of... exposed Partially exposed A B C D Above the treeline in windswept mountainous areas Alaska, in areas where trees do not exist within a 2-mile radius of site N/A 0.9 0.9 0 .8 0.7 1.1 1.0 1.0 0.9 0 .8 1.3 1.2 1.1 1.0 N/A 0.7 0 .8 N/A a See Table 6.5 for definition of categories The terrain category and roof exposure condition chosen should be representative of the anticipated conditions during the life of the structure . pcf): 4 70 22 29 4 32 41 6 55 27 31 33 34 37 42 57 35 33 36 38 41 47 64 6 49 63 8 52 35 40 43 45 49 56 77 45 50 53 55 59 66 87 8 67 86 10 50 42 49 53 56 61 70 98 54 61 65 68 73 82 110 10 84 1 08 115 155 12 48 49 58 63 66 72 84 119 63 72 77 80 86 98 133 12 102 131 *Weights. Ϫ63 ϩ13 Ϫ73 ϩ15 84 ϩ 18 Ϫ96 ϩ20 Ϫ1 08 100 ϩ4 Ϫ14 ϩ5 Ϫ16 ϩ6 Ϫ19 ϩ7 Ϫ24 8 Ϫ 28 ϩ10 Ϫ33 ϩ11 Ϫ 38 ϩ13 Ϫ44 ϩ15 Ϫ50 ϩ17 Ϫ56 10 ϩ13 Ϫ14 ϩ15 Ϫ16 ϩ 18 Ϫ19 ϩ22 Ϫ24 ϩ26 Ϫ 28 ϩ30 Ϫ33 ϩ35 Ϫ 38 ϩ40 Ϫ44 ϩ46 Ϫ50. includes the year in which the latest revision was approved. For example, A 588 /A 588 M-97 refers to specification A 588 , adopted in 1997. The M indicates that it includes alternative metric units. In