日本钢结构设计标准

CRC Solutions Design Standard for Steel Structure ⒸThe Architectural Institute of Japan CHAPTER 1 GENERAL 1.1 Scope of Application This Standard applies to the structural design of steel buildings. The Standard, however, need not apply to structural designs based on special research studies. 1.2 Structural Safety Verification Tests Where a design in involves connection and other structural details not expressly prescribed in this Standard, the structural safe& of such details shall be proved by tests or by other appropriate means. 1.3 Enlargement of Section Sections of various structural elements shall be enlarged as required, with due consideration for practical limitation in precision of structural designs, inadequacy in constructional workmanship, and such adverse factors as rusting, corrosion and wear of steel materials. 1.4 Nomenclature A Gross sectional area; nominal body area of a high-strength bolt; or sum of sectional areas of column components (mm2) AN Net section (mm2) Ad Sectional area of lacing element; or total sectional area of a pair of lacing elements in the case of double lacing (mm2) Af Cross-sectional area of compression flange; or cross-sectional area of either flange (mm2) Ap Sectional area of parts in contact (mm2) As Cross-sectional area of vertical or horizontal stiffeners (mm2) Aw Cross-sectional area of web plate (mm2) a Equivalent area loss due to rivet, bolt or high-strength bolt holes(mm2); or spacing of intermediate stiffeners (mm) a0 Net area loss due to rivet, bolt or high-strength bolt holes (mm2) b Width of compression element free at one edge and fixed at the other; width of rocker or roller; or longitudinal spacing or pitch of consecutive holes (mm) , but not larger than 2.3 Bending coefficient dependent upon moment gradient D Nominal outside diameter of steel pipe; or outside diameter of main steel pipe (mm) d Width of element stiffened along two edges; outside diameter of branch pipe; width of web plate; or diameter of pin (mm) d1 Minimum width of the portion of web plate divides by vertical or horizontal stiffener (mm) E Modulus of elasticity (N/mm2) e Distance between axes of gravity of components (mm) F Basic value used in determining allowable stresses (N/mm2) (N/mm2) f Allowable stress in members subject to repeated stress variation (N/mm2) fb Allowable bending stress (N/mm2) fb1 Allowable bending stress in bearing plates and similar elements subject to out-of-plane bending (N/mm2) fb2 Allowable bending stress in pins subject to bending (N/mm2) fc Allowable compressive stress (N/mm2) fc’ Allowable compressive stress in the toe of the web fillet of rolled shapes or build-up I-shaped members (N/mm2) fl Allowable bearing stress in plates in riveted or bolted joints (N/mm2) fp1 Allowable bearing stress for contact area of pins and for other milled surfaces (N/mm2) fp2 Allowable bearing stress for rockers or rollers (N/mm2) fs Allowable shear stress (N/mm2) fs0 Allowable shear stress for high-strength bolts (N/mm2) fst Allowable shear stress for high-strength bolts subject to combined tension and shear (N/mm2) ft Allowable tensile stress (N/mm2) ft0 Allowable tensile stress for rivets or bolts (N/mm2) fts Allowable tensile stress for rivets or bolts subject to combined tension and shear (N/mm2) g Transverse spacing between fastener gage lines (mm) h Depth of beam (mm) I0 Moment of inertia of intermediate stiffeners (mm4) IL Moment of inertia of horizontal or vertical stiffener (mm4) IS Required moment of inertia of the stiffeners on compression flanges (mm4) i Radius of gyration, taken about an axis in the plane of web, of a tee section comprising the compression flange plus one-sixth of beam depth radius of gyration of a section with respect to axis subject to buckling; or radius of gyration of horizontal or vertical stiffeners on the web (mm) i1 The least radius of gyration of sectional elements of compression members (mm) L Effective length of weld in branch connection of steel pipes (mm) l Length of member; or length of distributed load (mm) lb Unsupported length of compression flange (mm) ld Length of lacing element (mm) lk Effective length of compression member subject to buckling (mm) l1 Spacing of separators or tie plates; or length of hole in members with cover plates having holes (mm) l2 Longitudinal component of the length of lacing of a built-up member (cm) M Bending moment (N・mm) M1 Larger bending moment about the strong axis at the end of a member (N・mm) M2 Smaller bending moment about the strong axis at the end of a member (N・mm) m Number of components or groups of components connected by lacing or tie plates N Compression (N) N1 Larger compression (N) N2 Smaller compression (N) n Number of structural planes formed by lacing or tie plates in built-up members; or number of vertical or horizontal stiffeners P Concentrated transverse load or reaction; or compression for computation of bearing stress (N) p Spacing of holes (mm) Q Shear (N) r Radius of curvature of rocker or roller (mm) T Tension (N) T0 Design bolt tension for high-strength bolt (N) t Thickness of plate; wall thickness of pipe; thickness of web plate; or plate thickness of pin (mm) t0 Distance from edge of flange to toe of web fillet (mm) Zc Section modulus of compression side of cross-section (mm3) Zt Section modulus of tension side of a cross-section (cm3) α Distribution factor for compressive stress γ Fatigue factor θ Intersecting angle between two pipes Λ Critical slenderness ratio λ Slenderness ratio of compression member (lk/ i) λy Slenderness ratio of built-up compression member assumed to buckle as an integrated member λye Effective slenderness ratio of built-up compression members σ Maximum compressive stress in web plate (N/mm2) σ0 Allowable compressive stress in plate subject to buckling (N/mm2) cσb Bending stress of extreme fiber in compression (M/Zc) (N/mm2) tσb Bending stress of extreme fiber in tension (M/Zt) (N/mm2) σc Mean compressive Stress (N/A) (N/mm2) σP Bearing stress (N/mm2) σt Mean tensile stress (T//AN); or tensile stress which is proportional to the force acting upon bolts (N/mm2) σx,σy Normal stresses perpendicular to each other (N/mm2) σ1,σ2 Larger absolute value and smaller absolute value of stresses at the upper and lower limits of stress range for members subject to repeated stress variation (N/mm2) τ Shear stress produced in rivets or bolts; or mean shear stress in web plate (N/mm2) τ0 Allowable shear stress in plate subject to buckling (N/mm2) τxy Shear stress in the plane of normal stresses, σx andσy (N/mm2) CHAPTER 2 DRAWING PRACTICE 2.1 Rules of Representation Drawings shall be prepared in compliance with JIS Z 8302 [General Rules for Technical Drawing], JIS A 0150 [Drawing Office Practice for Architects and Builders (General Rules)], JIS Z 8201 [Mathematical Symbols] and JIS Z 3021 [Graphical Symbols for Welding]. 2.2 Items of Information to Be Given On Drawings (1) Drawings shall give complete information on dimensions, sectional shapes and relative positions of respective members. They shall also show, in terms of dimensions, all floor levels, column centers, and joints and connections of members. Drawings shall be prepared to scales large enough to give the foregoing information with clarity. (2) Where necessary, drawings shall show the qualities of steel materials to be used. (3) Where bolts or high-strength bolts are to be used, bolt qualities shall be distinctly shown on the drawings as necessary. (4) Cambers of trusses and beams shall be shown on the drawing as necessary. (5) Where parts are designed for metal-to-metal contact as in columns bearing on base plates, in column splices or in stiffeners bearing on beam flanges, the extent of milling or machining required for ends of such parts shall be indicated on drawings as necessary. CHAPTER 3 CALCULATION OF I.OADS AND STRESSES 3.1 General Loads Loads to be used in structural calculation shall, as a rule, be those prescribed in the Enforcement Order of the Building Standard Law. 3.2 Impact For structures carrying live loads which induce impact, the design loads shall be increased in accordance with the assessed effects of such impact. Where the effects of impact are not based on measurement, the design loads may be increased in accordance with the following: (1) For structural supports of elevators : 100% of the elevator Weight (2) For structural supports of overhead traveling cranes : Where the speed is less than 60 m/minute 10% of the wheel load Where the speed is 60 m/minute or over 20%of the wheel load If jointless rail is used, "60 m/minute'' in the above requirement may be replaced by "90 m/minute.” (3) For supports of motorized equipment: Not less than 20% of the equipment weight (4) For supports of equipment driven by reciprocating engines: Not less than 50% of the equipment weight (5) For hangers suspending floors or balconies: 30% of the live load thereon 3.3 Crane Runway Lateral Forces (1) Braking Force in the Direction of Crane Travel This shall be taken as 15% of each wheel load subject to braking force, as applied to the top of the crane rail. (2) Horizontal Forces Normal to the Direction of Crane Travel Crane supporting girders on both ends of a crane shall be considered as subjected simultaneously to 10% of the crane wheel loads acting normal to the direction of crane travel. For computation, the crane trolley and lifted load shall be assumed to be in the most unfavorable condition. (3) Diagonal Tension Where the load to be lifted is pulled by a crane in a diagonal direction, the stress induced in the structure by such operation shall be taken into account. (4) Earthquake Forces Earthquake forces acting on cranes shall be assumed as applied at the top of the crane rail. Unless otherwise specified, the weight of lifted load may be disregarded in computing the weight of a crane. 3.4 Repeated Variation of Stresses For members subjected to repeated variation of stresses, the design stresses shall be increased to allow for the effects of material fatigue in accordance with Chap. 7. 3.5 Thermal Stresses For structures subject to large variation of temperature, thermal effects shall be given due regard in structural design. 3.6 Combination of Stresses Stresses in each structural component shall generally be combined in accordance with Table 3. 1, and further as specified below: Table 3.1 Combination of Stress Loading conditions For general areas For areas subject to heavy snowfall Permanent loading Under normal load G + P G + P + S Temporary loading Under snow load Under storm load Under seismic load G + P + S G + P + W G + P + K G + P + S G + P + W G + P + S + W G + P + S + K Symbols G : Stress due to dead load as prescribed by the Enforcement Order of the Building Standard Law P : Stress due to live load as prescribed by the aforesaid Order S : Stress due to snow load as prescribed by the aforesaid Order W : Stress due to wind load as prescribed by the aforesaid Order K : Stress due to seismic load as prescribed by the aforesaid Order (1) In combining stresses, the stress induced by cranes in structural supports shall be regarded as stress due to live load. (2) Where more than one crane simultaneously acts on structural supports, the stresses due to cranes shall be combined for the most unfavorable case which is presumable in the course of actual crane operation. (3) For design computation of column joints and column bases, stress combinations in which storm or seismic load is involved shall also be investigated for cases where live loads are disregarded. CHAPTER 4 MATERIALS 4.1 Qualities Unless otherwise provided, structural materials shall be of the qualities specified in the applicable standards listed in Table 4.1. Table 4.1 Standards Prescribing Quality of Structural Materials Numbers Titles JIS G 3136 Rolled Steel for Construction Structure: SN 400 A, SN 400 B, SN 400 C, SN 490 B and SN 490 C JIS G 3101 Rolled Steel for General Structure: SS 400, SS 490 and SS 540 JIS G 3106 Rolled Steel for Welded Structure: SM 400 A, B and C ; SM 490 A , B and C ; SM 490 YA and YB ; SM 520 B and C and SM 570 JIS G 3114 JIS G 3475 Carbon Steel Tubes for Construction Structure: STKN 400 W, B, STKN 490 B JIS G 3444 Carbon Steel Tubes for General Structural Purposes: STK 400 and STK 490 JIS G 3466 Carbon Steel Square Pipes for General Structural Purposes: STKR 400 and STKR 490 JIS G 3138 Rolled Steel Bar for Construction Structure: SNR 400 A, B, SNR 490 B JIS G 3350 Light Gauge Steels for General Structures: SSC 400 JIS G 3353 JIS B 1186 Sets of High-Strength Hexagon Bolt, Hexagon Nut and Plain Washers for Friction Grip Joints JIS B 1178 JIS G 3104 Rolled Steel for Rivets JIS Z 3211 Covered Electrodes for Mild Steel JIS Z 3212 Covered Electrodes for High Tensile-Strength Steel JIS Z 3351 JIS Z 3352 Steel Wire for Submerged Arc Welding JIS G 5101 Carbon Steel Castings: SC480 JIS G 5102 Casting for Welding Structure: SCW 410, SCW 480 JIS G 5201 JIS G 3201 Carbon Steel Forgings 4.2 Shapes and Sizes Table 4.2 Standard Prescribing Shapes and Sizes of Structural Materials Numbers Titles JIS G 3192 Dimensions, Weight and Permissible Variations of Hot Rolled Steel Sections JIS G 3193 Dimensions, Weight and Permissible Variations of Hot Rolled Steel Plates, Sheets and Strip JIS G 3194 Shape, Dimensions, Weight and Tolerance for Hot Rolled Flat Steel JIS G 3191 Shape, Dimensions, Weight and Tolerance for Hot Rolled Steel Bar and Bar-in-Coil JIS G 3475 JIS G 3444 Carbon Steel Tubes for General Structural Purposes JIS G 3466 Carbon Steel Square Pipes for General Structural Purposes JIS G 3350 Light Gauge Steel for General Structures JIS G 3353 JIS B 1186 Sets of High-Strength Hexagon Bolt, Hexagon Nut and Plain Washers for Friction Grip Joints JIS B 1178 Based Bolts JIS B 1180 Hexagon Head Bolts JIS B 1181 Hexagon Nuts JIS B 1256 Plain Washers JIS B 1214 Hot Headed Rivets JIS E 1101 Rails JIS E 1103 Light Rails JIS A 5540 Turnbuckles for Structural Purpose Unless otherwise provided, structural materials shall be of the shapes and sizes prescribed in Table 4.2. 4.3 Constants Physical constants for structural materials shall, in general, be taken as the values given in Table 4.3. Table 4.3 Physical Constants for Structural Materials Material Modulus of elasticity (N/mm2) Shear modulus (N/mm2) Poisson’s ratio Coefficient of linear expansion (1/℃) Steel, Cast steal and Forged steel 205,000 79,000 0.3 0.000012 CHAPTER 5 ALLOWABLE STRESSES 5.1 Structural Steel Allowable stresses for structural steel under permanent loading shall be determined on the basis of the values of F given in Table 5.1. Table 5.1 Values of F (N/mm2) Steel for construction structures Steel for general structures Steel for welded structures SN400 SNR400 STKN400 SN490 SNR490 STKN490 SS400 STK400 STKR400 SSC400 SS490 SS540 SM400 SMA400 SM490 SM490Y SMA490 STKR490 STK490 SM520 SM570 F Thickness (mm) t ≤40 40 < t ≤100 235 215 325 295 235 215 275 255 375 ― 235 215 325 295 355 335 t>75, 325 400 400 (1) Allowable Tensile Stress On the net section as defined in 13.1 (5.1) where ft : allowable bending stress(N/mm2) (2) Allowable Shear Stress (5.2) where fs : allowable shear stress(N/mm2) (3) Allowable Compressive Stress (a) On the gross section : When λ≤Λ (5.3) When λ>Λ (5.4) (5.5) where fc : allowable compressive stress (N/mm2) λ : slenderness ratio of compression member ( see 11.1 ) E : modulus of elasticity (N/mm2) Λ : critical slenderness ratio (b) On the web of rolled shapes or built-up I sections at the toe of the fillet : Regardless of the requirement of (a) above, allowable compressive stress shall be as computed by Formula (5.6) below. (5.6) where fc’ : allowable compressive stress (N/mm2) (4) Allowable Bending Stress (a) For flexural members such as rolled beams, plate girders and other built-up members having symmetrical axis in the loaded plane (except for box-type members), and meeting the width-thickness ratio requirement of Chap. 8 and subjected to bending about the strong axis, allowable bending stress on extreme fibers in compression shall be taken as the larger value computed by Formula (5.7) or (5.8); however, such stress shall not exceed ft on extreme fibers in compression or in tension. (5.7) (5.8) where fb : allowable bending stress(N/mm2) lb : unbraced length of compression flange(mm) i : radius of gyration, taken about an axis in the plane of web, of a tee section comprising the compression flange plus one-sixth of the depth of beam(mm) , but not more than 2.3 M2 and M1 are the smaller bending moment and the larger bending moment, respectively, about the strong axis at the ends of a member subject to buckling. (M2 / M1)takes a positive value in the case of single curvature and a negative value in the case of double curvature. Where moment on the center of the portion subject to buckling is larger than M1 , C is taken as unity. h : depth of beam(mm) Af : cross-sectional area of compression flange(mm2) Λ : (see Formula 5.5) (b) For tubular and box-type steel members, for members having axes of symmetry in the loaded plane, subjected to bending about the weak axis and meeting the width-thickness ratio giving in Chap. 8,and for gusset plates loaded within their plane, allowable bending stresses on extreme fibers in tension and compression shall be taken as ft. (c) Allowable bending stress on extreme fibers in compression for channels and members not having axes of symmetry in the loaded plane and meeting the width-thickness requirement of Chap. 8 shall be as obtained from Formula(5.8), but not greater than ft. (d) Allowable bending stress in bearing plates and similar elements subject to bending outside their plane shall be as obtained from Formula (5.9). (5.9) where fb1 : allowable bending stress(N/mm2) (e) Allowable bending stress in pins subjected to bending shall be taken as the value computed by Formula(5.10). (5.10) where fb2 : allowable bending stress(N/mm2) (5) Allowable Bearing Stress (a) For contact area of pins and bearing stiffeners and for other milled surfaces, the allowable bearing stress shall be obtained from Formula (5.11). (5.11) When parts in contact area different in quality. F shall be taken as the smaller value, and bearing stress op shall be obtained by Formula (5. 12). (5.12) where fp1 : allowable bearing stress (N/mm2) P : compression (N) Ap : generally, sectional area of parts in contact (mm2); for pin/connections, Ap=td where t = plate thickness of pin (mm) and d = diameter of pin (mm) σp : bearing stress (N/mm2) ' (b) For rockers or rollers, allowable bearing stress shall be computed by Formula (5.13). (5.13) When parts in contact are different in quality , F shall be taken as the smaller value, and bearing stress op shall be obtained by Formula (5.14). (5.14) where fp2 : allowable bearing stress (N/mm2) P : compression(N) E : modulus of elasticity (N/mm2) b : width of rocker or roller (mm) r : radius of curvature of rocker or roller (mm) σp : bearing stress (N/mm2) 5.2 Rivets, Bolts and High-Strength Bolts (1) Allowable tensile and shear stresses of rivets, bolts and high-strength bolts under permanent loading shall be as given in Table 5.2. Allowable stresses shall be computed for the body area of fasteners. Table 5.2 Allowable Stresses on Rivets, Bolts and High-Strength Bolts (N/mm2) Materials Tension Shear Rivets SV 330 and SV 400 155 120 Bolts Semi-finished bolts made of SS 400 and SM 400 Other Semi-finished bolts 120 0.5F 70 0.3