【正文】 ffold. Height of scaffold Vertical distance from bottom surface of the base of standing pole to upper surface of rail on top of scaffold. Length of scaffold Horizontal distance between outer surfaces of standing pole longitudinally at two ends of scaffold. Width of scaffold Horizontal distance between outer surfaces of standing pole laterally at two sides of doublerow scaffold, or the distance from outer surface of outer standing pole to the wall for singlerow scaffold. Step spacing of standing pole (step) Axial distance between top horizontal pole and bottom horizontal pole. Spacing of standing pole Axial distance between two adjacent standing poles in scaffold. — 6 — Longitudinal distance of standing pole (span) Longitudinal distance between two standing poles in scaffold. Lateral distance of standing pole Lateral distance between two standing poles for doublerow scaffold。 or the distance from the axis of outer standing pole to the wall for singlerow scaffold. Main node Fastening point for close contacts of standing pole, longitudinal horizontal pole and lateral horizontal pole. Operation layer Laid with board for people to work on it. Symbols Load and load effect M—design value of bending moment。 MGK –bending moment created from scaffold’s standard own weight。 MQK—bending moment created from standard constructional load MW–bending moment created from designed wind load。 MWK—bending moment created from standard wind load。 N—design value of axial force。 NG1K –axial force created from structure’s standard own weight borne by standing pole of scaffold。 NG2K—axial force created from standard own weight of ponents and fittings。 Nl –designed axial force of wall connecting piece。 NLW –designed axial force of wall connecting piece created from wind load。 Σ NQK –sum of axial force created from standard constructional load。 R—designed vertical force transmitted by longitudinal or lateral horizontal pole to standing pole。 gK –structure’s standard own weight attached with every meter of standing pole p—average pressure at foundation’s bottom surface of standing pole。 v—flexibility。 wk—standard value of wind load。 wo—basic wind pressure。 — 7 — σ —positive stress. Property and resistance of material E—elastic modulus of steel material。 Rc—design value of antislip bearing capacity of fastener。 f—design values of tensile strength, pression strength and bending strength of steel material。 fg –design value of bearing capacity of foundation。 fgk –standard value of bearing capacity of foundation。 [v]—allowable deflection Geometrical parameters A— sectional area, area of foundation’s bottom surface。 An—windbreak area。 Aw—windward area。 Hs—erection height based on stability calculation。 [H]—erection height limit of scaffold (permissible erection height of scaffold)。 W—sectional modulus。 A— outreach length, protrusion length。 al—calculated outreach length。 φ , d—member diameter, outer diameter。 h—step spacing of standing pole。 i—section’s turning radius。 l—length, span, overlapping length。 la—longitudinal distance of standing pole。 lb—lateral distance of standing pole。 lo—calculation length。 s—spacing of member。 t—wall thickness of member. Calculation coefficients k—additional coefficient of calculation length。 kc –adjustment coefficient of groundsill’s bearing capacity。 — 8 — μ —calculation length coefficient of single pole with consideration of integral reliability of scaffold。 μ s—structure coefficient of wind load of scaffold。 μ stw –structure coefficient of wind load of scaffold structure as defined according to truss。 μ z coefficient of height variation of wind pressure。 ?—stability coefficient of pression ponent at axes, windbreak coefficient。 λ —ratio of length to diameter。 [λ ]allowable ratio of length to diameter. 3. Components and Fittings Steel Tube Steel tube of scaffold shall be No. 3 plain steel tube as specified in the current national standard GB/T13793 ―Transversal Joint Electric Welded Steel Tube‖ or GB/T3092 ―Welded Steel Tube for Transportation of Low Pressure Fluid‖, with its quality in pliance with the provision of class Q235A steel as specified in the current national standard GB/T700 ―Carbon Constructional Steel‖. Dimension of steel tube shall be in accordance with Table . The maximum weight of each steel tube shall not exceed 25kg. 216。48 x steel tube should be used. Table Dimension of Steel Tube of Scaffold (mm) Dimension of Section Maximum Length 216。, d Wall thickness ? Lateral horizontal pole Other poles 48 51 2200 6500 Dimension and surface quality of steel tube shall meet the following provision: 1. Dimension, surface quality and appearance of new or old steel tube shall be in pliance with the stipulations in Article and Article respectively。 2. Boring is forbidden on steel tube. Fastener — 9 — Fastener of buckled steel tube scaffold shall be made of feable cast iron, with its quality being in pliance with the current national standard GB 15831 ―Fastener of Steel Tube Scaffold‖. Fastener made of other material can be used only after it has been tested to meet the quality requirement in this standard. Fastener of scaffold must not be damaged at the moment when bolt tightenup torque moment reaches 65 N? m. Scaffold Board Scaffold board may be made of steel, wood or bamboo, and should not exceed 30kg for each piece. Stamped steel board shall have material in pliance with the requirement of Class Q235A steel as specified in the current national standard GB/T700 ―Carbon Constructional Steel‖, shall have its quality and allowable dimensional deviation in conformity to the stipulation in the first clause of Article 8. , and shall be provided with antislip measures. Wo