Gk: normal value of structural dead weight per meter on standard.
MGk: normal value of bending moment generated by the dead weight of ledger board.
MQk: normal value of bending moment generated by the construction loads.
MWk: normal value of bending moment generated by the wind load.
NG1k: normal value of axial force generated by the structural dead weight born by the standard of scaffold.
NG2k: normal value of axial force generated by the dead weight of members and accessories of scaffold.
∑ NGk: sum of normal values of axial forces generated by the permanent loads to the standard.
∑ NQk: sum of normal values of axial forces generated by the variable loads to the standard.
Nk: normal value of standard axial force transferred from the superstructure to the foundation top.
Pk: normal value of average pressure at the bottom of standard foundation.
Wk: normal value of wind load.
Wo: wind velocity pressure.
M: design value of bending moment.
Mw: design value of bending moment generated by the wind load.
N: design value of axial force.
Ni: design value of tie member axial force.
Niw: design value of tie member axial force generated by the wind load.
R: design value of vertical acting force transferred from longitudinal or transverse horizontal tube to standard.
V: deflection.
Σ: normal bending stress.
K: additional coefficient of standard effective length.
μ: effective length coefficient of a single rod considering the overall stability factor of scaffold.
μs: scaffold wind load shape factor.
μstw: wind load shape factor of scaffold structure determined by truss.
μz: height variation factor of wind pressure.
Φ: stability coefficient of axial compression components, wind shield coefficient.
The load acting on the scaffold can be divided into permanent (dead) loads and variable (live) loads.
The dead loads of a scaffold cover the following items.
| Category | Normal Value (kN/m²) |
|---|---|
| Stamped steel scaffold plank | 0.30 kN/m² |
| Category | Normal Value (kN/m²) |
|---|---|
| Scaffold for decoration | 2.0 |
| Concrete and masonry structural scaffold | 3.0 |
| Light steel structure and space grid structure scaffold | 2.0 |
| Common steel structure scaffold | 3.0 |
| The normal value of uniform distributed load on the stair stringer shall not less than | 2.0 |
The normal value of horizontal wind load on the scaffold shall be calculated in accordance with the formula listed below.
Wk = μz × μs × wo
Wherein,
Wk stands for the normal value of wind load, expressed in kN/m².
| Height Variation Factor of Wind Pressure μz | ||||
|---|---|---|---|---|
| Height Above Ground or Sea Level (m) | Terrain Rroughness Category | |||
| A | B | C | D | |
| 5 | 1.17 | 1.00 | 0.74 | 0.62 |
| 10 | 1.38 | 1.00 | 0.74 | 0.62 |
| 15 | 1.52 | 1.14 | 0.74 | 0.62 |
| 20 | 1.63 | 1.25 | 0.84 | 0.62 |
| 30 | 1.80 | 1.42 | 1.00 | 0.62 |
| 40 | 1.92 | 1.56 | 1.13 | 0.73 |
| 50 | 2.03 | 1.67 | 1.25 | 0.84 |
| 60 | 2.12 | 1.77 | 1.35 | 0.93 |
| 70 | 2.20 | 1.86 | 1.45 | 1.02 |
| 80 | 2.27 | 1.95 | 1.54 | 1.11 |
| 90 | 2.34 | 2.02 | 1.62 | 1.19 |
| 100 | 2.40 | 2.09 | 1.70 | 1.27 |
| 150 | 2.64 | 2.38 | 2.03 | 1.61 |
| 200 | 2.83 | 2.61 | 2.30 | 1.92 |
| 250 | 2.99 | 2.80 | 2.54 | 2.19 |
| 300 | 3.12 | 2.97 | 2.75 | 2.45 |
| 350 | 3.12 | 3.12 | 2.94 | 2.68 |
| 400 | 3.12 | 3.12 | 3.12 | 2.91 |
| ≥450 | 3.12 | 3.12 | 3.12 | 3.12 |
| Scaffold Wind Load Shape Factor μs | ||
|---|---|---|
| Conditions of buildings the scaffold lean against | Full closed wall | Open, frame and open hole walls |
| Scaffold conditions | Full closed and semi-closed | 1.0 φ, 1.3 φ |
| Open | μs tw | |
Notes:
|
||
| Wind Shield Coefficient φ of Open Style Single Pole Steel Tubular Scaffold, Double Pole Steel Tubular Scaffold, Fastener Steel Tube Full Hall Scaffold and Fastener Steel tube Full Hall Formwork Support | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Lift Spacing (m) | Longitudinal Spacing(m) | ||||||||||
| 0.4 | 0.6 | 0.75 | 0.9 | 1.0 | 1.2 | 1.3 | 1.35 | 1.5 | 1.8 | 2.0 | |
| 0.60 | 0.260 | 0.212 | 0.193 | 0.180 | 0.173 | 0.164 | 0.160 | 0.158 | 0.154 | 0.148 | 0.144 |
| 0.75 | 0.241 | 0.192 | 0.173 | 0.161 | 0.154 | 0.144 | 0.141 | 0.139 | 0.135 | 0.128 | 0.125 |
| 0.90 | 0.228 | 0.180 | 0.161 | 0.148 | 0.141 | 0.132 | 0.128 | 0.126 | 0.122 | 0.115 | 0.112 |
| 1.05 | 0.219 | 0.171 | 0.151 | 0.138 | 0.132 | 0.122 | 0.119 | 0.117 | 0.113 | 0.106 | 0.103 |
| 1.20 | 0.212 | 0.164 | 0.144 | 0.132 | 0.125 | 0.115 | 0.112 | 0.110 | 0.106 | 0.090 | 0.096 |
| 1.35 | 0.207 | 0.158 | 0.139 | 0.126 | 0.120 | 0.110 | 0.106 | 0.105 | 0.100 | 0.094 | 0.091 |
| 1.50 | 0.202 | 0.154 | 0.135 | 0.122 | 0.115 | 0.106 | 0.102 | 0.100 | 0.096 | 0.090 | 0.086 |
| 1.60 | 0.200 | 0.152 | 0.132 | 0.119 | 0.113 | 0.103 | 0.100 | 0.098 | 0.094 | 0.087 | 0.084 |
| 1.80 | 0.1959 | 0.148 | 0.128 | 0.115 | 0.109 | 0.099 | 0.096 | 0.094 | 0.090 | 0.083 | 0.080 |
| 2.00 | 0.1927 | 0.144 | 0.125 | 0.112 | 0.106 | 0.096 | 0.092 | 0.091 | 0.086 | 0.080 | 0.077 |
w 0 stands for reference wind pressure, expressed in kN/m². That is, the reference pressure of wind load. Generally, it is the average wind speed measured at a height of 10 m above the open, flat ground for 10 minutes.
When designing the load bearing members of scaffold, the most unfavorable combination of the possible load occurs in the working process shall be taken into consideration.
| Calculation Items | Load Effect Combination |
|---|---|
| Bearing capacity of longitudinal and horizontal ledgers and deformation | Permanent load and construction load |
| Bearing capacity of scaffold standard foundation Bearing capacity, stability and deformation of structural steel suspended beam |
Permanent load + construction load |
| Permanent load + 0.9 (construction load + wind load) | |
| Standard stability | Permanent load + variable load (excluding wind load) |
| Permanent load + 0.9 (variable load + wind load) | |
| Bearing capacity and stability of wall-connecting parts | Single pole scaffold, wind load + 2.0 kN Double pole scaffold, wind load + 3.0 kN |
