Study on Safe Usage of Bamboo and Mixed Scaffoldings Occupational Safety & Health Council 2016 Study on Safe Usage of Bamboo and Mixed Scaffoldings Table of contents TITLE PAGE i TABLE OF CONTENTS ii LIST OF FIGURES v LIST OF TABLES viii Chapter 1 Introduction ................................................................................................... 1 1.1 Background ...................................................................................................... 1 1.2 Research plan and methodology ...................................................................... 1 Chapter 2 Anchorage for Bamboo Scaffolding: Regional Reinforcement .................... 3 2.1 Mechanical properties of connection in bamboo scaffolding .......................... 4 2.1.1 Connection resistance with and without nodes ..................................... 5 2.1.2 Slipping stiffness of connection without nodes .................................... 6 2.1.3 Rotational stiffness of connection ......................................................... 6 2.2 Modeling of bamboo scaffolding ..................................................................... 8 2.2.1 Description of bamboo scaffolding ....................................................... 8 2.2.2 Finite element modeling of bamboo scaffolding .................................. 9 2.3 Regional reinforcement of bamboo scaffolding............................................. 10 2.3.1 Option 1 - Ledger reinforcement ........................................................ 10 2.3.2 Option 2 - Reinforcing two adjacent ledgers ...................................... 11 2.3.3 Option 3 - Platform reinforcement ...................................................... 13 2.3.4 Personal energy absorber (PEA) lanyard and self-retracting lifeline (SRL)............................................................................................................ 15 2.3.5 Critical cases for experimental test ..................................................... 16 2.4 Full-scale bamboo scaffolding test ................................................................ 17 2.4.1 Description of the scaffolding ............................................................. 18 2.4.2 Test arrangement ................................................................................. 18 ii Occupational Safety and Health Council Study on Safe Usage of Bamboo and Mixed Scaffoldings 2.4.3 Static point load test ............................................................................ 19 2.4.4 Drop load test ...................................................................................... 21 2.5 Scaffoldings with different configuration and dimensions ............................ 22 2.6 Multiple anchorages for Option 2 regional reinforcement ............................ 23 Chapter 3 Anchorage for Bamboo Scaffolding: Other Options ................................... 65 3.1 A safer scaffolding erection process............................................................... 65 3.2 Anchorages for bamboo scaffolding above roof level ................................... 66 3.3 Anchorages for bamboo scaffolding below roof level ................................... 68 Chapter 4 Use of Mixed Scaffolding ........................................................................... 72 4.1 Mechanical properties of connection ............................................................. 72 4.1.1 Normal steel tube-bamboo connection ............................................... 72 4.1.2 Anti-sliding steel tube-bamboo/normal steel tube connection ............ 74 4.1.3 Normal steel tube-normal steel tube connection ................................. 75 4.1.4 Thermal effect of steel tube on connection ......................................... 76 4.2 Design and modeling of mixed scaffolding ................................................... 77 4.2.1 Design of mixed scaffolding ............................................................... 77 4.2.2 Modeling of mixed scaffolding ........................................................... 77 4.3 Comparison among three types of mixed scaffolding ................................... 78 4.3.1 Construction cost and time.................................................................. 79 4.3.2 Weight and weight distribution ........................................................... 81 4.3.3 Load-carrying capacity ....................................................................... 81 4.3.4 Summary ............................................................................................. 85 4.4 Full-scale mixed scaffolding test ................................................................... 87 4.4.1 Description of the scaffolding ............................................................. 87 4.4.2 Test arrangement ................................................................................. 88 4.4.3 UDL test on platform .......................................................................... 88 4.4.4 Static point load test on connection .................................................... 90 4.5 Anchorages for mixed scaffolding ................................................................. 92 iii Occupational Safety and Health Council Study on Safe Usage of Bamboo and Mixed Scaffoldings Chapter 5 Use of Different Materials for the Working Platform ............................... 135 5.1 Types for the working platform ................................................................... 135 5.2 Mechanical properties of wooden boards and iron planks ........................... 135 5.3 Full-scale test of working platform .............................................................. 136 5.3.1 Test arrangement ............................................................................... 137 5.3.2 Test results......................................................................................... 138 Chapter 6 Conclusions and Recommendations .......................................................... 150 Appendix .................................................................................................................... 152 Appendix A Other types of connection and test fixture ..................................... 152 A1 Column (or beam/bracing) splice test .................................................. 152 A2 A special type of connection called “打戒指” ..................................... 154 A3 Fixture for beam-column connection test ............................................ 155 Appendix B Material properties of bamboo and steel tube ............................... 161 B1 Mechanical properties of bamboo ........................................................ 161 B2 Mechanical properties of steel tube ...................................................... 162 B3 Tube specimens and fixture for tensile test .......................................... 163 Appendix C Column buckling of structural bamboo in bamboo scaffoldings .. 170 C1 Effective length of the post in bamboo scaffoldings [10] .................... 171 C2 Non-prismatic parameter 휶 [34] .......................................................... 173 C3 Working example: column buckling of bamboo post using Kao Jue ... 174 Appendix D Allowable compressive load on metal post in mixed scaffoldings 176 References .................................................................................................................. 178 iv Occupational Safety and Health Council Study on Safe Usage of Bamboo and Mixed Scaffoldings Lists of figures Fig. 2-1 Setup of bamboo connection test ................................................................... 24 Fig. 2-2 Two failure modes for connection with node ................................................. 25 Fig. 2-3 Typical load-displacement curve for conection test with node ...................... 25 Fig. 2-4 Slippage failure for connection test without node .......................................... 25 Fig. 2-5 Vertical testing curves of BP-BP connection.................................................. 26 Fig. 2-6 Modeling of slippage stiffness for bamboo connection ................................. 27 Fig. 2-7 Setup of rotational stiffness test ..................................................................... 27 Fig. 2-8 Rotational test curves of BP-BP connection .................................................. 28 Fig. 2-9 Modeling of rotational stiffness for bamboo connection ............................... 29 Fig. 2-10 Two typical arrangements and configuration of DLBS ................................ 30 Fig. 2-11 Modeling of bamboo scaffolding ................................................................. 30 Fig. 2-12 Deformation of scaffolding after reinforcement .......................................... 31 Fig. 2-13 Reinforcement option: combining two adjacent ledgers with steel tubes .... 31 Fig. 2-14 Load-carrying capacities and moment distribution diagrams ...................... 32 Fig. 2-15 Modeling of contact surface with couplers .................................................. 32 Fig. 2-16 Load cases for Option 2 ............................................................................... 33 Fig. 2-17 Deformation of load case (2) at the position closest to the edge.................. 33 Fig. 2-18 Reinforcement option: installing steel tubes under the work platform ........ 33 Fig. 2-19 Load cases for Option 3.2 near the center of scaffolding ............................. 34 Fig. 2-20 Moment diagram for two types of bamboo