BS 5975:2019 – TC
$280.87
Tracked Changes. Code of practice for temporary works procedures and the permissible stress design of falsework
| Published By | Publication Date | Number of Pages |
| BSI | 2019 | 525 |
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | compares BS 5975:2019 |
| 2 | TRACKED CHANGES Test example 1 |
| 3 | BS 5975:2019 to BS 5975:2008+A1:2011 |
| 10 | Publication history |
| 17 | Foreword Publishing information Supersession Information about this document |
| 19 | Use of this document Presentational conventions Contractual and legal considerations |
| 20 | Introduction |
| 21 | Section 1: General 1 Scope 2 Normative references |
| 23 | 3 Terms and definitions 3.1 adjustable telescopic steel prop |
| 24 | 3.2 asset 3.23.3 backpropping 3.33.4 base plate 3.43.5 bay length 3.53.6 beam bearer 3.63.7 blinding 3.73.8 brace 3.83.9 camber 3.93.10 characteristic strength 3.10 Checks 3.10.1 check 3.10.2 design check 3.11 check list |
| 25 | 3.12 client 3.113.13 competent person/organization 3.123.14 component 3.15 contractor 3.133.16 coupler 3.17 design certificate 3.18 design statement 3.19 designated individual (DI) 3.20 domestic client |
| 26 | 3.143.21 effective length 3.153.22 factor of safety 3.163.23 falsework 3.173.24 floor centre 3.183.25 forkhead 3.193.26 formwork 3.203.27 frame 3.213.28 grade stress 3.29 hold point 3.30 inspection and test plan (ITP) 3.223.31 joint pin 3.233.32 joist |
| 27 | 3.243.33 kentledge 3.253.34 lacing 3.263.35 node 3.273.36 permissible stress 3.283.37 permit to load 3.29 permit to strike permit to dismantle 3.303.38 primary 3.313.39 prop 3.40 quality control check list 3.323.41 re-propping 3.333.42 scaffold 3.343.43 soffit 3.353.44 sole plate sill |
| 28 | 3.363.45 standard 3.373.46 strength class 3.383.47 strut 3.48 sub-consultant 3.49 sub-contractor 3.393.50 sway 3.40 temporary works 3.413.51 temporary works co-ordinator (TWC) 3.423.52 temporary works supervisor (TWS) 3.53 third party 3.433.54 top restraint 3.443.55 tower |
| 29 | 3.453.56 wedge 4 Abbreviations and symbols |
| 33 | 5 Legislation 5.1 General |
| 34 | 5.2 The Health and Safety at Work, etc. Act 1974 5.3 The Management of Health and Safety at Work Regulations 1999 5.4 The Personal Protective Equipment at Work Regulations 1992 |
| 35 | 5.5 Work at Height Regulations 2005 as amended by the Work at Height (Amendment) Regulations 2007 5.6 The Lifting Operations and Lifting Equipment Regulations 1998 |
| 37 | 5.7 The Provision and Use of Work Equipment Regulations 1998 (as amended) 5.8 Construction (Design and Management) Regulations 2007 |
| 40 | Other relevant regulations include: Reg. 33, Reports of inspections (and also Schedule 3); Reg. 34, Energy distribution systems, which deals with both electric power cables and other underground services (e.g. gas, water, etc.), including the risks to… 5 Overview of temporary works procedures and training 5.1 Overview of procedures 5.1.1 General |
| 42 | 5.1.2 Summary of control measures |
| 43 | 5.1.3 Organizations involved in temporary works |
| 44 | 5.1.4 Responsibilities where a contractor co-ordinates the temporary works |
| 47 | 5.1.5 Responsibilities where a contractor co-ordinates their own temporary works |
| 50 | 5.2 Training |
| 52 | Section 2: Procedural control of temporary works 6 Procedures 6.1 Introduction to procedural control 6.16.1.1 General |
| 53 | 6.2 Control of procedures |
| 54 | 6.3 Roles and responsibilities of organizations 6.3.1 Organizational aspects |
| 55 | 6.3.2 Site related aspects 6.1.2 Designated individual |
| 56 | 6.1.3 Control of risk |
| 58 | 6.1.4 Organization roles and procedures 6.2 Temporary works register |
| 59 | 7 Clients’ procedures 7.1 General (Commercial/public clients) |
| 60 | 7.2 Clients appointing contractors other than PCs 7.3 Client’s DI |
| 61 | 7.4 Domestic clients |
| 62 | 8 Designers’ procedures 8.1 General |
| 63 | 8.2 Designers’ DI 8.3 Permanent works designers |
| 64 | 8.4 Temporary works designers 8.4.1 General 8.4.2 Lead designers (in relation to temporary works design) 8.5 Principal designers |
| 65 | 9 Contractors’ procedures 6.49.1 Organizational interfaces |
| 66 | 9.2 Contractors’ DI |
| 67 | 9.3 Responsibilities 9.3.1 General |
| 68 | 9.3.2 Appointment of the PC’s TWC 9.3.3 Appointment of the TWC (not appointed by the PC) |
| 69 | 9.3.4 Appointment of the TWS 9.4 Principal contractor 9.5 Contractors other than PC 9.5.1 General |
| 70 | 9.5.2 Contractor(s) appointed by the client 9.6 Third-party employed contractor |
| 71 | 7 Appointment of the temporary works co-ordinator and the temporary works supervisor 7.1 Appointment of the temporary works co-ordinator 10 Supplier/manufacturer procedures 10.1 Suppliers of temporary works equipment 10.2 Suppliers’ DI 10.3 Suppliers’ procedures |
| 72 | 10.4 Verification of design information 10.5 Provision of information 10.6 Provision of design data |
| 73 | 10.7 Provision of information for the safe use of equipment 10.8 Standard solutions 7.211 Responsibilities of the temporaryTemporary works co-ordinator 11.1 General 11.2 The PC’s TWC 11.2.1 General 11.2.2 Role of the PC’s TWC |
| 75 | 11.2.3 Duties of the PC’s TWC |
| 76 | 11.2.4 Duties of the PC’s TWC in relation to other contractors 11.3 The TWC (other than the PC’s TWC) 11.3.1 General |
| 77 | 11.3.2 Role of the TWC 11.3.3 Duties of the TWC |
| 79 | 7.3 Appointment of the temporary works supervisor(s) 7.4 Responsibilities of the temporary works supervisor(s) 12 Temporary works supervisor 12.1 General |
| 80 | 12.2 Role of the TWS 12.3 Duties of the TWS |
| 81 | 813 Design briefof temporary works 13.1 General 13.2 Design brief |
| 83 | 913.3 Design guidance 9.1 General |
| 85 | 9.2 Design check 9.3 Avoidance of progressive collapse 9.413.4 Choice of temporary works solution |
| 86 | 9.513.5 Selection of materials and components 13.6 Design output |
| 87 | 13.7 Design check |
| 89 | 13.8 Resolution of queries raised by the design checker 10 Co-ordination and supervision of work on site |
| 90 | 11 Checking on site 11.1 General 11.2 When to check |
| 91 | 1213.9 Alterations 13.10 Standard solutions |
| 92 | 14 Site considerations 14.1 Co-ordination, supervision and checking of work on site |
| 93 | 14.2 Loading and unloading temporary works 1314.2.1 Loading (bringing ) the temporary works (into service)into use) 14.2.2 Unloading (taking out of use) |
| 94 | 1414.3 Dismantling |
| 95 | Section 3: Falsework 15 General 16 Materials 16.1 General considerations 16.1.1 Suitability of materials 16.1.2 Identification and properties 16.1.3 Handling of materials and components 16.2 Testing and inspection 16.2.1 Testing |
| 96 | 16.2.2 Inspection 16.3 Steelwork (other than scaffold tube) 16.3.1 Quality of steel 16.3.2 Identification of steel 16.3.3 Permissible stresses |
| 97 | 16.3.4 Section properties 16.3.5 Fatigue 16.3.6 Welding and rectification of steelwork 16.4 Timber 16.4.1 Timber quality |
| 101 | 16.4.2 Modification factors |
| 106 | 16.4.4 Grading used timber 16.5 Concrete and concrete components 16.5.1 Mix design |
| 107 | 16.5.2 Blinding concrete 16.5.3 Spread footings 16.5.4 New structural members 16.5.5 Second-hand structural members 16.5.6 Precast concrete |
| 108 | 16.6 Brickwork and blockwork 16.6.1 Design 16.6.2 Rate of building 16.6.3 Age of loading 16.6.4 Reinforced brickwork and blockwork 16.6.5 Salvaged bricks and blocks 16.7 Other materials 16.7.1 General 16.7.2 Permissible stresses 16.7.3 Deterioration |
| 109 | 16.8 Steel scaffold tubes, couplers and other fittings 16.8.1 Equipment in general use 16.8.2 Non-standard scaffold tubes 16.8.3 Loads on scaffold tube struts |
| 110 | 16.8.4 Straightening of scaffold tubes 16.8.5 Corrosion and deterioration of steel scaffold tube and fittings 16.8.6 Scaffold fittings 16.8.7 Deterioration of scaffold couplers and fittings 16.9 Manufactured components for falsework 16.9.1 Types of manufactured components |
| 111 | 16.9.2 Design and testing of manufactured components 16.9.3 Information from the supplier 16.9.4 Factors of safety 16.9.5 Framed or braced tower components for vertical load bearing |
| 112 | 16.9.6 Adjustable steel props |
| 115 | 16.9.8 Floor centres |
| 116 | 16.9.9 Proprietary beams 16.9.10 Spanning girders 16.9.11 Military trestling systems 17.1 General |
| 117 | 17.2 Weights of materials 17.3 Self-weights 17.4 Imposed loads 17.4.1 General 17.4.2 Permanent works loading |
| 118 | 17.4.3 Construction operations |
| 120 | 17.5 Environmental loads 17.5.1 Wind loading |
| 138 | 17.5.3 Snow 17.5.4 Ice |
| 139 | 17.5.5 Earth pressure |
| 141 | 18.1 General 18.1.1 Introduction |
| 142 | 18.1.2 Slope and stability 18.1.3 Depth of foundations 18.2 Site investigation for falsework foundations |
| 143 | 18.3 Testing of soils |
| 145 | 18.4 Allowable bearing pressures 18.5 Modification factors applied to presumed bearing pressures 18.5.1 Modification factor for reliability of site information 18.5.2 Settlements of the foundations underneath the falsework |
| 146 | 18.5.3 Ground water levels 18.6 Simple foundations on sands and gravels 18.7 Simple foundations on cohesive soils 18.8 Heavy vibrations |
| 147 | 18.9 Fill material 18.10 Piles 18.11 Protection of the foundation area |
| 148 | 19 Design of falsework 19.1 Preamble to design 19.1.1 General 19.1.2 CDM regulations and interface between design of permanent and temporary works 19.1.3 Design brief |
| 149 | 19.1.4 Choice of concept |
| 151 | 19.1.5 Selection of materials and components 19.2 Forces applied to falsework 19.2.1 General |
| 152 | 19.2.2 Vertical forces 19.2.3 Wind forces 19.2.4 Forces resulting from erection tolerance |
| 153 | 19.2.5 Forces resulting from out of vertical by design 19.2.6 Concrete pressure forces 19.2.7 Water and wave forces 19.2.8 Dynamic and impact forces 19.2.9 Notional lateral forces to be considered |
| 154 | 19.2.10 Forces from the permanent structure 19.3 Analysis of the structure 19.3.1 General (behaviour of the structure) |
| 155 | 19.3.2 Lateral restraint |
| 159 | 19.3.3 Combinations of forces |
| 161 | 19.3.4 Back-proppingBackpropping in multi-storey construction |
| 162 | 19.4 Design 19.4.1 General |
| 167 | 19.4.2 Check one – Structural strength |
| 174 | 19.4.4 Check three – Overall stability |
| 180 | 19.6 Foundations 19.6.1 Purpose of foundations |
| 181 | 19.6.2 Supported on permanent works foundations 19.6.3 Supported on the ground |
| 183 | 19.7.1 Clear span falsework systems 19.7.2 Independent towers in groups 19.7.3 Falsework (or centring) for arches |
| 185 | 19.7.4 Horizontal or raking falsework 19.7.5 Mobile and travelling falsework 19.7.6 Using scaffold tube and fittings |
| 187 | 19.7.7 Sloping soffits 20.1 Introduction 20.2 Specific design instructions 20.3 General workmanship 20.3.1 Critical factors of workmanship |
| 188 | 20.3.2 Accuracy of falsework |
| 190 | 20.3.3 Vertical movement 20.3.4 Top arrangements |
| 191 | 20.3.5 Wedging 20.3.6 Lacing and bracing 20.3.7 Importance of details |
| 192 | 20.4 Checking falsework 20.4.1 When to check 20.4.2 Items to be checked |
| 193 | 20.5 Application of loads to falsework |
| 194 | 20.6 Dismantling 20.6.1 General 20.6.2 Supports required after general dismantling |
| 195 | 20.7 Maintenance, inspection and identification of materials |
| 196 | Annex A (normative) A.1 Permissible stresses |
| 197 | A.2 Young’s modulus |
| 200 | Annex B (normative) B.1 Properties of steel scaffold tube complying with the requirements of BS EN 39:2001 and BS 1139-1:1982 B.2 Axial compressive stress γm = 1.1 |
| 201 | B.3 Safe working loads for scaffold fittings complying withconforming to the requirements of BS 1139-2.2:1991 |
| 206 | Annex C (normative) C.1 Introduction C.2 Tests on falsework equipment C.3 Prototype and initial testing |
| 207 | C.4 Quality control of manufacture |
| 208 | Annex D (normative) D.1 Concrete shrinkage and creep D.2 Coefficient of linear expansion/contraction D.3 Modulus of elasticity4) D.4 Density of reinforced concrete |
| 209 | D.5 Masses and densities of materials D.6 Masses of corrugated steel sheeting D.7 Some unusual loads that frequently require consideration |
| 212 | Annex E (normative) Wave forces E.1 Definitions E.1.1 bore E.1.2 clapotis E.1.3 fetch E.1.4 still water depth, d E.1.5 still water level E.1.6 wave height, H E.1.7 wavelength, L E.2 General |
| 213 | E.3 Non-breaking waves |
| 215 | Annex F (normative) F.1 Introduction F.2 General F.3 Preliminary appraisal F.4 Depths for investigation and sampling |
| 216 | F.5 Laboratory tests F.6 Final report and recommendations |
| 217 | Annex G (informative) G.1 Design brief for a motorway bridge |
| 218 | G.2 Design brief for a suspended floor in a building |
| 219 | Annex H (informative) H.1 General H.2 Freestanding support of sloping soffits H.3 Forces in a simple situation H.4 Forces when the top and base of concrete are sloping without a topform |
| 220 | H.5 Forces when the top and base of the concrete are sloping with a top form H.6 Forces when opposing forms are not tied together H.7 Application of forces to freestanding falsework |
| 221 | H.8 Support of sloping soffits cast against existing structures H.8.1 General H.8.2 Loads applied to falsework |
| 222 | H.9 Arch falsework |
| 223 | Annex I (informative) Blank |
| 224 | Annex J (normative) J.1 General J.2 Beams without bearing stiffeners |
| 229 | J.3 Design of bearing stiffeners |
| 230 | J.4 Hollow sections |
| 231 | Annex K (normative) Effective lengths of steel members in compression K.1 General K.2 Effective length for axial compression |
| 232 | K.3 Effective length for simply supported or continuous beams K.3.1 Beams with intermediate lateral restraints K.3.2 Beams without intermediate lateral restraints |
| 234 | K.4 Effective length for cantilever beams K.4.1 Cantilevers with intermediate restraints K.4.2 Cantilevers without intermediate restraints K.5 Effective torsional end restraint |
| 235 | K.6 Effective lateral restraint K.6.1 General K.6.2 Girder restraint bracing design K.6.3 Girder restraint from external points |
| 239 | Annex L (informative) L.1 General L.2 The BS EN 1991-1-4:2005+A1 basic equations |
| 241 | L.3 Derivation of wind calculation in BS 5975:2008+A1 L.3.1 General – Simplified velocity pressure for falsework, qp L.3.2 Altitude correction factor, calt The altitude correction factor calt in NA to BS EN 1991-1-4:2005+A1, NA.2.5 is used to adjust the basic wind speed for the altitude above sea level. or else for z > 10 m: (L.10) A is the altitude of the site in metres. |
| 242 | (L.11) L.3.3 Direction factor, cdir |
| 243 | L.3.5 Probability factor, cprob L.3.6 Orography factor, co |
| 244 | L.3.7 Topography factor, Twind |
| 246 | L.4 Wind calculation for structures >50 m where orography is significant L.4.1 General Where the value of z is greater than 50 m then the peak velocity pressure is calculated by applying a roughness factor cr(z) to the mean wind velocity vm and applying the peak factor model to it. The air is less turbulent at higher levels, and the ter… |
| 247 | L.4.2 Combined roughness factor, cr (z) cr,T Where a site is in a town, NA to BS EN 1991-1-4:2005+A1 applies a correction factor cr,T, shown graphically in Figure NA.4, to reduce the country roughness depending on how far the site is inside the town. Figure NA.4 regards any structure less than 0… If you consider 3 m high falsework in town, the reduction varies from 0.74 at 0.1 km, 0.65 at 2 km and 0.62 at 10 km inside the town. This standard considers towns if more than 2 km inside the edge of the town, then the designs will be conservative fo… The approach in this standard is to combine the graphical roughness factor cr(z) and the town correction factor cr,T into a combined roughness factor in Table L.3. The roughness correction factor cr,T is unity in the country. Values for reference heig… Table L.3 — Combined roughness factor, cr(z)cr,T L.4.3 Turbulence intensity, IV (z)flat |
| 248 | L.4.4 Orography factor, co |
| 249 | L.4.5 Peak velocity pressure for structures 50 m to 100 m with significant orography |
| 251 | L.5 The seasonal factor SS L.6 The probability factor, Sp |
| 252 | L.7 The simplified wind pressure equation |
| 253 | Annex M (normative) M.1 Shielding of falsework – General M.2 The shielding factor, η |
| 254 | Bibliography |
| 259 | Index |
| 284 | Foreword |
| 286 | Introduction |
| 287 | Section 1: General 1 Scope 2 Normative references |
| 289 | 3 Terms and definitions |
| 294 | 4 Abbreviations and symbols |
| 298 | 5 Overview of temporary works procedures and training 5.1 Overview of procedures |
| 302 | Figure 1 — Typical contractual interfaces between parties on a project |
| 304 | Figure 2 — Lines of responsibilities where a single contractor or a principal contractor (PC) is co-ordinating the temporary works |
| 306 | Figure 3 — Lines of responsibility where either a principal contractor’s (PC) appointed sub-contractor or a client’s contractor co-ordinate their own temporary works |
| 307 | Figure 4 — Schematic representation of relationships between principal contractor and contractor (client appointed or sub-contractor) including PC’s TWC and contractor’s TWC |
| 308 | 5.2 Training |
| 310 | Section 2: Procedural control of temporary works 6 Procedures 6.1 Introduction to procedural control |
| 313 | Table 1 — Implementation risk classes for temporary works and examples of mitigation measures |
| 314 | 6.2 Temporary works register |
| 315 | 7 Clients’ procedures 7.1 General (Commercial/public clients) |
| 316 | 7.2 Clients appointing contractors other than PCs 7.3 Client’s DI |
| 317 | 7.4 Domestic clients |
| 318 | 8 Designers’ procedures 8.1 General |
| 319 | 8.2 Designers’ DI 8.3 Permanent works designers |
| 320 | 8.4 Temporary works designers 8.5 Principal designers |
| 321 | 9 Contractors’ procedures 9.1 Organizational interfaces |
| 322 | 9.2 Contractors’ DI |
| 323 | 9.3 Responsibilities |
| 325 | 9.4 Principal contractor |
| 326 | 9.5 Contractors other than PC |
| 327 | 9.6 Third-party employed contractor 10 Supplier/manufacturer procedures 10.1 Suppliers of temporary works equipment 10.2 Suppliers’ DI |
| 328 | 10.3 Suppliers’ procedures 10.4 Verification of design information 10.5 Provision of information 10.6 Provision of design data |
| 329 | 10.7 Provision of information for the safe use of equipment 10.8 Standard solutions 11 Temporary works co-ordinator 11.1 General 11.2 The PC’s TWC |
| 332 | 11.3 The TWC (other than the PC’s TWC) |
| 335 | 12 Temporary works supervisor 12.1 General 12.2 Role of the TWS |
| 336 | 12.3 Duties of the TWS 13 Design of temporary works 13.1 General |
| 337 | 13.2 Design brief |
| 338 | 13.3 Design guidance |
| 340 | 13.4 Choice of temporary works 13.5 Selection of materials and components 13.6 Design output |
| 341 | 13.7 Design check |
| 342 | Table 2 — Categories of design check in temporary works |
| 343 | 13.8 Resolution of queries raised by the design checker |
| 344 | 13.9 Alterations 13.10 Standard solutions |
| 345 | 14 Site considerations 14.1 Co-ordination, supervision and checking of work on site |
| 346 | 14.2 Loading and unloading temporary works |
| 347 | 14.3 Dismantling |
| 348 | Section 3: Falsework 15 General 16 Materials 16.1 General considerations 16.2 Testing and inspection |
| 349 | 16.3 Steelwork (other than scaffold tube) |
| 350 | 16.4 Timber |
| 351 | Table 3 — Basic stresses and moduli of elasticity for the wet condition Table 4 — Softwood species which satisfy strength classes in accordance with BS 4978 |
| 352 | Table 5 — North American softwood species and grade combinations which satisfy strength classes in accordance with national lumber grades authority (NLGA) and national grading rules for dimension lumber (NGRDL) joist and plank rules Table 6 — Hardwoods which satisfy the strength classes graded to BS 5756:2007 |
| 353 | Table 7 — Preferred target sizes and actual dimensions for constructional sawn softwood timber |
| 354 | Table 8 — Modification factor K3 for duration of load on falsework |
| 355 | Table 9 — Modification factor K4 for bearing stress Table 10 — Maximum depth-to-breadth ratios |
| 356 | Figure 5 — Shear stress on a timber beam of rectangular cross-section |
| 357 | Table 11 — Depth modification factor K7 for solid timbers less than 300 mm depth |
| 358 | Table 12 — Permissible stresses and moduli of elasticity for general falsework applications Table 13 — Permissible stresses and moduli of elasticity for load-sharing falsework applications |
| 359 | Table 14 — Commercial grade timber suitable to produce mainly class C16 timber 16.5 Concrete and concrete components |
| 361 | 16.6 Brickwork and blockwork 16.7 Other materials |
| 362 | 16.8 Steel scaffold tubes, couplers and other fittings |
| 364 | 16.9 Manufactured components for falsework |
| 365 | Table 15 — Adjustable steel prop heights |
| 366 | Figure 6 — Safe working loads for BS 4074:1982 props erected 1.5° out-of-plumb |
| 367 | Figure 7 — Safe working load for BS 1065:1999 props erected 1° maximum out‑of‑plumb and with up to 10 mm maximum eccentricity of loading |
| 368 | 17 Loads applied to falsework 17.1 General |
| 369 | 17.2 Weights of materials 17.3 Self-weights 17.4 Imposed loads |
| 372 | 17.5 Environmental loads |
| 376 | Figure 8 — Fundamental basic wind velocity vb,map (in m/s) |
| 377 | Figure 9 — Topography factor Twind diagram |
| 378 | Table 16 — Combined exposure factor, ce(z)ce,T |
| 379 | Figure 10 — Displacement height diagram Figure 11 — Town, country and sea |
| 382 | Table 17 — Force coefficients cf for falsework |
| 384 | Figure 12 — Wind on soffit parallel to secondary bearers Figure 13 — Wind on soffit parallel to primary bearers |
| 386 | Figure 14 — Wind on two edge forms Figure 15 — Shelter factor |
| 387 | Figure 16 — Wind on more than two edge forms |
| 388 | Figure 17 — Wind loading – Combined formwork and unclad falsework (upper limit) |
| 395 | 18 Foundations and ground conditions 18.1 General 18.2 Site investigation for falsework foundations |
| 396 | Table 18 — Presumed allowable bearing pressure under vertical static loading |
| 397 | 18.3 Testing of soils |
| 398 | Table 19 — Identification and description of soils 18.4 Allowable bearing pressures |
| 399 | 18.5 Modification factors applied to presumed bearing pressures |
| 400 | Table 20 — Ground water level modification factor 18.6 Simple foundations on sands and gravels 18.7 Simple foundations on cohesive soils 18.8 Heavy vibrations 18.9 Fill material |
| 401 | 18.10 Piles 18.11 Protection of the foundation area 19 Design of falsework 19.1 Preamble to design |
| 403 | Figure 18 — Individual support members |
| 404 | Figure 19 — Panels to facilitate the erection of individual prop systems (elevation) Figure 20 — Individual fully braced tower Figure 21 — Proprietary system, partially braced by discrete panels |
| 405 | Figure 22 — Fully braced falsework system |
| 406 | 19.2 Forces applied to falsework |
| 408 | 19.3 Analysis of the structure |
| 410 | Figure 23 — Free-standing structure Figure 24 — Top-restrained structure |
| 411 | Figure 25 — Plate action (plan view) |
| 412 | Figure 26 — Restraint provided on one side of the plate (plan view) Figure 27 — Restraint provided on two perpendicular sides of the plate (plan view) Figure 28 — Restraint provided on two parallel (opposite) sides of the plate (plan view) |
| 413 | Figure 29 — Restraint provided on three sides of the plate (plan view) Figure 30 — Restraint provided on four sides of the plate (plan view) Figure 31 — Restraint provided by four permanent works columns (plan view) Figure 32 — Restraint provided by two permanent works columns (plan view) |
| 414 | Figure 33 — Concrete pressures applied and the subsequent rotational forces induced (typical falsework plan) |
| 416 | Figure 34 — Effects of eccentricity and sway on top-restrained structures Figure 35 — Effects of eccentricity and sway on freestanding structures |
| 417 | Figure 36 — Effects of FH on individual towers |
| 418 | Table 21 — Example of percentage of load transfer for less than 350 mm flat slabs 19.4 Design |
| 419 | Table 22 — Roles and responsibilities of temporary and permanent works designers |
| 420 | Table 23 — Requirements for stability checks in top-restrained falsework |
| 421 | Table 24 — Requirements for stability checks in free-standing structures |
| 423 | Figure 37 — Typical, free-standing, fully braced scaffolding (elevation) Figure 38 — Typical, top-restrained, fully braced scaffolding (elevation) |
| 425 | Figure 39 — Member stability check for top-restrained systems (elevation) Figure 40 — Considerations for partially braced frames |
| 426 | Figure 41 — Member stability check for free-standing systems (elevation) |
| 427 | Figure 42 — Considerations for free-standing partially braced frames |
| 428 | Figure 43 — Effective lengths in tube and coupler falsework |
| 429 | Figure 44 — Lateral stability check for top-restrained structures |
| 430 | Figure 45 — Lateral stability check for free-standing structures |
| 431 | Figure 46 — Working space and stability during erection, loading and dismantling |
| 433 | Figure 47 — Lateral restraint provided by friction |
| 434 | Table 25 — Recommended values of coefficient static friction μ |
| 435 | 19.5 Beams and lattice girders 19.6 Foundations |
| 438 | Figure 48 — Base detail on slopes |
| 439 | 19.7 Additional considerations affecting certain design solutions |
| 440 | Figure 49 — Suggested bracing arrangement for falsework erected on beams or girders |
| 442 | Figure 50 — Maximum deviation of load path |
| 443 | 20 Work on site 20.1 Introduction 20.2 Specific design instructions 20.3 General workmanship |
| 446 | Figure 51 — Points of measurement of tolerances for purposely fabricated steelwork |
| 447 | Figure 52 — Skew lapping of primary beams to minimize eccentricity of load |
| 448 | 20.4 Checking falsework |
| 450 | 20.5 Application of loads to falsework 20.6 Dismantling |
| 451 | 20.7 Maintenance, inspection and identification of materials |
| 452 | Annex A (normative) Permissible stresses and modulus of elasticity for steel grades generally used in falsework |
| 453 | Figure A.1 — I beam dimensions |
| 454 | Table A.1 — Permissible bending stress in compressive members, pbc, for beams |
| 455 | Table A.2 — Permissible axial compressive stress, pc, on cross-section Annex B (normative) Properties of components in tube and coupler falsework |
| 458 | Table B.1 — Section properties of scaffold tube |
| 459 | Table B.2 — Safe axial loads in compression for Type 4 steel scaffold tubes manufactured in accordance with BS EN 39:2001 |
| 460 | Table B.3 — Safe axial loads in compression for Type 4 steel scaffold tubes manufactured in accordance with BS 1139‑1:1982 |
| 461 | Table B.4 — Safe working loads for individual couplers and fittings Annex C (normative) Initial testing, quality control and inspection of falsework equipment |
| 463 | Annex D (normative) Data on material properties Table D.1 — Modulus of elasticity for concrete |
| 464 | Table D.2 — Density of reinforced concrete Table D.3 — Density ranges for lightweight concretes |
| 465 | Table D.4 — Masses of scaffolding material Table D.5 — Masses and densities of men and materials Table D.6 — Masses of corrugated steel sheeting |
| 466 | Annex E (normative) Wave forces |
| 468 | Figure E.1 — Non-breaking waves – Section diagrams Annex F (normative) Site investigations for foundations for falseworks |
| 470 | Annex G (informative) Examples of design brief contents |
| 472 | Annex H (informative) Forces from concrete on sloping soffits Figure H.1 — Distribution of forces on sloping soffits – Level surface, sloping base |
| 473 | Figure H.2 — Distribution of forces on sloping soffits – Sloping surface and sloping base Figure H.3 — Distribution of forces on sloping soffits – All surfaces sloping and with top formwork |
| 474 | Figure H.4 — Freestanding falsework |
| 475 | Figure H.5 — Formwork connected to an existing structure Figure H.6 — Arch falsework Annex I (informative) Blank |
| 476 | Annex J (normative) Design of steel beams at points of reaction or concentrated loads |
| 478 | Table J.1 — Effective lengths and slenderness ratios of an unstiffened web acting as a column |
| 479 | Figure J.1 — Stress dispersion – Buckling |
| 480 | Figure J.2 — Stress dispersion – Bearing |
| 482 | Table J.2 — Effective lengths of load bearings Annex K (normative) Effective lengths of steel members in compression |
| 483 | Figure K.1 — Positional restraint of steel members in axial compression |
| 484 | Table K.1 — Effective lengths of struts |
| 485 | Table K.2 — Effective lengths for beams without intermediate lateral restraint |
| 487 | Table K.3 — Effective lengths for cantilever beams without intermediate lateral restraint |
| 488 | Figure K.2 — Girder restraint (1) – Plan view |
| 489 | Figure K.3 — Girder restraint (2) – Plan view Annex L (informative) Wind calculations for falsework |
| 490 | Table L.1 — Source of the basic wind equations |
| 492 | Table L.2 — Values of direction factor, cdir |
| 497 | Table L.3 — Combined roughness factor, cr(z)cr,T |
| 498 | Table L.4 — Turbulence intensity, Iv(z)flat |
| 499 | Figure L.1 — Orography factor, co |
| 503 | Annex M (normative) Shielding factor η for unclad falsework Table M.1 — Shielding factor, η |
| 505 | Bibliography |
| 509 | Index |
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BS 5975:2019
Code of practice for temporary works procedures and the permissible stress design of falsework Published…
