Page 59 - Building Regulation and Design Guidelines - Structural (Grey Code)
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SECTION: 4  STRUCTURAL DESIGN GUIDELINES - STEEL STRUCTURES                           SECTION: 4  STRUCTURAL DESIGN GUIDELINES - STEEL STRUCTURES




                               •   Protective measures.                                                         3.   Structural members that support heavy vibrating machinery or
                                                                                                                    plant should be checked for fatigue resistance.
                               •   Whether inspection and maintenance are possible.
                                                                                                                4.   Where aerodynamic instability can occur, account should be taken
                               •   As an alternative to the use of protective coatings, weather
                                   resistant steels to BS EN 10155 may be used. Steels                              of wind induced oscillations.
                                   complying with other prominent international codes such as                   5.   Where fatigue is critical, all design details should be precisely
                                   the American and European codes are acceptable subject to                        defined and the required quality of workmanship should be clearly
                                   review and approval by the authority.                                            specified.
                    4.3.5   FOUNDATION                                                                          6.   Resistance to fatigue should be determined by reference to BS
                                                                                                                    7608 or applicable codes.
                          Foundations shall accommodate all forces imposed on them. Attention
                          should be given to the method of connecting the steel superstructure to         4.3.8   STRUCTURAL INTEGRITY
                          the foundations and to the anchoring of holding-down bolts.
                                                                                                                All buildings shall be effectively tied together at each principal floor level.
                          1.   Where it is necessary to quote the foundation reactions, it should
                              be clearly stated whether the forces and moments result are from                  1.   Each column shall be effectively held in position by means of
                              factored or unfactored loads. Where they result from factoed loads,                   horizontal ties in two directions, approximately at right angles, at
                                                                                                                    each principal floor level supported by that column.
                              the relevant factors for each load in each combination should be
                              stated.                                                                           2.   Horizontal ties shall be provided at roof level, except where the
                                                                                                                    steelwork only supports cladding that weighs not more than 0.7
                    4.3.6   HOLDING DOWN BOLTS                                                                      kN/m2 and that carries only imposed roof loads and wind loads.
                          Holding down bolts should be designed to resist tension due to uplift                 3.   Continuous lines of ties should be arranged as close as practicable
                          forces and tension due to bending moments as appropriate.                                 to the edges of the floor or roof and to each column line. Ties
                          1.   Holding-down bolts required to resist tension should be anchored                     designed and provided as shown in Figures (4.1) and (4.2) are
                              by a washer plate or other load distributing member embedded in                       acceptable.
                              the foundation. This plate or member should be designed to span
                              any grout tube or adjustment tube provided for the holdingdown                             Column ties                Edge ties
                              bolt.
                          2.   Alternatively, a bend or hook in accordance with the minimum
                              bend radius recommended in the codes may be used.                                                                    Re-entrant corner
                                                                                                                                                    Tie anchoring
                          3.   Expanding anchors or resin-grouted anchors are generally not                                                         re-entrant corner
                              recommended. If they are required in exceptional cases, it should                                                            Edge ties
                              be demonstrated that the required capacity can reliably be
                              achieved, both by the anchor and by the foundation.
                                                                                                                                                          A
                    4.3.7   FATIGUE                                                                                                                        Tie anchoring
                                                                                                                                                           column A
                          1.   Fatigue need not be considered unless a structure or element is
                              subjected to numerous significant fluctuations of stress.                              Edge ties        Beams not used as ties
                          2.   Stress changes due to normal fluctuations in wind loading need                       Fig (4.1) Tying of Columns – Beams connecting columns only and
                              not be considered.                                                                               at reentrant corners used as Ties


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