Page 36 - Building Regulation and Design Guidelines - Structural (Grey Code)
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SECTION: 2    STRUCTURAL DESIGN GUIDELINES – BUILDING STRUCTURES                      SECTION: 2  STRUCTURAL DESIGN GUIDELINES – BUILDING STRUCTURES




                          2.5.2.3  GENERAL CONSIDERATIONS                                                                 considered in design of vertical and horizontal members.
                                                                                                                          In  plane  section  modifiers  for  slabs  shall  be  reduced  to
                                1.   Where the structure is composed of a flexible upper                                  account for concrete cracked section area as per the code
                                    portion and lower stiffer basement/podium, the seismic
                                    scale factor shall be calibrated at foundation level to                               governing the design.
                                    design the basement elements and at top of basement to                           10.   Structural design shall accommodate shrinkage, creep and
                                    design the tower elements.                                                            thermal strains by providing appropriate reinforcement or
                                                                                                                          specifying control or expansion joints. Expansion joints
                               2.   The augmented section modifiers could be used to
                                    check the maximum drift and vibration acceleration only                               shall satisfy seismic requirements of relevant code.
                                    as  permitted  by  ACI,  provided  that  the  designer  has  to                  11.   Floor slabs shall be designed to be adequately supporting
                                    estimates  the  degree  of  cracking  and  comply  with  the                          the entire construction loads from the next slab without
                                    serviceability  limit  state  at  the  adopted  design  service                       compromising the ultimate or/and service limit states
                                    loads.                                                                                requirements.
                               3.   Permanent drift due to gravity loads to be checked and                           12.   Transfer element design shall be confirmed by alternative
                                    shall be eliminated or minimized with proper technical                                design method.
                                    arrangement.
                                                                                                                     13.   For dead loads & earth pressure/uplift load combinations,
                               4.   All structural framing elements and their connections, not                            the loads shall be factored as per clause 1909.2, UBC1997.
                                    required by design to be part of lateral–force-resisting
                                    system, shall be designed to be adequate to maintain                             14.   Individual pile caps and isolated footings subjected to
                                    support of design dead plus live loads when subjected to                              seismic forces shall be interconnected by ties. Such ties
                                    the deformation caused by seismic forces.                                             shall be designed as per clause 1807.2, UBC 1997.
                               5.   Effects of axial long term shortening due to elastic,                            15.   Third  party  structural  review  is  required  for
                                    shrinkage and creep effects shall be investigated and                                 specific structures as classified in CED circular Ref.
                                    accounted for in the design and construction. If measures                             CIRCULAR-52027/2009/sk dated 26-04-2009.
                                    to compensate for the effects of differential shortening
                                    are taken, consultant shall include such information on                     2.5.2.4  SERVICEABILITY LIMITS
                                    engineering drawings and relevant documents.                                      1.   All buildings shall be designed to limit maximum drift
                               6.   Manual take  down of gravity  loads for all key vertical                              under 50 years wind load to 1/500 of building height.
                                    elements to be compared with resulting loads from                                 2.   All buildings shall be designed to limit inter-story drift to
                                    analyzed model.                                                                       1/500 of the story height and not more than 10mm under
                               7.   Loading and Design shall be carried out in compliance                                 serviceability of 10 years wind. If no wind tunnel test results
                                    with the code that the governing load combination was                                 are available, 10 years serviceability wind speed of 38 m/s
                                    derived from.                                                                         can be adopted in Dubai for inter-story drift calculations.
                                                                                                                          Inter-story drift due to seismic shall be assessed and shall
                               8.   Calculation of effects of accidental eccentricities and load                          not exceed the limitations of clause 1630.10, UBC 1997.
                                    reductions shall be consistent with the code used for the
                                    structural design.                                                                3.   Adequate provisions shall be adopted to eliminate risk of
                                                                                                                          damage to non-structural elements due to inter-story drift
                               9.   Thermal  effects  shall  be  evaluated  based  on  realistic                          and long term deflection of beams and slabs.
                                    temperature distribution. Seasonal temperature change
                                    shall not be less than 25 deg. C or in accordance                                 4.   Wind induced vibration due to 10 years wind shall be
                                    with credible local climate record. This effect shall be                              limited to 15 milli-g for residential and hotel buildings

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