Page 35 - Building Regulation and Design Guidelines - Structural (Grey Code)

SECTION: 2 STRUCTURAL DESIGN GUIDELINES – BUILDING STRUCTURES SECTION: 2 STRUCTURAL DESIGN GUIDELINES – BUILDING STRUCTURES
i. Scale factors calculations.
j. Interconnection requirements
k. Wind loads parameters and coefficients or wind
tunnel study report.
l. Basic load combinations for ultimate and service
states design.
12. Extracts from analysis outputs: Modal mass participation
ratios, tension stresses in shear/core walls and modifiers
corrections, wind tunnel and code forces comparison, total
and inter-story drifts calculations, vibration acceleration
calculations, deflections and crack control calculations.
13. Software analyzed computer models conducted as per
CED’s requirements.
14. If applicable, third party report confirming the full
compliance of the submitted design documents with
the design provisions of the applicable codes and CED’s
design guidelines. The report shall be conducted as per
the relevant CED’s guidelines and requirements.
2.5.2.2 COMPUTER MODELS
1. The 3D model should reflect the actual geometry of the
structure / building and shall be in full compliance with
the design criteria and assumption.
2. The finite elements meshing shall appropriate to software
used for analysis. The designer shall ensure that the
analysis results are not affected by the quality of meshing.
3. The computer model shall have proper meshing of slab
and wall elements. For walls and slabs. The meshing
should have rectangular bias with elements of aspect
ratio not exceeding 2:1. Where openings are provided in
the slab or wall elements, the mesh nodes shall be located
at the corners of openings.
4. The designer shall ensure proper connectivity for slab
elements (Joints/Corner of one element should not be
connected to edge of other element, unless appropriate
calibration analysis is submitted with the model). The
mesh shall also have proper connectivity with columns
and walls elements.
68
5. Appropriately set-up auto-meshing could be used for
regular rectangular buildings. Care should be given to
connectivity and meshing constraints.
6. The computer model of concrete buildings shall be
analyzed considering realistic base restraint conditions
for cores, shear walls and columns. Adopted boundary
conditions shall be reflected in the design and detailing of
sub and super-structure members.
7. Modulus of elasticity shall be calculated as per the code
governing the design. Modulus of elasticity of high
strength concrete shall be determined as per ACI-363 –
Equations 6.1 to 6.8.
8. The analyzed computer model shall be free from any major
warnings or errors.
9. Section modifiers shall be applied as per clause 19.10.11.1
of UBC-97. For transfer elements, the section modifiers
shall be taken = 1.
10. Soil profile type and other seismic parameters used
in seismic analysis shall be as recommended in the
geotechnical investigation report.
11. Iterative method of estimating P-Delta effect shall be
considered in the analysis of buildings as requested by
clause 1630.1.3 of UBC 1997. Minimum of 3 iterations shall
be used.
12. Structures and buildings shall be analyzed by employing
Response Spectrum Analysis in full compliance with UBC
1997.
13. Tall buildings and other structures with structural system
sensitive to construction sequence shall be investigated
for the effects of construction sequence on internal load
distribution.
14. The design seismic case shall consist of combination of
two orthogonal excitation directions combined on the
SRSS basis as requested by clause 1633 of UBC 1997.
15. Seismic ductility factor shall be considered as per the
structural lateral resisting system definition, UBC 1997,
Clause 1629.6. Design of moment resisting frame system
shall satisfy the requirements of clauses 1626 & 1921.8,
UBC1997.
69