All the basic structural engineering snippets for all the structural engineers and also for civil engineers looking for career in structural engineering.
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STRUCTURAL ENGINEERING BASICS
• Tensile strength of concrete is 0.7*sqrt(fck) where fck is characteristic strength of
concrete.
• Modulus of elasticity of concrete is E = 5000*sqrt(fck)
• Factor of safety against overturning is 1.4.
• The lateral deflection under wind loads shall not exceed h/500 at top most point.
• Span for simply supported beam is either center to center of beam or clear span+effective
depth
• The maximum deflection shall be not less than l/250
• Span to depth ratios for cantilever is 7 , for simply supported is 20 and continuous beam is
26.
• A column or a compression member is slender if its l/b or l/d is more than 12.
• When depth of web is more than 750mm , 0.1% of web area should be provided as side
face reinforcement.
• Min spacing of shear reinforcement should be (0.87*fy*Asv) / (0.4*b)
• Maximum area of tension reinforcement is 0.04%*b*D
• Minimum reinforcement in slabs is 0.15 % and 0.12 % for mild steel and HYSD steel
respectively.
• Min and Max reinforcement in columns is 0.4 % and 6 % of sectional area respectively.
• Min dia of bar in colums is 12 mm
• Minimum 6 nos of bars shall be provided in circular column.
• Pitch of stirrups shall not be more than least of Least lateral dimension/ 16 times dia of
bar/300 mm.
• When ratio of long side/short side of slab is <2 , it is two way slab and vice versa.
• Span of stair is either center to center distance or beams, or center to center of landing
slab/1m which ever is small.
• Moment for the footing is taken at the face of column or wall.
• Crtical section for one way shear is at distance of eff depth from face or wall/column.
• For two wat shear, critical section is at distance of d/2 from the face of column/wall.
• Nominal reinforcement for concrete sections greater than 1m thick shall be 360 sq.mm
/meter length in each direction.
• Design strength of steel in limit state method is 0.87*fy.
• Torsion is not considered as limit state of serviceability.
• Maximum redistribution of moments can be upto 30 %