department of civil engineering ned university engineering & technology building prof sarosh...
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Department of Civil EngineeringNED University Engineering & Technology
Building
Prof Sarosh Lodi
Department of Civil EngineeringNED University Engineering & Technology
TOPICS COVERED Intro
Department of Civil EngineeringNED University Engineering & Technology
FLEXURAL MEMBERS OF SMRFGeneral Clear span not less than 4 times effective depth Width/depth ratio not less than 0.3 Width not less than 10 in Width not more than width of supporting member plus distance on each side of supporting member equal to ¾ of the depth of flexural member
Cont.
Department of Civil EngineeringNED University Engineering & Technology
FLEXURAL MEMBERS OF SMRFLongitudinal Reinforcement Reinforcement ratio not less than 200/fy Reinforcement ratio not more than 0.025 Two bars should be continuous in top and bottom +ve moment strength at joint face should not be less than ½ of –ve moment strength +ve or –ve moment strength at any section should not be less than ¼ of strength at joint face Lap allowed only with hoop or spiral reinforcement Lap splices are not allowed
within joints a distance of 2d from joint face
Department of Civil EngineeringNED University Engineering & Technology
FLEXURAL MEMBERS OF SMRFLongitudinal Reinforcement
Department of Civil EngineeringNED University Engineering & Technology
FLEXURAL MEMBERS OF SMRFTransverse Reinforcement Maximum hoop spacing shall not exceed
d/4 8 times dia of smallest longitudinal bar 24 times dia of hoop bar 12 in
Examples of hoops are
Cont.
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRFGeneral Shortest cross-sectional dimension is 12 in. Ratio of shortest dimension to perpendicular dimension shall not be less than 0.4
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRFReinforcement Longitudinal reinforcement ratio not less than 0.01 and not more than 0.06 Concrete cover for transverse reinforcement shall not exceed 4 in. Spacing of rings (s) shall not exceed
s=¼ of minimum column dimension s=6 times dia of longitudinal bar s=4+[(14-hx)/3] 4”< s <6”
Length of column (L) for above ring spacing shall not be less than depth of column 1/6 of clear span 18 in.
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRFReinforcement Spacing (S1) for the rest of column length is smaller of
6 times longitudinal bar dia 6 in.
Example of rings is
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRF
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRF
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRF
Department of Civil EngineeringNED University Engineering & Technology
COLUMNS FOR SMRFJoints Beam longitudinal reinforcement must be extended to the far face of column and anchored Column dimension parallel to the beam reinforcement not be less than 20 times bar dia Transverse reinforcement shall be provided in joint
Department of Civil EngineeringNED University Engineering & Technology
INTERMEDIATE MOMENT RESISTING FRAMEBeams +ve moment strength at joint face should not be less than 1/3 of –ve moment strength +ve or –ve moment strength at any section should not be less than 1/5 of strength at joint face First hoop provided at 2 in. from face of support Maximum hoop spacing shall not exceed
d/4 8 times dia of smallest longitudinal bar 24 times dia of hoop bar 12 in
Department of Civil EngineeringNED University Engineering & Technology
INTERMEDIATE MOMENT RESISTING FRAMEColumns Hoops provided at spacing (s) over length (L) from both ends s should be smallest of
8 times dia of smallest longitudinal bar 24 times dia of hoop bar ½ of smallest dimension of frame member 12 in
L should be largest of 1/6 of clear span of column Minimum dimension of column 18 in
Department of Civil EngineeringNED University Engineering & Technology
INTERMEDIATE MOMENT RESISTING FRAMEColumns Hoops provided at spacing (s) over length (L) from both ends s should be smallest of
8 times dia of smallest longitudinal bar 24 times dia of hoop bar ½ of smallest dimension of frame member 12 in
L should be largest of 1/6 of clear span of column Minimum dimension of column 18 in