Identification of Cracks
1a)
Answer:
Beam column Connection faliure:
Formation of Plastic hinge at undersirable locations The joint is not supposed to beam the weak link between 4 components (2 beams and 2 columns). These elements are subjected to very high shear force durig seismic activity. If these cracks are left unattended will lead to loss of strength and collapase. Shear failure governs in the beam column. Formation of plastic hinges must occur at the end of the beams not at the column and beam connections. It is also caused due to inappropriate detailing.
1b)
Answer:
Beam column Connection faliure:
Formation of Plastic hinge at undersirable locations The joint is not supposed to beam the weak link between 4 components (2 beams and 2 columns). These elements are subjected to very high shear force durig seismic activity. If these cracks are left unattended will lead to loss of strength and collapase. shear failure governs in the beam column. Formation of plastic hinges must occur at the end of the beams not at the column and beam connections. It is also caused due to inappropriate detailing.
1c)
Answer:
Beam column Connection faliure:
Formation of Plastic hinge at undersirable locations The joint is not supposed to beam the weak link between 4 components (2 beams and 2 columns). These elements are subjected to very high shear force durig seismic activity. If these cracks are left unattended will lead to loss of strength and collapase. shear failure governs in the beam column. Formation of plastic hinges must occur at the end of the beams not at the column and beam connections. It is also caused due to inappropriate detailing.
2a)
Shear faliure of column :It follows the mechanism of weak column and strong beam.
Longitudinal steel has buckled due to large compression forces.
2b)
Confinement faliure of the column:
This is caused due to inappropriate detailing of plastic hinge location .Under ductile response to earthquakes high compression strains should be accepted from combined effect of axial force in bending moment Adequate closed spaced well detailed transevered reinforcement needs to be done to avoid spalling of concrete followed by instability of compression reinforcement It should also be done to check the resistance of longitudinal reinforcement against buckilng.
2c)
Short column effect:
It is caused due to influence of partial height infill increasing column shear force (short column effect ) which causes undesirable mode of deformation . It happens due to ignoring the stiffening effects of non structural partial height masonary infill built hard up against the column. The shorter column attracts higher shear force which oftens leads to deformation or collapse.