Identification of Cracks
1 a.observation
1.concrete crushed and the reinforcement in exposed
2.concrete spalled beyond the reinforcement which may be sign of rupture
3.beam top portion looks safe because of the flange advantage from slab
4.the crackdevelops from bottom to top means rebar yielding occurs in support bottom only
answer
its form of flexural failure due to reversal of stress during earthquake
during stress reversal support top experience compression and bottom experience tension
top compression is managed by slab advantage .bottom tension was not satisfied by the provided reinforecement
since the reinforcement got yielded it can not be repaired
b
observation
cracks along beam-column edge
cracks seem to have developed through the structure as it looks much water
beam looks sepred from the column at joints concrete is not severaly crushed
answers
is a plasstic hinge failure
the damaged occured in the joint zone trist of all
cyclic lateral loading and stress reversal at the joints led to the damage
even the slab participated to its best to handle in the tension slab is severaly cracked has undergone tension
with its flange condition but uanble to control the damage
the joint can be strenthened
c observation
cracks are exactly at the joint of column of beam
cracks in beamdeveloped through its entire width
slab also developed more cracks along beam width direction
answers
its a beam pull out failures due to insufficent developedd length of reinforecement in the joints
during earthquake the horizontal movement of structure makes this condition worse and detached the beam member
from column
providing anchorage length two existing concrete is very difficult so not repairable
2a
observation
concrete damaged at top of a column
concrete damaged all around the column
beams are safe
the location of column looks at edge of the building
no walls are built along the column means probaly at ground floor for parking movement access
answers
its a soft storey failure technicallyplatic hinge formation
due to absence of infill walls at the ground floor
the platic hinge forms at the top of ground storey columns during lateral movement
based on the development of crush of concrete it can eitherr be repairable or non repairable
2b
obesrvation
concrete developed complete breakage diagonally
longitudinal reinforcemnt are intact
shear reinforcement spacing looks wider which means probaly lesser shear rebar provided
answer
its a pure shear failure
inadequate shear reinforcemnt compells concrete takes all the shear stresses
2c
observation
column failed completely
failure at top of column
therre are two connected to the column probably one at mid height of the column
the wooden piles might be a post failuree support after column failed providing temporary prop toavoid collapse of the structure
answer
its a short column failure
leads to the effectan additional slab or a beam connected to a column inmid heights leads to the effect
this leads to failure especially if the connection is unintentional are not accounted in design
the failure given in the picture is not at all repairable