Ahsanullah University Of Science and Technology
Department Of Civil Engineering
CE-418 Prestressed Concrete and Design Sessional
Presented By
Name : Md. Kamrul islam Roll : 10.01.03.056Section : A
Topic
Bearing&Punching Shear
What is Punching Shear?
Punching Shear Punching shear is a type of failure of reinforced
concrete slabs subjected to high localized forces. In flat slab structures this occurs at column support points. The failure is due to shear
The shear stress calculated by dividing the load on a column by the product of its perimeter and the thickness of the base or cap, or by the product of the perimeter taken at one-half the slab thickness away from the column and the thickness of the base or cap.
Punching shear in concrete slabs is a problem
Punching shear in concrete slabs is a serious problem in certain structural systems, such as flat slabs
Punching Shear
Punching Shear
Punching Shear
Bearing stress
• Bearing stress is a compressive stress applied to the contact surface between two connecting members. This stress can commonly be found on a pin & hole connection.
• Like general stress, bearing stress is not evenly uniform over the cross-sectional area but is generally assumed for simplicity.
• The average bearing stress is the force pushing against a structure divided by the area. Exact bearing stress is more complicated. Experiments have shown that the bearing stress distribution is more elliptical shaped and not uniform.
Bearing Stress Equation
σavg=P/Aσ avg – Stress (Average)P – Applied LoadA – Cross-Sectional Area (Preload) Bearing Stress
Bearing stress is a normal stress, not a shearing stress.
Bearing Stress
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