Reliability Analysis Of Shear Strength Of A Rcc

Reliability analysis of Shear Strength of a RCC beam by Hasofer Lind Method by

Rakesh Kumar S 3rd semester M.E(Structures)

Under the guidance of

Dr V Devaraj Professor UVCE Bangalore University Bangalore

introduction 

The evaluation of safety of a structure is a task of much importance.



The performance of any structure is assessed by its safety, serviceability and economy.



Input variables are never certain, precise and complete.



Shear Strength of the beam is one of the phenomenon which may be at risk.



Evaluation of this risk is done by Reliability Analysis.

Procedure  

FIRST STEP Collection of available data of the problem;



In this case,

     

       

breadth, B =150mm depth, D =450 mm length, L=6000mm live load, Q=4KN shear strength, =95N/sq mm

Limit state function 

Limit state of shear

   

as defined in I.S 456.



Load and resistance models 

Resistance =

  

Load =

g(x) =

Reliability analysis Hasofer Lind method is selected for reliability analysis.  1) = 115.15 N/ sq mm  = 242.1 mm  = 473.7 mm  = 3637 N 2)The basic variables are normalized.  Z= 3) Write the limit state function in terms of normalized co-ordinate system.  g(z1,z2,……,Zn)=0 for computational purpose 4)Select a value for and values for 



=1.

Start the iteration. Calculate the new value of  using the equation =  Calculate  k= 



Determine the values of

 

With these new values, start the new iteration.  Iterations are continued until the last two results of iterations matches within unacceptable errors. 

Results and discussions Results are compared with the Standard values.  For strength above 3 is safe.  For serviceability above 2.2 is safe.  For the problem, the result obtained after 8 iterations is 5.71, and it is safe. 

conclusions 

THE RELIABILITY INDEX OBTAINED IS 5.71 , WHICH IS SAFE.





DESIGNS MADE UNDER THE CODE AND OTHER STANDARD PROVISIONS ARE UNECONOMICAL RATHER MORE SAFE.