AASHTO LFD STANDARD CODE -- Shear Resistance Ratio calculation

Document Information

Document Type: FAQ

Product(s): LEAP CONSPAN/Precast/Prestressed Girder

Version(s): All

Original Author: Bentley Technical Support Group -VM

QUESTION: AASHTO LFD STANDARD CODE -- How the program is calculating Shear resistance ratio (Phi Vn / Vu) at 0.1L location ?

ANSWER:

Please follow the below mentioned procedure to calculate the shear resistance ration at 0.1L location . The code we are refereeing is AASHTO LFD code.

Stirrup Information :

No of Legs  =  2

Rebar Size = # 3

Rebar Dia = 0.11 in

Spacing = 12 in

General Information :

F'c = 5000 psi

Fy = 60 Ksi

d = 52 in

Phi = 0.9 for Shear

Calculation :

Av = 2 x 0.11 = 0.22 in^2

Vu = 44.9 kips

Vcw = 113.7 kips

Vci  = 179.5 kips

Vc = Min (Vcw,Vci) = 113.7 kips

Vs provd = (Av x Fy x d) / S

Vs provd = ( 0.22 x 60 x 52 ) / 12

Vs provd = 57.2 kips

Phi Vn = 0.9 ( Vs provd + Vc )

Phi Vn = 153. 81

Ratio = Phi Vn / Vu =  153.81 / 44.9

Ratio = 3.43

Please see the attached screenshot for more information.