Document Information

Document Type: FAQ

Product(s): LEAP CONBOX/CIP RC/PT Girder

Version(s): All

Original Author: Bentley Leap Bridge Technical Support Group – VM

QUESTION:  How the program is internally calculating the Live Load Reaction?

ANSWER:

1) A 2 span Box girder bridge was created in Leap Conbox. In the Load/Analysis TAB  I deleted all the trucks and kept only Design Truck and Design Lane.

2) Ran the analysis and clicked on View Analysis Button.

3) In the Analysis Results window I selected these options Final --> Truck/Lane --> Design Truck --> Min/Max Reaction.

4) For Abutment at Location 0.00 ft I noted down the Max Vertical Reaction as 58.01 kips.

5) I followed the same procedure and for Design Lane I noted down the Max Vertical Reaction as 16.53 kips.

6) In the Analysis Results window I selected these options Final --> Truck/Lane --> Design Truck --> Min/Max Forces.

7) After scrolling down halfway the user can see the Distribution Factors and Impact Factors for Service I, III and Strength I limit states at different POI.

8) Then in the Analysis Results window I selected Final --> Live Load  --> HL 93-Multi Span --> Min/Max Reaction option.

9) For Abutment at Location 0.00 ft I noted down the Total Max Vertical Reaction as 506.74 kips.

10) Please follow the following procedure to calculate the Final vertical Reaction.

11)  Design  Truck + Design Lane = (58.01 x 5.41 x 1.33 ) + ( 16.53 x 5.41 x 1 ) = 417.4 + 89.43

12) Total Vertical Reaction = 506.8 kips

Please see the attached screen shot for more information.