Lane Supports (Reactions at Interior Piers)

 

 

Assign the nodes constituting interior supports in a multiple span being considered for moving load analysis using traffic lane loads.

When the AASHTO LRFD load is applied and maximum reactions in the Z-direction are sought, the program automatically reflects the requirement of the effect of 90% of two design trucks spaced at 50 ft and 90% of the design lane load for maximum and minimum reactions in accordance with AASHTO LRFD. The requirement of 14 ft distance between the 32 kip axles is also maintained.

PennDOT Design Truck (PHL-93TRK)

For the reaction at interior piers only, 90% of the effect of two design trucks spaced a minimum of 50 ft. between the lead axle of one truck and the rear axle of the other truck, combined with 90% of the effect of the design lane load. The distance between the 32 kips axles of each truck shall be taken as 14 ft.. The two design trucks shall be placed in adjacent spans to produce maximum force effects. (PUB 15M (5-12) 3.6.1.3.1.)

PennDOT Tandem (PHL-93TDM)

For the reaction at interior piers only, 100% of the effect of two tandems with axle weights of 25 kips spaced from 26 ft. to 40 ft. apart combined with the effect of the design lane load. The two tandems should be placed in adjacent spans to produce maximum force effects. (PUB 15M (5-12) 3.6.1.3.1.)

 

 

 

From the Main Menu select Load > Moving Load > Lane Supports - Reactions at Interior Piers.

 

 

0-check.jpg Options

Add: Enter the selected nodes.

Delete: Select and delete previously entered nodes.

Note1

Lane Support is applied as per AASHTO LRFD.

“The extreme force effect shall be taken for reaction at interior piers only, 90 percent of the effect of two design trucks spaced at a minimum of 50ft between the lead axle of one truck and the rear axle of the other truck, combined with 90 percent of the effect of the design lane load."

Note2

Refer to AASHTO LRFD 3.6.1.3 - Application of Design Vehicular Live Loads.

AASHTO legal load (The Manual for Bridge Evaluation)

This function also automatically considers the requirement of the effect of a lane load of 0.2 klf combined with two AASHTO Type3-3 vehicles or state legal loads multiplied by 0.75 spaced at 30 ft for negative moment in accordance with the Manual for Bridge Evaluation by AASHTO .

In addition, for span lengths greater than 200ft, critical load effects shall be created by the AASHTO Type3-3 vehicles or state legal loads multiplied by 0.75 and combined with a lane load of 0.2klf.

Each State DOT legal load

This function also automatically considers the requirement of the effect of a lane load of 0.2 klf combined with two state legal loads multiplied by 0.75 spaced at 30 ft for negative moment in accordance with DOT Legal vehicles when specified using the LRFR method.

In addition, for span lengths greater than 200ft, critical load effects shall be created by the state legal loads multiplied by 0.75 and combined with a lane load of 0.2klf.