Shear at Midspan: HL93 loading

Please click on the attached Bentley Communities link which explains how the Max Shear is calculated at Mid span .

This example explains "Live Load Maximum Shear Calculation for SERVICE III Limit State" and the same procedure can be used to for other limit states.


communities.bentley.com/.../24933.live-load-maximum-shear-calculation-for-service-iii-limit-state

Hi. Based on this example, I see that Conspan is "patch loading" the design lane load. For example, at midspan, half of the span is loaded with the lane load. Is this how Conspan is interpreting AASHTO LRFD 3.6.1.3.1? "Unless otherwise specified, the lengths of design lanes, or part thereof, that contribute to the extreme force effect under consideration, shall be loaded with the design lane load." I thought that design lane loads had to be applied to the entire span. Am I interpreting AASHTO incorrectly?

Hi. Based on this example, I see that Conspan is "patch loading" the design lane load. For example, at midspan, half of the span is loaded with the lane load. Is this how Conspan is interpreting AASHTO LRFD 3.6.1.3.1? "Unless otherwise specified, the lengths of design lanes, or part thereof, that contribute to the extreme force effect under consideration, shall be loaded with the design lane load." I thought that design lane loads had to be applied to the entire span. Am I interpreting AASHTO incorrectly?

You are not interpreting AASHTO incorrectly , Conspan Lane Loads are analyzed by loading only those parts of the bridge that would cause a maximum moment or shear at each section which is complaint with AASHTO requirement.