Wasted Deck Concept

[maek]

I am looking at a rather unusual bridge configuration.

The girders are being skewed in a manner to decrease the span over a crossing. What you get is a bridge where the girders are skewed approximately 45 degrees with respect to LIVE LOAD TRAFFIC. The superstructure deck, therefore, is "wasted" outside of areas bounded by the concrete barriers.

Traditional live load distribution factors are out the window, naturally. Is there a live load distribution rationale that could be utilized to generate a reasonably accurate model without having to resort to finite element analysis? This is just to get a 30% layout complete. Subsequent submittal will utilize finite element analysis, just not at 30% if it it can be helped.

Thanks!

 

[broekie]

You could always use the lever rule, but that would be quite conservative. I couldn't find anything in Standard AASHTO or AASHTO LRFD relating to this as far as the live load distribution factors to the girders is concerned.

 

[maek]

That would be quite conservative.

The way that the girders are configured right now would allow 8 axles from multiple lanes to simultaneously influence as single girder.

Right now, I am trying to model it as a "new truck" with point loads per the level rule and axle spacing according to how the axles hit the girder.

Any other ideas?