Parking lot Grade brakes

[castiglian]

Does anyone knows about a good change in slope to use on a grade brake for driving puroposes on a parking lot?
I mean with a grade brake a low point without having a kind of vertical curve and don't bumbing the car?

Any help will be appreciated

Thanks
Francisco

 

[bussp]

I have always used a maximum difference in slope of 1% before using a vertical curve.

 

[Zenon]

I agree with the 1% rule BUSSP listed if your talking about longitudinal grade changes and not grade changes associated with an inverted crown section utilized to convey storm water.

 

[RWF7437]

If you have a copy of the venerable Architectural Graphic Standards look at page 615 ( 5th Edition). You'll need a suitable "low slung" design vehicle. Then build a paper model of it and try different grade break slopes. They can and often are quite extreme in places like parking structures and boat ramps. Speeds in such places are usually low.

Be sure to check both break overs and sags.

If you have plenty of money, and the suggestion above is too old fashioned for you, you may want to try a program called Autoturn. It can computer simulate turning movements for may kinds of vehicles ( and aircraft)and may, by now, also be able to model the situation you're interested in.

On city streets changes between 0.5% and 1% without a vertical curve are quite common in the US.

Good Luck

 

[bbakk]

transitioning via vertical curves for a 1 to 2% grade break for roads is typical, but I think that your question is related to parking lot grading ... It is not typical to put in vertical curves in parking lots (I think that the contractor is responsible for the smooth transitions, 1% minimum grade and 5% maximum are typical values for parking lot grades) ... but if your budget permits (ha ha ... it never does) by all means go in and grade every square foot of the parking lot trying to avoid 1 to 2% grade breaks ... in the end the contractor will not necessarily grade it that way (more likely will visually smooth it out) ... but vertical curves in roads and gutter lines are warrented for the 1% to 2% maximum grade breaks ... remember ... in parking lot grading, the contractor, not the engineer, is the hero of the day (that is why they get the big bucks) ...