Grade Change with out vertical curve
Grade Change with out vertical curve
(OP)
What is the max grade change with out a vertical curve?
We are reviewing a Parking Garage submittal by another engineering firm. The slope on a ramp is 13% with no vertical curve (one level to the next). We talked to the engineer and he said it was okay b/c the speed limit was 10 MPH. We told him that max would be 4-5% change in grade.
Is anyone familiar what criteria would govern?
We are reviewing a Parking Garage submittal by another engineering firm. The slope on a ramp is 13% with no vertical curve (one level to the next). We talked to the engineer and he said it was okay b/c the speed limit was 10 MPH. We told him that max would be 4-5% change in grade.
Is anyone familiar what criteria would govern?





RE: Grade Change with out vertical curve
Okay so practicality usually has no place in public entities and consultants want to hear cold hard reasoning if they have to change a design. What is the maximum allowable driveway grade in your area (even a commerical entrance driveway standard)? It would stand to reason that these were created using similar vehicular shapes (lengths, heights, clearence, etc) and vehicles in the parking garage should be able to attain those grades with out damage, and that criteria should be justifiable.
Something to remember if you are a public agency, and the garage is under private ownership, it would appear the PE consultant is under liabilty here to create a functional safe environment. I would be careful where you push him/her regarding design especially if there are no documented design criteria/standards.
Hope that Helps,
BD23
RE: Grade Change with out vertical curve
Have this other engineer measure a few cars (including his own). Unless he drives a pickup, this should convince him.
RE: Grade Change with out vertical curve
I was referred to ULI parking garage criteria which states that grade changes up to 15% should be transitioned by half the grade change over at least 15ft.