How good is the program DRIVEN?

[oldestguy]

This AASHTO sponsored computer program for estimating the lengths of driven piling is now apparently used by many highway depts. It apparently has been around for some time, but now is written in the Microsoft Windows environment.

I'd be interested in actual experience with how well it predicts the lengths, based upon actual construction experience.

I'm reluctant to drop the tried and true methods that I learned from Chellis. Hitting within 5 feet 95 % of the time is hard to beat.

Comments?

 

[garrettk]

It all depends on how good your input parameters are. I used it for several years when working on DOT projects and it was a very effective tool. If I recall correctly, some DOT's require it's use.

 

[Panars]

As garrettk says, it depends on your input parameters.

Most of the consultants working for the Ohio DOT use Driven. I compared the estimated pile length to actual driven pile length for Ohio DOT projects over a 3 year period. We generally use driven closed-end pipe piles and H-piles. However the H-piles are usually driven to rock, so the estimated length is just the depth to rock. Looking at the pipe piles, the average ratio of actual/estimated was quite good, 1.02, or within two percent. However, the standard deviation was quite high, 0.35. This was for about 120,000 feet of pile. Also, the actual pile length was that required to acheive the capacity as determined from PDA testing. PDA testing is standard for all Ohio DOT projects where piles are not driven to rock.

If you are getting within 5 feet, 95 percent of the time. I would not recommend switching. If it isn't broke, don't fix it. If someone is requiring you to use Driven, I would do both methods and compare them. If they don't agree, I would try to figure out why.