executing and checking earthwork by gps grader on site

[Mehreen1985]

So I am going to start cut and fill earth work on my site as a site engineer. I am new in earth work and I really need help
regarding how to execute cut and fill from drawing through a gps controlled grader and after that how to check that it has given the right cut and fill level.
Will highly appreciate your response

 

[oldestguy]

One of the inputs you will need is shrinkage going from cut to fill. It likely depends on soil type as well as what kind of compaction is involved. A skimpy cut and fill thickness probably is different than a major job as to these numbers also.

 

[GeoEnvGuy]

I seen those systems at work before, the contractor had the dozer run over the site to shoot there existing conditions, adjusted for the blade height off the ground. The drawing surface was input into the dozers gps. The dozer operator should be able to see how high or low his blade should be. As mentioned by OG account for compaction of the foundation especially on the spread fill. The spot checks are usually done by another surveyor.

 

[EireChch]

You need the data points with x,y and z info. Input them into the grader and off you go. You’re site engineer should do spot checks as geoenvguy says

 

[mikeofBelAir]

Check, recheck, and recheck again.
GPS can be a wonderful tool....but....
I was recently on an earth work job, doing compaction testing of Fill. There was no stake-out; GPS only. I asked the dozer operator to give me an elevation for an area I just tested. Then, for giggles, I had him move about 10 feet on the same lift--about the same elevation , within .5 feet, and the difference his GPS gave was 14'! I had the site supt. verify with his GPS receiver, and used his data. Never found out why the Dozer's GPS was giving odd data.