Section and Corridor EOP values do not match Proposed Profile Values

[mr756944]

The design of the road was done essentially in the profiles. We have a CL of the road matching the existing grade and then we have a saw cut line and new EOP alignment and vertical design. These elements are used for the corridor and then the sections (data shortcutted into a separate Corridor and Section dwgs) and they work well. It is a relatively simple design. The road is straight and has no horizontal curves.

We are finding some small discrepancies between the proposed vertical new EOP numbers on the profile and the same values within the corridor and the sections. We are showing the elevations on the profile and the sections and some do not match. The Engineer was checking the values and found some are off by .01. I looked at the ones that were off by 0.01 on the plans and I looked at ones that match and found them ALL to be off anywhere from .0005 to .0019 – the ones that are showing to be off by .01 are rounding using different values.

Ironically, the numbers do match for the corridor and the sections. But like I said the profile is the design value and what we would expect the values of that to persist throughout. So somehow when the data is being sent to the corridor and then to the sections the values change ever so slightly, and it is enough in some case to make the value change/display up to .01 from the profile and the design value.

We anticipate the NJ county reviewer to catch this and want the numbers to match. So please don't tell me we are not building a watch. We need to get the approvals and they will flag the discrepancy.

Thanks for any help.

[Opie]

I'm not even sure how to respond to this other than YOU may be building a watch, but the contractor is definitely not building a watch. You can get much large errors in how the surveyor stakes the data in the field.

Can the engineer not explain that off in review to a rounding error?

Are the locations being annotated the same in all regards? Is the Plan, Profiles, and Cross Sections labeling the same exact locations?

Do the corridors have a frequency line at that location where the profile elevation is different to the corridor? The corridors are not built using curves. It is all 3D tangents. The sections are built from Sample Lines crossing a corridor, surface, or other C3D element. You could increase your frequency lines on your corridor to see if that resolves the minute error you are seeing.

[mr756944]

I agree with you in principal. But we have to get the project reviewed and approval from the the township, county and sometimes the state. In this case, the county is very detailed and checks to see if the elevations match and will flag it if they don't. They don't take logic or reality into consideration. They just make demands. We are subject to their will to get the approvals.

Yes the same places are being annotated. The sections are on stations at 50 ft intervals just like the profile and its labels. I have checked them a few times when I tried fixes. I did try reducing the frequencies down to 1 foot but it didn't fix the issues. Remember I looked at ones that match and found them ALL to be off anywhere from .0005 to .0019.