AutoCAD Civil 3D

[#1]

Hi everyone, My Name is Marcelo, Im from Argentina.

I have a problem  with cut/fill volume calculations.(between the difference of  the  volume report and the calculation by hand)


so I  followed the Exercise 3: Generating a Volume Report - earthworks-2.dwg , from the help directory  (civil 3d 2011).

and I  found differences there too, I think that some volume sections are not right,(ie 6+50, 6+75 to 8+50,etc), or I´m missing something.?


An station exaple:


Area st 6+25= 2513.96
Area st 6+50 = 2560.24

cut/fill factor =1


the exaple is using the  Averange end area formula

Volume = (A1+A2)/2) *L 

so:

L= [6+50] - [6+25] =25 foot


Volume =(2513.96+2560.24)/2 )* 25 = 63427.5 cubic foot

to cubic yard (as the report)

Volume * 0.037037037 = 2349.17 cubic yard.

But the report shown 2479.06 cubic yard


Same with other stations, and metrics. What Im doing wrong? I missing something?


I tried this in civil 3d 2011service pack2 on a W7 64bits.


thanks in advance.

Marcelo


[#2]

You have used the AVERAGE END METHOD  to calculate your quantity.

Perhaps the computer is using the PRISMOIDAL METHOD.  I believe you have a choice.

Bill

[#3]

Bill,

Thanks for answering! I really appreciate you taking  time to answer my question.

I checked that, when I select  the average end area method the calculations are wrong (as I describe above), but  with prismodial method  the calculations are ok.

Thanks

Marcelo