AWOL GRADING BETWEEN BUILDING PADS

[christopher_c_donovan]

Can anybody explain what is going on here?  I have been experiencing odd results grading between objects in a new project that I have been unable to eliminate. The combinations and permutations as to what might be causing these errors seems to be fairly daunting  so I have gone back to the basics and set up a new drawing using an existing survey and placing a number of arbitrary Polyline Rectangles in it to see if I can't tease out where I am going wrong [I am relatively new to CIVIL3D] 

Trial Work Flow:-

1] Convert Rectangle 1 Top LHS to a Feature Line. Assign Site Elevation [Flat Pad]  and Grading Group

2] Apply a 3:1 Daylight criteria to external edges of Rectangle.

3] Apply 'infill' to interior of Rectangle 1

4] Repeat for Rectangle 2 Top RHS.

Result:- Image 1 

5] Repeat the above for Rectangle 3 MID LHS 

Result:- Image 2 

I also attach Image 3 which was a previous attempt using the above Work Flow BUT without applying an 'INFILL' to the Rectangles. 

NOTE:- I have also carried out the same Work Flow with two side by side Rectangles  [as per Rectangle 1 and 2] but where the 'Fill' slopes overlap. CIVIL3D simply adjusted the original 'Fill' slope of Rectangle 1 to incorporate the 'Fill' slope of Rectangle 2 when the 3:1 Daylight criteria were applied to it.  

Questions: 

A] If grading merges 'Side to Side' then why not 'Top to Bottom' Is it because one is a 'Cut' and the other a 'Fill' slope? Would not have thought so given that the Daylight criteria works for both Cut and Fill?

B] Should I place Rectangle [3 Mid LHS] in a different Site and then merge the two sites? 

c] Should Rectangle 3 it be in a different Grading Group? 

I appreciate all this must be very basic but I am clearly not grasping the correct Work Flow for multiple Grading Objects at what is surely  a comparatively simple level. 

[mjung]

Try adding a closed feature line around the 3 pads and apply the grading to that. Then infill the areas inside. If the feature lines are on the same site any vertical adjustments to the individual pad feature lines will have dynamic links to the outer one.  

[christopher_c_donovan]

Thanks - I gave it a go but no luck - also created a rectangle between the
two LHS rectangles.
1] Converted it to a feature line within the same Site.
2] Set Elevations in the four corners to match the Design surface between
the two rectangles.
3] Inserted an infill.

This did tidy things up a bit removing the contour lines that crossed into
the infill of each of the rectangles but the contour lines within the
infill [between the rectangles] still 'odd'.

I started again moving the rectangles closer together at their sides and
then graded the rectangles left to right and from the top down the slope.
Attached Images 1 to 6 show the results

Images 1-3 show the rectangles grading as you would expect but Image 4
shows the bottom LHS rectangle graded but with NO CONTOUR LINES or VISIBLE
SURFACE even though Infill symbols and the edges of the surface are clearly
shown.

I then tried regrading the bottom LHS rectangle to no effect, however, I
was able to grade the bottom RHS rectangle as Images 5 to 6 show with no
obvious errors.

I have to say it is becoming increasingly difficult to have confidence in
3DCIVIL with these almost constant errors being thrown in seemingly out of
nowhere. The attached is a very very simple 'Project'. If I am able to get
two different types of error in two attempts it bodes ill for more complex
projects ie: Design in the Real World!!

Could these errors be caused by my computer is simply inadequate to the
task ie graphics card/Ram etc?

[ChrisRS]

No attachments.

[jeff_rivers]

What happens if you create a new intermediate surface, paste the first two gradings into it, then use that intermediate surface as a target for the next two gradings?