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Creating surfaces from survey points


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I am having problems creting surfaces from points I imported into the drawing.

The surface form triangles but the points stay on the plane z=0

Also I get errors that crossed a breakline.

when rebuilding the surface after deleteing the breaklines ( i deleted some ) it forms a surface but the surface forms on the points with elevation of 0.

how do I fix this problem any help is appreciated.


My main pupose of the drawing is to create a drainage ditch and calculate the earthwork volume.

the process I think is correct but not sure

1) Import points from the txt file

2) create a surface from existing countours

3) Create a feature line along the path of the alignment

4) Create a alignment from the feature line

5) create a assembly for the desire design

6) create a corridor on the proposed alignment

7) compute the earthwork volume


Any help will be apprciated



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You imported points from a text file and the points are now in Civil 3d, but all have 0 z value? It sounds like the points were not assigned elevational values. Please post the text point file for evaluation if you don't mind.


When you create a surface from points the contours should be the result of those points. You should not create the existing surface from contours as you said in number 2 unless you have little or no other existing data to use.


To create the ditch you can use feature lines and grading tools or create an alignment and corridor. You may even use a hybrid of the two. I would be inclined to create a feature line as the flow line (center line) of ditch, assign elevations to said feature line, and then use the grading tools to grade out in both directions at the desired slopes.


If you will need to run sections of the ditch then a corridor might be best suited.

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Hi Rusty

sorry about that here are some points I imported




2,20809497.9720,1605059.4290,5456.2200,CALC INVERT

111,20802118.2880,1608738.2280,5504.0900,KTNX 1




1001,20807839.5460,1605720.2650,5471.6400,RW14 CHK


1003,20796768.6310,1610352.2210,5548.5600,RW32 CHK

1004,20796768.6210,1610352.2210,5548.5700,RW32 CHK

1005,20798246.4380,1615390.2270,5513.8500,CP MASTERS

1006,20798246.4220,1615390.2290,5513.8500,CP MASTERS CHK

1007,20790359.3340,1613497.1290,5632.8300,CONTRAVES 21

1008,20790359.3170,1613497.1340,5632.8400,CONTRAVES 21 CHK

1009,20807095.9200,1607674.0390,5462.0900,WEST TARGET

1010,20807095.9190,1607674.0240,5462.1400,WEST TARGET CHK

3000,20797398.2880,1612067.0830,5518.6700,EDGE CONC / EP

3001,20797403.2670,1612077.9460,5518.4400,EDGE CONC / EP

3002,20797406.9280,1612087.5280,5518.1900,AP CONC / EP

3003,20797406.8440,1612087.6910,5518.2200,AP CONC / EP

3004,20797407.5360,1612089.7350,5518.1400,AP CONC / EP



3007,20797391.1550,1612098.8930,5518.7100,BFC RET


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It looks like the z values are fine there.


When you create the surface and add these points to the surface does it give you contours?


If you go into the Surface Properties (select surface > right-click > surface properties) and look at the surface statistics what does it say under the minimum and maximum elevations?

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