Stratigraphy/Soil Layers (Combining two meshes into one solid)

Hey all,

I'm working on a project where we're analysing the soil composition for a site. We have all the borehole data drawn in CAD, so we've about 400 lines divided into parts representing the soil make up (sand, silt, clay etc.)

Because we don't have stratigraphy software, I'm trying to do this in grasshopper. My plan so far was to take the top and bottom points of each material, create two surfaces, and then maybe loft the edges together to make a big chunk of that material. I know it's not exact, but it's good enough for this stage of the project.

So far, the best way to represent the areas has been to make two Delaunay meshes, which groups the points into a mesh really well, but then turning those two meshes into a solid chunk is where I'm stuck.

Any suggestions?

Replies to This Discussion

Permalink Reply by Joseph Oster on January 22, 2017 at 8:52am

I guess no one else is interested in this discussion?

Here are a couple more things I learned by delving deeply, so to speak:

Scaling to magnify the data isn't as simple as you might think. At first, I scaled each curve (vertical line) using its bottom end point as the center. This left the bottom relatively flat and exaggerated only the top points. Then I used the middle point of each curve to scale it. Finally, I realized that a common point of reference for all curves was more accurate, so I got the median of all the mid-points using 'PtCloudCntr': 'PtCloudCntr':
Next, looking at the scaled curves, I noticed that many of the bore holes had multiple curves! I confirmed this by creating sets using the X and Y coordnates for each curve's start point: There are 178 unique X/Y coordinates (bore holes), not 303 (the number of curves on this soil layer). This is a MAJOR DIFFERENCE from my initial assumption that each hole had just one curve per soil layer! It explains why the Delaunay mesh from all start or end points is so complex and not easily resolved into a single surface. Not quite sure yet what to do with this information? One possibility would be to combine multiple curves for each hole by using the top point of the top curve and bottom point of the bottom curve, ignoring the stratification indicated. This would likely yield a "cleaner" top and bottom Delaunay mesh. Or...?

Permalink Reply by Joseph Oster on January 22, 2017 at 1:49pm

...looking at the scaled curves, I noticed that many of the bore holes had multiple curves [within a single "soil layer"]!

... One possibility would be to combine multiple curves for each hole by using the top point of the top curve and bottom point of the bottom curve, ignoring the stratification indicated. This would likely yield a "cleaner" top and bottom Delaunay mesh.

This insight turned out to have MAJOR SIGNIFICANCE. When implemented as described, ignoring the stratification within a "soil layer", all soil layers now return a single "Closed Brep". The code now runs quite a bit faster, including 'Volume' (11.8 seconds for all 21 layers).

This is the model now, scaled by a factor of 40:

Does anyone have a better idea for handling the stratification (multiple curves) within a soil layer? It varies for each bore hole.

Attachments:

stratigraphy_2017Jan22a.gh, 360 KB

Permalink Reply by Joseph Oster on January 23, 2017 at 4:30pm

I organized the data so I can view all the soil layers for just one bore hole at a time. These cylinders are magnified with a radius of 40 and Z scale factor of ~44.

Many things to learn here from studying this data but apparently the OP has lost interest already?