Unsure where to begin with this drawing, given the units are not something I'm used to

[andi_cabrales]

Hi everyone! I’m looking for help figuring out how to start and interpret this drawing. I’ve mostly worked with NCS standards, so I’m used to imperial units and architectural scales in inches. But this drawing uses decimal units—possibly decimal degrees—and includes measurements in micrometers, meters, and kN/m³.

The bigger issue is, I’m not even sure how to begin drawing it. Some of the measurements are unfamiliar or hard to visualize—like passive resistance in kN/m, diameters in micrometers, slopes, and angles. I’m struggling to understand how these elements fit together or how to lay them out accurately.

Would it make sense to change the units? If so, should I switch to engineering units, decimal degrees, or convert everything to meters? Also, what’s the best approach for drawing this—should I draw it to scale (1:1), trace over the original, or create a side-by-side reference image?

I know this might sound a bit convoluted, but I’d really appreciate any advice on how to approach this from the ground up.

Thanks so much in advance!

Below is the drawing.

[Brock_Olly]

What's your goal with this drawing?
Do you need to redraw it? Is it a DWG file or a picture?
This drawing shows how much force (kilo Newton per cubic meter kN/m^3) the wall can hold at that slope before collapsing due to the sideways pressure.
The dimensions aren't showing the size, only the angle of that stone wall and the height which can be read as 1.2, 2.1 or 3 meters.
Not much to go off if you want to redraw this. 

[andi_cabrales]

Hi, thank you for responding! My goal is to draw it as accurately as possible. But like you mentioned, there is not much to go by. For example, there is a slope shown 1,8 and 1,4, but with the meter height at 1.2, 3, and 2.1, I'm not sure if I just combine the 1.2 meters and 3 meters, and 2.1 meters to get 6.3 meters, given that the slope doesn't seem to match if I draw it, or perhaps it does and I'm overthinking it. The same applies to the 0.30 micrometers, as that is way smaller than 6.3 meters, so the dimensions seem just confusing to me.

[AllenJessup]

I would think this is saying that the calculations would be valid for those three heights. Was this captured from a specific website? That site might give more information.

OK it came from here https://www.fhwa.dot.gov/clas/ctip/rockery_design_construction_guidelines/ch_3_comparison.aspx

[Brock_Olly]

The μ = 0.30 is a Coefficient of friction between the wall base and foundation soil.
You're looking at this the wrong way though, this drawing is more of a structural engineering drawing.

Wherever you got this drawing from likely has a table that defines the width of those stones (B)

To draw this you have to follow the principles of this drawing; slopes for the wall and the slope for the soil/backfill. It isn't meant to be copied 1:1

[andi_cabrales]

No, it's just a random Google image, which leads to a blog, and I'm practicing detail drawings to help me focus on areas I lack. But the dimensions seem confusing because, for example, the height of one side is 6.3 meters combined, I believe, given that 3.0 meters, 1.2 meters, and 2.1 meters add up to 6.3 meters. But then you have the 0.3 micrometers, which appears really small compared to 6.3 meters and everything else, and that is why I'm confused. 

Also, I only ever worked in architectural units, but here I have my units set up as decimal for length, and decimal degrees for angle. But for the insertion scale, I have meters over inches. Is that correct? Or are my units incorrectly set up? 

Thank you for replying!

[andi_cabrales]

Thanks for the insight—you're absolutely right that this is more of a structural engineering drawing, and not something to be copied 1:1. That’s actually what I’ve been trying to figure out: when scaling it in AutoCAD, is it better to anchor the drawing based on the heights (like the 2.1 m, 1.2 m, and 3.0 m segments I combined into a 6.3 m vertical reference), or should I start from the slopes—like the 1:4 and 1:8 ratios shown for the wall and soil?

I’ve set my units to Decimal and Decimal Degrees, with meters as the insertion scale—even though I usually work in Architectural and inches, since that’s more typical for my projects. Just wanted to make sure that’s the right call for something like this.

Appreciate any thoughts on whether slope or height is the better anchor for scaling this kind of drawing. Also, it's just a Google image I'm using to practice because I haven't done much drawing for a year now and I'm a little (very) rusty.

[AllenJessup · Accepted solution]

It impossible to draw what is shown in that image without making suppositions. It's missing the depth below grade, the width of the base (B) and the width of the top. About the only thing you can start with is taking a height, I'd use 3m, and drawing a batter of 1 on 4 (14°). Except for the batter of the stone fill, There are no other usable dimensions in the image.

Now for a little more confusion. What you set your units at doesn't affect what you're drawing. A line one unit long can be 1 ft, 1m, 1 nanometer any unit you can imagine. Setting units only affects what dimension labels are created and the units shown for calculations such as area. So you set units based on what dimensions you need to use. Not what lengths you're entering.