3 ms·

> Yes my experience is dated and my memory none too good, thank you for expanding No worries, when I heard 25 degrees my gut reaction was "that can't be right"

> Yes my experience is dated and my memory none too good, thank you for expanding No worries, when I heard 25 degrees my gut reaction was "that can't be right". Then I did the calculation and saw that the common ratios used are a lot fewer degrees than I expected :) I was thinking of grades in percentage (rise divided by run expressed as a percentage - so 50% for a 2:1 slope, 33% for a 3:1, etc) > There's more laws now, and/or fewer fools with earth moving equipment I think stricter rules (or enforcement thereof) has led to the proliferation of long-reach excavators.

jaclaz 5y ago
In my experience "normal" slopes (without using any kind of reoinforced earth) are 1:1 (base/height i.e. 50 % slope degrees) for excavation and 3:2 (base/height i.e. 66% slope), with reinforced earth (depending on types, soils, etc.) you can usually go to 1:3 or 1:4 or even 1:5.
- SECProto 5y ago
  Yeah, I acknowledged 1:1 for excavation in a comment up a couple levels. That said, where are you that 3:2 is a standard slope for unreinforced permanent slopes? That's 34deg, which is outside the angle of repose for many materials, and doesn't leave much factor of safety even for a crushed stone. Reinforced earth is a different beast altogether for sure.
  - jaclaz 5y ago
    Yep, it is the the typical slope for earth moving, Italy here, thousands of km of roads are made with this slope, exceptionally it is lowered up to 4:1, a reference: https://www.manualihoepli.it/media/doc/pr141.pdf https://www.manualihoepli.it/media/doc/pr141.pdf What I mean by 3:2 (base divided by height) is often referred to as 2/3 (height divided by base) and is roughly the "natural" angle of repose of - say - gravel.
    - h2odragon 5y ago
      I towed my sheepsfoot roller around with a big Italian Same tractor in the 1980's, in West TN. We had those for the ground speed PTOs but they climb things like mountain goats, unique to the market at the time, which enabled some of the stupid tricks we built. By comparison to their source, our hills are pleasant soft sandcastles, all rubbery clays with veins of sand or gravel and never any excuse for explosives.
    - SECProto 5y ago
      Thanks for the reference. It's interesting that they work that close to the stability limits without just adding some slope reinforcement. It doesn't leave much room for error (execution error, erosion over time, unexpected surcharge load, stability changes with soil saturation, or earthquake).

jaclaz 5y ago

In my experience "normal" slopes (without using any kind of reoinforced earth) are 1:1 (base/height i.e. 50 % slope degrees) for excavation and 3:2 (base/height i.e. 66% slope), with reinforced earth (depending on types, soils, etc.) you can usually go to 1:3 or 1:4 or even 1:5.

SECProto 5y ago
Yeah, I acknowledged 1:1 for excavation in a comment up a couple levels. That said, where are you that 3:2 is a standard slope for unreinforced permanent slopes? That's 34deg, which is outside the angle of repose for many materials, and doesn't leave much factor of safety even for a crushed stone. Reinforced earth is a different beast altogether for sure.
- jaclaz 5y ago
  Yep, it is the the typical slope for earth moving, Italy here, thousands of km of roads are made with this slope, exceptionally it is lowered up to 4:1, a reference: https://www.manualihoepli.it/media/doc/pr141.pdf https://www.manualihoepli.it/media/doc/pr141.pdf What I mean by 3:2 (base divided by height) is often referred to as 2/3 (height divided by base) and is roughly the "natural" angle of repose of - say - gravel.
  - h2odragon 5y ago
    I towed my sheepsfoot roller around with a big Italian Same tractor in the 1980's, in West TN. We had those for the ground speed PTOs but they climb things like mountain goats, unique to the market at the time, which enabled some of the stupid tricks we built. By comparison to their source, our hills are pleasant soft sandcastles, all rubbery clays with veins of sand or gravel and never any excuse for explosives.
  - SECProto 5y ago
    Thanks for the reference. It's interesting that they work that close to the stability limits without just adding some slope reinforcement. It doesn't leave much room for error (execution error, erosion over time, unexpected surcharge load, stability changes with soil saturation, or earthquake).