I am pulling my hair out with this issue I am having...
I need to do a cut/fill analysis not residential site and this site has like 6 retaining walls there is a 6 foot difference in grade.
My surface is not recognizing the grade change when I make the polyline into a wall breakline.
I know I am doing something wrong here but I just cannot figure it out. Please help thank you
To more accurately show a wall in a suface, I need two breaklines, One for the top of the wall grade, and one for the bottom of the wall grade. I typically use a 0.5' offset to separate the breaklines. A single polyline cannot do the job.
Or am I missing something...
I typically don't connect them. Here's a sample of a recent wall in a surface we used on a project. Note the separation of the top and bottom breaklines. The black section between them is 15 vertical feet of contours stacked nearly on top of each other.
See attached for an example of a feature line retaining wall. The offset used here is computed from the block's batter angle for the maximum wall height. On larger walls you will want to account for batter in tight designs.
hi fellas! newbie question here. lets say I have my two feature lines one for top of wall and the other as bottom of wall that has an elevation assigned to each vertices, how do I add it up to my surface? As a standard or wall? Do I have to create a separate surface for my walls and have to paste it to my proposed surface so that it will reflect correctly on my surface? thanks in advance!
I usually don't include the actual wall in the proposed surface. I have a Featureline for the groundline at the back of the wall and one for in front of the wall. Then I mask the area of the wall. I don't show contours going through the wall. If I want the wall in a surface to show in 3D then I paste it in to a proposed surface.
BTW. You'll want a Featureline for the back top of the wall also. You can create that by offsetting the top front.
A designer should note and determine if they need to compute what the wall width will be in plan view. This will of course depend on materials and the wall's batter but a 6' high boulder wall could have a plan view width of 4-5' if you are using 3' diameter stone. A Keystone wall could have a 2-3' plan view width. This width may be very important if you are placing the wall close to building setbacks, property lines, structures or designing a serpentine driveway with limited distance between the parallel runs of the driveway. If the wall is placed on a property line and the wall has batter the designer should make sure that the embedded portion wall is not going to be on the neighbors lot.
I still use two feature lines separated by a small number, like 0.125', to depict the front face of the wall. For wall width, if significant like johnm's example, I'd take the top feature line and offset it by the wall width to show the top of the wall. I do this with curb lines all the time, and only do this with walls of top widths of 5-10' wide, like gabion walls and such.