Retaining walls

Make them draw the topo then they will understand. Having to produce surveys from crap field work (mine and others) did wonders for my field procedures when I first started working on a crew and in the office.

Stephen Ward, post: 341138, member: 1206 wrote: Make them draw the topo then they will understand. Having to produce surveys from crap field work (mine and others) did wonders for my field procedures when I first started working on a crew and in the office.

Moving from the field to the office certainly changed the way I do some things in the field for the better.

Agreed. Have them draw their own topo and see if they can figure it out. A light bulb will go off.

Set basic rules for topo shots on vertical elements. I learned this along time ago when engineering from field surveys and it begins with curb shots. Bottom of curb at the pavement line, top of curb at the back of the curb. It gives the topo software some room to work with the contour lines. Same rule works for laid back curb or curb-gutter, bottom of curb at the gutter line, top of curb will be to the outside and farther away from BC. Connect the points with 3D polylines and do not worry about curves. The only curves that are really a problem are curb returns and manually trimming and extending to the curb lines are close enough.

A retaining wall is just a really high curb, so base of wall at the front, top of wall at the back. If you really need to show the batter the field crew should note the width at the top and you can offset the 3D polyline the required amount. Almost all plans I do have the contour lines ending at the back and front of the structure, since the connectors disappear in the other line work at typical plan scale. On a small scale plan I may manually connect the contours within a curb or wall batter area.

Paul in PA, PE, PLS

I agree. Make them come draw it up. Most crew Chiefs don't grasp the concept and therefore have no understanding of how a tin works. I had a few field guys that could do topos very well. others not so much.

Also headwalls with culverts can be a challenge, too.

For headwalls I take 3-5 shots, 2 top back corners of headwall, 1 invert and if there are wingwalls, bottom corner at grade. 2 back shots to invert shot gives headwall thickness and the wingwallls are usually same width. A good sketch confirms headwall and wingwall width. also note if there is a concrete apron.

2 shots can usually define riprap, engineering note, the riprap elevation equals invert elevation.

6-8 shots can usually define a level spreader or stilling basin.

Paul in PA, PE, PLS

Stephen Ward, post: 341138, member: 1206 wrote: Make them draw the topo then they will understand. Having to produce surveys from crap field work (mine and others) did wonders for my field procedures when I first started working on a crew and in the office.

YES!!!

It is possible to explain, but only just. Most just do not get the concept, until they do the work themselves. When I first started out as a party chief, I was in the office one day for some reason, and was asked to get the line work drafted on a survey that I had done the field work for. (This was part of why I pushed for Field to Finish, BTW.) I was shocked at how hard it was to follow my own work, even though it was MINE. It made total sense when I was out there, but not behind the computer. I modified my procedures after that experience.

Retaining walls are very similar to sharp dropoffs in natural ditches. The ditch drops straight down. It does not have a side slope.

I think I have just witnessed a cosmic event. My post to this thread didn't kill it. Hmmm...

When I first started surveying, I got a crash course in field procedures. Fortunately, my chief had a good grasp of how to do topography work that would result in good topographic drawings. Rainy days brought me into the office where I was taught many things (like filing old maps, taking inventory of our supplies, and drafting the surveys that I had been doing). After about 2 years of doing just field work, I was "promoted" to being a "half-and-half" person. I spent half of my time in the office drafting surveys and the other half of my time in the field running our "part time" field crew.

That combined experience has been a foundation for my entire career. It taught me many things, one of which was that things that seem "obvious" when you're standing right in front of them can be completely unintelligible when you're looking at a set of points from a topo survey. So sketches, copious notes, and extra shots can be invaluable.

One other thing I learned (and I'm trying to pass this one along to my crews now) taking the time to "over shoot" something that might be confusing in the field is much more effective than trying to make it up in the office. I can always discard a couple of extra shots that I don't need. But I can't create just one shot that I DO need without sending the crew back to the site.

A related matter is a building with a low plinth around the base of the walls - typically a brick or block wide. If the ground is level then nobody messes it up (usually!). Either the main wall line gets picked up or the ground line of the plinth. The fun starts when the ground slopes and has been built up since the original construction of the building. Then part of the plinth disappears underground.

No matter whether a total station or a simple tape is used, well over half of survey crews can be expected to make a mess of it - sometimes measuring the plinth and sometimes measuring the wall, but NEVER making a note as to what they have done.

chris mills, post: 341305, member: 6244 wrote: A related matter is a building with a low plinth around the base of the walls - typically a brick or block wide. If the ground is level then nobody messes it up (usually!). Either the main wall line gets picked up or the ground line of the plinth. The fun starts when the ground slopes and has been built up since the original construction of the building. Then part of the plinth disappears underground.

No matter whether a total station or a simple tape is used, well over half of survey crews can be expected to make a mess of it - sometimes measuring the plinth and sometimes measuring the wall, but NEVER making a note as to what they have done.

yes, that dreaded plinth. easily one of the oddest sounding English words.

this topic is a good example of improving surveying top to bottom:

towards the top is the boss, who may or may not teach/instruct field crews how to map and take data collection to suit their own needs as well as the needs of the drafters, clients, and other parties in responsible charge.

also, the drafters, that may or may not understand field surveying, and may or may not teach/instruct field crews what exactly they need. in my opinion, the better drafters will collaborate with the field crews rather than issue mandates that only serve drafting advantages

and the field crews, that may or may not understand what happens after data downloads. it is my hope that they are willing and able to learn subsequent phases of their work, and collaborate with the other parties mentioned above

in a perfect world, I suppose, but it is a direction we should travel

Thanks for all the replies here. I totally agree that it's a teaching thing, or lack of teaching going on, or lack of proper teaching, or something like that.

I just end up dealing with some people who've been in the field a long time, and I've been told are very experienced, top-notch surveyors, excellent party chiefs.......etc. And then I see this kind of stuff, like it's a mystery to them.

Moe Shetty, post: 341317, member: 138 wrote:
towards the top is the boss, who may or may not teach/instruct field crews how to map and take data collection to suit their own needs as well as the needs of the drafters, clients, and other parties in responsible charge.

also, the drafters, that may or may not understand field surveying, and may or may not teach/instruct field crews what exactly they need. in my opinion, the better drafters will collaborate with the field crews rather than issue mandates that only serve drafting advantages

and the field crews, that may or may not understand what happens after data downloads. it is my hope that they are willing and able to learn subsequent phases of their work, and collaborate with the other parties mentioned above

in a perfect world, I suppose, but it is a direction we should travel

I may be swimming against the tide in this button pushing world, but until you can come in the office, download your data, adjust your traverse, and draft your topo, you're not a full fledge party chief in my book (or on my team).

"...adjust your traverse..."

You are a taskmaster, James. It seems like that is a skill beyond many PLSs.:bored: