Working for the DOT

I know I said that I was too busy to get out any stories. But I talked to one of my faithful blog readers last night. She mentioned how she was actually laughing out loud at some of my work stories with the two dingbats. So I thought I would get out another one for you real quick. I can study for the P.E. another night.

June 3, 2005

We had done some surveying which dealt with a level and a rod and shooting elevations at the slope intercept (where the construction limits meet the existing ground), the bottom of the ditchline and shoulder points of the road. This also required pulling an offset (the perpendicular distance from the centerline of the road to a given point) at each station. A station is every 100 feet. Knowing these points and offsets as well as knowing what the existing ground was before construction (the existing ground shots were taken by our surveyors before construction began), the amount of common excavation that the contractor performed can be calculated. Hopefully this concept doesn’t seem too difficult to you. I had helped Nura and Sue get set up the first day, where we pulled the offset and shot the elevations on the east half of one of the side roads. The next day they were going to shoot the west side. Now when you shoot elevations, you have to start with a benchmark which is a known location, for example a mark on an inlet cover or a spike in a telephone pole. This benchmark in our case was on an inlet cover. And every benchmark has a known elevation with respect to the world. So for example this benchmark had an elevation of 745.34 feet. So when you get your level set up, one person stands with the rod on the benchmark and you take a reading on the rod and write it down (For example 5.63 feet). Then you take the rod to all of the locations (slope intercept, ditchline and shoulder points) that you measured offsets for and take readings on the rod there(example 8.42 feet). Now to get the elevations at all of the locations that you measured, you take the benchmark add the reading at the benchmark and then subtract the reading at all of you locations from this number to get the elevation at each location. So for our example it would be 745.34 + 5.63 - 8.42 = 742.55. Again this isn’t too difficult. I knew what was going to happen the next day, they were going to continue where they left off from the east side stations. The only problem with that is on the second day they would be resetting up the level and you can not put those rod measurements on that same page because you are getting a different reading at the benchmark since in all likelihood they would not be setting up the level at the exact same height that they had it at the day before. Knowing that this would happen, I purposely went into the diary before they started and crossed out those stations. When I stopped in to check up on them, sure enough, I found that they had erased the “X”s that I made and began putting the measurements that they were taking in those stations. They had just set up the level without taking a measurement at the benchmark. So these readings they were taking weren’t related to anything. I explained to them their error. I also noticed that they had not got things set up quickly enough and the contractor had already come along and started placing gravel on top of their excavation. These morons were taking the shoulder elevations on top of the gravel. Which would mean that they were cheating the contractor out of up to 10 inches of excavation. Just so you know, before I sent them out to do these measurements I asked them if they understood what I was asking them to do, and I asked them if they had any questions. They told me that they understood and they didn’t have any questions. I told them that if they did have any questions to call me. But they didn’t. I realize that I went into a little too much detail on explaining basic surveying, but unfortunately there are more surveying stories to come. I am sure you will catch on faster than Nura and Sue.