No Small Potatoes
May 14, 2008
In just eight months, the city of Idaho Falls, Idaho, population 50,000-plus, proved that it’s no small potatoes.
Between February and October 2007, a three-person city survey crew completed phase three of the Sunnyside Road widening project, finalizing a three"'year endeavor to connect Interstate 15 Sunnyside Interchange to the city of Ammon. Phase three, which was administered by the Idaho Transportation Department using more than $10 million in local and federal funds, included reconstructing the 1.63-mile roadway from two to five lanes with additional rights of way, new curb and gutter, sidewalks, pathways, illumination, traffic signals, landscaping, storm and sanitary sewers, waterlines and a sound wall.
Amid the buzz of various state agencies, utility companies and a horde of contractors, city surveyors managed to sidestep natural obstacles, natural gas and a 46-kilovolt power line. Teamwork and technology were their keys to success.
Smooth Road Ahead“This phase of the Sunnyside project was the smoothest project I have ever seen built,” says Kenneth Roberts, PLS, the city’s party chief and a surveyor for 15 years. To start, his crew created layouts of the various project categories and logged them in eight binders. “One was road grades set out in Excel spreadsheets to draw the parabolic crown. We had a noise wall that we had to have designed; the electric and the sprinkler were in one binder, the storm, the sewer and the water in another one,” Roberts says. “The road was created in our computer before we ever went out.”
The survey crew’s level of organization benefitted the site contractors, too. “We precalculated the curb and gutter stakes in a Microsoft Excel 2003 spreadsheet before the project began,” Roberts says. “So all we did is take the laptop out into the field [with] a field printer.”
As the elevations were shot on the curb stakes, the crew typed the elevations into the spreadsheet. Before the rodman could even get back to the truck, Excel had computed the cuts or fills and they had a cut sheet to give to the contractor. “It was probably the best idea we came up with on the whole project--it was very slick,” he says. “It saved us more time than almost anything else--like ‘Lean Manufacturing for Surveyors.’”
The crew then used AutoCAD Map 3D 2008 ( www.autodesk.com ) and Eagle Point 2007 ( www.eaglepoint.com ) to generate models of the road surface and the subgrade, which were sent to Evanston, Wyo.-based Cowboy 3D Modeling, a data preparation company subcontracted by general contractor HK Contractors Inc. of Idaho Falls. Cowboy 3D turned around a .dgn file for use in HK’s Trimble ( www.trimble.com ) SCS900 GPS-based site positioning system.
“That went exceptionally well,” Roberts says of the conversion. “Everything the contractor cut out was perfectly square. All we ended up needing to do was to satisfy the state that the contractor was excavating and building the road per the plans. There was not one time that we did any cross-sectional checks where they were off by more than a tenth.”
Roberts credits HK’s Project Super-intendent, Karl Grover, for the seamless transitions. “He was the one who made sure everything was done and went right,” Roberts says. “His greatest tool is he is not afraid of using technology to be faster, better and more efficient.”
In addition to the smooth conversion made possible by the technology, teamwork was also key to getting the Sunnyside Road job done efficiently and on time. “Ken is an extremely intelligent person,” HK’s Grover says. “He is an excellent guy with the surveying. If we run into problems, he can modify it so quickly--the kind of people you need.”
Even with teamwork and technology working hand in hand, the project offered all the caveats and hurdles typical of a road job--and several unique ones.
The Long and Winding RoadThe area’s wetland-mitigation plan required site workers to install two ponds on Sunnyside Road with static water levels to create wetlands for the area’s duck population. Additionally, ground saturation issues called for numerous rolls of a carbon-fiber-based fabric to be placed underneath the road to keep mud from migrating through the road base.
And there were what Roberts calls the “special trees, a very nasty 500-psi natural gas line and a 46,000-volt power transmission line that needed to be moved.”
The “special trees” Roberts refers to were very old 100-plus-foot cottonwoods encountered on a particular landowner’s old homestead property on Sunnyside Road. As a part of a desert region, Idaho Falls doesn’t have many trees, and those that do exist were most likely planted. “From what I gathered from a friend at the local newspaper,” Roberts says, “they were a specific kind of tree called a Carolina poplar, and they live twice as long as a normal cottonwood tree.”
The owner of the property had gotten the family homestead eligible to be listed on the National Register of Historic Places, and because the trees are a part of that homestead, it prevented the road crew--because the project was federally funded--from removing them. Thus, the crew had to build a retaining wall on the other side of the street as well as elevate the road to drive around the cottonwoods. “This caused some interesting design issues early on−and some equally challenging field staking−not to mention a narrow spot on an otherwise five-lane road,” Roberts says. “We called them the ‘holy trees.’”
The trees, though, presented no obstacle like the 8-inch 500-psi natural gas pipeline the crew had to work around. Luckily, previous experience had schooled them in the proper handling of the threatening conduit that runs hundreds of miles long, Roberts explains.
“When this line was worked around in the [project’s] first phase, we had tremendous problems with it,” Roberts says. “Every time we’d get near it, the gas company would get scared. Pretty soon there were lots and lots of angry people yelling and screaming.
“At one point, they had scraped the top of an abandoned service line with one of the excavators. After the gas company isolated the breach to a smaller area of pipe, it blew natural gas until about four in the morning. After it had let off enough pressure in that small, isolated area, the gas company was able to weld the cap back on. At 500 psi, there’s no way they can fix it until the pressure is reduced. It was amazing that we didn’t have more incidents like this that could have turned into severe construction setbacks--if not tragedies,” Roberts says.
Roberts then explains that at one spot on the project, an excavator dented the pipe. Gas company employees informed the site workers that they would all have been dead if the line had been fully punctured because it would have killed everything within 500 feet. “Karl made sure this was the last Sunday he worked on the job,” Roberts says.
On the third phase, the gas company was on the scene with its own excavating crews. “It was just so much better organized,” Roberts says. “The gas company decided that their best course of action for this phase was to lower the line or, in some cases, replace the old gas lines to a safer location. This was all done in a very short time--and sometimes without a lot of notice. And even though I am certain we could have done things better, we certainly improved over the previous phase of the project.” He then adds: “And not a cross word was ever heard from our friends at the gas company--at least that I had to listen to.”
After winding around precious trees and an intimidating pipeline, the three circuits of high-voltage power were the next hurdle to overcome. Although the project’s design showed where the road was going to be built, the power line relocations needed to be designed by two separate power company owners.
Private contractor Sturgeon Electric Company Inc. was called in to move the power line. Over two-thirds of a mile of wood poles and steel towers were constructed on the north side of the street, and the steel-reinforced aluminum lines were transferred to the new poles. “It was done so incredibly fast it was unbelievable,” Roberts says. “Watching Sturgeon Electric work was like watching a Swiss watch!”
Technology on the GoFor a 22-square-mile city that’s just barely attained metropolitan status, the Idaho Falls survey crew used an arsenal of equipment fit for a large city. “We love our tools!” Roberts exclaims. “We use every tool that we have to its full functionality and try to never say, ‘That’s the way we have always done it.’ Our motto is, ‘Try to find a faster, easier way.’”
For leveling, the tool of choice was a Leica/Wild NA 2002 digital level purchased from the city’s local dealer, Bonneville Blueprint Supply. “You can run a loop and close it back on itself and the thing is flat,” Roberts says. “Compared to an optic[al] level, it’s off the chart. The office software can balance it so it balances your level loops perfectly without having to go through a long process.”
Early on in the project, the crew ran digital levels up and down the road to make sure everything was exactly the way they wanted it.
“Prior to the job,” Roberts explains, “we re-checked every one of the connections with the curb and gutter, and all the critical elevations were verified using our digital level. For most of the actual staking, though, we used our GPS [Leica Geosystems GPS 1200, www.leica-geosystems.us]. It has a very cool ‘Nearest Function,’ and it would tell us the closest point to us in the stakeout file.”
Roberts says that the system’s display masks and hot keys show only the pertinent information on the screen. “For example,” he explains, “in stakeout mode, we wanted to have a tab for code so we could tell the station and offset of the point we were staking so when we exported the coordinate file from Eagle Point, the station and offset shown was what we had placed in the code field of the ASCII file. Basically, we just picked the tools in the program we used the most and made them easy to access. I can honestly say there wasn’t a screen on our GPS unit that we did not have its settings adjusted.”
Another feature of the GPS system Roberts’ crew relied on was the programmable keys. “Since we are the only survey crew for the city of Idaho Falls, and because we had other projects going at the same time, we used our F8 key a lot,” Roberts says, referring to the key that converts measurements from metric to U.S. feet.
The GPS unit operated off a CORS station housed at Bonneville Blueprint Supply, which eliminated the need to set up a base station. “That was fabulous,” Roberts says, “because we only needed to buy one GPS unit.”
In areas the crew couldn’t go, such as private property, or to obtain above shots, the crew utilized its Leica TCR 1101 total station in reflectorless mode--or as Roberts calls it, “red laser.”
“Sometimes, if we couldn’t get a man into a hole, we’d red-laser the full length of the pipe so we could get an elevation without even sending a man in there,” Roberts says.
Proudly, Roberts then shares the story of assisting the machine control use on the Sunnyside Road project. “The only thing we blue-topped was the final gravel grade--and we probably would not have done that if HK hadn’t needed the machine control equipment on an airport job,” he says.
What’s more, the city crew was authorized in the spring to hire another person to pound stakes, but as time went on, and the machine control worked so efficiently, they decided they wouldn’t need him. “Occasionally, though,” Roberts says, “we did use the project inspector who was willing to beat stakes when our schedule got hectic.”
During initial setup, the crew set out a control point at 500 feet north and 500 feet south every half-mile of the street centerline and obtained state plane coordinates on each. They then ran levels through the control points so the vertical elevations were tight. HK contractors then used the published data to orient their machine control. “This was the procedure we used to set up robotic control for them,” Roberts says. “It was probably the most detailed--the most precise--thing we did on the whole project.”
“Machine control is an amazing tool,” Roberts continues. “You can look at the screen and see where the curb and gutter [are] going to be. When you dig an eighteen-foot-deep hole for a sewer manhole, the traditional way to stake it is to set two offsets from the centerline of the manhole in directions where they will most likely not be disturbed. For example, let’s say one is a 15-foot offset and the other one is a 25-foot offset at approximately 90 degrees from each other. From each of these stakes, the contractor would then use the two-tape method and drop a rock down into the hole, and wherever it lands, that’s where they set the center of the manhole--certainly not very high-tech--and you’ve got to have people in the hole, and you’ve got to have trench boxes.
“Using an excavator that has GPS on the back, you tell it which side of the bucket you want to use, and then by importing coordinates for the storm manholes into the machine, you can look at the in-cab monitor and just set the bucket down in the bottom of the hole and say, ‘This is where this manhole goes.’ You basically use the machine as a survey tool.”
Applying some of this work on the Sunnyside Road project required a little convincing, Roberts says, since most construction plans still use station and offset. “It’s hard to turn the Titanic sometimes, but with the technology we have access to, we need to be a little more creative,” he says. “Sometimes we would stake something that we were required to stake, and after spending some time staking it, it was never used.”
The Sunny Side of SurveyingWith obstacles overcome and the project completed, the sunny side of the Idaho Falls project is that 16,000-plus daily commuters can be sure they are traveling on an efficient new road--a road that was built with less labor, greater speed and ultimate organization thanks to today’s technology.
“Technology is your friend,” Robert says. “A lot of people think you’re losing people and good jobs because we’re creating a surveyorless environment. But I don’t think that’s the case. In this project, we took all the jobs that nobody wanted to do, and they were the ones that the technology handled the best. Nobody minds cross-sectioning and making sure it’s right, but everybody hates driving bluetops.
“We’re a small community able to use high-tech,” he adds. “I see it as the future of surveying.”