Site Prep Crucial to New S.C. Truck Stop

Wed January 25, 2012
Peter Hildebrandt

When you have 150 days to build a new truck stop operation there is very little time for mistakes or second guessing. Pilot-Flying J faces that challenge as they race to construct a large, brand-new truck stop at Exit 77 off I-95 in South Carolina.

This is standard operating procedure for how these facilities are constructed according to the director of construction and design at Pilot-Flying J, Patrick Deptula; most are built within less than 150 days. Cathy Adkins is the project manager on this job. This particular project started in the second week of October 2011 and is scheduled to open in early March 2012. The land on which it is being built was simply vacant land. The site will contain from 160 to 170 spaces for truck parking and 100 spaces for car parking.

The facility will have restrooms, regular driver amenities and even a Denny’s restaurant. Ten to twelve subcontractors are involved with the work onsite. The only employee of Pilot onsite is the superintendent. Individual contractors provide their own workforce, equipment and materials for the job being done.

This location will be a Flying J branded site. Pilot and Flying J merged two years ago. Pilot or Flying J stations are built depending upon the location of the site. The developed acreage of the site is approximately 12 acres. This is the normal size for a Flying J establishment; for a Pilot station they’re slightly smaller.

“Though this site was virgin ground it was used as something of an organic spoil area,” said Deptula. “There was already a great deal of mulch and trees on the grounds. I think a site contractor used to stockpile large amounts of topsoil and mulch as well and that had to be moved so we pushed it to the back of the site. That in turn caused some inherent problems with the sub-grade where we had to do a little overcutting to get suitable soils for our asphalt structure.

“We don’t take any weather days off with our schedule. As I mentioned we have to have the project completed in 150 days or less. That time period actually gives you some room just in case you do get some wet weather; we have a factor of safety in there.”

The major equipment company there on the site is Saunders Brothers, Charleston, S.C., who is doing the site work. Jones and Frank Inc., Raleigh, N.C., is doing the tank and line install for all the fuel piping.

These projects range between six and eight million dollars typically. Thirty-five thousand cu. yds. (26,759 cu m) of organic material had to be cut and an overcut of another 10,000 cu. yds. (7,645 cu m) had to be done for a total of close to 50,000 cu. yds. (38,227 cu m) of material handled.

“In our developments you are often looking at over a million dollars worth of asphalt work and you certainly don’t want to replace that by tearing it out in another year or so because of sub-base failure,” added Deptula.

“There is a bit of a high water table on the site but we are dealing with that with some well points. Our tank excavation is about 18 feet deep below grade so you’re either going to have to dig an OSHA hole or you are going to have to shore it. In this case since we did have a high water table we decided to shore both of the tank holes with steel piles.

“They then did well points around or inside the hole to keep the water down. At that point if it’s shored with metal sheeting at least now you know the workers are safe if you keep the water down,” according to Deptula.

“Whereas if you took the chance and even if you kept the hole to OSHA’s standards — especially in that type of soil — there is a good chance that the sides of the excavation are going to slough off and collapse into the hole. That’s why we decided to go with the sheet piling.

“You actually have a mixture of layers of sand and layers of clay, repeating that pattern. This condition in turn makes it very easy, especially with the water introduced into it, to have a collapse. Our first priority is keeping the guys safe,” Deptula added.

Deptula is onsite every other week if not each week, which has been sufficient so far. They have one other new build and six other acquisitions they bought which are existing facilities, modifying them to meet their standards. They are finishing up these this year.

Jones and Frank is the contractor installing the fuel tanks and the fuel piping for the site.

“What we originally had planned with the usual bid was not having to sheet pile the hole because there was no anticipation of hitting any groundwater or soft soils at the bottom of the hole,” explained Blake Bammer, construction manager of the Raleigh branch of Jones and Frank Inc. “But it ended up that when they dug a test hole and we did hit groundwater at about nine to ten feet down, there was a layer of clay and then a layer of sandy material below that the water was flowing through.

“This caused the soil classification to be changed. We had to put a rush on, get sheet piling designed, called in and make sure that was OK with everybody to facilitate a safe excavation. The reason that this was done was to be able to maintain the integrity of the excavation so the tanks to be put in are installed properly,” Bammer said.

Sheet piling is basically a steel set of plates which are bent and then fit together in a lock and groove-type position. There is a brace that goes on the inside and holds back the soil pressure as well as some of the groundwater to allow you to dig a hole per OSHA regulations. This way work does not require a sloping side; instead it can proceed in a location consisting of sides that are a straight up and down box. Sheet piling is constructed of heavy gage steel plates that are bent in what may be termed a “bent-W” shape.

“Those interlock,” said Bammer. “You typically will have to pre-dig the area that’s going to be driven into with a hydraulic hammer if the soils are pretty heavy — which these were — up on top. The soils were like that down below too; it’s kind of unusual. Once we’ve got that design overcome then hopefully we’re able to drop the sheets, lock them all together and then proceed with our excavation. This is a big part of what we do.”

On a new wide open site with no buildings, such as this one, there’s nothing that has to be protected. Typically, in such a setting they will try to do something called laying the hole back or sloping the hole to the proper dimensions.

“Sheet piling is normally where you have existing sites where you have to protect structures and slope the hole back to meet OSHA regulations for safety,” said Bammer. “Often present in such settings is groundwater or very unsuitable soils which are not cohesive or strong enough to hold together for safe digging to proceed.”

Jones and Frank uses heavy duty track hoes weighing anywhere from 75,000 to 85,000 lb. (34,020 to 38,555 kg) rating on those sites to do the excavation work. These have cubic yard buckets on them to dig the holes. This equipment is typically leased by Jones and Frank.

“We offer that service ourselves and also have an in-house sub guy we use on occasion to help us out if we’re too busy to get to everything,” added Bammer. “We don’t own the sheet piling. There are companies who specialize in that and you can rent those materials from them. They will give you an engineered design full-sized kit that you have projected that you’re going to need. A couple of the companies are United Rentals and Mabey Bridge and Shore.”

A number of excavators, Caterpillar and Komatsu as well as a number of others are available for lease to do this type of work, according to Bammer.

“Caterpillar and Komatsu are the main companies that we use. They are designed for this type of heavy excavation work. Work has already been completed on the gas tank portion of the job; those tanks are already in the ground on this site. The diesel tanks, four 20,000 gallon tanks, a 12,000 gallon tank and an 8,000 gallon tank — went in the ground more recently, in mid-November.

“This is the beginning of our second week involving everything related to piping. Then we’ll be going out there and finishing up with our in-ground piping as soon as the general contractor is done with all their paving and underground storm drains — there’ll be quite a lot of that type of work involved. Ours will be done and backfilled, waiting for him to pour the concrete,” explained Bammer.

“When all that work is completed we will re-mobilize in the direction of where all their work has been done onsite and once they’re done with their part, installation of all the dispensing equipment starts,”?Bammer continued. “This includes the equipment that goes on the fueling island that actually hooks your car or truck up to in order to fill it with fuel. That will take a couple of weeks of work before the electrician hooks up the wire in order to program, purge, test and certify the operations with the environmental department and for Pilot.”

Their work will take six to eight weeks. There is a huge amount of site work needing to be done, though at least the shell of the building is almost completely finished.

“Once the sheet piling issue came up due to conditions we discovered in the soil, it took us a little bit extra time. But once that was taken care we jumped on what we needed to do at this work site and were Johnny-on-the-spot,” Bammer concluded. CEG

This story also appears on Construction Equipment Guide.