The new Dilawri Auto Mall was a sizeable, heavy civil project on a 6ha site. Rabb needed to level and grade the site for the four car dealer elevated building pads and their surrounding inventory lots and customer parking. The contract included excavating three storm water runoff retention ponds, while Rabb was also responsible for constructing the sewage systems.
The project site was uneven as it was previously a quarry where blasting had been carried out in the 1970s to break out the rock, with the blasted material then being reduced to produce crushed stone. After extraction ceased, the large open pit was converted into a dump site for clean fill.
“We were supplied a full set of design drawings, grading plans, storm water management plans and structural plans, which were completed by a team of consultants and designers,” said Brenda Burrows-Rabb, general manager of Rabb Construction. “Using this design information, we developed a 3D site model to use with our
Burrows-Rabb said, “We had a fairly aggressive timetable in order to accommodate the two dealerships that were to be built as soon as we finished the site preparation. Plus, there was a commitment for the third dealership, and we needed to complete enough work on the fourth location to help the owner market it.”
The dynamic compaction process was completed first, with the stone building pad elevated 1–2m above existing grade. Once the building pads were constructed, the site was ready for the initial work to begin.
To handle the earthmoving, Rabb used four
“The Topcon systems helped us achieve grade on this challenging site and saved us time, which has helped us meet the tight deadlines,” Burrows-Rabb said. “The ROI on the technology was immediately obvious to us. We don’t feel a need to quantify what we already know, which is why we purchased a second unit as quickly as we did.”
Help in selecting the GPS machine control systems and with training was provided by GeoShack Canada, based in Ottawa. According to Burrows-Rabb, the operator training on the GPS controls made a difference with the confidence for using the technology. “We’ve eliminated the necessity for multiple passes and there is no need to revisit any of our work.”
The X-53i 3D control for excavators boosted the Cat 321D’s versatility. According to Burrows-Rabb, the system’s 3D positioning capabilities helped the excavator with sewer installation for bedding grade, rough grade, and “just about every task – it is very useful.”
“We knew about Topcon machine control for some time – however, it is an expensive investment,” stated Burrows-Rabb. “It became evident as we used it that it is worth the capital investment. Our efficiency has improved. For example, with the grading of the parking lot stone the D6R dozer with GPS control can be operated without foreman supervision. This frees up key personnel to complete other required work.”
For Rabb Construction achieving the correct grade according to the provided design drawings and elevations was critical, since the firm was preparing the sub-grade for the asphalt paving and concrete contractors. All quantities of crushed stone, asphalt, and concrete materials to be supplied are based on the Rabb-produced sub-grade elevation. The elevation needed to be accurate and match the city-approved grading and servicing plans.
As Burrows-Rabb reflected, “We were met with difficult site conditions and a very aggressive schedule. Certainly, having the machine control technology has helped us tremendously.”
