MDP Case Study

Machine Drive Power Helps eliminate thousands of passes,
more than doubles working speed

George Nathanailidis and his TENA SA crew faced an enormous soil compaction challenge on a dam jobsite near Triantafullia in northern Greece.

TENA was responsible for placing 42 m (138 ft) of compacted materials on an existing embankment of 33 m (108 ft). The earthmoving volume for the massive earthen dam exceeded 350,000 m3 (457,765 yd3). The material had to be applied in 20 cm (7.8 in) layers and compacted to 15 cm (5.9 in)—at a length of 364 m (1,194 ft) and at a width of 18 m (59 ft).

Volume was only part of the challenge. “We worked in sandy clay,” Nathanailidis says. Achieving uniform compaction would prove difficult, while monitoring densities would be challenging and less than comprehensive.

TENA SA turned the nightmare job into a dream with the help of new machine-integrated soil compaction measurement technology called Machine Drive Power, or MDP.

“MDP saved us considerable time and certainly money,” says Nathanailidis, president and chief executive officer of TENA SA, one of the largest construction companies in northern Greece.

Nathanailidis has numbers that support the statement:

• In compacting approximately 280 layers, he estimates the use of MDP enabled him to eliminate a stunning 9,520 passes, or 34 passes per layer, with an average length of 364 m (1,194 ft) per pass.
  
  
• Productivity was more than doubled on the passes that were still required, as MDP also enabled the Cat® CS66B Soil Compactor to increase its working speed from 2 km/h to 4.5 km/h (from 1.2 mph to 2.8 mph).
  
  
• TENA SA reports several other key MDP benefits, beyond the productivity improvements.
  
  
• MDP proved reliable in clay soils, where an accelerometer-based system would suffer from high variability—and therefore provide questionable readings. Without MDP, TENA SA would not have been able to show that target densities were achieved—and the passes would not have been eliminated.
  
  
• Quality control was improved by spotting problems early and taking immediate corrective action.

MDP Defined

MDP is a significant change in compaction measurement technology. It is not a breakthrough in how machines compact. Instead, it evaluates the rolling resistance.

That resistance provides an indication of soil stiffness and load-bearing strength, and whether compaction is adequate to structurally support the road, parking lot, building or whatever is planned for the site.

"MDP SAVED US CONSIDERABLE TIME AND CERTAINLY MONEY."

The ultimate benefit of MDP, a proprietary technology developed by Caterpillar, might be summed up in one word: uniformity. Is the entire site compacted the same way, or are there areas where structural integrity is compromised?