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Cranfield University

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Laboratory Studies Into Undercarriage Systems<br />

Depth (mm)<br />

0<br />

100<br />

200<br />

300<br />

400<br />

500<br />

600<br />

700<br />

800<br />

Penetrometer Resistance (MPa)<br />

0 0,5 1 1,5 2 2,5<br />

900/5/0.5 @0.28 m/s<br />

900/5/0.5 @ 0.85 m/s<br />

900/5/0.5 @ 1.52 m/s<br />

Control<br />

Figure 23: Penetrometer resistance at three speeds and a multi pass of the 900/5/0.5<br />

3.1.2.2 Soil Displacement<br />

Soil displacement caused by the three different speeds is shown in Figure 24 without the<br />

surface value and the last value at 600 mm depth to remove the systematic outliers origi-<br />

nating from the lugs at the surface and the bottom of the bin. With increasing speed soil<br />

displacement decreased. Statistically all combinations were significantly different from<br />

each other with p-values between 0.014 and < 0.0001 whereby the LSD is 3.6 mm. In the<br />

speed range from 0.29 m/s up to 0.85 m/s the soil seemed more prone to changing its be-<br />

havior than at speeds higher than 0.85 m/s. In Figure 25 the influence of speed on the aver-<br />

age increases in DBD is evaluated; the average increase in DBD is gained as described in<br />

2.2.1.1 utilizing the slope of the soil displacement graphs of Figure 24.<br />

Depth (mm)<br />

0<br />

100<br />

200<br />

300<br />

400<br />

500<br />

600<br />

Displacement (mm)<br />

0 5 10 15 20 25 30 35 40<br />

Ph.D. Thesis Dirk Ansorge (2007)<br />

LSD<br />

0.29 m/s<br />

0.85 m/s<br />

1.52 m/s<br />

Figure 24: Soil displacement vs. depth for different speeds for the 900/5/0.5<br />

LSD<br />

34

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