Caterpillar Performance Handbook, January 2017, SEBD0351-47

Ground Pressures

Hydraulic Mining Shovels

GROUND PRESSURE The ground pressure specifies the specific weight load transferred to the surface, and can be an indicator for the stability against subsidence. Though such conditions typically apply to smaller excavators in heavy earthmov- ing operations, there could be rare instances where this may apply in mining applications. Nevertheless, the vast majority of hydraulic mining shovels are delivered with standard track shoes. The value is determined by setting the machine weight force in relation to the ground contact area of the tracks. Ground Contact Area

Keys A = Width of standard track shoe

B = Track length, idler center to sprocket center C = Overall track length, grouser bar to grouser bar To define the ground contact area on soft ground the following formula is applied: 2 × A × (B + (C – B) × 0.35) Optional Track Pads In addition to the standard track shoes, optional track pads with different widths are available; however, these optional track pads are only procured on machine orders, and may therefore effect the lead time of the entire hydraulic mining shovel. Furthermore, a front shovel (FS) configured machine equipped with wider track pads increases the risk of track pad damage frombucket strikes.

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