Ground-Supported Working Platforms for Tracked Plants and Mobile Cranes - Interaction Effects Investigated by Model Tests, Field Measurements and Numerical Simulations-Paper

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The paper examines how heavy tracked construction machinery and mobile cranes interact with temporary working platforms, particularly over weak, compressible ground. Inadequate platform design can threaten machinery stability and worker safety, yet existing design methods rely on simplified assumptions and can produce substantially different estimates of required platform thickness.<br /><br />The University of Stuttgart research combined full-scale field measurements, large- and small-scale model tests, analytical methods, and numerical simulations. It investigated ground pressures beneath crawler tracks, the performance of unreinforced and geogrid-reinforced granular layers, and the effects of cyclic loading, settlement, and consolidation.<br /><br />Field measurements showed that track pressures are strongly non-uniform and can exceed values predicted by simple linear calculations. Eccentric loading, uneven settlement, and shifting contact conditions may increase tipping risk. Tests on a reinforced platform over very soft peat revealed nonlinear, time-dependent settlement and greater strains in the lower geogrid layer. Model tests found that geogrid reinforcement can increase resistance to bearing failure by up to 100% and significantly limit the accumulation of deformation under repeated loading. A two-layer reinforcement arrangement can reduce deformation, with the lower layer providing the greater strength and stiffness.<br /><br />Overall, platform performance depends on complex interactions among machinery, granular layers, reinforcement, and subsoil. The findings support improving design methods to account for realistic machine loads, layered ground, cyclic effects, and time-dependent deformation. The research is intended to inform a German Geotechnical Society recommendation for planning, designing, and maintaining temporary working platforms.

Keywords

temporary working platforms

heavy machinery

mobile cranes

crawler tracks

ground pressure

geogrid reinforcement

bearing capacity

soft peat

cyclic loading

settlement