Consideration of the Variable Contact Geometry in Vibratory Roller Compaction

Abstract

Vibratory rollers are mainly used for the near-surface compaction of granular media for a wide variety of construction tasks. In addition to the pronounced depth effect, vibratory rollers have offered the possibility of work-integrated compaction control (intelligent compaction) for decades. State-of-the-art measurement values for intelligent compaction (ICMVs) only take into account, if at all, a constant geometry of the contact area between the drum and soil. Therefore, this paper introduces a comparatively simple mechanical model, which describes the dynamic interaction between the vibrating drum and the underlying soil during compaction to investigate the influence of the changing geometry of the contact area on the motion behavior of the vibrating drum. The model is tested on realistic soil and machine parameters, and the results of the simulation with varying drum contact geometry are compared to a conventional simulation with a fixed contact geometry. The analysis shows that only a consideration of the varying drum contact geometry can map the dynamic interaction between the vibrating drum and soil sufficiently and provide a motion behavior of the drum that is in good accordance with the field measurements.

An advanced ICMV for vibratory roller compaction

“…The contact geometry between drum and soil, if it is taken into account at all, is described by means of formulas for Hertzian pressure and, in addition, the impact distance is kept constant during compaction. However, the variable drum contact width has a significant influence on the system reaction of roller and soil [22]. Likewise, the ratio of roller speed to excitation frequency (i.e., the impact distance) determines how much energy per unit length is introduced into the underlying soil layer.…”

“…The challenging contact conditions between drum and soil surface characterize the dynamic interaction system of a vibratory roller [22]. In addition to the periodic or aperiodic loss of contact between drum and soil, the area between the two contact partners is a variable quantity during the loading phase, due to the cylindrically curved drum.…”

“…A most recent study [22] discussed the relevance of the variable contact geometry between vibrating drum and soil surface and introduced a simple mechanical model that enables the calculation of realistic force-displacement curves that are in good accordance with measurements.…”