Contents lists available at ScienceDirect Transportation Geotechnics journal homepage: www.elsevier.com/locate/trgeo Fundamentals of roller integrated compaction control for oscillatory rollers and comparison with conventional testing methods Johannes Pistrol ⁎ , Dietmar Adam Institute of Geotechnics, TU Wien, Karlsplatz 13/200-2, A-1040 Vienna, Austria ARTICLE INFO Keywords: Compaction Control CCC Dynamic plate load test ABSTRACT Oscillatory rollers are used for compaction work in sensitive areas like inner city construction sites or near vibration-sensitive structures due to their ability to cause very low ambient vibrations. The fundamentals of oscillatory roller compaction and Continuous Compaction Control (CCC) with oscillatory rollers are discussed within the present paper. The influence of the soil stiffness on the motion behaviour of an oscillatory drum was studied to introduce a novel CCC value for oscillatory rollers based on these findings. The algorithm for the calculation of this novel CCC value for oscillatory rollers is tested on real acceleration measurements obtained from experimental field tests. Moreover, the CCC value is extensively compared to the results of dynamic load plate test by means of the Light Falling Weight Device and to the results of CCC measurements with vibratory rollers. Introduction Dynamic compaction methods have become the most popular technique for the compaction of soils over the recent decades. Vibro compactors are used up to great depths for the compaction of non-co- hesive soils. Cohesive soils usually require the application of vibro re- placement, which can also be used for compaction work in great depths. The gap between dynamic deep vibrators (vibro compaction, vibro re- placement) and dynamic near-surface compactors has been closed by the rapid impact compactor [1]. Numerous structures in geotechnical engineering, such as dams and embankments for roads and railways, are built by compacting layers of granular soils. Therefore, the near-surface compaction is of great im- portance for the construction of these structures. Usually, dynamic rollers are used for earthworks. The drum of a dynamic roller uses ro- tating eccentric masses inside the drum to cause a vibration of the drum, which makes the compaction work much more efficient by transmitting dynamic forces into the soil. Various types of dynamic drum excitation have been developed during the past decades, which do not only differ in their design, but also in their operating principle. The vibrating rollers have gained the widest use in practical applica- tion, mainly because of their simpler drum excitation system and better compaction depth compared to oscillatory rollers. Dynamic rollers improved the daily output of compaction work significantly, which increased demands for sufficient methods of quality control. Conventional spot like testing methods, e.g. the static load plate test or the dynamic load plate test [3], are not able to cover the compaction success of large areas or require a significant number of tests, which are time consuming and expensive. Therefore, numerous research projects were conducted over the past decades to develop a better understanding for the interaction between the vibrating drum of a dynamic roller and the compacted soil [2,5,7,9,15]. Based on the findings of these research works a novel method for a work- and roller- integrated Continuous Compaction Control (CCC) was developed. Various roller manufacturers adopted the idea and introduced their own CCC systems for vibrating rollers. Therefore, CCC became an ac- cepted method for compaction control with dynamic rollers and got introduced to numerous standards and guidelines [10,14]. The cited research projects focused on the compaction with vibrating rollers, while hardly any research works (with exception of [8]) were con- ducted for another important group of dynamic rollers, the oscillatory rollers. Due to the low research activities, a CCC system for oscillatory rollers has not been developed until recently, which was a drawback for the application of oscillatory rollers in earthworks. In the present paper, the development of the first functional CCC system for oscillatory rollers is shown based on the characteristic motion behaviour of an oscillatory drum. https://doi.org/10.1016/j.trgeo.2018.09.010 Received 2 July 2018; Received in revised form 27 September 2018; Accepted 27 September 2018 ⁎ Corresponding author. E-mail address: johannes.pistrol@tuwien.ac.at (J. Pistrol). Transportation Geotechnics 17 (2018) 75–84 Available online 29 September 2018 2214-3912/ © 2018 Elsevier Ltd. All rights reserved. T