V okviru 77. doktorskega seminarja Grajeno okolje bo imel dr. Johannes Pistrol, ki je doktoriral na Tehniški univerzi na Dunaju, predavanje z naslovom:
Compaction and Continuous Compaction Control (CCC) with Dynamic Rollers,
na katerem bo predstavil razvoj in najnovejša dognanja na področju zgoščanja zemljin in metodah kontinuirne kontrole zgoščanja.
Doktorski seminar bo v četrtek, 23. 2. 2017, ob 13. uri v svečani dvorani UL FGG (II. nadstropje), Jamova c. 2.
Continuous Compaction Control (CCC)
… In contrast to spot like testing methods continuous compaction control (CCC) is a roller and work integrated method for the identification of soil stiffness. The roller is not only used as compaction equipment but also serves as a measuring device at the same time. The basic principle of a CCC system is to detect the soil stiffness by evaluating the motion behaviour of the drum.
The initial research development of roller integrated measurement dates to 1974 when Heinz Thurner performed field studies for the Swedish Highway Administration with a 5-ton tractor-drawn Dynapac vibratory roller instrumented with an accelerometer. The tests indicated that the ratio between the amplitude of the first harmonic and the amplitude of the excitation frequency could be correlated to the compaction effect and the stiffness of the soil as measured by the static plate load test. In 1975 Thurner founded the company Geodynamik with his partner Åke Sandström to continue the development of the roller-mounted compaction meter. In cooperation with Lars Forssblad (of Dynapac) Geodynamik developed and introduced the compaction meter and the compaction meter value (CMV) in 1978 (Thurner & Sandström).
In the late 1980s Bomag developed the OMEGA value and the corresponding Terrameter® system. The OMEGA value provided a continuous measure of compaction energy and at that time it served as the only CCC alternative to CMV. In the late 1990s Bomag then developed the measurement value Evib, which provided a measure of dynamic soil modulus (Kröber, 2001). Ammann followed suit with the development of a soil stiffness parameter kB (Anderegg & Kaufmann, 2004). These latter Evib and kB parameters signalled an important evolution towards the measurement of more mechanistic soil properties, e.g. soil stiffness and deformation modulus. …
Več o vsebini predavanja v priponki.