Naslov
Measurement of soil-grid interaction in pullout

Autori
Minažek, Krunoslav

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Abstracts of the Fifth International PhD, DLA Symposium / Miklos Ivanyi - Pečuh : University of Pecs Pollack Mihaly Faculty of Engineering, 2009, 44-45

ISBN
978-963-7298-34-9

Skup
Fifth International PhD, DLA Symposium

Mjesto i datum
Pečuh, Mađarska, 19.10.2009. - 20.10.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
soil ; grid ; interaction ; measurement ; pullout test

Sažetak
Reinforced soil is increasingly used in today's engineering structures, enabling construction of steeper slopes, effective supporting wall structures, more rigid road base and subbase layers and improving foundation soil. The geosynthetics prevail as reinforcement material. The most common procedure in designing these structures is to take into account geosynthetic's tensile force with certain factor of safety so that equilibrium is satisfied. That procedure doesn’t take into account type of a geosynthetic and moreover, the reinforcement element is treated in calculation the same way - whether geogrid or geotextile, using model of pure friction between geosynthetic and soil. It is clear that there is always some soil-grid interaction that should be included in design. The benefit of understanding of the interaction mechanism between some soil and some grid lies in use of positive effects that geogrid has on improvement of soil characteristics and characteristics of the composite - the reinforced soil. The choice of grid type for a particular soil and distance between the grids in the reinforced zone should be based on the knowledge of the relevant interaction mechanism. In the scope of the research project related to reinforced soil, research group at the Civil Engineering Faculty at Osijek University in Croatia constructed a specially equipped large pullout testing device. A specially equipped pullout apparatus, dimensions of 1.9 x 0.9 x 1.2 m, has been developed to measure the soil-grid interaction during pullout. The purpose of the testing is to explore the nature of the soil-grid interaction in such a way to enable a more efficient design of reinforced soil in unbound materials. This phenomena has been investigated in two ways: a) testing of bearing capacity of a grid in a simple pullout test, using grids with and without transversal ribs, and b) characterising soil grid interaction by measuring velocity of waves travelling through the reinforced soil in perpendicular direction towards the grid. Specially adopted accelerometers were used to determine the arriving time of compressive and shear waves when propagating through reinforced soil, at different vertical distances from the reinforcing grid - higher wave velocity means stiffer material and that indicates better soil-grid interaction). Several geosynthetic and metal grids were tested in pullout in sand and middle gravel, at different vertical stresses.

Izvorni jezik
Engleski

Znanstvena područja
Građevinarstvo

POVEZANOST RADA