Determination of uniaxial stregth of hard soils and weak rocks

Osnovni cilj rada je utvrđivanje značajki flišne stijenske mase. Kompleksnost ove sedimentne stijene leži u njezinom samom postanku, strukturi i sastavu stijene, te stupnju trošnosti. U radu je dan i pregled dosadašnjih ispitivanja flišne sijenske mase na području Hrvatske. Pobliže su opisani problemi prilikom ispitivanja flišnih stijenskih masa; problemi trošenja stijenske mase prilikom uzorkovanja materijala, pripremu uzoraka za potrebe ispitivanja, te tijekom samog ispitivanja u laboratoriju. Najveći doprinos rada je laboratorijsko ispitivanje čvrstoće uzoraka stijene za čije potrebe se izvelo uzorkovanje stijenske mase te postupak bušenja blokova stijene bušilicom sa dijamantnom krunom. Mjesto uzorkovanja bilo je Sovinjak, Istra. Zbog nemogućnosti dobivanja adekvatnih uzoraka, odnosno neporemećenih uzoraka prilikom postupka bušenja, odustalo se od ispitivanja triaksijalnim uređajem te se naknadno odlučilo za određivanje čvrstoće PLT metodom. Na kraju je provedena analiza rezultata laboratorijskih ispitivanja, te se pokazalo kako je flišna stijenska masa heterogena, anizotropna, relativno mekana te izrazito podložna trošenju.The main goal of the work is to determine the characteristics of a flysch rock mass. The complexity of this sedimentary rock mass lies in its very creation, then a structure and composition of the rocks, and the degree of weathering. This thesis has given an overview of previous tests conducted in Croatia. Problems during testing of these rocks; problems of weathering of the rock mass during material sampling, then during preparation of test samples and problems during the tests in the laboratory are closely described in the later part of the thesis. The most important contribution of the thesis is the laboratory strength tests for whose needs is performed the sampling of the rock mass and the procedure of rock block drilling with diamond crown. The samples were taken in Sovinjak, Istra. Due to failure of samples during the drilling procedure, the idea of triaxial testing was droped and then was decided to determine the rock strength using Point Load Test. Finally, an analysis of laboratory test results was done, and the results showed that the flysch rock mass is heterogeneous, anisotropic, relatively soft material and highly susceptible to weathering