Comparative Study of Different Faliure Criterion on rock

Abstract

Rock is a solid aggregate of the one or more minerals. Rocks are of various types depending on their formation. Rocks are generally categorized as Igneous, Sedimentary and metamorphic. The general theory which prevails for the formation of rock is, melted rocks or rather magma that comes out earth crust cools and later solidifies to form different types of rocks.Rocks are heterogeneous in nature.Being heterogeneous in nature, it is very challenging to predict the behavior of rocks and to give a general theory of failure. There are various factors which affects the behavior of the rock. The factors which affect the most are confining pressure, temperature, rock type etc. The only way to know the behavior of rock is by testing in the laboratory. As the in-situ rocks are subjected to various type of loading. Rocks in the laboratory were subjected to similar type of conditions. Two types of testing were done i.e. destructive and non-destructive. Destructive testing is technique in which application is made to fail in uncontrolled manner to find out major principal stress, minor principal stress, tensile strength, compressive strength, cohesion, angle of friction. The test which were conducted to find out the above mentioned parameters are slack durability test, Brazilian tensile test, Triaxial test,Protodyakonov impact strength. Ultrasonic and rebound hammer techniques were used for non-destructive testing. These techniques were used to find out some other mechanical parameters. There are myriad types of failure criterion which are used to analyze the failure of rock. The criteria which were used are Mohr-coulomb, Hoek-Brown, Yudhbir and Ramamurthy respectively to find out the best failure criteria for Basundhra region. It was concluded that the Ramamurthy comes out to be the best failure criteria for Basundhra region