Determination of Uniaxial Compressive Strength: Part I скачать в хорошем качестве

Determination of Uniaxial Compressive Strength: Part I

INTRODUCTION One of the important engineering properties of the rock, which plays an essential role in designing various geotechnical applications such as underground mines, tunnel, and dam is the Uniaxial Compressive Strength (UCS) of the core specimen. Compressive strength is a key value for the design of underground structures. The determination of compressive strength involves the use of a cylindrical specimen of rock loaded axially between platens in a testing machine. The stress value at failure is defined as the compressive strength of the specimen. There is no load along an axis perpendicular to the loading axis. The loading condition simulates the condition of pillars supporting the mine roof in the case of underground mines. The Uniaxial compressive strength depends on the friction between platens and end surfaces, specimen geometry, rate of loading, and water content. If the friction between the loading plate and the rock specimen is more, the specimen will fail in shear, whereas in case of a smooth contact between the loading plate and the specimen, the specimen will fail in tension. The compressive strength of rocks usually increases with an increase in the rate of loading of the specimen. The strength of the specimen usually decreases with an increase in their size and when the ratio of length to diameter increases the compressive strength will be decreased. Dry specimens have high compressive strength and saturated specimens have low values. SCOPE This method of test is intended to measure the uniaxial compressive strength of a rock sample in the form of specimens of regular geometry. The test is mainly intended for strength classification and characterization of intact rock. Instructor: Dr. Radhakanta Koner, Department of Mining Engineering, IIT(ISM) Dhanbad Acknowledgment Prabhat Kumar Mandal Krishna Murari Birju Gope Vijay Karanga