Wyznaczanie odporności skał na pękanie na przykładzie granitu ze złoża Grabina Śląska
Abstract
Determination of rock fracture toughness based on measurements of the Grabina Śląska granite.
A b s t r a c t. This paper discusses some aspects of rock fracture mechanics which should be considered in
the design of excavations and slopes stability analyses in jointed rock masses. Fracture toughness is a key parameter in a fracture criterion commonly used to predict crack initiation and propagation. Such a criterion is widely known but still not applied in practical geo-engineering calculations because of the inherent complexity of rock masses. A review of tensile fracture toughness measurement methods of rocks is presented, with a detailed description of the chevron bend method employed to determine the tensile fracture toughness of the Grabina Śląska granite with consideration of the material micro-structure. Noticeable differences in the magnitude of this parameter in three orthogonal directions have been observed, as their three values are equal to 0.78 MPa · m1/2, 1.24MPa · m1/2 and 1.43 MPa · m1/2, with variations of about 10%.
A b s t r a c t. This paper discusses some aspects of rock fracture mechanics which should be considered in
the design of excavations and slopes stability analyses in jointed rock masses. Fracture toughness is a key parameter in a fracture criterion commonly used to predict crack initiation and propagation. Such a criterion is widely known but still not applied in practical geo-engineering calculations because of the inherent complexity of rock masses. A review of tensile fracture toughness measurement methods of rocks is presented, with a detailed description of the chevron bend method employed to determine the tensile fracture toughness of the Grabina Śląska granite with consideration of the material micro-structure. Noticeable differences in the magnitude of this parameter in three orthogonal directions have been observed, as their three values are equal to 0.78 MPa · m1/2, 1.24MPa · m1/2 and 1.43 MPa · m1/2, with variations of about 10%.