- Q1 A Group Of Students Wanted To Determine The Strength Parameters For The Rock Samples They Collected In Site During 1 (62.23 KiB) Viewed 42 times
Q1: A group of students wanted to determine the strength parameters for the rock samples they collected in site. During their first uniaxial compression test, the equipment failed to measure the peak axial load, but they did observe that the specimen failed by the formation of a single fracture inclined at 120° to the vertical loading axis. In a subsequent triaxial test, as the confining pressure was being increased before application of the axial stress, the specimen failed prematurely when the confining pressure in the Hoek cell was 65 MPa. The students have no more samples for further testing. Would you please help them, based on the existing results, propose a failure criterion in the form a1 = 203 + b for the rock? Q2: The line of intersection between two planes trends approximately northwest and plunges at 38°. The orientation of one of the planes is 256/50 (trend plunge), and the strike of the other is 132º. What is the trend of the line of intersection and what is the dip of the second plane? Q3: Add together the following 2-D rock stress states, and (1) firstly calculate the resultant stress tensor; (2) determine the principal stresses and their corresponding directions. 20 MPa 5 MPa 45° 30° 15 MPa 20 MPa 5 MPa 20 MPa х