9405836 Haimson The PI will conduct laboratory experiments on borehole breakouts and core disking under far-field boundary conditions and stress paths most closely simulating real field situations. Tests will be carried out on a granite and a sandstone. Samples will be carefully characterized microstructurally for failure mechanisms. The net result will be a more realistic simulation of the two related phenomena, a better understanding of the strength criteria leading to core and borehole failure, and practical conclusions regarding the relationships of breakouts and core disks to in situ stress magnitudes in terms of working models and calibrated numerical models for each of the two rock types. ****
