Geothermal slide-hold-slide experiments on bare surface Westerly granite
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Laboratory slide-hold-slide tests, combined with flow through tests, conducted on Westerly granite with 30 degree sawcut. Tests were conducted with a constant confining pressure of 30 MPa with an average pore pressure of 10 MPa at temperatures of 23 and 200 degC. Three fluid flow conditions were examined (1) no flow, (2) cycled flow, and (3) continuous flow.
Hydrothermal friction experiments in quartzite: The effect of temperature and normal stress on strength recovery
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Laboratory slide-hold-slide tests were conducted in a conventional triaxial deformation configuration on 3/4-inch diameter cylindrical cores of Eureka quartzite bisected by a sawcut oriented at 30 degrees from vertical. Tests were conducted at constant normal stresses of 30, 110, and 210 MPa with a 10 MPa pore fluid pressure. The pore fluid was deionized water. Experiments were conducted at temperatures of 22, 100, and 200 degC.
Hydrothermal friction experiments in quartzite: The effect of temperature and normal stress on strength recovery
공공데이터포털
Laboratory slide-hold-slide tests were conducted in a conventional triaxial deformation configuration on 3/4-inch diameter cylindrical cores of Eureka quartzite bisected by a sawcut oriented at 30 degrees from vertical. Tests were conducted at constant normal stresses of 30, 110, and 210 MPa with a 10 MPa pore fluid pressure. The pore fluid was deionized water. Experiments were conducted at temperatures of 22, 100, and 200 degC.
Utah FORGE Hydrothermal Friction-Hydraulic Transmissivity Laboratory Experiments
공공데이터포털
Submission includes data from laboratory slide-hold-slide tests, combined with flow through tests, conducted on Westerly granite with 30 degree sawcut. Tests were conducted with a constant confining pressure of 30 MPa with an average pore pressure of 10 MPa at temperatures of 23 and 200 degC. Three fluid flow conditions were examined (1) no flow, (2) cycled flow, and (3) continuous flow. Data were collected to asses the effect of temperature and pore fluid on frictional healing rates in granite at geothermal conditions. Data is available in XML and JSON data types.
Laboratory Experiments Examining the Effect of Thermal and Mechanical Processes on Hydraulic Transmissivity Evolution
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Using laboratory slide-hold-slide experiments, at temperatures from 22 to 200 degrees C, to examine effects of fracture reactivation and quasi-static loading on the evolution of fluid transport properties of simulated fractures in Westerly granite. At all temperatures, the in-plane hydraulic transmissivity consistently decays during hold periods resulting in an overall reduction in transmissivity. During the first three to fifteen hours of an experiment, transmissivity decreases rapidly due to the generation of wear products, development of a sliding surface, and compaction of the resulting gouge. Once the sliding surface has developed, the long-term transmissivity decay rate at 22 and 100 degrees C is significantly lower than the transmissivity decay rate during the initial 3-15 hours of the experiment. However, at 200 degrees C, the decay of hydraulic transmissivity remains high throughout the experiment. The long-term decay of hydraulic transmissivity can be fitted with a power law model with more rapid reduction of hydraulic transmissivity at higher temperature. Periods of sliding on the fracture surface result in transient increases in the transmissivity, due to shear dilation, as is expected for Coulomb materials. These transients are superimposed on the long-term decay. When sliding ceases and a new hold period commences, there is a rapid reduction in transmissivity and return to the long-term rate of transmissivity decay. The rate of decay of the transmissivity transients is inversely correlated with temperature, in contrast to the long-term decay and the expected behavior for processes like subcritical crack growth and indentation creep. The higher decay rates that are observed during the initial 3-15 hours of the tests and following sliding, are associated with times that the porosity of the gouge is expected to be high. The difference in decay rates suggests that when the gouge is driven far from equilibrium by active shearing, densification may be dominated by a different mechanism from long-term compaction.