SIMULATION OF TEMPERATURE INCREASES DUE TO UNDERGROUND MOTION: A NUMERICAL MODEL APPROXIMATION

Abstract:

The frictional energy generated during an earthquake has been well studied in the last decades. Quite a few laboratory experiments have been carried out recently with the objective to quantify and describe this type of energy in a better way. In this research we have modelled the temperature rise and the consequent released heat during a simulated seismic event using the ANSYS® Mechanical software. Our approach uses Finite Element Method to model a symmetrical fault plane where several parameters such as density, pressure, and structural and thermal material characteristics were set according the conditions of a compressional triaxial stick-slip test. Using a temporal window similar to a realistic situation, we were capable to observe the effects of the stick-slip during the coseismic rupture process. In the same way, the selected time lapse allowed us to solve and identify how the heat is generated and transferred around the fault plane. The geometry was modelled as an 80 mm high cylindrical probe with a diameter of 40 mm and a created 80 mm long fault plane at an angle of 30° (with respect to the axial axis). As preliminary results, a variation of approximately 39°C was obtained for this probe considering 160 MPa of confining pressure, 240 MPa of vertical pressure, and velocities in the order of 0.3 m/s.