Seismic soil-structure interaction analysis considering a layered half space subjected to geothermal induced seismicity

In the near future, geothermal energy is bound to play a critical role in the transition to sustainable energy sources. Micro-earthquakes may be induced by the underground operations performed at the geothermal power plants. In most cases, these vibrations are considered a general nuisance similar to the vibrations resulting from railway track operations. However, given the heightened public concern regarding induced seismicity, it is crucial to identify and analyze the effects of these micro-seismic events on the built environment. In this contribution, we present a numerical technique for the simulation of buildings subjected to geothermal induced seismicity. We apply a substructure method, where the soil is represented as a continuum using the integral transform method (ITM) and the building as a discrete structure using the finite element method (FEM). For the semi-analytical elastodynamical solution, as in the ITM case, the seismic excitation can be converted to an equivalent load acting at the interaction nodes between soil and structure. To obtain these equivalent loads, one has to compute in advance the free field displacements at these interaction nodes. We apply the presented approach to a plate underlain by a layered half space that is subjected to a geothermal-induced earthquake with characteristics typical for the Greater Munich Area in Germany.