A practical study on the induced seismicity in Groningen and the seismic response of a masonry structure

Abstract

In this paper the man-induced earthquakes in Groningen (the Netherlands) are studied in terms of site response analyses and liquefaction evaluation. A particular soil profile in Loppersum is employed and soil properties are determined based on available geotechnical data. Clayey soil layers are modelled by means of the Generalised Hardening Soil (GHS) model. Sandy soil layers are modelled either with the GHS model or with the UBC3D-PLM model, depending on the purpose of the analysis. The UBC3D-PLM model is used to assess the liquefaction potential. Numerical results are verified against analytical formulations. The non-linear site response of the relatively soft soil deposit is captured well by PLAXIS. Special focus is given to a practical application, considering the response of a shallow-founded masonry structure under seismic excitation. The masonry is simulated by means of the Jointed Rock (JR) model, which constitutes an anisotropic elastic perfectly plastic constitutive model. Two orthogonal slide planes are used in correspondence with the horizontal and the vertical joints of the masonry. A Coulomb criterion is used to simulate failure in each individual plane. Failure mechanisms, such as vertical, horizontal or shear cracking, developed in the body of the superstructure, are identified.