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Effects of Soft Soil Structure Interaction on
non-ductile Concrete and Masonry Structures
During Induced Seismic Event
Armin Masroor, Iraklis Koutrouvelis, Yuli Huang, Rob Smith
Arup, San Francisco, California, USA
ABSTRACT
Induced seismicity due to gas extraction in the Groningen region of the Netherlands, has affected a substantial number of
buildings. Unreinforced Masonry (URM) and non-ductile concrete structures, which are the most common construction
types in this region, were not designed or constructed with seismic considerations; as a consequence they are vulnerable
to seismically induced damage. To assess the impact of the induced seismicity on the seismic performance of these
vulnerable buildings in Groningen, Soil-Structure-Interaction (SSI) models were developed using the finite element
program LS-DYNA. This paper describes the streamlined process being used to analyze a large number of buildings while
considering the effects of the foundation flexibility, nonlinear site response analysis and SSI on response of the building.
More specifically, this paper examines the performance of a muti-storey non-ductile concrete apartment building during a
hypothetical extreme induced seismic event. The predicted performance challenges many of the assumptions about
seismic performance and how induced seismicity differs from tectonic seismicity in terms of structural response. In
particular, the paper will focus on the duration of the earthquake, its frequency content, the effect of soft soil, and the
performance of non-ductile wall structures. State of the art soil structure interaction using 3D soil blocks within LS-DYNA
was used. It is found that, while the relatively high peak ground acceleration may cause damage and cracking, the relatively
low induced displacement significantly reduces the chance of collapse in multi-story buildings. In addition, a detailed soil
structure interaction analysis shows that the soft soil effectively reduced the applied motions into the building by a
combination of both concentrating damage within the foundation and by damping within the soil.