Most of the existing approaches for trajectory modelling propose to enrich struc-tured spatiotemporal trajectories with semantics. In social sciences, the term of " trajectory " is often used to describe some evolution that is not necessarily related to some geographical movement. In this paper, we propose ontological design patterns that i) allow modelling multiple spatial or aspatial trajectories and ii) include explanatory factors for a better understanding of trajectory events. Algorithms for the exploitation of our patterns are also presented. As a case study, we model the multiple trajectories that compose a life trajectory having in mind to focus on and study residential choices. This is an important issue for decision makers and urban planning experts in metropolitan areas who need to better understand choices citizens make. We show how our trajectory model, once instantiated , can be exploited using temporal, spatial and thematic dimensions.