| dc.description.abstract | This dissertation is on monitoring of structural health and danger state for safety and
sustainability of infrastructure systems. It consists of a synopsis, in addition to journal and
conference papers and manuscripts.
The general considerations for structural health monitoring (SHM) of infrastructure systems
are introduced, as well as the monitoring of dangers relevant to structural safety. Danger state
monitoring (DSM) is defined along with related terms. The integration of these two
monitoring systems with consideration of multi-hazards is described and termed as structural
health and safety monitoring (SHSM). Next, the perspective of dams and reservoirs is
discussed, with an outline of geohazards and definition of a dam SHM. The case in Iceland of
Hálslón Reservoir and its dams is introduced. This case discusses the aspects of concrete faced
rockfill dams (CFRDs) in conjunction with the main dam. Finally, the synopsis is related to the
main research, which encompasses two studies, referred to as Study A and Study B.
Study A relates to elements of a dam SHM. The study focuses on the settlement behaviour of
Hálslón Reservoir’s main dam, a CFRD, statistical analysis of settlement data, and
development of a statistical prediction model considering visco-elasto-plastic constitutive
material models and unloading/reloading behaviour. The study brings forth the importance of
scrutinizing and processing raw readings and data from full-scale monitoring instrumentation.
It further shows that statistical analysis provides a means to compare responses from many
instruments at different locations. This comparison aids in defining trends in a data set,
seasonal components, changes in behaviour and/or outliers. Additionally, the analysis
produces details for a comprehensive understanding of dam settlement behaviour.
Study B relates to elements of DSM as well as SHSM with regard to multi-hazards. The study
focuses on geodangers that may threaten reservoirs and dams and the associated hazards
(termed geohazards). The planning and organization of a danger-monitoring program is
described and explained through the case of Hálslón Reservoir. Subsequently, geohazards and
their monitoring are defined in the general context of reservoirs and dams. A new
methodology is set out for enhancing safety by linking multi-source monitoring to multihazards
threatening infrastructure systems. An application of the methodology is demonstrated
with a conceptual model of two systems. One system includes the infrastructure, a reservoir
and its dams, along with settings for geohazards. The other system contains the associated
monitoring. Interrelations between and within the two systems are quantitatively explored by
applying an existing method of systems theory, extended to include multiple systems. This is
used to investigate hazard-triggering potential, interaction intensity and dominance. It is
further used to explore the reaction of monitoring components to geohazard action as well as
safety values of the monitoring system and its components. The interrelations established have
general relevance to reservoirs and dams. A case study illustrates these points. Moreover, the
interrelations can be used for defining hazard chains in multi-hazard assessment, planning of
monitoring programs and detecting precursory pathways within a monitoring system. The
methodology constitutes the basis for comprehensive safety and risk management, embracing
multi-hazard assessment as well as structural health monitoring. | nb_NO |
