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A. Eichhorn, J. Fabiankowitsch, M. Haberler-Weber, A. Reiterer:
"Analysis of Thermal Deformations of an Arched Theatre Ceiling";
Talk: The XXX FIG General Assembly and Working Week 2007, Hong Kong; 2007-05-13 - 2007-05-17; in: "Proceedings of the XXX FIG General Assembly and Working Week (CD); FIG, The Hong Kong Institute of Surveyors (Hrg.)", (2007), ISBN: 978-87-90907-59-4; Paper ID TS1F, 13 pages.

The listed "Etablissement Ronacher" was constructed in 1871 and is one of the most famous theatres in Vienna. In the course of an extensive renovation the old wooden truss was replaced by a modern steel construction. In expectance of significant deformations of the auditorium ceiling with a priori unknown statics our institute was authorised by the construction management to install a monitoring system. Major goals are the real-time detection of vertical displacements with min. 2-3/10 mm up to 25 mm and the realisation of an automated alarm process in case of exceeding tolerance boundaries. Special challenges are the required high accuracy and reliability of the sensor system which has to work autonomously for nearly one year in a permanent construction environment.
The first part of the paper contains a short description of the construction process, the monitoring system with a TCA1800 as central sensor and the strategy for alerting. The second part contains the investigation of the measured time-series with a length of nearly 8 months and a sampling rate of Δt = 10 minutes. Special focus is set on the analysis of the thermal effects (thermal bend of the arched ceiling) which could be significantly detected up to 1/10 mm. To derive the causal relationship between temperature changes and deformation quantities different non-parametric methods are applied: spectral analysis, weight functions, neural networks and Neuro-Fuzzy methods. The different calculations (especially for deformation predictions) are compared and evaluated. In this context one interesting point is the required memory of system input parameters. The resulting thermal deformation model(s) provides a significant improvement for understanding and prediction of this complex structure.

Project Head Johannes Fabiankowitsch:
Entwicklung und Einführung eines Geo-Monitoring Systems (KE 2007 offen)