Rabaiotti, C, Iten, M & Fischli, F 2015, 'Implementation of fibre-optic vertical extensometers for safety monitoring', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 631-644, https://doi.org/10.36487/ACG_rep/1508_45_Fischli
(https://papers.acg.uwa.edu.au/p/1508_45_Fischli/)
Abstract: The Westlink is one of the major city development projects of the Swiss federal railway company (SBB CFF FFS) in Zürich: three tall office buildings (total 70,000 m2 for office, flats and shops) have been recently constructed in close proximity to the railway tracks. An existing water pipeline of 2.1 m in diameter is running below the buildings at a depth of 10 m. The pipeline is an important component within the city’s water supply system with an internal pressure of 10 bar. 

To assure the pipeline safety and integrity, an assessment of the tolerable pipeline displacement during construction was carried out and monitoring was implemented. The assessment consisted of modelling the depth-dependent soil deformation during construction using a three-dimensional finite element modelling. The modelling allowed predicted settlement and allowed definition of critical values for the safety of the pipeline. Subsequently, implementation of a sophisticated monitoring system based on fibre-optic sensors and conventional geotechnical monitoring methods was carried out. Thus, the combination of advanced modelling and monitoring allowed reliable risk assessment for the pipeline and the building through all the construction phases.