Salcher, M 2015, 'Robust monitoring for high risk underground excavations', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 409-422, https://doi.org/10.36487/ACG_rep/1508_27_Salcher (https://papers.acg.uwa.edu.au/p/1508_27_Salcher/) Abstract: This paper discusses methods for monitoring underground excavations in rock, such as tunnels, caverns and underground mine openings. A case study, the excavation of a major railway cavern, is used to present a set of instruments that may be used to obtain valuable data where the failure of a critical instrument has the potential to cause delays to the project. Modern instruments such as shape acceleration arrays, electronic rod extensometers and photogrammetric techniques are compared to conventional devices such as inclinometers, automated total stations and tape extensometers. Some of the practicalities involved in taking readings and installing these systems are highlighted. It will be demonstrated that while the most recent advances in technology may offer convenience when functioning properly, conventional instruments are preferred for a robust monitoring system for high risk underground excavations.