New multi-inclinometric geotechnical monitoring systems — the importance of alignment calibration and testing for reliability and correct data interpretation

Authors: Foglino, V; Foglino, L; Foglino, S; Lovisolo, M Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_rep/1508_07_Foglino

Cite As:
Foglino, V, Foglino, L, Foglino, S & Lovisolo, M 2015, 'New multi-inclinometric geotechnical monitoring systems — the importance of alignment calibration and testing for reliability and correct data interpretation', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 161-171, https://doi.org/10.36487/ACG_rep/1508_07_Foglino



Abstract:
Recent legislative guidelines (Eurocodes, national standards, etc.) for design in geotechnical field of particularly complexity point out the possibility to use the observational method and the need to monitor stability in design, construction, structural testing and post-construction phases. A good answer to these legislative guidelines may be provided by modern geotechnical monitoring systems with the use of multiinclinometer instrumentation. In recent years, thanks to technological advances related to micro-electro-mechanical systems (MEMS), are developing multi inclinometer digital systems that allow to realise instrumented columns designed to study significant segments of the subsoil or the structure–ground interaction. The concatenation of many inclinometric modules determines problems related to the axes-alignment and/or the spiralling, which depend both on construction techniques used for assembly the various mechanical components both on the installation mode. These problem may cause errors also very relevant in movement direction evaluation (that the builders does not always consider) which must be adequately compensated/corrected in such a way that permitting a correct and consistent measure. C.S.G. S.r.l. is the leader in multiparametric monitoring field, having with its patents in the year 2000 introduced in addition to the multi-inclinometer also the multi-parametric system and realising fully instrumented columns of length greater than 150 m known as DMS ™, the acronym for differential monitoring of stability. To ensure the accuracy in module series alignment, C.S.G. S.r.l. has developed both a special automatic machine which ensures particularly effective mechanical alignment that involves the assembly stage of the column, both a whole procedure of testing on the column itself through a specific testing field and a software specially designed to detect and compensate any misalignments of the direction of each sensor. The article describes these techniques, procedures and algorithms used for the tests with the hope that soon there will be a unique technical standard on this topic.

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