Feasibility study for in-situ dynamic testing of structures and geotechnical systems

An evaluation of alternative techniques of in-situ dynamic testing for the calibration of fragility functions and finite element models of existing structures and geotechnical systems subjected to seismic ground motions is discussed in this paper. The cases of excitation of bridge structures, buildings and soils are considered, remembering that also effects on components, non-structural elements and dams can be studied. The advantage of these techniques is to perform in-situ tests on full scale systems in their real conditions and state of maintenance imposing ground motions or effective dynamic excitations, even at low frequencies. A dynamic testing system consisting of a totally independent mobile laboratory has been specifically designed and constructed. Peculiar requirements are necessary to achieve the test set-up, including the development of specific methods to build the reaction system and to prepare the base of the buildings. Finally, a feasibility study to evaluate the capability of the proposed dynamic testing system to study the phenomenon of liquefaction in-situ has been carried out by means of three-dimensional coupled dynamic analysis based on the effective stress approach.