Responding to an increasing demand of underground

infrastructures monitoring of hydro-geotechnical and structural

parameters during the construction of urban tunnels in soils

and rock (except hard rock) is a field of activity which has seen

impressive technological changes and progress in the past years.

In the majority of the cases the construction of such urban

underground infrastructures is to be carried out in difficult ground

conditions and / or with limited knowledge about the ground

parameters. In consequence the so-called ‘observation method’

according to Eurocode 7 is applied:

Eurocode 7, Section 2, chap. 2.7 Observation method (1) If

the prediction of the geotechnical behavior is difficult, it may be

appropriate to apply the so-called observation method which

consists in the control and, case given, in the modification of the

design during the construction.