Induced deformation during tunnel excavation: Evidence from geodetic monitoring

Coulomb stress changes: From earthquakes to underground excavation failures

“…This deformation or even collapse of tunnel segments which, according to dominating concepts should be considered stabilized (induced or rejuvenated deformation), has been explained on the basis of an hypothesis of strain transfer from a ''source area'' (usually the excavation front) to rather remote tunnel segments through low-strength rocks [4]. This concept of ''induced'' deformation is a more complicated process than the simple modification of ambient stresses due to mining in the vicinity of the excavation front.…”

A Distributed Wireless Soil Displacement Measurement System for Active Monitoring of the Excavation Front of a Gallery

“…On the basis of the above observations, one can conclude that improving this measurement process is fundamental: (1) to guarantee the highest possible security to the excavation workers and the technicians which perform the reading operations and (2) to follow the front deformation movements "real-time," without any discontinuity between a reading operation and the next one.…”

“…As seen earlier, two stages can be identified: the first is the installation of the instrument; the second is the covering of 1 An inter-reading cycle coincides with the sequence of read operations of the data sent by the network Slaves, interrogated sequentially one after the other. This inter-reading cycle coincides, therefore, with the time interval between two consecutive interrogations, by the Controller, of the same Slave of the network.…”

“…The control of soil displacements during gallery excavation is of paramount importance for both preventing possible collapses which might make the life of workers at risk and for the definitions of procedures required to reinforce the front [1].…”

Tunneling and other engineering works in volcanic environments: Sousaki and Thessaly

“…A characteristic example is the Kallidromo railroad tunnel, in central Greece, where closures of up to lm were detected at sections crossing a fault zone. Excavation had to stop in 2003 and long parts of the tunnel were re-profiled (Kontogianni and Stiros 2005). Supplementary geological and geotechnical studies were carried out and Figure 1 -Map of Greece with the main N-S the project is to continue with great delay and E-W routes for the Highway and the Rail under a new contract and a revised construction technique.…”