Pile driving interaction with existing tunnel

The Netherlands is a densely populated country. Any situation where infrastructure needs to be extended there is a probability that this may interfere with existing structures in the vicinity; this may even involve a tunnel. As tunnels in general are not under piled, they may be vulnerable to imposed deformations or loads. Due to the soft soil in the Netherlands, new infrastructure, e.g. bridges will be built on piles; mostly driven piles. Pile driving due to its nature may create deformations and loads, as the soil original soil is displaced from the position of the pile. This volume needs to be absorbed either by compression or kinematically absorbed due to displacement of soil outward from the pile. Near the Thomassen tunnel in Rotterdam, piers need to be built for overbridging of the approach to the Thomassen tunnel in the extension of the Harbour Railway. In order to estimate the deformation effects of pile driving a test was performed on a nearby location. Pile intrusion was monitored with inclinometers at different distances to a series of test piles. The result was applied as input for 3D FEM analysis for the erection of one of the bridge piers. In this paper, test results will be discussed as also the results of the analyses.