ABSTRACT
One of the major geotechnical risks to the public, posed by construction of new underground structures, is related to the impact of tunnelling works on adjacent structures. The paper presents the most important aspects covered in the newly developed national guideline, prepared by members of the Polish Tunnelling Association, for predicting the impact of tunnelling on ground deformations and existing structures. Provided guidance is already aligned with the semi-probabilistic framework of the 2nd generation of Eurocodes as the basis of the assessment. The proposed design methodology evolved from the well-established methods and calculations models, which are already used in tunnelling practice. However, the recommended design parameters (e.g. volume loss, trough width parameters), where possible and where sufficient local comparable experience was available, were calibrated based on statistical analysis. It involved a large number of real-scale observations from previous tunnelling works in the region, to provide a probability-based framework for the assessment and to aid design decisions on future projects.
