COMPUTATION OF LABORATORY TEST RESULTS TO ESTIMATE THE LOSS OF AIR IN COMPRESSED AIR TUNNELLING

Compressed air in combination with NATM is a technique to prevent water inflow during tunnelling construction. Under certain conditions, this technique is an appropriate method in tunnelling below ground water table in soils in urban areas. However, the amount of air loss is the major factor to consider when using this technique. In order to gain more accuracy in predicting the amount of air loss, large scale tests were performed in the laboratory of the Institute for Soil Mechanics and Foundation Engi- neering at Graz University of Technology. Mean- while, a numerical simulation of this laboratory test was modelled using the software code TOUGH2. Agreements between measured results and computa- tional results were found. The results of the numeri- cal simulation are discussed in this paper. An outlook on future research work will be given.