TY - JOUR N2 - The steel pipe umbrella is a widely used technology when tunnelling in weak soils in order to create pre-support ahead of the tunnel face. The design of steel pipes is frequently done through simplified analytical approaches which are easy to apply but require proper assessment of the loads acting on the pipe. To provide information on this key design aspect, the results of the comparison between a three-dimensional numerical model developed with the code FLAC 3D and an analytical model based on the approach of a beam on yielding supports is presented and discussed. The comparison refers to a shallow tunnel with an overburden of three times its diameter for two different types of weak rock masses. The obtained results provide suggestions about the load that has to be applied in the analytical model for the design phase. L1 - http://journals.pan.pl/Content/115484/PDF-MASTER/pan_doi_blank.pdf L2 - http://journals.pan.pl/Content/115484 PY - 2017 IS - No 4 EP - 147 KW - Tunnel construction KW - pre-reinforcement KW - steel pipes KW - numerical modelling KW - analytical models A1 - Peila, D. A1 - Marchino, C. A1 - Todaro, C. A1 - Luciani, A. PB - WARSAW UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING and COMMITTEE FOR CIVIL ENGINEERING POLISH ACADEMY OF SCIENCES DA - 15.12.2017 T1 - Comparison of the results of analytical and numerical models of pre-reinforcement in shallow tunnels SP - 135 UR - http://journals.pan.pl/dlibra/publication/edition/115484 T2 - Archives of Civil Engineering ER -