2008世界隧道大会.pdf

World Tunnel Congress 2008 - Underground Facilities for Better Environment and Safety - India Design of the Patnitop tunnel Martin Srb, Petr Svoboda Matous Hilar D2 Consult Prague s.r.o., Czech Republic SYNOPSIS: The Patnitop tunnel will be part of Udhampur to Banihal Transport Corridor on the National Highway NH-1A in Kashmir in India. The decision about four-laning of the NH – 1A has been made as a part of this massive infrastructure development in India. Different alternatives have been investigated for tunnel crossing of the Patnitop range in stationing km 90 to km 130 of the existing NH-1A. Five tunnel alternatives varying from 1.2 km length to 9.2 km length have been assessed and presented during feasibility studies. As the optimum alternative, the longest one base tunnel was approved for further stages. A proposed NATM tunnel is 9120 m long and it is currently the longest prepared road tunnel in the southeast Asia. The maximum tunnel overburden is 1050 m, the tunnel profile is from 147 m2 to 175 m2 . Procedure of very long and deep NATM tunnel design is described in the paper. The paper highlights design issues as evaluation of alignment options, geological conditions, numerical modelling, excavation and support classes, tunnel cross section, specifications, safety, etc. To manage large deformations expected during tunnel excavation in some sections, the concept of yielding elements (Lining Stress Controllers) has been adopted. 1. INTRODUCTION American company Louis Berger Inc. The work load included carrying out variant designs for The Patnitop tunnel is part of the project having the possible tunnels under the massif of Pantinop,