Vast knowledge has been developed in the area of tunnelling in weak rocks over the years, and this book bridges an important gap by bringing all the information together for the benefit of the tunnelling Industry. In particular, tunnelling in poor conditions is a huge challenge for engineers and designers, and this book tackles all typical problems headon. Topics covered include classification approach, design approaches for site-specific grounds, a new invention on shielded tunnel boring machine, case histories, tunnel mechanics, risk engineering and management culture. It is based on extensive field research experiences in Himalayan region and Alps. It includes exclusive chapters on tunnelling hazards, squeezing ground conditions (a full detailed case study), swelling ground conditions, critical state rock mechanics, etc. It is supported by over 180 figures and 90 tables of data, and test examples (with solutions).