Axel Nitschke has over 20 years of experience in wide-ranging aspects of tunneling, including design, management, QA/QC, safety and construction. During his career, he has gained particular experience in conventional tunneling and the New Austrian Tunneling Method (NATM), often referred to as the Sequential Excavation Method (SEM), as well as tunneling with tunnel boring machines (TBM). He has applied different tunneling methods and ground improvement measures in ground conditions ranging from soft ground to hard rock. He worked on road, rail and utility tunnels in both highly congested urban areas and remote conditions as well as on mining projects. Dr. Nitschke has held key positions including SEM Manager, Contract/Claim Manager, Risk Manager, Project Manager, and Project and Shift Engineer on tunneling projects in the United States, Canada, South America and Europe. His practical experience builds on a solid scientific knowledge of tunneling, which he has gained during his graduate and post-graduate studies as a research assistant at Bochum University in Germany.