The 2016 World Tunnel Congress will be held on 22-28  April 2016 in San Francisco, California. With as many as 600 unique technical presentations, short courses and breakout sessions visitors will have the chance to interact with more than 200+ exhibitors from around the world, and companies representing all types of products and services for the tunneling and underground construction industry.  View accepted papers for the WTC 2016. New papers are being added regularly so check back often. Registration is now open. Visit http://www.wtc2016.us. 52/15.