Zhao, J.Gong, Q.M.Eisensten, Z.2007-06-042007-06-042007-06-04200710.1016/j.tust.2006.10.002https://infoscience.epfl.ch/handle/20.500.14299/7516WOS:00024675300000310635Tunnelling through a frequently changing and mixed ground : a case history in Singaporetext::journal::journal article::research article