Back analysis techniques for estimation rock mass modulus (E) and horizontal to vertical ratio in situ stresses in tunneling (K). Illustrated with case study (KAKAREZA tunnel)

Category Engineering Geology
Group GSI.IR
Location 3rd Iranian rock mechanics conference
Holding Date 10 March 2008
      Back analysis techniques was developed and applied to determine the main parameters of rock mass that are effective in tunneling design and underground structures, elastic modulus (E) and ratio of horizontal to vertical in situ stress (K).to find suitable back analysis technique among the optimization techniques, direct search methods were adopted. In this paper univariate, alternative univariate and pattern search techniques were explained, and univariate method further illustrated with a case study by using FLAC. The case study deal with water transfer KAKAREZA tunnel. it showed that the back analyzed results elastic modulus (E)and ratio of horizontal to vertical in situ stress are reliable and representative for the actual project