Modifying Tunnel's Hazard Warning Levels based on the Laboratory Studies on Different Rock Types
Ako Abdollah Daraei
ako.daraei@soran.edu.iq
Abstract- Sakurai proposed hazard warning levels (HWLs) on the basis of the critical strain concept to evaluate the stability of tunnels. When the measured strain values remain smaller than HWL III, the stability of the tunnels is confirmed. The collapses occurred in a number of tunnels existing in Iran have questioned the accuracy of the Sakurai's criterion in spite of the smaller values of tunnel strains comparing to the HWL III. This study renders an account of the HWLs modified on the basis of the results of 162 uniaxial compression strength (UCS) tests conducted on ten types of rocks and soils.
Keywords-hazard warning levels, critical strain, modified tangent modulus, tunneling
Date: 20/04/2020
Place: Via Online