Application of TBM operational parameters to estimate the drop modulus, case study: Karaj–Tehran water conveyance tunnel of Iran

摘要: The drop modulus is an important parameter to estimate the post peak behavior of rock mass. It slope for softening stage mass that related quality and confinement stress as increasing in decreasing can increase it true inversely. One most applications this predict burst, squeezing etc because mentioned phenomena are directly In study, a new empirical method proposed using double shield TBM specifications Karaj–Tehran water conveyance tunnel Iran. estimated based on penetration rate TBM, equivalent thrust per cutter torque TBM. result shows there inverse relations between with direct relation cutter. power equations respectively. Also linear equation suggested Finally, useful achieved ratio product function three parameters.