호남고속철도 계획노선에서의 피에조콘 관입시험(CPTu)에 의한 연약지반 특성 평가

초록

Piezocone penetration testing(CPTu) results such as cone resistance(qc), sleeve friction(fs), and pore pressure(u), have been carried out at 5 sites in Honam high-speed railway areas of Korea, in order to continuously estimate the characteristics of soil layers and the undrained shear strength(Su) in a soft ground. For the applications of the conventional CPTu results to undrained shear strength, the cone factors(Nkt) were deduced based on Field vane tests, and Monte-Carlo Simulation(MCS). Moreover the correlations of the undrained shear strength of CPTu by soil depths were compared and revised with the results of triaxial compression(UU test), field vane and Dilatometer tests(DMT). The depths of soft foundation at 5 sites in Honam high-speed railway areas were calculated based on the results of the various field tests in addition CPTu. The applicability of CPTu for a soft foundation criterion referred to the criteria of high-speed railway and related agencies in Korea was evaluated.