Large diameter shield tunnel becomes increasingly popular for under water and undersea channels built in cities. The probability of going through multi-layered ground formation within the tunnel depth is increasing as the diameter of shield tunnel increases. So it is necessary to consider the influence of ground variation on deformation and internal forces of shield tunnel within the range of tunnel depth. In this paper, two dimensional elastic modulus random field model which is lognormal distributed is employed to characterize the ground variation. Five parameters including tunnel diameter, tunnel buried depth, mean value and COV of ground elastic modulus, and vertical SOF of elastic modulus random field are changed in orthogonal test to study how these parameters influence tunnel internal forces and deformation. Monte Carlo simulation is performed and distributions of tunnel deformation and internal forces are all normally distributed. Mean value of tunnel deformation and internal forces are almost negative linear with mean value of ground elastic modulus, but not sensitive to COV of ground elastic modulus. Tunnel crown bending moment has the largest variability while invert axial force has the smallest variability among all structural response indicators.

LOKASI: Ruang Koleksi Umum
Rak; 2