It is well known that geotechnical parameters impact dramatically soil-tunneling mechanics. Spatial random field theory has been widely used for a single variable, including aleatory uncertainty, spatial variability and local singularity. Current challenge is focused on analyzing cross-correlation of multiple soil layers. Coefficient of cohesion, internal friction angle, and compression modulus are accounted in reliability index analysis of ground surface settlement due to shallow-buried tunneling excavation. At first, convert multiple non-stationary soil layers into anisotropic random field using a local detrending method, and define the geostatistical parameters. Then, assume spatial variability of geotechnical parameters into aleatory randomness, and response surface method is utilized into reliability index analysis. Co-sequential Gaussian discretization is designed into spatial random field, in which failure probability of ground surface settlement is calculated directly by classical and subset Monte-Carlo simulations, respectively. This approach is applied into the paralleling zone of four shield tunnels of the 5th and 6th metro lines intersecting to West Huanhu Road station, Tianjin China. Results prove that reliability index of considering geotechnical parameters as random variables is lower than that of spatial random field assumption, which would support substantially to construction control and design optimization in complex shallow-buried shield tunneling projects.

LOKASI: Ruang Koleksi Umum
Rak: 2