Analysis of the Influence of Spatial Variability of Surrounding Rock
on the Reliability of a Tunnel Structure
(1 Department of Geotechnical Engineering, Tongii University, Shanghai 200092;
2 Anhui Comprehensive Transportation Research Institute Co. Ltd., Hefei 230000)
Abstract：
A random field model can be used to effectively simulate the spatial variability of surrounding rock. In this paper, the local average random field theory, finite difference method, and Monte-Carlo simulation are combined, and the Monte-Carlo random finite difference method is developed. Based on this method, a calculation program for the structural reliability of a tunnel considering the spatial variability of surrounding rock is worked out, and the influence of the rock's vertical and horizontal correlation distance on the tunnel's structural reliability is also researched by regarding the rock density, elastic module, and internal friction angle as 3D normal random fields. The results show that: to obtain a more economical and reasonable support scheme, it is necessary to take the spatial variability of surrounding rock into account in the design, since it has a significant effect on the tunnel's structural reliability; the tunnel failure probability increases with the increase of the vertical or horizontal correlation distance, but there is a greater effect from the vertical spatial variability. So once the geotechnical investigation fee is limited, the majority of the cost can be focused on a survey of the vertical correlation distance.
FANG Chao-1,
2 ,
Xue-Ya-Dong-1
.Analysis of the Influence of Spatial Variability of Surrounding Rock
on the Reliability of a Tunnel Structure
[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(5): 41-47
2014, Vol. 51 