Reliability analysis of ground movement in tunnelling in spatially variable soil using equivalent parameters

Abstract

The evaluation of the ground movement induced by tunnelling is of vital importance for the tunnel construction and the safety of the adjacent facilities. As the spatial variability of soil was widely acknowledged, more and more researches take insight into the uncertainty analysis for tunnelling. However, reliability analysis considering the spatial variability of soil is still a tough task since the accurate failure probability generally needs time-consuming calculation of random finite element/difference. Instead of conducting the direct Monte-Carlo simulation, this study utilizes a simplified framework to analyze the reliability of the ground movement of tunnelling. The main concept of this framework is adopting random variable model with equivalent parameters by producing the comparable failure probability as the results of random field model. Coupling with the variance reduction technique, the reliability analysis of tunnel ground movement considering more than one spatial variable can be addressed. Two tunnel cases are studied to explain the adaptability and accuracy of this simplified framework in tunnelling. The characteristic of the spatially variable soil is thoroughly comprehended through various parametric study, based on the robustness of the simplified framework. Results show that the simplified framework precisely predicts the tunnel reliability considering spatially variability of soil in a relatively efficient manner.

Numerical analysis of ground surface settlement induced by shield tunnelling considering the soil parameter spatial variability in loess strata

“…Where Smax denotes the maximum GSS for each random calculation. In this study, SLim was 20 mm (Gong et al 2018;Cheng et al 2019b;Yang et al 2022). According to the reliability analysis theory (Melchers and Beck 2018), because the performance function Z adheres to a normal distribution, the corresponding reliability index (β) and reliability (Pf) of GSS can be computed utilising the following expression:…”

“…Wang et al (2022) employed a Bayesian method based on spatial random fields and calibrated the statistical characteristics to predict the GSS caused by shield tunnelling. Yang et al (2022) utilised the RFM and the variance reduction technique to assess the reliability of ground movement during tunnelling. Wu et al (2024) developed a stochastic finite element model that integrates the spatial variability of soil properties and the influence of existing buildings, comprehensively studying the uncertainties associated with GSS.…”

Influence of Support Parameter and Excavation Methods on Statistical Distribution Characteristics of Surrounding Rock Pressure in Shallow-Buried Metro Tunnel

“…Te study of underground space tunnel cannot be separated from the determination of surrounding rock pressure, and the calculation of surrounding rock pressure is also a hot issue in tunnel design. Because tunnels exist in complex geological bodies, there will be many uncertainties, such as the uncertainty of surrounding rock pressure load and the uncertainty of physical and mechanical parameters of geological bodies [2,3]. Te size, property, and distribution of these uncertain factors directly afect the selection and design of tunnel support system and the determination of construction methods.…”