Probabilistic analysis for twin tunneling-induced longitudinal responses of existing shield tunnel. (February 2022)

• Record Type: Journal Article
• Authors: Gan, Xiaolu; Yu, Jianlin; Gong, Xiaonan; Zhu, Min
• Is Part Of: Tunnelling and underground space technology. Volume 120(2022)
• Publication Date: 2022-02
• Subjects: Twin-tunnel undercrossing -- Tunnel responses -- Probabilistic analysis -- Sparse polynomial chaos expansion (SPCE) -- Monte Carlo simulation (MCS); Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2021.104317
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: Probabilistic analysis is conducted for tunnel response to twin tunneling. Metamodel is built based on SPCE method to reduce computational effort. Global sensitivity analysis on input random parameters is performed. Failure probabilities of tunnel deformations exceeding thresholds are evaluated. Uncertainties in parameters affect tunnel response and failure probability greatly. Abstract: This paper performs a probabilistic-based analysis for evaluating the longitudinal responses of the existing shield tunnel to the twin tunneling underneath. A deterministic model based on the two-stage analysis method is proposed for calculating the twin tunneling-induced deformations of existing tunnels. An efficient metamodel is built using sparse polynomial chaos expansions to surrogate the deterministic model and carry out the sensitivity analysis. Afterward, the metamodel and Monte Carlo simulation method are combined to assess the failure probabilities of the tunnel deformations exceeding allowable thresholds under given volume losses. The analysis results show that uncertainties of the random parameters lead to a significant effect on the tunnel responses and failure probabilities, indicating the necessity of probabilistic analysis on this problem. The uncertainties in the greenfield soil settlement dominate the assessment of the tunnel settlement, and the parameters associated with the soil-tunnel interaction influence the curvature radius and joint deformations more remarkably. An approximately linear increase in the allowable volume loss can be seen with increasing horizontal distance between twin tunnels. The reduction in the skew angle strengthens the influence of the failure mode of the tunnel settlement on the probabilistic evaluation of the system.