Risk Assessment and Decision-Making under Uncertainty in Tunnel and Underground Engineering

Abstract

Abstract:The impact of uncertainty on risk assessment and decision-making is increasingly being prioritized, especially for large geotechnical projects such as tunnels, where uncertainty is often the main source of risk. Epistemic uncertainty, which can be reduced, is the focus of attention. In this study, the existing entropy-risk decision model is first discussed and analyzed, and its deficiencies are improved upon and overcome. Then, this study addresses the fact that existing studies only consider parameter uncertainty and ignore the influence of the model uncertainty. Here, focus is on the issue of model uncertainty and differences in risk consciousness with different decision-makers. The utility theory is introduced in the model. Finally, a risk decision model is proposed based on the sensitivity analysis and the tolerance cost, which can improve decision-making efficiency. This research can provide guidance or reference for the evaluation and decision-making of complex systems engineering problems, and indicate a direction for further research of risk assessment and decision-making issues.

Entropy-Based Risk Control of Geological Disasters in Mountain Tunnels Under Uncertain Environments

“…The former has been widely discussed, but the latter has not attracted enough attention. Dong et al [27], Xia et al [28] based on the characteristics of tunnel engineering, the latest risk theory and the advantages of entropy to quantify uncertainty information [29], the entropy-hazard model was constructed to discuss the risk control problem under uncertain information. The target is to assess the impact of uncertainty and determine whether measures needed to reduce uncertainty, which represents significant progress for risk control in tunnel engineering; however, there are still some deficiencies in the related research results, mainly including: (1) as there are many factors that affect the uncertainty, the available measures to reduce the uncertainty will be much, and there will be blind to decision-making by these models.…”

“…This preliminary judgment can improve the efficiency of decision-making and reduce blindness. Table 1 lists four typical combinations quoted from the literature [28]. For the first situation, no risk control measures will be taken, and in the second case we will choose measures to reduce the hazard.…”

Study on Risk Control of Water Inrush in Tunnel Construction Period Considering Uncertainty

“…Aiming at this problem in the EU-E model, Dong, Lu, Xia, and Xiong (2016) proposed an entropy-hazard model, which uses the concept of tolerance cost to analyse and control the impact of uncertainty on risk, however, the computational efficiency of the model is low, and it is difficult to determine a reasonable scheme of uncertainty control. Xia, Xiong, Dong, and Lu (2017) and Xia, Xiong, Wen, Lu, and Dong (2018) conducted sensitivity analysis based on the entropy-hazard model to narrow the scope of alternatives offered, improve computational efficiency, and selected the optimal risk control scheme based on stochastic decision theory; however, because the mechanism of water inrush during tunnel construction is complex and there are many factors influencing it, determining the exact relationship between risk factors and the probability of water inrush disaster is difficult, so the above method cannot be directly applied. In addition, risk assessment and decision-making usually require the participation of expert groups.…”

Risk Control Technology for Water Inrush during the Construction of Deep, Long Tunnels

“…For the problem of water inrush risk control during tunnel construction, there are not only geological uncertainties, but also human uncertainties, and it is an important way to improve the reliability of water inrush risk assessment results to deal with the above uncertainties scientifically. For example, Xia et al [4,31] stated that if uncertainty is not properly handled, it may lead to a large difference between the assessment results and the actual risk, which may result in a mismatch between the risk control scheme and the real risk, thus failing to achieve the expected risk control effect. As there are differences in information acquisition and quantification between geological and construction factors, it is necessary to deal with the uncertainty information of initial risk scientifically according to the characteristics of different information.…”