Safety-Risk Assessment for TBM Construction of Hydraulic Tunnel Based on Fuzzy Evidence Reasoning

Abstract

Due to multiple factors influencing the construction safety of TBM hydraulic tunnels, risk assessment is a critical point of a construction management plan to avoid possible risks. In this paper, a safety-risk evaluation index system of TBM construction for hydraulic tunnels is built based on the identification and analysis of possible sources of risk in techniques, geologic, equipment, management, and accidents. Considering the influence of factors such as the experience level and the expertise of decision makers, a combination assignment method of index weights is proposed based on binary semantics. On the basis of a fuzzy normal distribution used as the subordinate function distribution of fuzzy evaluation levels, the subordinate function distribution of fuzzy evaluation levels under multi-level intersection situations is introduced, and a comprehensive evaluation model of safety risks for TBM tunnel construction is built. The validity and practicality of the evaluation model is examined with the combination of a long-distance water conveyance tunnel project. Results show that the construction safety-risk of the TBM hydraulic tunnel project belongs to the middle-high level, and the safety accident risk belongs to the low level. The study provides guidance of evaluation and control of risks for this tunneling construction being successfully completed.

Safety risk assessment of subway shield construction under-crossing a river using CFA and FER

“…In the above Equations, m n i denotes the basic fuzzy confidence value of risk index r i at the fuzzy risk level of FH n , m H i denotes the uncertain risks due to lack of information, which includes can be presented in Equations 9-12 (60,61).…”

Safety Risk Evaluation of Metro Shield Construction When Undercrossing a Bridge

“…. ., L), the weights of these indexes r i are ω i and that every risk index follows the fuzzy belief model FBS(D i ) = FH n , β n i , we can calculate the mass number of each risk index, as presented in Formulas ( 5)-( 8) [60].…”

“…In the above formulas, m n i denotes the basic fuzzy belief value of risk index r i at the fuzzy risk level of FH n , and m H i denotes the uncertain risks due to a lack of information, which includes m H i and m H i . Let m n I(i) denote the belief degree to the nth evaluation level of an upper-level risk index that the first i lower-level indexes support; m H I(i) denotes the retained probability after all the first i lower-level risk indexes have been assigned to all the evaluation levels; thus, the recursive processes of m n I(i) and m H I(i) are expressed in Formulas ( 9)-( 12) [60,61].…”

Construction practice of water conveyance tunnel among complex geotechnical conditions: a case study

“…These methods include shallow buried asymmetric tunnels, deep buried tunnels in weak surrounding rocks, landslide geological body tunnels, etc., which can effectively prevent water seepage and support excavations while also protecting the environment and construction safety 18 . Based on the control of tunnel construction progress, some researchers put forward the research ideas, technical routes and construction methods of underground tunnel-group construction, developed the online monitoring system of underground tunnel-group construction progress, and applied it to hydropower stations, water diversion and other large-scale water conservancy projects, and achieved good results in improving the construction progress 19 . Some researchers have carried out the comparison between the traditional drilling and blasting method and the full-face tunneling method, and concluded that the tunneling speed of TBM is much higher than that of drilling and blasting method.…”