Research on construction risk assessment method of shield tunnel based on subjective and objective weights

Abstract Various risks often exist in metro construction and building, and how to assess the risk when metro is constructed by shield method and establish the construction risk indicator system has become a hot research topic nowadays. In this paper, HHM (hierarchical holography method) is firstly used to list the initial 26 risk indicators, and the risk list is optimized by using vague set theory to get 13 risk indicators. Then, the risk indicators are assigned by a combination of the G1 method (order-relationship hierarchy method) and the COWA method (order-weighted average operator) to determine the weights of the construction safety risk evaluation indicators of the shield construction method of metro tunnels. At the same time, to reduce the influence of the uncertainty, randomness and ambiguity of the shield construction of metro tunnels and more intuitively represent the risk weights of the indicators, and the cloud theory is used to objectively display the risk weights of the indicators. Finally, the subway tunnel shield method construction safety risk evaluation model introduced into the Tianjin Metro an interval case for risk assessment, and test of the scientific nature of the model, applicability, the evaluation results obtained, and the actual results are consistent with the validation of this paper to build the subway tunnel shield method construction safety risk evaluation model of scientific applicability and reliability, enriching the subway tunnel engineering construction safety risk evaluation method for subway tunnels. Construction safety risk evaluation provides a scientific basis for decision-making, but also for the further development of risk prevention measures, reduces the risk of construction of subway tunneling projects to provide a basis for promoting the healthy and rapid development of the construction of urban subways, and provides guidance for similar projects.