Research On Complete Set Of Methods And System Design For Quantitative Analysis Of Ground Settlement In Shield Tunneling

With the wide application of the shield method in tunnel construction,the requirements for shield construction safety are getting higher and higher.Many cities in China have begun to develop data platforms related to subway construction safety to make the shield construction process more precise.security management.The settlement induced in the process of shield tunneling is one of the common diseases in the construction process.Accurate prediction of surface settlement is one of the important problems in tunnel engineering.In response to this problem,many scholars at home and abroad have proposed a variety of prediction methods,but a good research system has not yet been formed.This paper studies three subsidence prediction methods,analyzes their characteristics and applicable conditions,and embeds the relevant results into the surface subsidence prediction module of the subway platform.This study takes a shield tunnel construction subway section in a city as the engineering background,and mainly carries out the following work:(1)The Peck formula and its correction method and the Plaxis 3D numerical calculation method are used to predict the surface subsidence,and a prediction model for the study tunnel section is established.The results show that the Peck formula method is easy to calculate and the results are reasonable,but there is a strong regionality,which needs to be revised.Plaxis 3D numerical calculation method has powerful simulation performance,high accuracy and reliability of prediction results,but high modeling difficulty and timeconsuming calculation.(2)Establish a settlement prediction model based on Gradient Boosting Decision Tree(GBDT),and obtain the importance ranking of 69 influencing factors related to settlement through the embedding method-GBDT model.With 9 features,the model performs best.The model prediction performance is further improved by adjusting the loss function and optimizing the hyperparameters using grid search methods.The research results show that the artificial intelligence method can effectively solve the nonlinear problems faced by geotechnical engineering,with high prediction accuracy and fast speed.powerful.(3)Based on the evaluation of the accuracy of the three methods,modeling time,calculation speed,number of parameters,degree of visualization,universality,reliability,and number of influencing factors,it is proposed to map the safety risk level to settlement.The strategy of the prediction method makes this study meet the needs of the prediction method under different subsidence safety risk levels.From qualitative analysis to quantitative analysis,the suggestions for the use of each prediction method under different working conditions are summarized and verified by examples.Based on a tunnel engineering project in Wuhan,this research analyzes and compares the application of empirical formula method,numerical calculation method and artificial intelligence method in engineering,summarizes the applicable working conditions of each method,and builds a universal and efficient settlement prediction tool framework.The proposed method is evaluated in terms of dimensions.The research results have practical engineering significance and high application value,and have reference value for the construction of tunnel construction informatization.