Predicting Model of Dual-Mode Shield Tunneling Parameters in Complex Ground Using Recurrent Neural Networks and Multiple Optimization Algorithms  
[PERSON]  
1 School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430083, China; [EMAIL_ADDRESS] (T.Y.) [PERSON]  
1 School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430083, China; [EMAIL_ADDRESS] (T.Y.) [PERSON]  
2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China 2*  
composite stratigraphy dual-mode shield TBM can better adapt to geological conditions, enhancing construction efficiency and safety. When using a dual-mode shield TBM for variable excavation modes in complex geological conditions [1; 2; 3], it is necessary to comprehensively consider factors such as engineering geology and excavation mode and propose reasonable adjustments to the equipment excavation parameters. Optimizing the shield TBM excavation parameters is crucial for ensuring stable and effective tunneling [4]. Improper excavation parameter settings may lead to various issues, such as over-ex excavation, deviation of the TBM axis, instability of the face support [5], excessive tool wear, and in severe cases, may even result in TBM accidents. Therefore, in the shield construction process, careful attention must be paid to the setting and adjustment of excavation parameters, and strict adherence to relevant construction regulations and standards is essential to ensure the safety and efficiency of shield construction [6; 7; 8]. During the construction of composite stratigraphy shield tunnels, the tunneling speed of the TBM may be influenced by various factors, including geological conditions, shield construction parameters, and environmental factors [9; 10; 11]. The relationship between these factors and the TBM's tunneling speed involves complex mathematical relationships, requiring further in-depth research and analysis. Precise control and adjustment of these factors are necessary to ensure smooth construction. Early tunneling speed prediction models are primarily based on empirical, theoretical, or a combination of both approaches. These models explore the operational patterns of tunneling speed and other characteristics via formula derivation and simulated experiments. [PERSON] et al. [12] utilized statistical methods to establish relationships between shield tunneling parameters and strata, conducting a thorough analysis. In the context of composite strata, [PERSON] et al. [13] employed orthogonal experiments combined with nonlinear regression analysis to develop a mathematical model for the tunneling speed of Earth Pressure Balance (EPB) shield tunneling. [PERSON] et al. [14], via a study of monitoring data from three tunnels, found a close correlation between excavation rate and rock mass classification, which could be fitted with a quadratic regression equation. Based on on-site measured data, [PERSON] et al. [15] established a regression model for excavation rate, with statistical analysis results indicating a close correlation with rock properties. [PERSON] et al. [16], using data from the Nowsood Tunnel No. 2, established an empirical formula for excavation rate about different geological parameters, finding a particularly close correlation with rock cuttability, especially the field penetration index. [PERSON] et al. [17], based on model test results, successfully developed a structural model to study EPB shield tunneling. They derived specific mathematical expressions for the total thrust, soil chamber pressure, screw conveyor speed, and tunneling speed. [PERSON] et al. [18] conducted multivariate regression analysis and discovered a certain robustness between shield tunneling speed and cutterhead torque. [PERSON] [19], via experiments, identified key shield construction parameters and studied their adaptive relationships with soil properties.