Synergistic optimization design method for tunnel support structure system and its application

The design method for tunnel support structure system is the basic requirement of stability control of surrounding rock of tunnels. How to determine the reasonable support parameters is the key to ensure the safety of tunnel construction. Therefore, the synergetic principle is introduced to the design of tunnel support, and the synergetic support system of surrounding rock of tunnels is established, and the system composition, research level and characterization parameters are expounded. The core of the synergetic support is to give full play of the performance of the support system, structures and elements, thus resulting in a synergistic enhancement effect. Its characteristics of timely linking, stiffness matching and deformation coordination are revealed. The purpose of synergetic design of the support system is to achieve the stability of surrounding rock with the minimum support cost, which is essentially a multi-objective optimization problem. Furthermore, taking the deformation of surrounding rock, supporting force and support cost as the design objectives, a method for membership representation of objective function based on grouping weighting is established, thus a multi-objective synergetic optimization design method for tunnel support system is proposed. The method is applied in the large-span transition section of the new Badaling Great Wall station of Beijing-Zhangjiakou high-speed railway. After optimization, the supporting performance is more efficient, and the design is more reasonable than the original design scheme, which provides an idea for the optimal design of the support structure system.