Influence and Optimization of Geometric Parameters for Small-Radius Curved Tunnel Based on Response Surface Method

Abstract

Compared with straight tunnels, small-radius curved tunnels are more common and have more complex influencing factors in urban underground traffic. Therefore, the seismic evaluation of small-radius curved tunnels is of great significance for the safe operation of underground structures. This paper used numerical analysis and the response surface method to analyze the influence of buried depth, curve angle and curve radius on the seismic response of a small-radius curved tunnel. For this purpose, seventeen three-dimensional (3D) numerical analysis models of the small-radius curved tunnel considering different geometric parameters are established. In addition, the optimal geometric parameters of displacement response and acceleration response of the small-radius curved tunnel are studied by using the method of multi-objective optimization design. The results show that buried depth has a pronounced influence upon the displacement response of the small-radius curved tunnel, whilst the buried depth and curve radius are the key parameters affecting the acceleration response of the small-radius curved tunnel. The optimal parameter configuration of the small-radius curved tunnel is the maximum buried depth, the maximum curve angle and the maximum curve radius within the value domain.