An Iterative Calculation Method for Internal Forces of Straight-wall Arch Tunnel Lining Considering the Effect of Elastic Resistance

Abstract Accurate analysis of the stress characteristics of straight-wall arch tunnel lining is a prerequisite for the design of support structures and stability analysis. In this paper, an elliptical curve is employed as the fitting curve for the top of the straight-wall arch, upon which a mechanical analysis model is established. An iterative method is proposed to determine the distribution pattern and scope of elastic resistance, revealing the stress characteristics of the straight-wall arch tunnel lining under the combined action of external loads and elastic resistance. To simplify the iterative process, an iterative transfer coefficient K is introduced, enabling accurate and rapid calculations of the internal forces of the lining. The superiority and practicality of the proposed method are verified through example calculations and comparative analysis.