Health status evaluation of highway tunnel inverted arch based on variable weight and extension cloud model

Abstract

Accurate assessment of the inverted arch's health status in tunnels is pivotal for preventing floor heave and ensuring traffic safety. This study investigated the condition of inverted arches in 237 highway tunnels in Gansu Province, China. An evaluation system was developed to assess the health of inverted arches, focusing on the disease characteristics and occurrence frequencies of tunnel pavements. Additionally, a new variable weight calculation method was established, incorporating the extension cloud and variable weight theory based on cloud correlation degrees. Established grading standards were used to assign scores for determining the health status of the inverted arches. The completed health status evaluation model was applied to a case study of the Taiyangshan tunnel, demonstrating its effectiveness and applicability. The results show that the evaluation method, applying variable weights based on health levels of indicators, effectively uncovers potential risks to deteriorating inverted arches. In the Taiyangshan tunnel, three inverted arches were classified as sub-healthy, relatively dangerous, and dangerous. Intensified inspection is required for sub-healthy sections. For areas categorized as relatively dangerous, employing 'miniature steel pipe piles + H-shaped steel support' has proven effective. This methodology yields essential insights for developing effective treatment strategies for inverted arches in similar tunnel engineering projects.