Study on Stability of Bridge Piers Pierced by Tunnels based on Factor Analysis and Extension Theory

Abstract

To guide the safe construction of tunnels and ensure the safe operation of roads and bridges, a bridge pier stability evaluation model based on factor analysis and extension theory method was proposed. Firstly,10 factors affecting the stability of the pier are selected as evaluation indicators from the three aspects of rock formation deformation, pier sturdiness, and tunnel impact. Secondly, the 12 bridge piers of the Kuiba tunnel underneath the Yanba highway bridge are actually implemented. The principle of factor analysis is used to process the resulting index decision matrix, construct the comprehensive evaluation function of the index, and determine the indicators that need to be focused on the governance and ordering. Finally, combined with the theory of extenics, the multi-index comprehensive correlation degree of each bridge pier on different stability levels was obtained,and the integrated stability grade of the under piers of the 12 tunnels was further judged. In all 12 bridge piers, except for one which is in an unstable grade, all others are at stable level. The evaluation results are consistent with the unascertained evaluation results of the bridge pier stability in literature, which can provide reference for the evaluation of the stability of piers.