Theoretical Prediction and Safety Evaluation of Adjacent Pipeline Deformation Caused by Connecting Channel Excavation Reinforced with Freezing Method

Abstract

Underground excavation by freezing method can ensure the safety of the surrounding structures. The influence of excavation of a connecting channel between two tunnels by freezing method on adjacent pipelines is studied in this paper. Combined with field measurement, numerical simulation, and theoretical analysis, the stress and deformation law of the whole process of channel excavation by freezing method is studied. Based on Euler–Bernoulli beam theory prediction, the influence of temperature field and excavation parameters on the longitudinal deformation of pipeline is analyzed. The results show that the excavation rate significantly affects the pipeline settlement, and the settlement surges when the excavation rate exceeds 1.0 m/d. At the same time, the thick frozen soil wall formed by low freezing temperatures enhances the supporting ability and effectively reduces the formation disturbance and settlement. The study focuses on the influence of connecting channel excavation on the pipelines under uniform formation conditions, and puts forward the evaluation method of pipeline safety to provide a theoretical reference for engineering practice.