Research on Prediction Model of Ground Settlement for Ultra-Large Diameter Double-Line Shield Tunnel

Abstract

The construction of double-line parallel tunnels causes significantly more surface settlement than single-track tunnels. To accurately forecast the surface settlement brought forth by the building of extremely large diameter double-track parallel shield tunnels, by introducing the correction coefficient M(x) of the formation loss rate, a model of prediction for the surface settling of super-large diameter double-line parallel tunnels is created in accordance with the Peck formula. And validate the prediction method based on a mega-diameter shield Project in Changsha. The results indicate that the double disturbance effect will cause obvious additional settlement. When considering its influence, the location of the maximum surface settlement of soil on the backward tunnel side is shifted by 2.28 m towards the advance tunnel, causing the settling curve on the backward tunnel and the overall surface settling curve to be distributed asymmetrically; Soils on the advance tunnel side are more sensitive to secondary disturbance effects; The prediction model applies to the surface settlement prediction of the super-large diameter double-line shield project in Changsha area, and the study’s findings can serve as suggestions for undertakings of a similar nature.