Control effect of partition piles on tunnel horizontal displacement during excavation based on DIC displacement measurement technology

Abstract

Centrifuge model tests and numerical analysis were conducted to study the impact of excavation in dry sand strata on adjacent tunnels and the protective effect of partition walls. The DIC displacement measurement technology was innovatively introduced into the centrifuge model tests to measure soil displacement, determining the approximate range of the traction and blocking zones of the soil within the influence range of the partition piles during excavation. An empirical formula for the control efficiency of partition piles on tunnel displacement was proposed. The experimental results indicate that the partition piles act as barriers for shallow soil and as traction forces for deeper soil. The numerical results show that both the increase in pile length and pile top embedment depth first enhance and then reduce the efficiency of controlling the horizontal displacement of tunnels.