Numerical Optimization of Mini Centrifuge Modelling Test Design of Excavation Unloading Influence on Existing Tunnel Controlled by Partition Piles

Abstract

Partition piles are widely used in tunnel displacement control under excavation. However, the control effect of partition piles has not been systematically studied, and the centrifuge model test is lacking. In view of this situation, the centrifuge model test design of the deformation of the adjacent existing tunnel caused by the excavation in terms of the partition piles under the dry sand foundation was carried out, and a series of optimization designs were carried out in the experimental design process according to the numerical simulation results. In addition, the numerical simulation of the centrifuge model test was carried out, and the calculated results were discussed and analyzed. The conclusions were obtained as follows: The magnesium-aluminum alloy materials were used to model the structural members, and its elastic modulus was close to that of common reinforced concrete; the high precision digital image correlation technology (DIC) was used to measure the horizontal and vertical displacement of the tunnel. The results of numerical simulation show that the embedded partition piles can play a better role in controlling the tunnel displacement than the non-partition piles and the non-embedded partition piles.