Abstract To investigate the disturbance pattern of asymmetric synchronous grouting on the ground during the con? struction process of large-diameter shield tunnel, this paper simulates the synchronous grouting process at the shield tail through the finite element method based on the construction of super large diameter slurry balance shield at the launching section of the south bank of Qianjiang Tunnel, and compares the simulated data with the field monitoring data for analysis. Based on the existing analytical solution, the study realizes the non-uniform distribution pattern of synchronous grouting pressure of the finite element model through secondary development, which can fully reflect the non-symmetric grouting case. In the simulation, it considers the effects of asymmetric grouting pressure ratio, grouting rate, and distribution pattern of grouting defects (i.e., positions of local grouting pressure deficiencies)on the ground disturbance. The study shows that asymmetric grouting pressures can result in the irregular shape of settlement trough, with the side with higher grouting pressures being prone to ground surface uplift, and the asymmetric grouting pressure and stratum loss rate show a negative linear correlation. As the grouting rate increases, the settlement value of deep soils will also increase, and this trend will be more pronounced as the depth increases. The distribution pattern of different grouting deficiencies has different degrees of impact on ground settlement. Particularly, the pressure from the top grouting hole has a greater influence on the extent of ground settlement, while the pressure of the waist grouting hole has a greater impact on the width coefficient of the ground settlement trough, and the pressure from the bottom grouting hole has a relatively small influence on ground settlement.
Abstract：
To investigate the disturbance pattern of asymmetric synchronous grouting on the ground during the con? struction process of large-diameter shield tunnel, this paper simulates the synchronous grouting process at the shield tail through the finite element method based on the construction of super large diameter slurry balance shield at the launching section of the south bank of Qianjiang Tunnel, and compares the simulated data with the field monitoring data for analysis. Based on the existing analytical solution, the study realizes the non-uniform distribution pattern of synchronous grouting pressure of the finite element model through secondary development, which can fully reflect the non-symmetric grouting case. In the simulation, it considers the effects of asymmetric grouting pressure ratio, grouting rate, and distribution pattern of grouting defects (i.e., positions of local grouting pressure deficiencies)on the ground disturbance. The study shows that asymmetric grouting pressures can result in the irregular shape of settlement trough, with the side with higher grouting pressures being prone to ground surface uplift, and the asymmetric grouting pressure and stratum loss rate show a negative linear correlation. As the grouting rate increases, the settlement value of deep soils will also increase, and this trend will be more pronounced as the depth increases. The distribution pattern of different grouting deficiencies has different degrees of impact on ground settlement. Particularly, the pressure from the top grouting hole has a greater influence on the extent of ground settlement, while the pressure of the waist grouting hole has a greater impact on the width coefficient of the ground settlement trough, and the pressure from the bottom grouting hole has a relatively small influence on ground settlement.
ZHENG Shuang1,
2 LIU Chao3 ZHU Delin3 LIU Hai3 JIA Xinjuan1
.A Study on Disturbance Pattern of Asymmetric Synchronous Grouting on Ground during Large Diameter Shield Tunnelling[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(2): 168-177
2023, Vol. 60 