Since the silty fine sand formation has the characteristics of low bearing capacity,large permeability coefficient,and poor self-stabilization ability,the setting of construction parameters for large-diameter shield tunneling is crucial.This article explores the parameter control of shield tunneling machines during excavation in fine sand formations,based on the river-crossing tunnel project between Wuhan Metro Line 12 Science Park and Danshuichi.The results showed that:(1)based on on-site monitoring data,it was found that the thrust and penetration of shield tunneling were positively correlated with excavation speed,while the incision pressure was negatively correlated with excavation speed;(2)numerical analysis was used to analyze the shield tunneling construction process,and the settlement simulation values were compared with the measured values to verify the effectiveness of the model;(3)during shield tunneling,the soil within a range of 30 meters away from the excavation face will experience settlement,the closer it is to the excavation surface,the greater the settlement rate,and the maximum settlement rate occurs at a distance of 0-15 m from the excavation surface;(4)the settlement of strata under different support pressures was simulated in the fine sand layer,increasing the support pressure can effectively reduce surface settlement and enhance the stability of excavated soil.
关键词
大直径盾构/粉细砂层/数值分析/掘进参数/地层沉降
Key words
large-diameter shield/silty fine sand formation/numerical analysis/driving parameter/formation settlement
维普
万方数据