中文摘要：

由于软土地区深部地层超孔隙水压等因素存在,调整盾构参数对土体位移的影响往往具有一定的滞后性,该时段施工参数调整效应并不完全发生在当前时段,更多影响该断面土体的后期位移。在上海软土地区盾构施工现场设置两相同断面监测土体位移,在盾构施工不同阶段调整关键施工参数,分析各参数对土体位移扰动的时效性。在盾构靠近监测断面前调整土仓压力,穿越断面时调整掘进速度,在盾尾脱出时调整注浆量。通过监测数据以及关联系数时间效应分析得,在盾构穿越断面时土体位移受前期调整的土仓压力的扰动影响,盾尾脱出时的土体位移体现穿越断面掘进速度所引起挤土效应改变,而后期固结阶段土体位移量体现出盾尾脱出时注浆量增大所带来稳定控制效应。因此,施工时不仅需关注当前土体变形,还应对参数调整后土体变形趋势预测给以足够重视,以避免因忽略滞后效应而导致事故发生。

英文摘要：

Due to excess pore pressure and other factors of deep soft soil, the effect of adjusting the shield parameters on the soil displacement tends to have a certain delay. The adjustment of construction parameter in current session influences more on the soil displacement in later session rather than current. Two same monitoring sections are set up to survey the soil displacement from the shield tunnel in Shanghai soft soil. The effect of each parameter adjustment to the displacement disturbance is analyzed by changing the key shield parameters in different stages during construction. Chamber pressure is adjusted before the shield cutter reaching the monitoring section. Advancing speed is adjusted while shield cutter crosses the monitoring section. Grouting quantity is adjusted when shield tail reaching the monitoring section. Through the monitoring data and the time-effect analysis of the correlation coefficient, it is found that the soil displacement is affected by the disturbances of the pre-adjusted soil pressure when the shield crosses the cross-section, and the soil displacement at the shield tail reflects the squeezing effect caused by advance rate, while the displacement of soil at the late consolidation stage shows the stabilizing effect caused by the increase of the grouting amount when the shield tail prolapse. Therefore, it is not only necessary to deal with the current soil deformation, but also to pay attention to the deformation and prediction of the soil after the adjustment of the parameters so as to avoid the occurrence of accidents due to the delay effect in soft soil.