基于弱光纤光栅的盾构穿越全过程土体扰动特性研究

Research on soil disturbance characteristics of shield traversal based on ultra-weak fiber barge gratings

城市中大规模的地铁建设对地下建筑物及管安全造成一定影响,研究盾构隧道施工引起深部地层的扰动变形规律对保护临近建(构)筑物及地下管线具有重要的意义。文章依托苏州轨道交通S1号线工程,基于弱光纤光栅感测技术,研究盾构隧道掘进全过程引起深部土体变形规律。监测结果表明:盾构掘进时,距隧道中心轴线上方一定范围内土体主要发生隆起变形,而靠近地表范围内的土层主要发生沉降变形,距离隧道越近,隆起变形范围越大;深部土层的变形与地表变形规律一致,可分为四阶段,即随着盾构的掘进表现为先隆起、后沉降、再隆起、最后沉降的趋势,并在盾构远离约10 d后趋于稳定。利用弱光纤光栅监测技术可以精确定位盾构过程中主要变形层位,实现周边土层扰动自动化监测,为地下管线、临近建筑物变形提供参考。

The large-scale subway construction in the city has a certain impact on the safety of underground buildings and pipelines,and it is very significant to study the disturbance deformation law of the deep strata caused by the shield tunnel construction in protecting the adjacent buildings(structures)and underground pipelines.Based on Line S1 Project of Suzhou Rail Transit,the article studies the deformation law of deep soil caused by the whole process of shield tunneling by using the weak fiber optic grating sensing technology.The research results show that,during the shield tunneling,the soil mainly deforms by uplift in a certain range above the central axis of the tunnel,and the uplift is smaller as the distance from the central axis of the tunnel gets farther;while the soil near the surface mainly deforms by settlement,the settlement is larger as the distance from the central axis of the tunnel gets farther.The deformation of the deep soil layer is similar to the surface deformation law,showing a trend of first uplift,then settlement,then uplift,and finally settlement as the shield tunneling progresses,the shield tends to settle steadily after about 10 days away.Using the weak fiber grating monitoring technology,the main deformation layers during the shield tunneling can be accurately located,and the automatic monitoring of disturbance in surrounding soil layers can be efficiently realized,which can provide reference for similar projects in the future.