盾构法联络通道周围地层注浆施工影响研究

Study on the Influence of Grouting Construction in the Ground Surrounding the Connecting Passage by Shield Tunneling

新型盾构法地铁联络通道在与主隧道T接施工过程,需要通过注浆工艺弥补切削施工造成的地层损失以及实现隧道结构纠偏抬升目的,从而对周围软土地层形成不可避免的扰动影响。以宁波某地铁联络通道工程为背景,通过建立联络通道注浆施工三维有限元分析模型并结合现场监测数据验证,研究注浆施工对地表及周边土层的抬升影响规律。分析表明:采用整体非均匀注浆,在提高结构整体性同时可以略微弥补地层损失等造成的沉降,对宁波软土地区,通过控制合适注浆压力为0.4-0.5MPa,可使地层抬升隆起约1.0-1.5mm;受注浆施工影响,靠近联络通道正上方位置,尤其是联络通道跨中和与主隧道接口处,地层隆起明显,联络通道所穿越的周围土层隆起量相对于其他土层隆起量更明显,对于灵敏度高的软土,应加强控制减少施工对周围土层扰动影响。

During the construction process of the new shield tunnel connecting channel with the main tunnel T,grouting technology needs to be used to compensate for the ground loss caused by the cutting construction and to achieve the purpose of rectifying and lifting the tunnel structure,thus forming an inevitable disturbance to the surrounding soft soil layer.Taking a subway connecting passage project in Ningbo as a background,by establishing a three-dimensional finite element analysis model of connecting passage grouting construction and verifying it with on-site monitoring data,the effect of grouting construction on the uplift of the surface and surrounding soil layers is studied.The analysis shows that the use of overall non-uniform grouting can improve the structural integrity and slightly compensate for the settlement caused by formation loss.For soft soil areas in Ningbo,by controlling the appropriate grouting pressure to 0.4-0.5MPa,the formation can be uplifted by approximately 1.0-1.5mm.Affected by grouting construction,it is close to the position directly above the connecting passage,especially at the middle of the connecting passage and the interface with the main tunnel.The stratum uplift is obvious.The uplift of the surrounding soil layer that the connecting passage passes through is relative to other soil layers.The uplift is more obvious.For soft soils with high sensitivity,control should be strengthened to reduce the impact of construction on the surrounding soil disturbance.