软弱地层盾构穿越老旧民居变形规律分析

Analysis of deformation law of shield tunneling cross old residential buildings in weak strata

老旧浅基础民居安全性较低,盾构穿越会对其造成不利影响。本文以杭州某出入线段盾构穿越老旧民居为背景,分析盾构穿越民居变形规律,探讨盾构穿越民居掘进参数最优区间。结果表明,出入线段无论先下穿后侧穿或先侧穿后下穿,民居竖向位移曲线较一致,且第一次穿越前后变形较小,第二次穿越时变形迅速增大,主要表现为沉降;盾构埋深、注浆参数等对老旧民居变形、倾斜影响较大;地表沉降曲线大致呈漏斗形,出线段施工对地表变形影响较小,入线段施工对出线段地表变形影响较大,对自身上部土体变形影响较小。

The safety of old and shallow foundation residential buildings is relatively low,and shield tunneling through it can have adverse effects.Taking an entrance/exit line of Hangzhou subway as the background,the deformation law of shield tunneling through old residential buildings is analyzed,and the optimal range of excavation parameters for shield tunneling through residential buildings is explored.The results show that the vertical displacement curve of residential buildings is relatively consistent,whether they pass through from the below or from the side first.The deformation before and after the first crossing is relatively small,but when the second crossing occurs,the deformation of residential buildings increases rapidly,mainly manifested as settlement.The burial depth of shield tunneling and grouting parameters have a significant impact on the deformation and inclination of old residential buildings.The surface settlement curve is roughly in a funnel shape.The construction of the exit section has a relatively small impact on surface deformation,while the construction of the entrance section has a relatively large impact on the surface deformation of the exit section and a relatively small impact on the deformation of the upper soil.