盾构隧道掘进地表沉降监测数据分析及模型研究  

Monitoring Data Analysis and Model Research on Surface Settlementof Shield Tunneling

作　　者：方金文 FANG Jinwen(SGIDI Engineering Consulting(Group)Co.,Ltd.,Shanghai 200438,China)

机构地区：[1]上海勘察设计研究院(集团)有限公司,上海200438

出　　处：《城市勘测》2024年第2期142-146,共5页Urban Geotechnical Investigation & Surveying

摘　　要：以广西某地铁盾构隧道掘进期间监测数据为基础,分析盾构施工中地表沉降的变化规律。分为两个部分:一是沿掘进方向,轴线上方地表点历时变化统计分析,通过多项式拟合得出轴线上方地表沉降点的沉降变化模型;二是垂直于掘进方向,不同监测断面的累计沉降量分析,在Peck公式的基础上,综合考虑双线掘进的叠加影响,通过对实测数据进行拟合分析,得出双线盾构掘进沉降槽宽度系数和土体损失率参数。结果显示:(1)多项式模型对轴线沉降点相对掘进前后80 m范围内变化拟合较符合,整体呈现S型,前期略有抬升,后逐渐下沉,沉降主要集中在前后20 m期间,后趋于平缓;(2)Peck沉降公式拟合模型适用于该项目,预测值与实测数据吻合良好,综合多个监测断面拟合结果,提出广西地区参考沉降槽宽度参数K为0.42±0.13和土体损失率Vs为0.42±0.2。Based on the monitoring data of a subway shield tunneling in Guangxi,the variation law of ground settlement during shield tunneling is analyzed.It is divided into two parts:firstly,along the excavation direction,the statistical analysis of the duration change of the surface points above the axis,and the settlement change model of the surface settlement points above the axis is obtained through polynomial fitting;The second is the analysis of the cumulative settlement of different monitoring sections perpendicular to the excavation direction.Based on the Peck formula,the superposition effect of double track excavation is comprehensively considered.Through fitting and analyzing the measured data,the width coefficient and soil loss rate parameters of double track shield tunneling settlement trough are obtained.The results show that:①The polynomial model fits well with the change of the axis settlement point within the range of 80 meters before and after the excavation,showing an overall S-shape,slightly rising in the early stage,then gradually sinking,and the settlement is mainly concentrated in the period of 20 meters before and after the excavation,and then tends to be flat;②The Peck settlement formula fitting model is applicable to this project,and the predicted value is in good agreement with the measured data.Based on the fitting results of several monitoring sections,it is proposed that the reference settlement trough width parameter K in Guangxi is 0.42±0.13 and the soil loss rate Vs is 0.42±0.2.

关 键 词：盾构隧道 地表沉降 沉降预测模型 多项式拟合 PECK公式 

分 类 号：P642.26[天文地球—工程地质学]