基于武汉地层盾构隧道施工的Peck经验公式修正

隧道施工引起的地表沉降大小受到很多因素的影响,Peck经验公式中,参数的变化会使预测结果容易出现较大的偏差。以武汉地铁3号线盾构下穿铁路工程为依托,结合施工和土质参数及实测沉降数据,采用回归分析的方法对Peck经验公式作线性拟合并进行了对比分析,同时研究了沉降槽宽度系数与盾构切口距监测断面间距的关系以及地表最大沉降量与注浆倍数的关系,并拟合得出了相应的函数计算式来对原系数进行修正。实践验证表明,修正后的Peck公式能很好地预测隧道施工引起的地表沉降,且预测曲线与实测曲线吻合度高。

Peck Empirical Formula Modification for Subway Tunnel Construction in the Stratum of Wuhan City

There are many factors that could affect the ground subsidence during tunnel construction,due to the variability of parameters in Peck empirical formula,the prediction of ground subsidence tends to produce greater deviation.In this paper,based on the subway shielding of Wuhan metro Line 3 which crosses under the existing railway line,and combined with the construction parameters,soil parameters and measured settlement data,the regression analysis method is adopted to fit with the linear transformation of Peck empirical formula,the fitting formula is also compared with the measured surface subsidence data.At the same time,the relationships between the settlement trough width coefficient and the distance of shield tunnel incision,between the maximum ground settlement and the grouting multiples are studied,corresponding function calculation formula is gained through fitting to modify the original coefficient.The results show that the revised Peck formula can better predict the ground settlement caused by tunnel construction,the alignment of prediction curve and measured curve is also higher.