西安富水砂层盾构施工Peck沉降预测公式改进

Modifying of Peck's Settlement Calculation Formula Related to Metro Tunnel Construction in Xi'an Water-rich Sand

隧道开挖引起的地表沉降预测主要有公式法、数值法、解析法等,由于Peck公式法的合理、简便,被广泛应用于隧道开挖引起的地表沉降预测中。但由于Peck公式的局限性,在不同地层中预测隧道开挖引起的地表沉降时需要对其进行修正。本文以西安地铁某区间盾构穿越富水砂层为背景,通过现场实测数据、线性回归方法并引入地表最大沉降修正系数α和沉降槽宽度修正系数β两个参数对原始Peck公式进行修正,得出α的取值范围为0.106 7~0.354 4、β的取值范围为0.539 0~0.681 9,将修正后的公式和现场数据对比发现拟合效果较好,参数取值合理。相关结论可供盾构在富水砂层中施工作为参考。

The main methods of surface subsidence prediction caused by tunnel excavation are numerical method,numerical method and analytic method. Due to the reasonable and simple Peck formula method,it is widely used in the prediction of surface subsidence caused by tunnel excavation. However,due to the limitation of Peck formula,it is necessary to modify when the surface settlement caused by tunnel excavation in different strata. This paper takes Xi ＇ an subway shield across the water rich sand as the background,in this paper,the original Peck formula is modified by the two methods of the maximum sedimentation correction coefficient α and the settling groove width correction coefficient β,which is based on the actual measurement data and the linear regression method. The range of α is 0.106 7 ~ 0.354 4,and the range of β is 0.539 0 ~ 0.681 9. The modified formula and the field data are compared to find that the fitting effect is better and the parameter value is reasonable. The relevant conclusions can be used as a reference for shield construction across in water-rich sand.