土岩复合地层隧道盾构开挖地表沉降Peck公式修正

Modification of Peck formula for ground settlement caused by shield tunneling in soil-rock composite stratum

为了准确预测土岩复合地层中隧道盾构开挖引起的地表沉降量,采用数理统计中的线性回归拟合方法,对青岛地铁8号线某区间隧道盾构掘进时的地表沉降监测数据进行拟合,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对Peck公式进行修正。结果表明,采用线性回归方法拟合隧道横断面地表沉降得到的曲线与实际数据吻合度高,修正系数α∈(0.2,0.5),β∈(1.0,1.4)时得到的修正Peck公式精度最高,对应回归常数项a∈(1.6,2.8),回归线性系数b∈(0.010,0.022)得到的线性拟合曲线吻合度高。研究成果成功了预测青岛地铁8号线开挖过程中地表沉降量,还可为类似土岩复合地层中隧道盾构施工提供一定的理论指导。

In order to accurately predict the amount of ground settlement caused by shield tunnel construction in soil-rock composite stratum,the linear regression fitting method in mathematical statistics was adopted to fi the monitoring data of land subsidence of shield tunneling in a certain section of Qingdao metro line 8,and the Peck formula was corrected by introducing the correction coefficientαof the maximum surface settlement and the correction coefficientβof the settlement trough width.The results showed that the curve obtained by using linear regression to fit the horizontal settlement of the earth’s surface had a high degree of agreement with the actual data,and the fitting result was highly significant,the accuracy of the modified Peck formula was the highest when the correction coefficientαwas in the range of(0.2,0.5),βwas in the range of(1.0,1.4),and the linear fitting curve was obtained when the corresponding regression constant term a was in the range o(1.6,2.8) and the regression linear coefficient b was in the range of(0.010,0.022).At the same time,the research results could provide some theoretical guidance for shield tunnel construction in similar soil-rock composite stratum.