Ground Subsidence Prediction and On-Site Monitoring Analysis of Shield Tunneling Under the Ancient City
[Purposes]In order to obtain the ground subsidence law of the shield tunneling section of the South Extension of Heping Avenue in Wuhan City,this paper conducted fitting analysis of the field settlement monitoring results through the Peck formula,and revised the formula.[Methods]A monitoring point symmetrically distributed along the upper part of the tunnel is set every 30 m for on-site surface settlement monitoring.Four of the most representative section settlement results are selected for Peck for-mula fitting analysis,and the Peck formula is verified.The Peck formula is modified based on the actual settlement situation.[Findings]It shows that there is abnormal settlement at the upper part of the tunnel axis.Therefore,the settlement is controlled by adjusting the excavation parameters of the subsequent ex-cavation section,strengthening the synchronous grouting behind the wall and monitoring measurement,and the settlement trough curve obtained is matched with the Peck formula.The goodness of fit R2 be-tween the measured settlement data of the four sections and the fitting curve is higher than 0.85.[Con-clusions]The high fit between the settlement groove curve of the shield tunnel section and the Peck for-mula calculation results can be used to predict the settlement in Wuhan area.Choosing a stratum volume loss rate of 0.95%and a settlement groove width coefficient of 0.55 can make the Peck formula more simple and efficient in predicting subsequent settlement after correction.
shieldon-site monitoringsurface subsidence predictionPeck formulasettlement control
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