Monitoring Data Analysis and Model Research on Surface Settlement of Shield Tunneling
Based on the monitoring data of a subway shield tunneling in Guangxi,the variation law of ground settlement during shield tun-neling is analyzed.It is divided into two parts:firstly,along the excavation direction,the statistical analysis of the duration change of the sur-face points above the axis,and the settlement change model of the surface settlement points above the axis is obtained through polynomial fit-ting;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 meas-ured 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 excava-tion,showing an overall S-shape,slightly rising in the early stage,then gradually sinking,and the settlement is mainly concentrated in the pe-riod 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.
shield tunnelground surface settlementsettlement prediction modelpolynomial fittingPeck formula
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万方数据
