基于双面弹性地基梁的大直径盾构隧道管片上浮预测方法

Prediction Methods for Segment Uplift in Large-diameter Shield Tunnels Based on Double Elastic Foundation Beams

  • 摘要: 基于双面弹性地基梁理论、修正纵向等效连续化模型以及浆液环向充填理论,在考虑上浮力时变性的基础上,进一步综合考虑了盾构施工步叠加效应、浆液压力分布和盾构台车的影响,构建了管片上浮预测模型,讨论了现有研究中浆液未凝固区域等效地层抗力系数的两种计算方式对预测结果的影响。结果表明,提出的双面弹性地基梁修正计算方法能够较好体现周围土层对管片的抗浮作用;浆液未凝固区域的等效地层抗力系数采用盾尾区域和浆液凝固区域的等效地层抗力系数取平均值的方法,计算结果和实测结果更为接近。

     

    Abstract: Based on the double elastic foundation beam theory, the modified longitudinal equivalent continuous model, and the grout circumferential filling theory, this study constructs a segment uplift prediction model taking into account the time-variability of uplift force with further consideration of the impact of superposition effect of shield construction steps, grout pressure distribution and the shield machine weight. The impact of two calculation methods of the equivalent formation resistance coefficient in uncoagulated grouting areas on the prediction results is also discussed. The results show that the modified double elastic foundation beam calculation method put forward by the study can better reflect the anti-floating effect of the surrounding soil layers on the segments, and when the subgrade reaction coefficient of the uncoagulated grouting areas is obtained by averaging the subgrade reaction coefficients of the shield tail area and the coagulated grouting area, the calculation results are closer to the actual measured results.

     

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