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Prediction Methods for Segment Uplift in Large-diameter Shield Tunnels Based on Double Elastic Foundation Beams
(1. China Railway 14th Bureau Group Mega Shield Construction Engineering Co., Ltd., Nanjing 211800; 2. College of Civil Engineering, Zhengzhou University, Zhengzhou 450001; 3. CRCC Underwater Tunnel Engineering Laboratory, Jinan 250101;4. China Railway 14th Bureau Group Co., Ltd., Jinan 250101)
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.
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.
ZHANG Jianyong1 LI Mingyu2,
3 CHEN Jian3,
4 YU Liucheng2 LI Yixiang1 YANG Gongbiao3 etc
.Prediction Methods for Segment Uplift in Large-diameter Shield Tunnels Based on Double Elastic Foundation Beams[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(2): 159-167
2023, Vol. 60 