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Analysis and Control of the Settlement of Super-large Diameter Shield Tunnel Passing under the Yellow River Embankment
(1. Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu 610031;2. China Railway 14th Bureau Group Mega Shield Construction Engineering Co., Ltd., Nanjing 250032)
Abstract To reasonably control the settlement of the slurry shield with a super-large diameter in the process of tun? nelling under the Yellow River embankment, this paper carries out a case study on the Jiluo Road Tunnel Project passing under the Yellow River. Firstly, the parameters configuration was put forward for the shield passing under the embankment through theoretical analysis. Secondly, the pattern and characteristics were analyzed of settlement in the embankment section where the shield tunnel is passing through according to the field measured data. Thirdly,a numerical calculation model was established to accurately and dynamically simulate the excavation process of the shield tunnel and to analyze the impact of the shield parameters on the settlement of the Yellow River embankment according to the slurry pressure and grouting pressure. Finally, the transition schemes of excavation parameters were compared for the section of the embankment with variable slope. The results show that the initial speed of settlement in the embankment section is greater and more susceptible to disturbances in the phase of the shield tail leaving the segment, compared to the ordinary ground section, and the top of the embankment is more sensitive to disturbance from deep soil masses; In the process of passing under the embankment, it is conducive to settlement control to im? prove the tunnelling parameters of the shield tunnel, though with an upper limit to the degree of control, while adjusting the tunnelling parameters in advance would be beneficial to further reduce the settlement. Therefore, it is recommended to gradually increase the slurry pressure from 300~350 kPa to 500~550 kPa in the process of passing under the embankment and carry out parameter transition 10~15 rings in advance.
Abstract：
To reasonably control the settlement of the slurry shield with a super-large diameter in the process of tun? nelling under the Yellow River embankment, this paper carries out a case study on the Jiluo Road Tunnel Project passing under the Yellow River. Firstly, the parameters configuration was put forward for the shield passing under the embankment through theoretical analysis. Secondly, the pattern and characteristics were analyzed of settlement in the embankment section where the shield tunnel is passing through according to the field measured data. Thirdly,a numerical calculation model was established to accurately and dynamically simulate the excavation process of the shield tunnel and to analyze the impact of the shield parameters on the settlement of the Yellow River embankment according to the slurry pressure and grouting pressure. Finally, the transition schemes of excavation parameters were compared for the section of the embankment with variable slope. The results show that the initial speed of settlement in the embankment section is greater and more susceptible to disturbances in the phase of the shield tail leaving the segment, compared to the ordinary ground section, and the top of the embankment is more sensitive to disturbance from deep soil masses; In the process of passing under the embankment, it is conducive to settlement control to im? prove the tunnelling parameters of the shield tunnel, though with an upper limit to the degree of control, while adjusting the tunnelling parameters in advance would be beneficial to further reduce the settlement. Therefore, it is recommended to gradually increase the slurry pressure from 300~350 kPa to 500~550 kPa in the process of passing under the embankment and carry out parameter transition 10~15 rings in advance.
ZHU Muyuan1 WEI Lifeng1 FANG Yong1 FU Qiang2 GAO Tengda2 PU Song1
.Analysis and Control of the Settlement of Super-large Diameter Shield Tunnel Passing under the Yellow River Embankment[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(3): 211-219
2022, Vol. 59 