Deformational responses of operated shield tunnel to extreme surcharge: a case study

作者：Huang, Hongwei; Shao, Hua; Zhang, Dongming^*; Wang, Fei

来源：Structure and Infrastructure Engineering, 2017, 13(3): 345-360.

DOI：10.1080/15732479.2016.1170156

• Shield tunnels
• lining deformation
• field case
• extreme surcharge
• joint behaviour

A field case of operated shield tunnel disrupted by unexpected extreme surcharge in Shanghai is reported in this paper. The deformational responses of segmental lining, in terms of convergences, settlements and joint open width, are highlighted. The surcharge caused by unexpected dumped soils with a maximum height of 7 m is six times larger than the design value of surcharge. Three hundred and sixty segmental lining rings of the operated metro shield tunnel below this surcharge are severely affected. The measured horizontal convergence to outer-diameter ratio (Delta D/D-out) ranges from 16.6 to 35.7 parts per thousand, which is far beyond the averaged value for normal condition, i.e. 5.1 parts per thousand. The trend of tunnel deformation (e.g. horizontal convergence and settlement) varying with surcharge level is found to be significantly nonlinear. Correspondingly, the longitudinal joints are also severely disrupted and have large open widths. The rubber packer for joint near-tunnel springline loses its function of waterproof due to the release of 6 mm pre-compressive deformation. The majority of steel bolts of joint near-tunnel crown have passed yield state, while some are fractured. However, the circumferential joints are found to be in a sound workability.

• 出版日期2017
• 单位上海防灾救灾研究所; 同济大学