STRATA SUBSIDENCE CHARACTERISTICS OF SHIELD TUNNELING IN COASTAL SOFT SOIL AREA
Keywords:Coastal soft soil area, Shield tunnel, Numerical simulation, Displacement, Pore water pressure, Stress
In order to study the subsidence characteristics caused by large diameter shield tunneling in coastal soft soil area, based on the project of North Oujiang shield tunnel in Wenzhou City, the displacement field, seepage field and stress field of surrounding rock during shield tunnel construction process under fluid-solid coupling were analyzed by using finite difference method. The results show that when the shield tunneling passes through the monitoring section of the tunnel, the surrounding rock in a certain range of this section above the tunnel will be uplifted. Shield tail grouting can effectively control the settlement of the ground, and the increasing range of the ground subsidence gradually decreases. With the advance of the shield the pore water pressure increases, and the pore water pressure in the soil layer will rise sharply due to the shield tail grouting. When the shield passes through the monitoring section of the tunnel, the strata stress above the tunnel increases due to uplift extrusion, and the strata stress below the tunnel decreases due to stress releasing. When the grouting at the tail of the shield is completed and gradually moves away from the monitoring section, the stress releasing results in the decrease of the stress in the surrounding stratum and shows a funnel-shaped form.
Peck R. B., 1969. Deep Excavations and Tunneling in Soft Ground. In the 7th ICSMFE. Mexico, 311-375.
Mair R. J., Taylor R. N., Bracegirdle A., 1993. Subsurface settlement profiles above tunnels in clays. Géotechnique , Vol. 43: 315-320. https://doi.org/10.1680/geot.19188.8.131.525
Celestino T. B., Gomes R. A. M. P., Bortolucci A. A., 2000. Errors in ground distortions due to settlement trough adjustment . Tunnelling and Underground Space Technology, Vol. 15:97-100. https://doi.org/10.1016/S0886-7798(99)00054-1
Jiang X. L., Zhao Z. M., Li Y., 2004. Analysis and calculation of surface and subsurface settlement trough profiles due to tunneling. Rock and soil mechanics, Vol. 5: 1542-1544. https://doi.org/10.1007/BF02911033
Qu J. L., Ge X. R., 2005. Analysis of characteristics of settlement trough induced by shield construction in soft soil area. Industrial Construction, Vol. 35: 42-46.
Zhang Z. X., Zhang H., Yan J. Y., 2013. A case study on the behavior of shield tunneling in sandy cobble ground. Environmental Earth Sciences, Vol. 69: 1891-1900. https://doi.org/10.1007/s12665-012-2021-4
Li Z. C., Chen R. P., Meng F. Y., et al., 2015. Tunnel boring machine tunneling-induced ground settlements in soft clay and influence of excavation parameters. Journal of Zhejiang University, Vol. 49:1268-1275. https://doi.org/10.3785/j.issn.1008-973X.2015.07.010
Shen Y. S., He Y. H., Zhao L., et al., 2017. Improvement of Peck formula of surface construction settlement of rectangular tunnel in soft soil area. Journal of Railway Science and Engineering, Vol. 14: 1270-1277.
Cai Y., Zhang C. P., Min B., et al., 2019. Deformation characteristics of ground with voids induced by shallow metro tunnelling [J]. Chinese Journal of Geotechnical Engineering, Vol. 41: 534-543.
Lu D. C., Lin Q. T., Tian Y., et al., 2020. Formula for predicting ground settlement induced by tunnelling based on Gaussian function. Tunnelling and Underground Space Technology, Vol. 103: 1-22. https://doi.org/10.1016/j.tust.2020.103443
Rowe R. K., Kack G. J., 1983. Theoretical examination of the settlements induced by tunnelling: four case histories. Canadian Geotechnical Journal, Vol. 20: 299-314. https://doi.org/10.1016/0148-9062(83)90716-7
Sagaseta C.,1987. Analysis of undrained soil deformation due to ground loss. Géotechnique, Vol. 37: 301-320. https://doi.org/10.1680/geot.19184.108.40.2061
Liu B. C., Zhang J. S., 1995. Random medium method for surface subsidence caused by near surface excavation. Chinese Journal of Rock Mechanics and Engineering, Vol. 14: 289-296.
Yang J. S., Liu B. C., 1998. Surface movement and deformation caused by extrusion shield tunneling. Rock and soil mechanics, Vol. 19:10-13.
Zhu Z. L., Zhang Q. H., Yi C. H., 2001. Stochastic theory for predicting longitudinal settlement in soft - soil tunnel. Rock and soil mechanics, Vol. 22:56-59.
Shi C. H., Peng L. M., 2004. Application of stochastic medium theory to predicting settlement in longitudinal surface due to tunnel construction by shield. Rock and soil mechanics, Vol. 25: 320-323.
Fang T., Xu X. C., 2015. Improved calculation of parallel twin tunnel settlement based on stochastic medium Theory. Urban Mass Transit, Vol. 18:19-23.
Liu B., Yang W. H., 2019. Prediction model and application of three-dimensional ground surface settlement induced by tunnel excavation considering time effect. Journal of Mining Science, Vol. 4: 384-393.
Chen S. L., Gui M. W., Yang M. C., 2012. Applicability of the principle of superposition in estimating ground surface settlement of twin- and quadruple-tube tunnels. Tunnelling and Underground Space Technology, Vol. 28:135-149. https://doi.org/10.1016/j.tust.2011.10.005
Liang R. Z., Xia T. D., Lin C. G., et al., 2015. Analysis of ground surface displacement and horizontal movement of deep soils induced by shield advancing. Chinese Journal of Rock Mechanics and Engineering, Vol. 34: 583-593. https://doi.org/10.13722/j.cnki.jrme.2015.03.016
Lv J. B., Li X. L., Fu H. L., et al., 2020. Influence of shield tunnel construction on ground surface settlement under the condition of upper-soft and lower-hard composite strata. Journal of Vibroengineering, Vol. 22: 1126-1144. https://doi.org/10.21595/jve.2020.20967
How to Cite
Copyright (c) 2022 Stavební obzor - Civil Engineering Journal
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).