Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis
Ground settlement is often the most serious concern when tunneling under an old city with numerous historic monuments. A successful engineering design under these conditions would require getting the most out of the ground strength parameters and avoiding any weakening maneuver throughout the operat...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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University of Tehran
2013-06-01
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| Series: | International Journal of Mining and Geo-Engineering |
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| Online Access: | http://ijmge.ut.ac.ir/article_50087_025eeb80fc613726b697b8fc5260c3cc.pdf |
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| author | Amir Hossein Haghi Mohammad Reza Asef Ali Taheri Mohsen Mohkam |
| author_facet | Amir Hossein Haghi Mohammad Reza Asef Ali Taheri Mohsen Mohkam |
| author_sort | Amir Hossein Haghi |
| collection | DOAJ |
| description | Ground settlement is often the most serious concern when tunneling under an old city with numerous historic monuments. A successful engineering design under these conditions would require getting the most out of the ground strength parameters and avoiding any weakening maneuver throughout the operation. Knowing that surface settlement is highly affected by tunneling parameters in EPB shield tunneling lead us to estimate the optimum values for the machine heading pressure with the lower amount of the ground settlement in fragile structure of the old city for the Esfahan Subway Project. Tunnels were dug underneath some of the most prominent historical sites along the path of the project. To improve precision and efficiency in tunneling operation, at the first step, tunnel heading confinement pressure is calculated by using an advanced 3D mathematical approach based on the limit equilibrium theory. Then, a promoted 3D finite element model is developed, taking into account the tunneling procedures and the designed heading confinement pressure from the first step. Settlements were pre-calculated and the surface displacement was checked at all sensitive locations. At the third step, settlement is estimated by exerting executed face supporting pressure to the tunnel face and the concluded amounts for displacement are compared with the outputs of extensometers. This comparison leads us to check the reliability of calculated settlements and the accuracy of the designed tunnel heading confinement pressure. Furthermore, evaluating the relation between extensometer outputs and executed tunnel face pressure at the points of extensometers stations validates the assumption that the safe face supporting pressure causes least surface displacement. Although the minimum pressure occurred in short term fluctuations, this approach confirms the sensibility of settlement with the least executed face supporting pressure.. It is also found that higher executed face supporting pressures could reduce the tunnel face stability. Therefore, documentation of appropriate software facilitates design procedures. Yet a further achievement of this study concerns effective decision implementations under strictly limited. |
| first_indexed | 2024-04-12T11:58:53Z |
| format | Article |
| id | doaj.art-522f545ebd214b72a83efd25d637e538 |
| institution | Directory Open Access Journal |
| issn | 2345-6930 2345-6949 |
| language | English |
| last_indexed | 2024-04-12T11:58:53Z |
| publishDate | 2013-06-01 |
| publisher | University of Tehran |
| record_format | Article |
| series | International Journal of Mining and Geo-Engineering |
| spelling | doaj.art-522f545ebd214b72a83efd25d637e5382022-12-22T03:33:55ZengUniversity of TehranInternational Journal of Mining and Geo-Engineering2345-69302345-69492013-06-01471133250087Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical AnalysisAmir Hossein Haghi0Mohammad Reza Asef1Ali Taheri2Mohsen Mohkam3National Iranian South Oilfields Company, Ahvaz, IranGeology Department, Kharazmi University, Tehran, IranZaminfanavaran Geotechnical Consulting Engineers (ZAFA), Esfahan, Iran,Ecole National des Travaux Publics de L’Etat (ENTPE), Laboratoire Geomateriaux, FranceGround settlement is often the most serious concern when tunneling under an old city with numerous historic monuments. A successful engineering design under these conditions would require getting the most out of the ground strength parameters and avoiding any weakening maneuver throughout the operation. Knowing that surface settlement is highly affected by tunneling parameters in EPB shield tunneling lead us to estimate the optimum values for the machine heading pressure with the lower amount of the ground settlement in fragile structure of the old city for the Esfahan Subway Project. Tunnels were dug underneath some of the most prominent historical sites along the path of the project. To improve precision and efficiency in tunneling operation, at the first step, tunnel heading confinement pressure is calculated by using an advanced 3D mathematical approach based on the limit equilibrium theory. Then, a promoted 3D finite element model is developed, taking into account the tunneling procedures and the designed heading confinement pressure from the first step. Settlements were pre-calculated and the surface displacement was checked at all sensitive locations. At the third step, settlement is estimated by exerting executed face supporting pressure to the tunnel face and the concluded amounts for displacement are compared with the outputs of extensometers. This comparison leads us to check the reliability of calculated settlements and the accuracy of the designed tunnel heading confinement pressure. Furthermore, evaluating the relation between extensometer outputs and executed tunnel face pressure at the points of extensometers stations validates the assumption that the safe face supporting pressure causes least surface displacement. Although the minimum pressure occurred in short term fluctuations, this approach confirms the sensibility of settlement with the least executed face supporting pressure.. It is also found that higher executed face supporting pressures could reduce the tunnel face stability. Therefore, documentation of appropriate software facilitates design procedures. Yet a further achievement of this study concerns effective decision implementations under strictly limited.http://ijmge.ut.ac.ir/article_50087_025eeb80fc613726b697b8fc5260c3cc.pdfEPB shield tunneling machineextensometerheading confinement pressurenumerical modeling settlements |
| spellingShingle | Amir Hossein Haghi Mohammad Reza Asef Ali Taheri Mohsen Mohkam Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis International Journal of Mining and Geo-Engineering EPB shield tunneling machine extensometer heading confinement pressure numerical modeling settlements |
| title | Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis |
| title_full | Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis |
| title_fullStr | Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis |
| title_full_unstemmed | Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis |
| title_short | Evaluation of the Heading Confinement Pressure Effect on Ground Settlement for EPBTBM Using Full 3D Numerical Analysis |
| title_sort | evaluation of the heading confinement pressure effect on ground settlement for epbtbm using full 3d numerical analysis |
| topic | EPB shield tunneling machine extensometer heading confinement pressure numerical modeling settlements |
| url | http://ijmge.ut.ac.ir/article_50087_025eeb80fc613726b697b8fc5260c3cc.pdf |
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