148 O.F. Usluogullari et al. 15.5 Conclusion In this case study the excavation induced lateral deformations and vertical movements were investigated during the construction of a cut and cover tunnel in the Capital City of Turkey, Ankara. This study focused on, comparison of predicted and measured results of lateral deformation of piles and effects of seismic loads developed by an earthquake. Based on the results of the excavation case study and numerical finite element analysis following conclusions can be advanced: 1. In the Mecidiye-Belediye part of Ankara metro the excavation induced settlements at soil near to adjacent buildings and at top of piles and maximum lateral deformations were at 1.5 mm, 2.0mmand 11.0 mm levels, relatively. This relatively less numbers were assumed to be the result of having a stiff soil and using secant piles which makes the piles behaves similar to a diaphragm wall. 2. The predicted lateral deformations and vertical movements show similar patterns with measured results. 3. Performed seismic analysis comparing to static analysis the support system presented in this study, shows that in seismic loading maximum lateral deformation increase approximately three times when the seismic load applied in the direction of excavation. 4. The ratio between lateral deformations and settlements were around 8–10, which indicates that lateral deformations are major concern at excavation induced movements. 5. Having a database about tunnel excavations in Turkey is a neglected issue, this work aims to be a sample for future studies in this area. References 1. Finno RJ, Atmatzidis DK, Perkins SB (1989) Observed performance of a deep excavation in clay. J Geotech Eng 115(8):1045–1064 2. Tan Y, Li MW (2011) Measured performance of a 26 m deep topdown excavation in downtown Shanghai. Can Geotech J 48(5):704–719 3. Ou CY, Chiou DC (1993) Three-dimensional finite element analysis of deep excavation. In: Proceedings of 11th Southeast Asia geotechnical conference, Institution of Engineers Malaysia, Kuala Lumpur, pp 769–774 4. Wong IH, Poh TY, Chuah HL (1997) Performance of excavations for depressed expressway in Singapore. J Geotech Geoenviron Eng 123(7):617–625 5. Ou CY, Liao JT, Lin HD (1998) Performance of diaphragm wall constructed using the top-down method. J Geotech Geoenviron Eng 124(9):798–808 6. Finno RJ, Harahap IS (1991) Finite element analyses of HDR-4 excavation. J Geotech Eng 117(10):1590–1609 7. Whittle AJ, Hashash YMA, Whitman RV (1993) Analysis of deep excavation in Boston. J Geotech Eng 119(1):69–90 8. Kung GTC (2009) Comparison of excavation-induced wall deflection using top-down and bottom-up construction methods in Taipei silty clay. Comput Geotech 36:373–385 9. Ou CY, Chiou DC, Wu TS (1996) Three-dimensional finite element analysis of deep excavation. J Geotech Geoenviron Eng 122(5):337–345 10. Wang X, Zhao DS, Xu ML (2012) Numerical study on the effect of twin-tube shield excavation on adjacent pipe-lines. Appl Mech Mater 170:1491–1496 11. Sharma S, Judd WR (1991) Underground opening damage from earthquakes. Eng Geol 30(263):276 12. Power MS, Rosidi D, Kaneshiro JY (1998) Seismic vulnerability of tunnels and underground structures revisited. In: Proceedings of North American tunneling ’98, Balkema Rotterdam, Newport Beach, pp 243–250 13. Kaneshiro JY, Power M, Rosidi D (2000) Empirical correlations of tunnel performance during earthquakes and aseismic aspects of tunnel design. In: Proceedings of the conference on lessons learned from recent earthquakes on earthquakes in Turkey 1999, 8 Nov 2011 14. Dao TPT (2011) Validation of PLAXIS embedded piles for lateral loading. Master of science thesis, Delft University of Technology, The Netherlands
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