Seismic Investigation on the Effect of Surface Structures and Twin Tunnel on the Site Response in Urban Areas
Site response has a profound effect on earthquake damages. Seismic interaction of urban tunnels with surface structures could also affect seismic site response. Here, we use FLAC 2D to investigate the interaction of a single tunnel and twin tunnels-surface structures on the site response. Soil stratification and properties are selected based on Line. No 7 of the Tehran subway. The effect of surface structure is considered in two ways: Equivalent surcharge and geometrical modeling of the structure. Comparison of the results shows that consideration of the structure geometry is vital in dynamic analysis and leads to the changes in the magnitude of displacements, accelerations and response spectrum. Therefore it is necessary for the surface structures to be wholly modeled and not just considered as a surcharge in dynamic analysis. The use of twin tunnel also leads to the reduction of dynamic residual settlement.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3299635Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 197
 Kramer, S. L. (1966), “Geotechnical Earthquake Engineering. Prentice Hall”, Upper Saddle River, New Jersey, pp. 254-280.
 Seed H. B., (1975), “Earthquake Effects on Soil-Foundation System”, Foundation Eng. Handbook, Winterkom and Frang, P.P. 700-732.
 Udwadia, F. E. and Trifunac, M. D. (1973), “Ambient Vibration Test of Full Scale Structures,” Proc. of the 5th World Conf. On Earthquake Engineering, Rome, pp.
 Mirhabibi, A. and A. Soroush, “Effects of surface buildings on twin tunneling-induced ground settlements. Tunneling and Underground Space Technology, 2012. 29: p. 40-51.
 Dimmock, P. S., Mair, R. J., 2008. “Effect of building stiffness on tunneling-induced ground movement”. Tunn. Undergr. Space Technol. 23, 438–450.
 Potts, D. and T. Addenbrooke, “A structure's influence on tunneling induced ground movements”. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering, 1997. 125(2): p. 109-125.
 Ghaemi, H. (2017). “Comparison of tunnel stability in soft ground using glass fiber reinforced glass and conventional methods” Master Thesis, Khajeh Nasir Toosi University of Technology.
 Seed, H. Bolton, et al. “Module and Damping Factors for Dynamic Analyses of Cohesionless Soils, “Journal of the Geotechnical Engineering Division, ASCE, Vol. 112, No. GT11, pp. 1016-1032, November 1986.
 Ishihara, K., (1996), “Soil behaviour in earthquake engineering”, Clarendon, Oxford.
 Itasca Consulting Group,inc.(2011), “FLAC2D-Fast Lagrangian Analysis of Continua in 3 Dimensions-User’s Guide”.