The impact of subway tunnels on the seismic response of overlaying structures

Spyrakos, CC; Vasileiou, DN

dc.contributor.author	Spyrakos, CC	en
dc.contributor.author	Vasileiou, DN	en
dc.date.accessioned	2014-03-01T02:53:29Z
dc.date.available	2014-03-01T02:53:29Z
dc.date.issued	2011	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/36361
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-80054825683&partnerID=40&md5=f8c173167a94ddfef4c06250365895ab	en
dc.subject	Earthquake response	en
dc.subject	Metro stations	en
dc.subject	Subway	en
dc.subject	Tunnels	en
dc.subject.other	Accelerograms	en
dc.subject.other	Design spectrum	en
dc.subject.other	Earthquake response	en
dc.subject.other	Finite element software	en
dc.subject.other	Geometrical characteristics	en
dc.subject.other	Geotechnical data	en
dc.subject.other	Ground accelerations	en
dc.subject.other	Making decision	en
dc.subject.other	Metro stations	en
dc.subject.other	Nonlinear soil behavior	en
dc.subject.other	Overlaying soil	en
dc.subject.other	Seismic behavior	en
dc.subject.other	Seismic excitations	en
dc.subject.other	Shallow tunnel	en
dc.subject.other	Soil stratum	en
dc.subject.other	Suburban areas	en
dc.subject.other	Subway tunnels	en
dc.subject.other	Surface ground motion	en
dc.subject.other	Civil engineering	en
dc.subject.other	Computational methods	en
dc.subject.other	Computer software	en
dc.subject.other	Earthquakes	en
dc.subject.other	Engineering geology	en
dc.subject.other	Linear systems	en
dc.subject.other	Mathematical models	en
dc.subject.other	Railroads	en
dc.subject.other	Seismic response	en
dc.subject.other	Soils	en
dc.subject.other	Structural dynamics	en
dc.subject.other	Subway stations	en
dc.subject.other	Underpasses	en
dc.subject.other	Seismic design	en
dc.title	The impact of subway tunnels on the seismic response of overlaying structures	en
heal.type	conferenceItem	en
heal.publicationDate	2011	en
heal.abstract	The seismic response of structures overlaying soil strata has been extensively studied. Also, numerous studies can be found in the literature regarding the deformations imposed on structures during the excavation of tunnels in suburban areas. However, the impact of the presence of a tunnel on the seismic response of overlaying structures has drawn very limited attention. The goal of this study is to examine the considerable influence that the existence of a tunnel has on ground acceleration, as well as to point out the limits of parameters, such as the tunnel depth and the horizontal distance of a structure from the axis of the tunnel, beyond which the difference in ground acceleration cannot be neglected. The corrected accelerograms of the Athens(Greece), Kobe(Japan) and Duzce (Turkey) earthquakes are used in this investigation. The geotechnical data has been drawn from the drillings that took place during the construction of the subway in Athens. For the Athens earthquake two approaches were applied. In the first approach the soil stratum with the tunnel were modeled as a linear system with the finite element software called Plaxis. In the second approach the part of the soil stratum over the bedrock and up to a distance of 2.5 m below the lower part of the tunnel were modeled with software capable to account for nonlinear soil behavior, while the upper part including the tunnel were modeled as a linear system using Plaxis. The second approach is considered as more realistic especially for the latter two seismic excitation cases. The results of this study showed that the presence of the shallow tunnels considerably modify the surface ground motion within a range that depends on their geometrical characteristics. Even though this is a limited study, the results clearly indicate that the phenomenon should be considered when : i) evaluating the anticipated seismic behavior of overlaying structures, ii) deciding on strengthening measures in order to protect structures with inferior strength, iii) specifying the design spectra of new buildings to be constructed in the vicinity of such tunnels and iv) making decisions regarding relocation of a tunnel to be constructed.	en
heal.journalName	ECCOMAS Thematic Conference - COMPDYN 2011: 3rd International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering: An IACM Special Interest Conference, Programme	en