Nonlinear response of deep immersed tunnel to strong seismic shaking

Anastasopoulos, I; Gerolymos, N; Drosos, V; Kourkoulis, R; Georgarakos, T

dc.contributor.author	Anastasopoulos, I	en
dc.contributor.author	Gerolymos, N	en
dc.contributor.author	Drosos, V	en
dc.contributor.author	Kourkoulis, R	en
dc.contributor.author	Georgarakos, T	en
dc.date.accessioned	2014-03-01T01:56:20Z
dc.date.available	2014-03-01T01:56:20Z
dc.date.issued	2007	en
dc.identifier.issn	10900241	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/28071
dc.subject	Dynamic analysis	en
dc.subject	Earthquakes	en
dc.subject	Nonlinear response	en
dc.subject	Seismic effects	en
dc.subject	Soil-structure interaction	en
dc.subject	Tunnels	en
dc.subject	Vibration	en
dc.subject.other	Ground excitation	en
dc.subject.other	Immersed tunnels	en
dc.subject.other	Acceleration	en
dc.subject.other	Dynamic analysis	en
dc.subject.other	Seismic design	en
dc.subject.other	Soil structure interactions	en
dc.subject.other	Vibration analysis	en
dc.subject.other	Wave propagation	en
dc.subject.other	Tunnels	en
dc.subject.other	deformation	en
dc.subject.other	dynamic analysis	en
dc.subject.other	ground motion	en
dc.subject.other	peak acceleration	en
dc.subject.other	seismic design	en
dc.subject.other	seismic response	en
dc.subject.other	shaking table test	en
dc.subject.other	soil-structure interaction	en
dc.subject.other	strong motion	en
dc.subject.other	structural response	en
dc.subject.other	tunnel	en
dc.subject.other	tunneling	en
dc.subject.other	vibration	en
dc.subject.other	wave propagation	en
dc.subject.other	analysis	en
dc.subject.other	design	en
dc.subject.other	soil reinforcement	en
dc.subject.other	vibration	en
dc.title	Nonlinear response of deep immersed tunnel to strong seismic shaking	en
heal.type	journalArticle	en
heal.identifier.primary	10.1061/(ASCE)1090-0241(2007)133:9(1067)	en
heal.identifier.secondary	http://dx.doi.org/10.1061/(ASCE)1090-0241(2007)133:9(1067)	en
heal.publicationDate	2007	en
heal.abstract	Critical for the seismic safety of immersed tunnels is the magnitude of deformations developing in the segment joints, as a result of the combined longitudinal and lateral vibrations. Analysis and design against such vibrations is the main focus of this paper, with reference to a proposed 70m-deep immersed tunnel in a highly seismic region, in Greece. The multisegment tunnel is modeled as a beam connected to the ground through properly calibrated interaction springs, dashpots, and sliders. Actual records of significant directivity-affected ground motions, downscaled to 0.24 g peak acceleration, form the basis of the basement excitation. Free-field acceleration time histories are computed from these records through one-dimensional wave propagation equivalent-linear and nonlinear analyses of parametrically different soil profiles along the tunnel; they are then applied as excitation at the support of the springs, with a suitable time lag to conservatively approximate wave passage effects. The joints between the tunnel segments are modeled realistically with special nonlinear hyperelastic elements, while their longitudinal prestressing due to the great (7bar) water pressure is also considered. Nonlinear dynamic transient analysis of the tunnel is performed without ignoring the inertia of the thick-walled tunnel, and the influence of segment length and joint properties is investigated parametrically. It is shown that despite ground excitation with acceleration levels exceeding 0.50 g and velocity of about 80 cm/ s at the base of the tunnel, net tension and excessive compression between the segments can be avoided with a suitable design of joint gaskets and a selection of relatively small segment lengths. Although this research was prompted by the needs of a specific project, the dynamic analysis methods, the proposed design concepts, and many of the conclusions of the study are sufficiently general and may apply in other immersed tunneling projects. © 2007 ASCE.	en
heal.journalName	Journal of Geotechnical and Geoenvironmental Engineering	en
dc.identifier.doi	10.1061/(ASCE)1090-0241(2007)133:9(1067)	en
dc.identifier.volume	133	en
dc.identifier.issue	9	en
dc.identifier.spage	1067	en
dc.identifier.epage	1090	en