Behaviour of deep immersed tunnel under combined normal fault rupture deformation and subsequent seismic shaking

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

dc.contributor.author	Anastasopoulos, I	en
dc.contributor.author	Gerolymos, N	en
dc.contributor.author	Drosos, V	en
dc.contributor.author	Georgarakos, T	en
dc.contributor.author	Kourkoulis, R	en
dc.contributor.author	Gazetas, G	en
dc.date.accessioned	2014-03-01T01:28:01Z
dc.date.available	2014-03-01T01:28:01Z
dc.date.issued	2008	en
dc.identifier.issn	1570-761X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/18664
dc.subject	Dynamic analysis	en
dc.subject	Earthquake	en
dc.subject	Fault rupture propagation	en
dc.subject	Fault rupture-soil-tunnel interaction	en
dc.subject	Immersed tunnel	en
dc.subject	Soil-structure interaction	en
dc.subject.classification	Engineering, Geological	en
dc.subject.classification	Geosciences, Multidisciplinary	en
dc.subject.other	Deformation	en
dc.subject.other	Dynamic analysis	en
dc.subject.other	Earthquakes	en
dc.subject.other	Finite element method	en
dc.subject.other	Mathematical models	en
dc.subject.other	Fault rupture propagation	en
dc.subject.other	Fault rupture-soil-tunnel interaction	en
dc.subject.other	Immersed tunnel	en
dc.subject.other	Soil-structure interaction	en
dc.subject.other	Tunnels	en
dc.subject.other	deformation	en
dc.subject.other	earthquake	en
dc.subject.other	normal fault	en
dc.subject.other	seismic wave	en
dc.subject.other	soil-structure interaction	en
dc.subject.other	tunnel	en
dc.title	Behaviour of deep immersed tunnel under combined normal fault rupture deformation and subsequent seismic shaking	en
heal.type	journalArticle	en
heal.identifier.primary	10.1007/s10518-007-9055-0	en
heal.identifier.secondary	http://dx.doi.org/10.1007/s10518-007-9055-0	en
heal.language	English	en
heal.publicationDate	2008	en
heal.abstract	Immersed tunnels are particularly sensitive to tensile and compressive deformations such as those imposed by a normal seismogenic fault rupturing underneath, and those generated by the dynamic response due to seismic waves. The paper investigates the response of a future 70 m deep immersed tunnel to the consecutive action of a major normal fault rupturing in an earthquake occurring in the basement rock underneath the tunnel, and a subsequent strong excitation from a different large-magnitude seismic event that may occur years later. Non-linear finite elements model the quasi-static fault rupture propagation through the thick soil deposit overlying the bedrock and the ensuing interaction of the rupture with the immersed tunnel. It is shown that despite imposed bedrock offset of 2 m, net tension or excessive compression between tunnel segments could be avoided with a suitable design of the joint gaskets. Then, the already deformed (""injured"") structure is subjected to strong asynchronous seismic shaking. The thick-walled tunnel is modelled as a 3-D massive flexural beam connected to the soil through properly-calibrated nonlinear interaction springs and dashpots, the supports of which are subjected to the free-field acceleration time histories. The latter, obtained with 1-D wave propagation analysis, are then modified to account for wave passage effects. The joints between tunnel segments are modeled with special non-linear hyper-elastic elements, properly accounting for their 7-bar longitudinal hydrostatic pre-stressing. Sliding is captured with special gap elements. The effect of segment length and joint properties is explored parametrically. A fascinating conclusion emerges in all analysed cases for the joints between segments that were differentially deformed after the quasi-static fault rupture: upon subsequent very strong seismic shaking, overstressed joints de-compress and understressed joints re-compress-a ""healing"" process that leads to a more uniform deformation profile along the tunnel. This is particularly beneficial for the precariously de-compressed joint gaskets. Hence, the safety of the immersed tunnel improves with ""subsequent"" strong seismic shaking! © 2007 Springer Science+Business Media B.V.	en
heal.publisher	SPRINGER	en
heal.journalName	Bulletin of Earthquake Engineering	en
dc.identifier.doi	10.1007/s10518-007-9055-0	en
dc.identifier.isi	ISI:000255031200004	en
dc.identifier.volume	6	en
dc.identifier.issue	2	en
dc.identifier.spage	213	en
dc.identifier.epage	239	en