Initiation of earthquake-induced slope failure:influence of topographical and other site specific amplification effects[J]

• Published in: Journal of seismology Vol. 7; no. 3; pp. 397 - 412
• Main Authors: Havenith, H.-B., Vanini, M., Jongmans, D., Faccioli, E.
• Format: Journal Article Web Resource
• Language: English
• Published: Dordrecht Springer 01.07.2003; Springer Nature B.V; Kluwer Academic Publ
• Subjects: 3D topography; Earth sciences; Earth sciences & physical geography; Earth, ocean, space; Earthquakes; Earthquakes, seismology; Engineering and environment geology. Geothermics; Exact sciences and technology; Ground motion; Internal geophysics; Kemin earthquake; Landslides; Marine and continental quaternary; Natural hazards: prediction, damages, etc; numerical modeling; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; Rocks; Sciences de la terre & géographie physique; Seismic activity; Seismology; site effects; slope failure; Surficial geology; Tien Shan; Far East; China; strain; damage; topography; digital simulation; case studies; ground motion; finite element analysis; earthquakes; wave amplification; bedrock; Asia; fabric; numerical models; rockslides; landslides; three-dimensional models; fault zones; scarps; site effects; seismograms
• ISSN: 1383-4649; 1573-157X; 1573-157X
• DOI: 10.1023/A:1024534105559

Increased structural damage caused byearthquakes on hilltops and along ridgeshas often been related to amplification ofground motion due to the presence oftopography. However, comparison betweenobservations and numerical modeling hasshown that amplification is only partlydependent on the prominent surfacemorphology. Strong effects are also inducedby soft layers, such as weathered rockmaterial or colluvium, covering thetopographies.Numerous seismically triggered landslidesare reported to occur in the same materialsthat are likely to amplify ground motions.Therefore, it can be suspected that groundmotion dynamics significantly contribute tothe observed slopes failures. Thispotential relationship is the subject ofthe present case study, the Ananevorockslide in the northeastern Tien Shanmountains. The survey included geophysicalprospecting, earthquake recordings andstructural analyses of the rock fabric. Onthe basis of the field data, observedamplification effects could be related tothe local geological conditions andparticularly to the surface morphology andto the presence of low-velocity layers -deeply weathered rocks - on the top of thebedrock. Surface layer- andtopography-dependent amplification has alsobeen studied numerically by 2D and 3Dfinite element modeling of ground motiondynamics. The present paper focuses onadditional effects that may be induced bythe presence of a fault zone and of thelandslide scarp. Further, observed andcomputed ground motion dynamics areconnected with slope failuresusceptibility: 2D numerical simulationsreveal that strain localization is closelyrelated to wave amplification in surficiallow-velocity layers, particularly belowconvex surface morphologies.[PUBLICATION ABSTRACT]