三点激振下人工地震增油技术试验研究     

于海力 《地震工程与工程振动》2005,25(5):177-180

本文介绍一种新的现场试验方式：三点激振，研究了在不同类型起振机、不同形状振动基础条件下的人工地震增油技术，观察了增油效果。  相似文献   

几种辅助设备在强震仪中的应用     

高峰魏继武  杨立志 《地震工程与工程振动》2005,25(5):181-185

本文介绍了GPS、eMODEM、DE-211串口设备服务器等辅助设备在GDQJ-2型固态地震动强度记录仪中的应用，包括各自的功能、作用、实现方法以及和强震仪的接口。  相似文献   

Simulations of strong ground motion in SW Iberia for the 1969 February 28 (M_s= 8.0) and the 1755 November 1 (M∼ 8.5) earthquakes – II. Strong ground motion simulations     

Raphaël Grandin  José Fernando Borges  Mourad Bezzeghoud  Bento Caldeira  Fernando Carrilho 《Geophysical Journal International》2007,171(2):807-822

This is the second paper of a series of two concerning strong ground motion in SW Iberia due to earthquakes originating from the adjacent Atlantic area. The aim of this paper is to use the velocity model that was proposed and validated in the companion paper for seismic intensity modelling of the 1969 ( M _s= 8.0) and 1755 ( M = 8.5–8.7) earthquakes.
First, we propose a regression to convert simulated values of Peak Ground Velocity (PGV) into Modified Mercalli Intensity (MMI) in SW Iberia, and using this regression, we build synthetic isoseismal maps for a large ( M _s= 8.0) earthquake that occurred in 1969. Based on information on the seismic source provided by various authors, we show that the velocity model effectively reproduces macroseismic observations in the whole region. We also confirm that seismic intensity distribution is very sensitive to a small number of source parameters: rupture directivity, fault strike and fault dimensions. Then, we extrapolate the method to the case of the great ( M = 8.5–8.7) 1755 earthquake, for a series of hypotheses recently proposed by three authors about the location of the epicentral region. The model involving a subduction-related rupture in the Gulf of Cádiz results in excessive ground motion in northern Morocco, suggesting that the source of the 1755 earthquake should be located further west. A rupture along the western coast of Portugal, compatible with an activation of the passive western Iberian margin, would imply a relatively low average slip, which, alone, would could not account for the large tsunami observed in the whole northern Atlantic ocean. A seismic source located below the Gorringe Bank seems the most likely since it is more efficient in reproducing the distribution of high intensities in SW Iberia due to the 1755 earthquake.  相似文献   

Geodetic data inversion based on Bayesian formulation with direct and indirect prior information     

Mitsuhiro Matsu'ura  Akemi Noda  Yukitoshi Fukahata 《Geophysical Journal International》2007,171(3):1342-1351

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Spatial variability and non-linearity of strong ground motion near a fault     

Hayrullah Karabulut  Michel Bouchon 《Geophysical Journal International》2007,170(1):262-274

We present observations of ground accelerations recorded at a small array close to the fault during the Düzce earthquake and its early aftershocks. The records show the strong spatial variability of ground acceleration over distances of only a few hundred metres. During the main shock, the peak horizontal acceleration values ranged from 0.3 to about 1.0 g at stations distant of 1.5 km only. We attribute this spatial variability to a fault zone site effect as peak ground acceleration steadily increases as the distance to the fault trace decreases. The spectral ratio between the ground motion recorded near the fault and the one outside the fault zone shows a shift of the spectral peak to lower frequencies with increasing peak accelerations. Such an observation suggests a non-linear behaviour of the fault zone due to the strong ground shaking. As much as a 45 per cent reduction in the shear wave velocity is necessary for the observed shifts. The opening of pre-existing cracks throughout the fault zone is the proposed mechanism to account for the observed shear wave reductions. The observation that elastic fault zone properties are soon recovered following episodes of large strains shows that cracks and fissures close rapidly after the strong shaking is over.  相似文献   

Seismic hazard on the French Riviera: observations, interpretations and simulations     

F. Courboulex  C. Larroque  A. Deschamps  C. Kohrs-Sansorny  C. Gélis  J. L. Got  J. Charreau  J. F. Stéphan  N. Béthoux  J. Virieux  D. Brunel  C. Maron  A. M. Duval  J-L. Perez  P. Mondielli 《Geophysical Journal International》2007,170(1):387-400

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Near-fault strong motion complexity of the 2003 Bam earthquake (Iran) and low-frequency ground motion simulation     

M. R. Ghayamghamian  Y. Hisada 《Geophysical Journal International》2007,170(2):679-686

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Post-seismic motion following the 1997 Manyi (Tibet) earthquake: InSAR observations and modelling   总被引：2，自引：0，他引：2  

Isabelle Ryder  Barry Parsons  Tim J. Wright  Gareth J. Funning 《Geophysical Journal International》2007,169(3):1009-1027

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Ground motion characterization and seismic hazard assessment in Spain: context,problems and recent developments     

Belén Benito  Jorge M. Gaspar-Escribano 《Journal of Seismology》2007,11(4):433-452

This article points out some particular features conditioning seismic hazard assessments (SHA) in Spain, a region with low–moderate seismicity. Although sized earthquakes occurred in the past, as evidenced by historical documents and neotectonic studies, no large events occurred during the last decades. The absence of strong motion records corresponding to earthquakes with magnitude larger than 5.5 is an important obstacle for the development of ground motion models constrained by local data, with the consequent difficulty in SHA studies. In this paper, some recent developments aiming at providing solutions to these difficulties are presented. Specifically, a strong motion databank containing a massive collection of accelerograms and response spectra from different configurations source-path-site corresponding to earthquakes all over the world is introduced, together with software utilities for its management. A first application of this databank is the development of specific ground motion models for Spain and for the Mediterranean region that predict peak ground accelerations as a function of several definitions of magnitude, distance and soil class. The predictive power of these ground motion models is tested by contrasting their estimates with recently recorded ground motions. The comparison between our ground-motion models with others proposed in the literature for other areas reveals a regular overestimation of the expected ground motions at Spanish sites by the non-local models. Consequently, SHA studies based in external models may overestimate the predicted hazard at the Iberian sites. In the last part of the paper a method for checking whether the response spectra proposed in the Spanish Building Code (NCSE-02) are consistent with actual accelerometric data from recent low magnitude earthquakes is applied. The spectral shapes of the Spanish Building Code NCSE-02 are compared with the response spectral shapes deduced from the available accelerograms by normalising the response spectra with the recorded PGA. It is appreciated that the NCSE-02 spectral shapes are exceeded by a large number of actual spectral shapes for short periods (around 0.2 s), a result to be taken into account in further revisions of the NCSE-02 code. The issues tackled in this work constitute not only an improvement for ground-motion characterisation in Spain, but also provide guidelines of general interest for potential applications in other regions with similar seismicity.  相似文献   

Physics of basic motions in asymmetric continuum     

Roman Teisseyre  Marek Górski 《Acta Geophysica》2007,55(2):119-132

We consider the advantages of a formalism based on concept of the asymmetric continuum and we present some equivalence theorems relating it to the asymmetric elasticity and to micropolar and micromorphic theories as founded by Nowacki, Cosserats and Eringen. We consider the basic processes in an asymmetric continuum which could be reduced to the point basic motions/deformations. The co-action of spin and shear motions is assumed to play the main role in fracturing process, while the constitutive relation between the antisymmetric stresses and rotations replaces the friction constitutive law.  相似文献