SOIL-STRUCTURE AND SOIL-STRUCTURE-SOIL INTERACTION: EXPERIMENTAL EVIDENCE AT THE VOLVI TEST SITE

This paper shows the results of two passive experiments carried out at the European Volvi test site where a scaled building has been constructed. The first experiment was performed to study the motion of the structure excited by two small earthquakes. For one month, six strong-motion recorders were installed within the structure, at the top and at the basement. The analysis of the deformation of the structure has been assessed by computing the spectral ratio between the top and the bottom, with a special focus on soil-structure interaction. An analytical model was then proposed to reproduce the structure and soil-structure system behaviour. The soil-structure interaction was accounted for by using impedance functions. During the second experiment, we concentrated our efforts on the effect of the building vibration on the surface ground motion. An explosive shot was fired and several strong-motion recorders were installed on the ground close to the structure that allowed us to clearly identify a monochromatic wave coming from the building, in the time and frequency domains. This experiment allows us to demonstrate the non-negligible effect of the soil-structure-soil interaction that may disturb the surrounding ground motion.     

ATTENUATION RELATION FOR WEST EURASIA DETERMINED WITH RECENT NEAR-FAULT RECORDS FROM CALIFORNIA,JAPAN AND TURKEY

Strong ground motion close to a fault can be expected to be very large, so its estimation is essential for human safetv. Although a few strong-motion data exist for the west Eurasian region, we proposed in a previous work [Berge-Thierry et al., 2003] an attenuation relation for spectral acceleration using strong-motion data recorded in west Eurasia (mainly in Europe) and some in the western United States: this relationship was derived for the French Safety Rule, which is applied for seismic hazard assessment at nuclear power plants. In this study, we propose a constraining of the amplitude saturation term related to the proximity of the fault, and an adding of an amplitude saturation term in the regression model. We add, to the data-set previously used to derive the west Eurasian attenuation relationship strong-motions recorded during recent large earth-quakes: the 1995 Hyogo-ken Nanbu (Kobe) event in Japan and the 1999 Kocaeli (Izmit) event in Turkey. The regression analysis, adopted from Fukushima and Tanaka [1990], is non-linear, so an iterative procedure is applied. The determined regression coefficients lead to a prediction of a peak ground acceleration of about 0.7 g for soil site conditions at a fault distance of 0.5 km. The Q coefficient deduced, from the distance coefficient is in agreement with scattering Q models. The introduction of the saturation term leads to significantly lower predictions of average spectral accelerations at short distances as compared with using the Berge-Thierry et al. [2003] empirical model.     

Jeux D’échelles. Une Histoire Internationale

The book Jeux d’échelles. La microanalyse à l’expérience, which appeard in 1996 under the direction of Jacques Revel, was translated in Italy in 2006 by the Viella editions under the title Giochi di scala. La microstoria alla prova dell’esperienza. This occasion seemed propicious for a historiographic and epistemological return to the microhistorical experience between France and Italy. It had to do with cross reperencing the reflections of a french historian and those of an italian philosopher to seek to place in evidence, from a distance, the theoretical presuppositions of microhistory, and to measure the displacements undergone.     

Présentation

Sans résumé Président du Comité d'organisation du colloquePensée et science, ancien professeur invité de l'EPF, Lausanne.     

Le territoire englouti de Mologa

The fate of the people of Mologa, a provincial village in central Russia, was forever marked by two consequences stemming directly from a single major event when the Rybinsk dam went into service in 1941. Not only did the waters of the lake it created cover their homes, but ene entire population was displaced as well. From then on, the inhabitants' new-found mobility was assimilated to the attachment to their territory, which on a symbolic level constituted their collective identity. In this sense, their forced displacement was incorporated into a culture of mobility: based on the spatial overlaying of individual and collective identities, it expressed its true dynamic nature in the principle of a potential return. The case of the community of Mologa is in many ways emblematic of the Soviet redistribution of populations; the bond between identities (personal, familial, or collective) and a territory seems to have been constructed in such a way that the displacement, rather than putting this bond into jeopardy, established or activated it. It did this by stimulating a living relationship within the spatial dimension. This dialectical movement between distance and return contributed to the formation and the preservation of a communal identity taking the form of mobility.     

Functional specialization across space: a case study of the Canadian Electricity Industry, 1971–2001

This article examines the location of functions within the electricity sector in Canada from 1971 to 2001, using a centre‐periphery model. Power generation, distribution and retailing are generally carried out by multiestablishment crown corporations. Location patterns of different functions—management, scientific, production, etc.—are analyzed via the use of occupational groups. The spatial distribution of functions is found to be generally consistent with centre‐periphery relationships, with evidence of a growing functional specialization between large metropolitan and nonmetropolitan locations. However, differences emerge depending on power generation sources: fossil fuels, hydro, nuclear, solar or biomass. The choice of a power generation source has consequences for local economies.