scholarly journals Overestimation of liquefaction hazard in areas of low to moderate seismicity due to improper characterization of probabilistic seismic loading

2019 ◽  
Vol 116 ◽  
pp. 681-691 ◽  
Author(s):  
Kevin W. Franke ◽  
Bret N. Lingwall ◽  
T. Leslie Youd ◽  
Jenny Blonquist ◽  
Jingwen He Liang
Author(s):  
Zoltán Bán ◽  
Erzsébet Győri ◽  
László Tóth ◽  
Zoltán Gráczer ◽  
András Mahler

The seismicity of Hungary can be considered moderately active, nevertheless contemporary reports from the past approx. 350 years documented surface manifestations of liquefaction occurrences. The last such earthquake was the 1956 Dunaharaszti ground motion, for which the location of two liquefied sites could be identified approx. 60 years after the event. This provided an excellent opportunity to analyze possibly the only accessible liquefied sites in Hungary. Analysis of the two sites included field and laboratory tests allowing the back-calculation of maximum horizontal ground acceleration of the earthquake. This parameter was previously unknown because the closest seismometer saturated during the event. The performed back-analysis using the principles of paleoliquefaction studies was the first of such analyses in the country. In areas with low to moderate seismicity, geotechnical engineers often neglect and overlook liquefaction hazard, however, when it is addressed, the hazard is often overestimated due to improper characterization of the seismic loading and site characterization. To explore this observation more deeply, probabilistic seismic and liquefaction hazard assessment were carried out at the two liquefied sites and it was found that this conclusion is also valid for Hungary, but the degree of conservatism of the pseudo-probabilistic procedures decreases with increasing earthquake return period (lower annual probability of occurrence).


2017 ◽  
Vol 82 ◽  
pp. 223-236 ◽  
Author(s):  
Vicente Mercado ◽  
Waleed El-Sekelly ◽  
Mourad Zeghal ◽  
Tarek Abdoun ◽  
Ricardo Dobry ◽  
...  

2019 ◽  
Vol 817 ◽  
pp. 571-578
Author(s):  
Francesco Monni ◽  
Enrico Quagliarini ◽  
Riccardo di Nisio ◽  
Andrea Benedetti

This paper illustrates the results of the activities of analysis and structural assessment of the Assumption of the Virgin Mary chapel, in Prague. The chapel, an oval-shaped building covered with a dome, was built at the end 16th century and can be considered the last example of renaissance architecture and at the same time the first example of baroque architecture in Prague: it is a significant testimony of the close connection between local artists and their Italian teachers. The building closed to visitors during the last decades for the presence of some structural damages and because severely degraded due to lack of maintenance, was reopened in the 2017 after a notable restoration process. This paper gives attention to the interdisciplinary approach used to diagnosis and structural assessment of the chapel, based on the activities of the “knowledge path,” the subsequent structural analysis and the intervention design. Particular attention was paid to the contribution of the historical review, geometric laser scanner survey and mechanical characterization of the structural materials. All these steps result necessary to identify potential vulnerabilities and to enable the understanding of the effective structural models, also in view of proposing adequate retrofit solutions. A numerical model of the chapel was prepared and calibrated. Finally, the structural assessment for the vertical and seismic loading was performed.


Author(s):  
B. L. Soloff ◽  
T. A. Rado

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.


Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.


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