Extraction of natural resources such as shale gas can disrupt the internal structure of rock, leading to the release of vast amounts of energy in the form of earthquakes. Is the risk of such human-induced quakes high in Poland? Scientists from the PAS Institute of Geophysics are trying to find the answer.
Messina in the stories of Polish travelers over the course of centuries: the double face of the city – The article presents Messina’s ‘verbal postcards’ left by Polish participants in the Grand Tour and travelers who visited Sicily in later times. Travelers whose accounts are widely known, such as Anonymous (1595), Michał Borch, Julian Ursyn Niemcewicz, Chrystian Kamsetzer (XVIII c.), Zygmunt Krasiński (nineteenth century), but also less well-known ones such as writer Zofia Sokołowska, arriving in Sicily in the tragic year of the earthquake (1908), left descriptions from their stays in Messina about the emotional charge they felt, one closely related to the historical moment in which they arrived on the island. This will therefore be a thorough analysis of a fragment of the Sicilian journey concerning Messina left by some Polish travelers, taking into account their professions, areas of interest and the period in which they were in Sicily.
The article presents a disastrous in the consequences earthquake between Sicily and Calabria described by different travelers of Grand Tour after 1783 and analyses the style and method of commenting these historical, tragic events. Several Polish intellectuals and politicians, disappointed in t he situation in the country had chosen the Southern Italy (Sicily, Calabria) and Malta as Destination of their travel. Who arrived there after the terrible earthquake and observed in Messina and/or Reggio Calabria the ruins of these important towns leaved very emotional description in their travel reports. The purpose of the article is to compare different human reactions as well as different ways of describing, from many points of view, the situations they found and observed.
The paper presents an estimation of liquefaction susceptibility of some soils from the coast of the Marmara Sea, which was heavily
striken by the Kocaeli earthquake in 1999. Firstly, the results of field investigations are summarized. Then, the results of laboratory investigations of physical and mechanical properties of the soils collated from the sites investigated are presented. The mechanical properties relate to the compaction/liquefaction model of saturated soils. This model is briefly outlined, then respective experimental procedures dealing with its calibration described, and values of material parameters listed. Liquefaction potential of investigated soils is analysed using standard procedures, based on the grain size distribution curves and SPTs. Finally, the simulation of pore-pressure generation and onset of liquefaction of Turkish soils is carried out, using the compaction/liquefaction model. Discussion of some standard empirical procedures of estimation of liquefaction potential of saturated soils, conducted from the analytical point of view, is also presented.
Considering concrete nonlinearity, the wave height limit between small and large amplitude sloshing is defined based on the Bernoulli equation. Based on Navier-Stokes equations, the mathematical model of large amplitude sloshing is established for a Concrete Rectangle Liquid-Storage Structure (CRLSS). The results show that the seismic response of a CRLSS increases with the increase of seismic intensity. Under different seismic fortification intensities, the change in trend of wave height, wallboard displacement, and stress are the same, but the amplitudes are not. The areas of stress concentration appear mainly at the connections between the wallboards, and the connections between the wallboard and the bottom.
Several recent earthquakes have indicated that the design and construction of bridges based on former seismic design provisions are susceptible to fatal collapse triggered by the failure of reinforced concrete columns. This paper incorporates an experimental investigation into the seismic response of nonductile bridge piers strengthened with low-cost glass fiber reinforced polymers (LC-GFRP). Three full-scale bridge piers were tested under lateral cyclic loading. A control bridge pier was tested in the as-built condition and the other two bridge piers were experimentally tested after strengthening them with LC-GFRP jacketing. The LC-GFRP strengthening was performed using two different configurations. The control bridge pier showed poor seismic response with the progress of significant cracks at very low drift levels. Test results indicated the efficiency of the tested strengthening configurations to improve the performance of the strengthened bridge piers including crack pattern, yield, and ultimate cyclic load capacities, ductility ratio, dissipated energy capacity, initial stiffness degradation, and fracture mode.
The growth in high-rise building construction has increased the need for hybrid reinforced concrete and steel structural systems. Columns in buildings are the most important elements because of their seismic resistance. Reinforced concrete (RC) columns and steel columns were used herein to form hybrid structural systems combining their distinct advantages. Eleven 3D building models subjected to earthquake excitation with reinforced concrete beams and slabs of 12 floors in height and with different distributions of mixed columns were analyzed by the SAP2000 software in order to investigate the most suitable distributions of a combination of reinforced concrete and steel columns. Top displacements and accelerations, base normal forces, base shear forces, and base bending moments were computed to evaluate the selected hybrid structural systems. The findings are helpful in evaluating the efficiency of the examined hybrid high-rise buildings in resisting earthquakes.