Linking of adjacent three-storey buildings for mitigation of structural pounding during earthquakes     

Robert Jankowski  Sayed Mahmoud 《Bulletin of Earthquake Engineering》2016,14(11):3075-3097

The reports after major earthquakes indicate that the earthquake-induced pounding between insufficiently separated buildings may lead to significant damage or even total collapse of structures. An intensive study has recently been carried out on mitigation of pounding hazards so as to minimize the structural damages or prevent collisions at all. The aim of this paper is to investigate the effectiveness of the method when two adjacent three-storey buildings with different (substantially different) dynamic properties are connected at each storey level by link elements (springs, dashpots or viscoelastic elements). The results of the study indicate that connecting the structures by additional link elements can be very beneficial for the lighter and more flexible building. The largest decrease in the response of the structure has been obtained for links with large stiffness or damping values, which stands for the case when two buildings are fully connected and vibrate in-phase. Moreover, by comparing the effectiveness of different types of link elements, it has been confirmed that the use of viscoelastic elements reduces the peak displacement of the structure at lower stiffness and damping values comparing to the case when spring and dashpot elements are applied alone. On the other hand, the results of the study demonstrate that applying the additional link elements does not really change the response of the heavier and stiffer building. The final conclusion of the study indicates that linking two buildings allows us to reduce the in-between gap size substantially while structural pounding can be still prevented.  相似文献   

Enhanced nonlinear static analysis with the drift pushover procedure for tall buildings     

Farhad Behnamfar  Sayed Mehdi Taherian  Arash Sahraei 《Bulletin of Earthquake Engineering》2016,14(11):3025-3046

In this study a new method for nonlinear static analysis based on the relative displacements of stories is proposed that is able to be implemented in a single stage analysis and considers the effects of an arbitrary number of higher modes. The method is called the extended drift pushover analysis procedure (EDPA). To define the lateral load pattern, values of the relative displacements of stories are calculated using the elastic modal analysis and the modal combination factors introduced. For determining the combination factors, six different approaches are examined. Buildings evaluated in this study consist of four special steel moment-resisting frames with 10–30 stories. Responses including relative displacements of stories, story shear forces and rotation of plastic hinges in each story are calculated using the proposed approaches in addition to modal pushover analysis and nonlinear dynamic time history analyses. The nonlinear dynamic analysis is implemented using ten consistent earthquake records that have been scaled with regard to ASCE7-10. Distribution of response errors of story shears and plastic hinge rotations show that a major part of error corresponds to the second half of the buildings studied. Thus, the mentioned responses are corrected systematically. The final results of this study show that implementing the EDPA procedure using the third approach of this research is able to effectively overcome the limitations of both the traditional and the modal pushover analyses methods and predict the seismic demands of tall buildings with good accuracy.  相似文献   

Shear wave velocity prediction using seismic attributes and well log data   总被引：3，自引：1，他引：2  

Raoof Gholami  Ali Moradzadeh  Vamegh Rasouli  Javid Hanachi 《Acta Geophysica》2014,62(4):818-848

Formation’s properties can be estimated indirectly using joint analysis of compressional and shear wave velocities. Shear wave data is not usually acquired during well logging, which is most likely for cost saving purposes. Even if shear data is available, the logging programs provide only sparsely sampled one-dimensional measurements: this information is inadequate to estimate reservoir rock properties. Thus, if the shear wave data can be obtained using seismic methods, the results can be used across the field to estimate reservoir properties. The aim of this paper is to use seismic attributes for prediction of shear wave velocity in a field located in southern part of Iran. Independent component analysis (ICA) was used to select the most relevant attributes to shear velocity data. Considering the nonlinear relationship between seismic attributes and shear wave velocity, multi-layer feed forward neural network was used for prediction of shear wave velocity and promising results were presented.  相似文献   

Conceptual hydrosalinity model for prediction of salt load from wastewater flows into soil and ground water   总被引：1，自引：1，他引：0  

M. Abbaspour  S. A. Mirbagheri  M. Monavvari  A. H. Javid  H. Zarei 《International Journal of Environmental Science and Technology》2009,6(3):359-368

Dynamic hydrosalinity models are available, but are not used extensively on a large scale soil which receives wastewater from industrial areas, partly because adequate database are expensive to be obtained. Thus, for this reason, there is an urgent need to assess the salt and other pollutant loads collected in wastewater flows into the soil and/ or ground water systems. A conceptual hydrosalinity model was used on two major underlying principals of mass balance and steady state. This model was initially tested on the 4,117 km² plains west of the Yazd-Ardakan district in the central part of Iran. This model was used at a time when the soil and ground water salinity problem was serious due to the high shortage of water. It was possible to calibrate the model with ± 2 % of the flow volume and total dissolved solids of the industrial wastewater discharge from over 2,000 factories. The verification results were 98 % of the measured values. Moreover, this model was tested for the verification of the model data from the analysis of 36 wells’ water in the area where industrial wastewater discharge was used. The results showed that most of the indices of total dissolved solids, total suspended solids, biological oxygen demand and chemical oxygen demand are above standard levels. The results of the model can be used for the management practice of the reduction of salt pollutant load in the area to achieve sustainable development for location of industries in the study area.  相似文献   

Region-specific deterministic and probabilistic seismic hazard analysis of Kanpur city     

Anbazhagan P  Ketan Bajaj  Nairwita Dutta  Sayed S R Moustafa  Nassir S N Al-Arifi 《Journal of Earth System Science》2017,126(1):12

A seismic hazard map of Kanpur city has been developed considering the region-specific seismotectonic parameters within a 500-km radius by deterministic and probabilistic approaches. The maximum probable earthquake magnitude (M _max) for each seismic source has been estimated by considering the regional rupture characteristics method and has been compared with the maximum magnitude observed \(\left ({M_{\max }^{\text {obs}}}\right )\), \(M_{\max }^{\text {obs}} +0.5\) and Kijko method. The best suitable ground motion prediction equations (GMPE) were selected from 27 applicable GMPEs based on the ‘efficacy test’. Furthermore, different weight factors were assigned to different M _max values and the selected GMPE to calculate the final hazard value. Peak ground acceleration and spectral acceleration at 0.2 and 1 s were estimated and mapped for worst-case scenario and 2 and 10% probability of exceedance for 50 years. Peak ground acceleration (PGA) showed a variation from 0.04 to 0.36 g for DSHA, from 0.02 to 0.32 g and 0.092 to 0.1525 g for 2 and 10% probability in 50 years, respectively. A normalised site-specific design spectrum has been developed considering three vulnerable sources based on deaggregation at the city center and the results are compared with the recent 2011 Sikkim and 2015 Nepal earthquakes, and the Indian seismic code IS 1893.  相似文献   

The influence of preform on the modes of vibrating beams     

James M. Kelly  Jerome L. Sackman  Ahmad Javid 《地震工程与结构动力学》1991,20(12):1145-1157

A theoretical analysis is presented of a vibratory system in which it is possible to eliminate an unwanted mode of vibration by using that mode as an initial deformation of the system. The analysis shows that this is possible in straight beams with end restraints in axial deformation. The mathematical problem leads to an eigenvalue problem of a type not normally encountered. In the paper examples are given for the changes in eigenfrequency and mode shape produced by the initial preformed shape of the beam for cases where the preform is proportional to a mode of the straight beam and when the preform is unrelated to any mode. The analysis shows that, while elimination of a mode in the strict sense is not achieved, the results can be interpreted for practical purposes in this way.  相似文献   

Der Geologische Aufbau der Umgebung von Palmyra in Syrien     

Ulrich Jux  Sayed M. Omara 《International Journal of Earth Sciences》1960,49(2):467-486

Zusammenfassung Das Gebiet um Palmyra (Syrien) wird stratigraphisch und tektonisch beschrieben. Das Profil reicht von Anhydriten und Gipsen des Präcenomans über cenomaneExogyra- Mergel bis zu den Neogenschottern, die eozäne Nummulitenkalke überlagern. Strukturell bestimmend sind die turonischen Schloßberg-Dolomite. Sie bilden die Flanken von zwei großen Sattelzügen (J. Qalaat Tourk und Râss el Manntâr), deren Achsen an einer querenden E–W Linie abtauchen. Im Kern dieser Sättel sind salinare Gesteine mobilisiert worden, die im kartierten Gebiet von wesentlicher Bedeutung für das spezielle tektonische Bild und die örtliche Hydrologie sind. Die allgemeinen geologischen Erscheinungen werden erörtert und mit dem generellen Bild der Palmyraketten in Beziehung gebracht.  相似文献   

Germanium in meteorites     

Sayed A. Wardani 《Geochimica et cosmochimica acta》1956,10(5-6):321-322

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Programmable Hand Calculator Programs for Pumping Test Analyses by Least Squares' Method Using Jacob's Modification of Theis' Equation     

Shabbir A. S. Sayed 《Ground water》1982,20(2):156-161

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Isotopic composition of some egyptian galena by thermal emission mass spectrometry     

Sayed B. El Kholy  Ezzat T. M. Selim 《Pure and Applied Geophysics》1971,87(1):192-202

Summary The present paper contains some lead isotope analyses on galena specimens occuring in the central part of the Eastern Desert of Egypt. Thermal emission mass spectrometric technique is applied to these analyses. Recent methods of calculations for galena dating are used in determining the geochronological significance of the data. The lead isotopic composition of the samples has revealed the possible existence of two orogenic events accompanied with metallization that took place about 1000 m.y. and 600 m.y. ago.  相似文献