Vulnerability of RC Shear wall Structures under Near Field Seismic Loading

Khalil, Mostafa; Ghanem, Mostafa

dc.contributor.author	Khalil, Mostafa	en
dc.contributor.author	Ghanem, Mostafa	en
dc.date.accessioned	2018-04-30T10:26:28Z
dc.date.available	2018-04-30T10:26:28Z
dc.date.issued	2018-04-30
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/46909
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.8008
dc.description	Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Δομοστατικός Σχεδιασμός και Ανάλυση των Κατασκευών”	el
dc.rights	Αναφορά Δημιουργού 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by/3.0/gr/	*
dc.subject	Earthquake Engineering	en
dc.subject	Near Fault	en
dc.subject	Structural Engineering	en
dc.subject	Chile Code Provisions	en
dc.subject	Seismic	en
dc.title	Vulnerability of RC Shear wall Structures under Near Field Seismic Loading	en
heal.type	masterThesis
heal.generalDescription	Near-field ground motions have caused much damage in the vicinity of seismic sources during recent earthquakes. It is found that ground shaking near a fault rupture is characterized by a short-duration impulsive motion which is clearly obvious in the velocity time history record. This impulsive motion exposes the structure to high input energy at the beginning of the record unlike what happens in ground shakings far from the fault rupture. In the near-fault region, which is usually assumed to extend about 20 to 60 km from the seismic source, the short travel distance of the seismic waves does not allow enough time for the high frequency content to be damped out of the record as is normally observed in far field records. The effect of this pulse type motion on the response is important in the design of structures for near-fault events. This phenomenon requires consideration in the design process for structures that are located in the near-field region, unfortunately the seismic design codes are based on “far-fault” ground motion data only without taking into consideration the characteristics of the near fault ground motion therefore the design of structures for near-fault events is inappropriate according to the seismic design code provisions, except for the American seismic design code”ASCE” which recently this phenomenon is taken into consideration. In this study the effect of near-fault ground motions are investigated, along with other seismological parameters such as earthquake magnitude and distance from the fault, to evaluate the seismic response of an eight-story RC combined structural system building (MRF and Shear walls), and perform a damage assessment for that building under certain earthquake events. Furthermore, suggesting appropriate solution to mitigate the damage reached in practically applicable and economic approach. Using Seismostruct software, a static non-linear pushover analysis is performed, in order to calculate the yield acceleration of the building (ay) which is used later in picking up the suitable ground motion records expected to cause considerable damage. Subsequently, a nonlinear inelastic dynamic time history analysis is performed, using a sample of 16 near fault ground motion records from Aquila and Norcia earthquakes in Italy, to obtain the displacement time history of each record, which will be used to determine the damage limit states achieved according to “T. Rossetto, A. ElNashai” vulnerability relationships. This thesis consists of seven chapters, the first chapter is an introduction to the procedures used in the thesis, and a summary for each chapter.parameters is discussed with mentioning the difference between near and far fault, followed by the pulse characteristics and its effect on the elastic response spectrum. In Chapter 3, A description of the building, and it’s modelling in Seismostruct are provided, including the building layout, material characteristics, typical reinforcement detailing of the structural elements, applied loads, seismic characteristics, and additionally eigenvalue and pushover analyses are performed. In Chapter 4, a brief description of the ground motion records used, including maps and figures showing the projection of the rupture surface, each station distance from the epicenter, and the criterion of picking up pulse like records (Pulse Indicator). In Chapter 5, a description of the new Chilean seismic code provisions, which are used to mitigate the damage reached is provided, the mitigation is in form of strengthening the building with the required number of shear walls in Y-direction only, and additionally eigenvalue and pushover analyses are performed. In Chapter 6, the results from subjecting the building to the near fault ground motion records are obtained, these results are the maximum top floor displacement that the building undergoes due to a certain ground motion record. The displacement value indicates the structural damage state of the building, the results are illustrated in plots and tabulated forms for each earthquake showing the inter-storey drift (maximum roof displacement/building height) and the corresponding predefined limit damage state. In Chapter 7, the conclusions upon reviewing the results obtained are summed up in the form of figures and tables representing the damage limit states reached by the original and strengthened buildings, and showing the improvement percentage.	en
heal.classification	Structural Engineering	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2018-03-06
heal.abstract	In this paper the seismic risk of an eight storey reinforced concrete building in Athens is investigated. The structure is exposed to a near field ground motions from Italian Aquila and Norcia earthquakes, due to the similarity in the geotectonic environment between Greece and Italy. The purpose of this investigation is to estimate the damage occurred to the building and the effect of the seismological parameters such as, moment magnitude, forward directivity, acceleration time history density and amplitude. As a first step, a sample of 16 near fault ground motion records from Aquila and Norcia earthquakes in Italy is exposed to the building, to obtain the displacement time history of each record, which will be used to determine the damage limit states achieved according to “T. Rossetto, A. ElNashai” vulnerability relationships. Then suggesting a solution to improve the seismic response of the building, and an appropriate solution is found and applied according to the new Chilean seismic code provisions which states that typical buildings include a large number of shear walls, with ratios of wall cross-sectional area to floor plan area of roughly 3% in each principal direction, with light reinforcement. After implementing the Chilean code provisions and investigating the building in Y-direction only, the results have shown a significant improvement in the building response and a reduction in the damage limit states reached for most of the records. After reviewing all the results, it was found that the moment magnitude value isn’t the predominant affecting factor, and the acceleration time history density is more effective in the damage caused by the near field records. Eventually, it is concluded that estimation of damage intensity is mostly affected by the energy contained in the ground motion which is introduced as the “energy flux” index.	en
heal.advisorName	Φραγκιαδάκης, Μιχαλής	el
heal.advisorName	Ταφλαμπάς, Ιωάννης	el
heal.committeeMemberName	Ταφλαμπάς, Ιωάννης	el
heal.committeeMemberName	Φραγκιαδάκης, Μιχαλής	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών. Τομέας Δομοστατικής. Εργαστήριο Αντισεισμικής Τεχνολογίας	el
heal.academicPublisherID	ntua
heal.numberOfPages	118
heal.fullTextAvailability	true