http://localhost:8081/jspui/handle/123456789/113 Fri, 29 May 2026 20:56:46 GMT 2026-05-29T20:56:46Z http://localhost:8081/jspui/handle/123456789/21105 Title: Time-Frequency Analysis Of Accelerogram Authors: Maitra, Satyajit Abstract: In signal processing, time-frequency analysis consists of studying a signal in time and frequency domains simultaneously. Rather than viewing a 1-dimensional signal (a function, real or complex-valued, whose domain is the real line) and some transform (another function whose domain is the real line, obtained from the original via some transform), time-frequency analysis studies a two-dimensional signal– a function whose domain is the two-dimensional real plane, obtained from the signal via a time-frequency transform. These high-level representations such as time-frequency maps convey a wealth of useful information, but they involve a large number of parameters that make statistical investigations of many signals difficult at present. In this paper, we will describe a method that performs a drastic reduction in the complexity of time-frequency representations through modeling of the maps by elementary functions, Artificial Intelligence, and Machine learning. The method is validated on artificial signals and subsequently applied to signals recorded at original stations. We will show different methods of doing Time-frequency analysis using techniques like FFT(Fast Fourier Transform), wavelet methods, and how by applying Artificial neural networks, deep learning can significantly reduce the complexity of time-frequency analysis with more return in result. We will try to validate the advanced technological improvement in this field to show the potential and promise of technology in this area. Tue, 01 Jun 2021 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21105 2021-06-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21104 Title: Risk Targeted Seismic Design of RC Frame Buildings Authors: Singh, Devendra Abstract: The Design criteria specified in Seismic codes implicitly explains the performance objectives and non-linear response of buildings through response. The Response reduction factor is used to reduce the design forces in structure to incorporate non-linear behaviour and capacity in post yield region. The focus of present study is to determine values of performance factors and compare these values with the suggested values from different seismic codes. Risk targeted seismic design utilizes the probabilistic framework to acquire risk levels within the desired limits iteratively. The methodology of probabilistic framework to quantify the seismic performance factor of RC moment-resisting frame is adopted. The non-linear analyses are performed using 22 ground motion sets on 3 RC frame buildings located in seismic zone IV of IS 1893 (2016). The detailed modelling of low and mid-rise buildings is done as per the Indian seismic standards. Validation of analytical modelling at member and global response level are carried out to eliminate propagation of modelling errors in the total uncertainty. The effects of timer period on available response reduction factor, conditional probability of collapse and the annual rate of collapse exceedance have been studied. It has been found that designing RC moment-resisting frame building for the higher time period does not reduce available response reduction neither increases the annual rate of collapse exceedance when other codal provisions, such as capacity design, and Strong column weak beam are followed. Tue, 01 Jun 2021 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21104 2021-06-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21103 Title: Seismic Evaluation of Existing Buildings Authors: Thakuria, Alakesh Abstract: Open ground storey buildings are commonly provided in India since they provide much-needed parking space in an urban environment. These buildings are observed to be the most vulnerable type of vertically irregular buildings. NCT Delhi has been chosen as the area of study due to availability of microzonation study. Most of the buildings in Delhi are open ground storey. The Model Building Bye-Laws 2016 of Delhi direct plot owners to accommodate all vehicles inside the plot area in order to avoid traffic congestion on the road. FAR norms are relaxed for buildings with stilt parking. So owners opt for it. Again some buildings are designed for only gravity loads. Delhi lies in Seismic Zone IV of the Seismic Zoning Map of India. But as per microzonation study conducted, different parts are assigned different zones from III, IV, V based on their PGA values. Few sites have even more PGA than that assigned to zone V. Delhi lies in a region liable to moderate damages. Earthquake occurring in Himalayas also affect Delhi. The project aims to find the vulnerability of various types of buildings with different storeys, bays, etc. in various parts of Delhi. Vulnerability assessment of two G+4 storied buildings having different plan dimensions, both located in Wazirabad, have been taken up. Fragility curve of the buildings are obtained using Incremental Dynamic Analysis. Hazard curve is plotted for the selected site in Delhi. Collapse risk is estimated for the buildings by convoluting fragility curves and site specific hazard curve. Tue, 01 Jun 2021 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21103 2021-06-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/21102 Title: SEISMIC RETROFITTING OF EXISTING REINFORCED CONCRETE STRUCTURES Authors: Gupta, Srajan Abstract: For a long time, structural deficiency has been one of the major issues in the construction areas. Even the newly built structures show seismic deficiency due to negligence of various factors and guidelines laid down by the Governing bodies. The structures already built might have become deficient according to the latest versions of the codes or the codes and detailing might not have been considered from seismic point of view. According to a census conducted by NDMA, 65-70 percent of the structures in India were either constructed before the latest versions of the code or have not been built earthquake resistant. A complete demolition and reconstruction of those structures is very uneconomical and thus the need of retrofitting arises. The structures may have become vulnerable due to many reasons which need to be overcome by several techniques. In our particular case, the building considered is the newly constructed building located in city and built by masons using the old thumb rules. The building can withstand gravity loads but is seismically deficient. The retrofitting techniques include the use of infill panels, shear walls, steel bracings, concrete and steel jacketing and energy dissipation methods. The comparison of the seismic demand according to the various editions of IS 1893:part 1 shows the increase in the demand along with the upgradation of the codes. Various seismic retrofitting techniques have different efficiencies based on the soil type and the height of the building. Higher buildings respond well to the tubular tension ties than the X-Bracings, soil type being the same. The efficiency of a particular retrofitting scheme, for instance, the use of steel bracings at a beam-column joint also depends on the type or model of the joint. Connections of the retrofitting scheme to the element being retrofitted are of utmost importance. The anchor bolts, for instance, show less strength if a higher tensile force is in play. This report is focused on the connections between steel and concrete using the anchor bolts. The types of anchor bolts also play a significant role in the performance under cyclic loading, on the basis of failure during high cycle fatigue or low cycle fatigue. Till date, we experience that the buildings frames retrofitted with shear walls show better performance than the buildings frames ii retrofitted with the bracings. For columns, reinforced concrete jacketing shows good results. A detailed study and review of the various retrofitting schemes for Reinforced concrete structures are present in the report. A detailed analysis of behaviour of steel X-Bracings in Open Ground Storey buildings is included in this report. Various retrofitting schemes which are essential for sustaining the older, vulnerable reinforced concrete structures are also considered. The report includes application of Shear walls and inverted-V bracings. Tue, 01 Jun 2021 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21102 2021-06-01T00:00:00Z