Response Spectrum Analysis Method Research Articles

Seismic vulnerability analysis of hospitals and school buildings considering the Gaussian regression algorithm

This study combines the Gaussian regression algorithm to propose a nonlinear regression model that can be used to evaluate the seismic vulnerability of regional hospitals and school buildings. The failure features and disaster mechanisms of hospital and school buildings affected by the Jishishan (JSS) earthquake on December 18, 2023, and the Wenchuan (WC) earthquake on May 12, 2008, were reported. The samples of 252 damaged buildings (37 hospitals and 215 schools) in Dujiangyan city affected by the Wenchuan earthquake for which the author participated in the survey were collected and counted. Hospitals and school buildings were classified according to the types of reinforced concrete (RC) and masonry structures, and earthquake vulnerability probability matrices for hospital and school building clusters were established considering the actual failure probabilities. A total of 2103,213 acceleration records (from the Wenchuan earthquake) monitored by 12 real stations were selected. Using dynamic time history and response spectrum analysis methods, time history and spectrum curves were generated, considering the influence of different seismic directions. Using the developed Gaussian regression model, vulnerability comparison curves and parameter matrices considering multiple regression algorithms were generated. This paper considers the effects of the construction year and number of floors on the seismic vulnerability of hospital and school buildings. Seismic vulnerability curves and failure probability matrices were generated and established on the basis of actual structural failure probabilities. According to regression and vulnerability surface analysis, the evaluation results of the proposed model are highly consistent with actual field observations.

Seismic Performance Evaluation of Irregular Auditorium Building based on ASCE 41-23

This study discusses the seismic performance evaluation of an irregular auditorium building. The building is an educational facility which has roof span up to 46 meters, column height up to 10 meters, beam span up to 15 meters, cantilever up to 6.50 meters, 2 inclined columns with the angle up to 54.72°, and 1 transfer column with 1 transfer beam. The evaluation process was carried out using Tier 3 method with linear dynamic procedure which consisted of Response Spectrum Analysis (RSA) and Linear Time History Analysis (LTHA) according to ASCE 41-23 using SAP2000 subjected to short (S s ) and long (S ) period of earthquakes. The building is designed to Risk Category IV, which the target performance levels for structural components are Immediate Occupancy (IO) for Basic Safety Earthquake 1 for New Building (BSE-1N) and Life Safety (LS) for Basic Safety Earthquake 2 for New Building (BSE-2N). Even though the building had a torsional strength irregularity, the percentage of components with a Demand-Capacity Ratio value that did not meet the requirements was 9.87% of the total components; hence the linear procedure was assumed to be still applicable. Analyses showed that the average acceptance criteria ratio of the components with the RSA method was lower than with the LTHA method but the percentage of the components with acceptance criteria ratio exceeding 1 using RSA method was higher than using the LTHA method. In addition, the results indicated that the average performance level of the components was IO for BSE-1N and LS for BSE-2N, which both results had met the expected performance level targets. However, the maximum performance level of the components did not meet the IO performance level target for BSE-1N and did not meet the LS performance level target for BSE-2N.

Alternative data evaluation methodology for infrared thermography analogous to the Shock Response Spectrum analysis method

We propose an alternative method for processing infrared thermography (IRT) data based on a thermal 1-layer model. The method is based on the analogy of the Shock Response Spectrum (SRS) analysis for mechanical systems (ISO 18431). A thermal Q-factor, similar to the resonance sharpness (Q-factor) of a mechanical oscillator, is introduced as a parameter for selecting a specific thermal 1-layer model. Two main aspects of this method and corresponding properties have been considered: the strictly model-based treatment of this methodology and an empirical introduction of additional bandpass filters. The method is validated with two practical examples: for a homogeneous polymer sheet with blind holes and an inhomogeneous plate made of carbon fiber reinforced polymer (CFRP) with artificial defects, the capability of defect detection is compared with established methods. The comparison of the results with the commonly used data processing methods of IRT as Pulsed Phase Thermography (PPT) and Modified Differential Absolute Contrast (MDAC) shows equivalent or sometimes improved performance.

Deep learning‐based response spectrum analysis method for building structures

AbstractThe response spectrum method has gained widespread acceptance in practical applications owing to its favorable compromise between accuracy and practical efficiency. The method predicts the peak responses of multi‐degree‐of‐freedom (MDOF) systems by combining modal responses. The Square Root of the Sum of Squares (SRSS) and Complete Quadratic Combination (CQC) rules are commonly used for modal combinations. However, it has been widely known that these rules have limitations in accurately predicting responses influenced by higher modes and cross‐modal correlations. To improve the accuracy of the response spectrum analysis method for building structures, this paper proposes a Deep learning‐based modal Combination (DC) rule by introducing modal contribution coefficients predicted by a deep neural network (DNN) model. The DC rule enhances prediction accuracy by considering the characteristics of ground motion and the dynamic properties of a structural system. The DC rule provides more accurate predictions than the conventional rules, particularly for irregular response spectra and responses affected by higher modes. The efficiency and applicability of the DC rule are demonstrated by numerical investigations of multistory shear buildings and steel frame structures with regular and irregular shapes. The source codes, data, and trained models are available for download at https://github.com/tyongkim/ERD2.

Response Spectrum Analysis of Adding External Elevators to Existing RC Buildings

In contemporary society, elevators stand as indispensable facilitators, particularly for users in tall buildings, contributing significantly to convenience. Their role becomes even more crucial for individuals with disabilities, serving as a vital means of transport to enable them to partake in modern life. However, a challenge emerges in the form of buildings erected during the 1970s or 1980s, lacking initial designs of elevators. This absence of elevator well designs presents substantial issues for building users, especially residents. However, many of these buildings have not reached the end of their service life. Undertaking removal and reconstruction efforts, while a potential solution, raises serious environmental concerns. The associated carbon dioxide emissions and the environmental impact of such activities underscore the need for alternative, environmentally conscious approaches. In this context, the introduction of external elevator structures to existing buildings emerges as a meaningful and sustainable avenue for researchers to explore. The proposed solution not only addresses the practical challenges faced by residents but also aligns with broader environmental goals, contributing to the reduction of carbon emissions and the preservation of existing building structures. Many researchers emphasize the critical importance of assessing structural performance under seismic loads to ensure safety. This research, centered on a typical educational RC frame structure at Kyungpook National University, employs the RSA (Response Spectrum Analysis) method to comprehensively evaluate seismic performance. This research specifically compares analytical results using RSA for the RC frame with and without the external elevator structure (RCE and RC, respectively).

SEISMIC BEHAVIOR OF MULTI-STORIED RC BUILDING WITH RE-ENTRANT CORNER

Nowadays, buildings often feature irregular floor plans for functional, aesthetic, or economic reasons. Constructing earthquake-resistant structures in seismic areas, especially with irregular shapes like re-entrant corners, poses challenges. Such corners are common when maximizing limited space is a priority. In earthquakes, re-entrant corners in structures pose major vulnerabilities, causing stress concentration and torsion problems. The main aim of this paper is to develop finite element structural analysis models of 10, 12, and 15-storied L-shaped RC buildings with a re-entrant corner under different seismic zones using equivalent static analysis (ESA) and response spectrum analysis (RSA). This research also focuses on the overall behavior of analysis results (story drift, overturning moment, base shear, etc.) with the influence of re-entrant corner. It also investigates the performance of columns and beams near re-entrant corners as the number of stories increases in different seismic zones. For the current study, ETABS V19 is used. Models consider seismic, dead, and live loads. The Bangladesh National Building Code (BNBC) 2020 is used to examine the equivalent static analysis (ESA) and the response spectrum analysis (RSA) methods. It has been concluded from the study that re-entrant corner beams consistently exhibit the highest bending moments and torsion levels across all seismic zones. Similarly, re-entrant corner columns consistently demand the most axial force and rebar when compared to similar column types. Furthermore, the study identifies maximum stress levels in re-entrant corner slabs across all seismic zones.

Investigating Three-Dimensional RCC Frames under Seismic Loading with Various Soil Conditions

Equivalent lateral forces are used in earthquake engineering to build structures that can survive seismic shocks. Considering seismic waves affect how the Earth moves, buildings in India’s seismically active areas must be built to withstand earthquakes. This study examines how multistorey reinforced concrete building frames function seismically while taking into account different soil types, loading scenarios, and seismic Zones IV. For a twelve-storey skyscraper, the analysis includes earthquake reaction storey displacement. This study looks into how soil changes in seismic zone IV affect buildings’ responses, as well as how seismic zones themselves affect them. The building’s natural time periods were evaluated using both response spectrum analysis and time history analysis methods. These results provide insightful information about the complex interaction between soil type and seismic zone, Member stresses and maximum displacement are calculated using static and dynamic analysis. In India’s seismically active region, the necessity for earthquake-resistant structures is highlighted by seismic waves that alter the motion of the earth. Response spectrum analysis combines modal responses via techniques including SRSS, CQC, and ABS, taking into account a variety of response modes. This study compares earthquake loads using various soil types in Zone IV to evaluate building performance during earthquakes. This project’s primary goal is to analyse a multistorey building’s seismic response. Staad Pro Software does load calculations in order to analyse the entire structure. Staad-Pro analysis employs the Limit State create approach, which complies with the Indian Standard Code of Practice.

Seismic resilient performance of code-designed, base-isolated slender steel buildings in firm soils

The seismic response of slender base-isolated structures can be significantly compromised during strong earthquakes, as significant tensional forces or uplifts can be demanded to exterior and corner base isolators. Nevertheless, there are few studies published in the literature where the expected seismic response of fully-designed base-isolated buildings according to a given base-isolation code or standard is shown and discussed when subjected to ground motions records related to the design earthquake scenario. In this paper, the authors present the results obtained from the cases of study of four code-designed base-isolated buildings, from 8 to 24 stories in height, with different global slenderness ratios H/L: 2.0, 2.5, 4.0 and 6.0. Subject buildings were assumed to be located at the city of Puebla, Mexico, in firm soil sites. Buildings were designed according to current base-isolation guidelines for the Manual of Civil Works (MOC) using the modal response spectrum analysis method while neglecting the vertical component in the design process. The base isolation system was composed of high-damping rubber bearings (HDRB). The considered structural system above the isolation system was a dual system composed of special concentrically steel braced frames (SCBFs) and special moment steel frames (SMFs). The resulting base-isolated (TI) to fixed-base (Tfb) natural periods ratio for the designed buildings was within the range 2.55 ≤ TI/Tfb ≤ 3.02. Nonlinear dynamic analyses were conducted for the designed buildings when subjected to five strongest pairs of orthogonal ground motions recorded during the September 19, 2017 Puebla-Morelos earthquake, which correspond to the design earthquake scenarios considered in MOC. In addition, the impact of the vertical ground motion component was evaluated for the most critical station. From the obtained results, it can be concluded that for the studied buildings, the modal response spectrum design method was safe enough to achieve resilient seismic designs. Nevertheless, net tensile forces and uplifts were triggered in corner base isolators, particularly for ground motion records which corresponding displacement spectra was close to the code displacement spectra for the target design base-isolated period TI. Tensile forces and uplifts in base isolators were slightly increased when considering the action of the vertical ground motion component of the critical station. In addition, peak accelerations at the floor levels were moderately increased when considering the vertical component, which may have detrimental effects in acceleration-sensitive non-structural components and the shear capacity of floor systems.

Response spectrum method for structures subjected to vertical ground motions: Absolute acceleration method

AbstractAlthough a wide variety of response spectrum methods have been developed to estimate peak horizontal building responses, much less attention has been devoted to study the applicability of those methods for the vertical direction or to develop new methods to estimate peak vertical building responses. Vertical building responses can be significant for structures located close to the earthquake rupture, and for buildings with fundamental period of vibration within the range of most energy content of the vertical component of the ground motion (typically 0.05 to 0.15 s). The frequency content of the vertical component is significantly different to that in the horizontal components; thus, it is not clear if previous methods are applicable. We present a new alternative response spectrum analysis (RSA) method to estimate absolute accelerations in the vertical direction, which is a modified version of a previously studied modal combination rule developed for the horizontal components of motion. This formulation is derived based on the use of modal absolute accelerations, and we compare it to the traditional complete quadratic combination (CQC). In the proposed method, we develop simplified equations to estimate the necessary correlation coefficients for the vertical direction which are calibrated to fit empirical correlations computed from the vertical response of single degree of freedom systems subjected to a set of 90 vertical components of recorded ground motions. We also compute these correlations by using an improved power spectral density (PSD) function, which is as an enhanced version of the modified Kanai‐Tajimi PSD to represent the frequency content in the vertical direction which differs from that in the horizontal direction. To evaluate the proposed modal combination rule, we compare the RSA results to those obtained using response history analyses (RHA) of peak responses for a simplified model consisting of a prismatic bar fixed only at one end, as well as for 2D frames. We show that the proposed modal combination rule can estimate peak building responses with higher accuracy than the commonly used CQC modal combination rule, for any general building configuration at any structural location.

Influence of Positioning of Shear Wall on the Torsional Response of Building

Abstract: It would be ideal if all buildings have their lateral-load resisting elements symmetrically arranged and earthquake ground motions would strike in known directions. Due to scarcity of land in big cities, architects often propose irregular buildings in order to utilize maximum available land area and to provide adequate ventilation and light in various building components. However, it is quite often that structural irregularity is the result of a combination of both types. Most buildings have some degree of irregularity in the geometric configuration or the distribution of mass, stiffness, and/or strength. Due to one or more of these asymmetries, thestructure’s lateral resistance to the ground motion is usually torsionally unbalanced creating large displacement amplifications and high force concentrations within the resisting elements which can cause severe damages and at times collapse of the structure. Eccentric arrangement of non-structural components, asymmetric yielding, presence of rotational component in ground motions and the variations in the input energy imparted by the ground motions also contribute significantly to the torsional response of buildings. So, this research work demonstrates the importance oflocation of shear wall is should be checked before the sequential failure defined by the Response spectrum analysis method. In Numerical Tool like SAP-2000 which are uses worldwide for pushover analysis method.

EVALUASI KINERJA STRUKTUR BANGUNAN GEDUNG TAHAN GEMPA DENGAN METODE ANALISIS RESPONS SPEKTRUM DAN TIME HISTORY

The city of Bandung is one of the cities that is prone to earthquakes because it is passed by the Lembang fault. Therefore, buildings in the city of Bandung should have implemented the concept of earthquake-resistant buildings in their construction. To avoid the occurrence of damage or collapse of the structure of the building against an earthquake, it is necessary to analyze the building against the earthquake. This study aims to determine how many deviations occur in the building due to the earthquake and the performance of the building structure. The method used is the response spectrum and time history analysis method and then evaluates the performance of the structure against earthquakes using the ATC-40 standard. The building that is the case study is the Directorate of Drugs and the Directorate of Intelligence and Security for the West Java Police, which consists of 5 floors. Structural modeling and analysis were performed using ETABS v20. Earthquake records used are Imperial Valley, Kobe and Trinidad earthquakes. Based on the results of the analysis of the maximum deviation with the response spectrum method 26.74 mm in the X direction and 26.46 mm in the Y direction. Meanwhile, for the time history analysis, it was obtained 33.05 mm in the X direction and 28.96 in the Y direction. The maximum value of the total deviation obtained 0.0016 m and the maximum value of inelastic deviation obtained 0.0014 m so that it shows the level of performance of this building structure based on ATC-40 is Immediate Occupancy (IO), which means the structure is in a safe condition.Keywords : ATC-40, earthquake resistant buildings, spectrum response, time history,

A Review Paper on Influence of Positioning of Shear Wall on the Torsional Response of Building

Abstract: It would be ideal if all buildings have their lateral-load resisting elements symmetrically arranged and earthquake ground motions would strike in known directions. Due to scarcity of land in big cities, architects often propose irregular buildings in order to utilize maximum available land area and to provide adequate ventilation and light in various building components. However, it is quite often that structural irregularity is the result of a combination of both types. Most buildings have some degree of irregularity in the geometric configuration or the distribution of mass, stiffness, and/or strength. Due to one or more of these asymmetries, the structure’s lateral resistance to the ground motion is usually torsionally unbalanced creating large displacement amplifications and high force concentrations within the resisting elements which can cause severe damages and at times collapse of the structure. Eccentric arrangement of non-structural components, asymmetric yielding, presence of rotational component in ground motions and the variations in the input energy imparted by the ground motions also contribute significantly to the torsional response of buildings. So, this research work demonstrates the importance oflocation of shear wall is should be checked before the sequential failure defined by the Response spectrum analysis method. In Numerical Tool like SAP-2000 which are uses worldwide for pushover analysis method.

A Review Paper on Linear and Nonlinear Analysis of G+15 Story Building with and without Shear Wall by using Time History Analysis Method

Abstract: An earthquake is the result of the rapid release of deformation energy stored in the earth's crust, which generates seismic waves. The structures are sensitive to earthquakes and structural damage. In order to take preventive measures against damage to structures due to ground motion, it is important to know the characteristics of ground motion. The most important dynamic characteristics of an earthquake are peak ground acceleration, frequency content, and duration. These characteristics play the main rule in the study of the behavior of structures during earthquake ground motion. Earthquake analysis of a multistory structure is performed using linear and non-linear methods. The response spectrum analysis method is linear dynamic analysis. The time history method is used for nonlinear dynamic analysis. In this paper, the response spectrum method is used for linear analysis. The time history method is used for nonlinear analysis. For the time history method Both analyzes are performed using ETABs software. Linear Time History analysis of RCC building considering 4 different time histories is carried out. The time history data of Bhuj earthquake, Chamba earthquake, Chamoli earthquake and NE (Myanmar) earthquake has been considered. Here, a building has been modelled using Etabs software for seismic analysis and time history analysis. This paper highlights the effects of different time histories of different region on the same structure. The effects under considerations are story shear, building deflection and story drif

PERFORMANCE ANALYSIS OF ECCENTRIC PORTAL BRACING TO VERTICAL AND HORIZONTAL LINK CLASSIFICATION

Indonesia, which has tectonic conditions in the form of a large meeting point of the world's plates and several small plates, makes the region in Indonesia the center of earthquake occurrences and earthquake-resistant buildings are an absolute necessity. Eccentrically Braced Frames (EBFs) are a model of earthquake-resistant steel building structures that can limit inelastic behavior only to link elements, where the use of these links, especially replaceable links, can facilitate post-earthquake building repairs without having to reconstruct the main building. This study will analyze the stability, behavior, performance levels, and energy dissipation capabilities of six EBF models by combining vertical link and horizontal link configurations for different building height classifications, namely low, medium, and high buildings. Analysis uses the Response Spectrum Analysis and Pushover Analysis methods with the help of structural analysis software. From this analysis, 3-storey H-EBF has the highest stability, 10-storey V-EBF has the fastest time to reach the first yielding condition and consumes the most energy, 3-storey V-EBF has the highest ductility, and 3-storey H-EBF has the highest stiffness. highest. However, the performance level of all EBFs is in the form of Immediate Occupation and similar collapse mechanisms.

Improvement of Response Spectrum Analysis Method of Crane Pile Mooring Facilities

In this study, we analyzed the problems of the conventional response spectrum analysis method. Thereafter, we derived methods to improve it by considering the dynamic behavioral characteristics of a pile-type mooring facility with a crane. The applicability of the standard design response spectrum analysis method of crane pile mooring facilities was analyzed, and the results of previous studies on dynamic behavioral characteristics were reviewed to derive improvements and the applicability of the derived improvements in practice. when the analysis was performed with the application of the improvement, the stress of the pile during the earthquake was 70% of that of the conventional method. As a result of the study, in the recent trend where more stringent seismic design standards are required, applying the derived improvements will enable a more precise analysis than the conventional method, and reduce unnecessary costs of seismic retrofitting, contributing to the improvement of cost efficiency.

Development of a New Response Spectrum Analysis Approach for Determining Elastic Shear Demands on Shear-Dominated Steel Building Frames

This research is focused on improving the conventional response spectrum analysis (CRSA) method for the elastic shear demands estimation of shear-dominated steel building frames. An alternative approach named the improved response spectrum analysis (IRSA) method is proposed and validated in this paper. A simplified procedure to capture the dynamic features of a continuous shear beam (CSB) with stepped stiffness is first presented, and then validated. The CSB is employed in IRSA to replace the original eigenvalue analysis in CRSA to provide the modal parameter estimation for the considered system. A modified SRSS (MSRSS) mode superposition based on a genetic algorithm is then proposed and employed in IRSA. Based on the analyses conducted in this research, it is found that using first three modes in MSRSS to execute mode superposition could provide a great estimation of the elastic shear demands distribution. The amplification of weighting coefficients for the second and third mode contribution indicates the underestimation of the high mode effect in CSRSS. Further, response history analyses (RHA) are performed on two demonstration building frames to evaluate the improvement of the IRSA. The results indicate that IRSA provides a more precise estimation on the elastic shear force demand distribution in shear-dominated steel building frames under seismic effects compared with that which was achieved by CRSA.

The soil-structure interaction effect on the seismic vulnerability assessment and retrofitting of existing bridges

The bridges seismic vulnerability is a relevant subject, since a significant part of existing bridges has been designed without considering any seismic action or using technical references that suggested seismic actions generally lower than those currently defined. This generally leads to unsuitable structural performance of existing bridges against earthquakes. Moreover, it must be considered that, in the response spectrum analysis method, the seismic stresses are significantly dependent on the structure vibration periods, which is also a consequence of modelling structure base constraint. This work aims to study the effect of soil-structure interaction (SSI) on the seismic vulnerability of typical reinforced concrete viaducts, considered by modelling the deformable base constraint. Starting from the real case study of a viaduct with prestressed concrete beams and reinforced concrete piles, the carried-out analyses show the soil-structure interaction effect in terms of the ratio between stress and resistance of the piles, also varying the soil type and the piles slenderness. It is also possible to draw some interesting remarks in terms of the influence of the soil-structure interaction on the possible seismic retrofitting interventions.

Simplified Criterion for Low Gravity Center Cable-Stayed Bridge Based on Response Spectrum Analyses

The seismic response characteristics of a cable-stayed bridge are closely related to the structural system. At the same time, the influence of the height of the gravity center cannot be ignored in the structural system selection of cable-stayed bridges. For convenience, to make the scheme comparison and structural system selection in the preliminary design stage of a cable-stayed bridge, the judgment criterion of a low gravity center cable-stayed bridge was proposed, based on the simplified calculation of the fundamental frequency of cable-stayed bridges with two kinds of the structural system and combined with the response spectrum analysis method. The comparison of the results of the finite element model and the calculating results of the criterion showed that the judgment criterion has high accuracy and reliability, and can be applied to the preliminary design, the scheme comparison of cable-stayed bridges, and help select structural systems in the preliminary design stage of cable-stayed bridges.

Seismic Analysis of Historic Stone Structure: A Review Paper

Abstract: This general report is prepared from the selected 25 papers which are in the area of seismic analysis of structures. An earthquake is the result of a rapid release of strain energy storied in the earth crust that generates seismic waves. Structures are vulnerable to earthquake ground motion and damages the structures. In order to take precaution for the damage of structures due to ground motion, it is important to know the characteristics of the ground motion. The most important dynamic characteristics of earthquake are peak ground acceleration, frequency content, and duration. These characteristics play predominant rule studying the behavior of structures under the earthquake ground motion. The earthquake analysis of multistorey structure is done by linear and nonlinear methods. Response spectrum method of analysis is linear dynamic analysis. For nonlinear dynamic analysis time history method is used. In this paper, response spectrum method is used for linear analysis. For nonlinear analysis, time history method is used.

Benefits of Backstay Effect in Design of Podium Structure for Tall Building as Per IS 16700:2017

In a multi-functional tall building, generally the building has a more extensive plan area and higher lateral resistance at the lower story level than the above story levels. So, the scope of this study is to understand the realistic behaviour of such structures under lateral loads considering the backstay effect as per IS: 16700(2017). The present work focus on the effect of podium structure of single tower structure connected by a common podium at the interface level under seismic load. For this purpose, the simulation model with varying tower height and podium height is created in the ETABs and it is analysed for the equivalent static and response spectrum method. In this study, the effect on the top displacement of the tower connected with podium structure under equivalent static and response spectrum method of analysis is observed. The backstay forces that are developed to resist the lateral overturning actions at the interface when the lateral horizontal forces are transferred from the tower to the podium are studied. The unfavourable effect of podium on the shear force distribution at and above the interface level of the structural wall is observed. The positioning of the tower on the podium structure is found to be the reason for the differential displacement between the structural walls.