Seismic Response Of Multi-story Buildings Research Articles

Seismic Response of Multi-Story Buildings Subjected to Luding Earthquake 2022, China Considering the Deformation Saturation Theory

Seismic Response of Multi-Story Buildings Subjected to Luding Earthquake 2022, China Considering the Deformation Saturation Theory

Parametric Study of Three Dimension RCC Frame Structure for During Earthquake Condition

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 CQC, and ABS, taking into account a variety of response modes. This study compares earthquake loads using various soil types in Zone III and evaluates building performance during seismic events. The primary goal of the entire project is to analyse the seismic response of multistory buildings. Staad Pro Software does load calculations in order to analyse the entire structure. The outcomes turned out to be incredibly exact and precise. A G+7 and G+10 storey building was examined for every potential load combination (seismic, live, and dead loads) during my analysis and design process. The highly interactive and user-friendly user interface of Staad. Pro allows. Numerous factors that may impact earthquake ground movements and associated reaction spectra are included in analytical approaches for site response analysis. To ensure that assessments of earthquake ground motons at the site are reliable, it is crucial to look into how these parameters affect site reaction analysis. The parametric study presented in this work looks into how site factors affect ground motion during earthquakes. We calculated the response reduction of the common moment-resisting body case and the unique moment-resisting frame values Tall Construction’s seismic reaction using the Staad Pro programme.

Analysis of Coupled Site and Soil–Structure Interaction Effects on the Seismic Response of Multistory Buildings According to EC-8 and ASCE7-16 Code Provisions

Analysis of Coupled Site and Soil–Structure Interaction Effects on the Seismic Response of Multistory Buildings According to EC-8 and ASCE7-16 Code Provisions

Seismic Response of Multistory Buildings with Double Telescoping Self-Centering Energy-Dissipative Brace (DT-SCED)

Telescopic Self-Centering braces are one of the very successful examples of Self-Centering braces which perform well in seismic loading. In this study, a new example of Telescopic Self-Centering brace is introduced, which has superior features over other telescopic braces. These include: high axial load capacity, use of shorter cables in brace construction, simplicity of construction, use of separate cables for compressive and traction modes, less fatigue in cyclic loads and, allowing for more dynamic loading cycles. In this paper, a sample was designed with an axial force capacity of 300kN. Modeling of behavior (DT-SCED) was accurately expressed using numerical relationships. nonlinear incremental stiffness analysis method was also used to calculate the hysteresis brace behavior. The cyclic load test was applied to this brace and the result showed complete Self-Centering behavior. Then, a sample building with the double telescoping Self-Centering Energy-Dissipative Brace (DT-SCED) was subjected Single direction pushover analyses and the results are compared with the sample buildings with the Self-Centering Energy-Dissipative Bracing (SCED) and the Telescoping Self-Centering Energy-Dissipative Bracing (T-SCED). The results of the analysis and comparing with other samples confirm the seismic superiority of performance of the DT-SCED brace over other samples.

Numerical Study of Alternative Seismic-Resisting Systems for CLT Buildings

Changes to building codes that enable use of materials such as cross-laminated timber (CLT) in mid- and high-rise construction are facilitating sustainable urban development in various parts of the world. Keys to this are the transition to multi-performance-based design approaches along with fewer limitations on heights or the number of storeys in superstructures constructed from combustible materials. Architects and engineers have increased freedom to apply new design and construction concepts and methods, as well as to combine timber with other structural materials. They also have started to develop wall arrangements that optimise interior space layouts and take advantage of the unique characteristics of CLT. This paper discusses the seismic response of multi-story buildings braced with a CLT core and perimeter shear walls anchored to foundations and floor platforms using modern high-capacity angle brackets and hold-downs, or X-Rad connectors. Linear dynamic finite element (FE) models of seismic responses of superstructures of various heights are presented, based on experimentally determined characteristics of wall anchor connections. Particular attention is given to fundamental vibration periods, base shear and uplift forces on walls, as well as inter-story drift. Discussion of FE model results focuses on structural engineering implications and advantages of using CLT to create shear walls, with emphasis on how choice of wall anchoring connections impacts the possible number of storeys and configurations of superstructures. Employing CLT shear walls with X-Rad or other types of high capacity anchoring connections makes possible the creation of building superstructures having eight and potentially more storeys even in high seismicity regions. However, it is important to emphasise that proper selection of suitable arrangements of shear walls for CLT buildings depends on accurate representation of the semi-rigid behaviors of anchoring connections. The linear dynamic analyses presented here demonstrates the need during engineering seismic design practices to avoid use of FE or other design models which do not explicitly incorporate connection flexibilities while estimating parameters like fundamental periods, base shear and uplift forces, as well as inter-story drift.

Soil-Structure Interaction Effects on Seismic Response of multi-story Buildings on Raft Foundation

The investigation on the energy transfer mechanism from soils to buildings during earthquakes is critical for the design of earthquake resistant structures and for upgrading existing structures. Thus the need for research into Soil-Structure Interaction (SSI) problems is greater than ever. Moreover, recent studies show that the effects of SSI may be detrimental to the seismic response of structure and neglecting SSI in analysis may lead to un-conservative design. Despite this, the conventional design procedure usually involves assumption of fixity at the base of foundation neglecting the flexibility of the foundation, the compressibility of soil mass and consequently the effect of foundation settlement on further redistribution of bending moment and shear force demands. Hence the soil-structure interaction analysis of multi-story buildings is the main focus of this study; the effects of SSI are analyzed for typical multi-story building resting on raft foundation. Three methods of analysis are used for seismic demands evaluation of the target moment resistant frame buildings: equivalent static load (ESL); response spectrum (RS) methods and nonlinear time history (TH) analysis with suit of nine time history records. Three-dimensional FEM model is constructed to analyze the effects of different soil conditions and number of stories on the vibration characteristics and seismic response demands of building structures. Numerical results obtained using soil structure interaction model conditions are compared to those corresponding to fixed-base support conditions. The peak responses of story shear, story moment, story displacement, story drift, moments at beam ends, as well as force of inner columns are analyzed. The analysis results of different approaches are used to evaluate the advantages, limitations, and ease of application of each approach for seismic analysis.

An isolation device for near-fault ground motions

Seismic isolation is an appreciable control strategy that reduces the vibrations of structural and nonstructural systems induced by strong ground motions. However, under near-fault (NF) ground motion, the seismic isolation devices might perform poorly because of large isolator displacements caused by long-period large velocity and displacement pulses associated with such strong motion. The objective of this paper is to assess the effectiveness of a new seismic isolation device, referred to as roll-in-cage (RNC) isolator, in protecting against NF ground motions. The device is intended to achieve a balance in controlling isolator displacement demands and structural accelerations. The RNC isolator provides in a single unit all the necessary functions of rigid support, horizontal flexibility with enhanced stability, and energy dissipation characteristics. Moreover, it is distinguished from other isolation devices by two unique features: (i) it has a built-in energy-absorbing buffer to limit the design displacement under strong excitation, and (ii) it has a built-in linear recentering mechanism that prevents residual displacement after earthquakes. The seismic response of multistory buildings isolated by the RNC isolator is investigated under three recorded NF earthquakes and three synthetic ground motions. The results show that the RNC isolator is a convenient isolation system in protecting against NF earthquakes.

Seismic Response of Multistory Buildings with Self-Centering Energy Dissipative Steel Braces

This paper examines the seismic response of 2-, 4-, 8-, 12-, and 16-story steel framed buildings with self-centering energy dissipative (SCED) bracing members. The structures are assumed to be located in Los Angeles, California. Identical buildings equipped with buckling restrained braces (BRB) are also studied for comparison purposes. Incremental static analysis and nonlinear dynamic analysis under ground motion ensembles corresponding to three hazard levels were performed. The SCED frames generally experienced smaller peak story drifts, less damage concentration over the building height, and smaller residual lateral deformations compared to the BRB system. Higher floor acceleration peaks were observed in the SCED frames due to the sharper transitions between elastic and inelastic response assumed in the analysis. The study also indicated that higher design seismic loads may be needed for low-rise SCED and BRB frames in order to improve their collapse prevention performance.

Optimum friction pendulum system for near-fault motions

The analytical seismic response of multi-story buildings isolated by the friction pendulum system (FPS) is investigated under near-fault motions. The superstructure is idealized as a linear shear type flexible building. The governing equations of motion of the isolated structural system are derived and the response of the system to the normal component of six recorded near-fault motions is evaluated by the step-by-step method. The variation of top floor absolute acceleration and sliding displacement of the isolated building is plotted under different system parameters such as superstructure flexibility, isolation period and friction coefficient of the FPS. The comparison of results indicated that for low values of friction coefficient there is significant sliding displacement in the FPS under near-fault motions. In addition, there also exists a particular value of the friction coefficient of FPS for which the top floor absolute acceleration of the building attains the minimum value. Further, the optimum friction coefficient of the FPS is derived for different system parameters under near-fault motions. The criterion selected for optimality is the minimization of both the top floor acceleration and the sliding displacement. The optimum friction coefficient of the FPS is found to be in the range of 0.05 to 0.15 under near-fault motions. In addition, the response of a bridge seismically isolated by the FPS is also investigated and it is found that there exists a particular value of the friction coefficient for which the pier base shear and deck acceleration attain the minimum value under near-fault motions.

Wave-Propagation Formulation of Seismic Response of Multistory Buildings

This paper presents a discrete-time wave-propagation method to calculate the seismic response of multistory buildings, founded on layered soil media and subjected to vertically propagating shear waves. Buildings are modeled as an extension of the layered soil media by considering each story as another layer in the wave-propagation path. The seismic response is expressed in terms of wave travel times between the layers and wave reflection and transmission coefficients at layer interfaces. The method accounts for the filtering effects of the concentrated foundation and floor masses. Compared with commonly used vibration formulation, the wave-propagation formulation provides several advantages, including simplicity, improved accuracy, better representation of damping, the ability to incorporate the soil layers under the foundation, and providing better tools for identification and damage detection from seismic records. Examples are presented to show the versatility and the superiority of the method.