Seismic Resistance Of Buildings Research Articles

Investigation of seismic resistant structures with various moment-resisting frame systems and pushover analysis

Earthquakes are a serious threat in the construction of multi-storey buildings in Indonesia, which are divided into several seismic design categories. The design of seismic-resistant buildings requires the management of plastic hinges to reduce seismic loads. The aspects of seismic-resistant structural design in Indonesia are regulated by SNI 1726:2019, SNI 1727:2020, and SNI 2847:2019. Intermediate Moment Resisting Frame System (IMRFS) and Special Moment Resisting Frame System (SMRFS) are used based on seismic category and earthquake intensity. Pushover analysis is used to analyze the structures behavior when exposed to seismic loads. This research designs seismic resistant structures with IMRFS and SMRFS at different locations with the aim of assessing structural performance and gaining reinforcement to the concrete ratio, which is relevant for the design and construction of multi-storey buildings in Indonesia. The results of this research are the structural performance levels, reinforcement volume, concrete volume, and the reinforcement to concrete volume ratio. Both IMRFS and SMRFS reached Immediate Occupancy to Life Safe performance levels after the earthquake because their monitored displacement was not significantly different. The structural failure modes of both systems meet the Strong Column–Weak Beam requirements. The distribution of plastic hinges also remains in the Immediate Occupancy category.

Private housing compliance with public seismic safety measures after 2015 Gorkha earthquake in Nepal

After the Gorkha earthquake in 2015, the Nepalese government introduced a series of seismic-resistant building designs to reconstruct and repair residential dwellings. The objective of this research was to explore the extent of compliance with the new prescribed or recommended seismic-resistant features in rebuilt residential structures in two Nepal districts that were severely damaged during the earthquake. The primary source of data was a field survey conducted with a structural questionnaire among 332 affected households during October and November 2022. The survey also utilized informal interviews at three study sites in August 2023, with results showing that 95%–97 % of total respondents reconstructed their houses according to earthquake-resistant standards. The same percentage of respondents withdrew the final payment from the National Reconstruction Authority (NRA). Most reconstructed houses were smaller than before the earthquake; many respondents rebuilt one-room, one-story structures. In addition, housing typologies at the study sites changed from brick/stone and mud-based masonry to cement-based construction. Key Words: Gorkha earthquake, seismic-resistant guidelines, compliance with government safety measures, reconstructed houses, NRA.

Evaluation of The Current Level of Knowledge of The Residents of Dhaka City Regarding Earthquake Hazard

An earthquake is a sudden disaster that is not possible to predict. This impulsive behavior makes it very dangerous for humankind. Precautionary measures are immense for reducing damage. The first step of preventive measures for an earthquake is raising awareness. Dhaka City has a high earthquake risk due to its large population and urbanization. Researchers have said that an earthquake in this zone can be fatal, resulting in heavy casualties with structural damage. For this reason, proper awareness is essential for the residents of this area. The aim of this study is to find out the current knowledge level of the residents of Dhaka City about Earthquake risk of this city. Online questionnaire was used to collect data from random residents of Dhaka. Survey data indicates that many people lack Knowledge of what to do before and during an earthquake. Especially school and college-going students are unaware of the essential things to do during an earthquake incident. Many people still don’t know the importance of a seismic-resistant building system and are unprepared for a seismic event. This study brings these aspects together to learn about the knowledge level, which can help policymakers raise awareness among this city's residents.

The comparison of X-braced frame and moment frame on structural building (case study: government office of North Toraja, South Sulawesi, Indonesia)

The seismic force can damage the building and harm the occupants. Therefore, its structure needs to be designed seismic-resistant. One of the essential things in seismic-resistant building is the effect of lateral force to its structural rigidity. It can be improved by using the lateral resistant element such as bracing and shear wall. The lateral element used in this study is concentric X-bracing. This study conducted an optional structural model of the office of North Toraja Regent, Panga, South Sulawesi. The building was originally analyzed as a whole unit structure, but it has already rotated in its first mode shape due its irregularity. The comparison analysis is conducted by using the same existing structure configuration, except with the addition of X-bracing. The analysis results of the dynamic response are the fundamental building period, mode shape, base shear, lateral displacement and P-delta effect. The fundamental building period using X-bracing is smaller than moment frame building. It indicates that the use of X-bracing lead to the stiffer building. The use of the X-bracing results in a larger base shear value than the moment-frame building. The difference in base-shear between X-braced frame with moment frame is about 211.77% and 212.10% for seismic force with X-direction and Y-direction respectively.

A site-specific earthquake ground response analysis using a fault-based approach and nonlinear modeling: The Case Pente site (Sulmona, Italy)

In this paper we present the ground response analyses (GRA) of a site where an industrial facility is planned. Due to its location on an active normal fault system known as a relevant seismic gap, the Mt. Morrone Fault system (MMF), and at the edge of a basin filled with slow velocity continental deposits, a inter-disciplinary and non-standard approach has been applied to assess the seismic input of the dynamic numerical analyses. It includes geological, seismological, geotechnical and engineering contributions. Two fault scenarios, MMF1 and MMF2, were considered and scenario-based (SSHA) and probabilistic (time-dependent, TD, and time-independent, TI) seismic hazard (PSHA) analyses were implemented. Comparison among the spectra corresponding to the 90th percentile of the SSHA statistical distribution and the PSHA average ones shows that the SSHA MMF2 has values similar to the PSHA TD model. The SSHA 90th percentile distribution was selected as target spectra to retrieve the seismic input for GRA. Nonlinear numerical simulations of seismic wave propagation were implemented to derive surface ground motion parameters. GRA acceleration response spectra and their PGA are notably higher, and thus on the side of safety, than those obtained following the Italian code approach for seismic resistant buildings. These results confirm that a scenario-based methodology can better capture the shaking effect in near-field conditions, avoiding possibly unconservative underestimations of the seismic actions and in view of a more robust performance-based approach used by engineers for either new design and/or assessment/retrofit purposes of the built environment.

Perbandingan Ketentuan dan Analisis Detailing Hubungan Balok-Kolom Berdasarkan SNI 2847:2013 dan SNI 2847:2019

Recent earthquakes in Indonesia have caused significant damage to many buildings, especially because the beam-column joints did not satisfy the detailing requirements for the seismic-resistant building. SNI 2847: 2013 is an Indonesian code for designing concrete buildings, which has been updated to SNI 2847:2019, consist of several new provisions related to detailing beam-column joints. This study discusses the comparison of detailing requirements based on the two codes and compares the analysis of detailing of the beam-column joints in a focused building, a five-story building which represents a medium rise building. The comparison of detailing requirements for beam-column joint according to SNI 2847:2013 and SNI 2847:2019 showed that SNI 2847:2019 has several new requirements related to the height of the joint, standard hooks in an exterior joint, headed bar, and transverse reinforcement in the joint. Then, comparing the results of analysis of detailing of the beam column joints in the focused building showed that there is no different on the detailing results of the joints according to SNI 2847:2013 dan SNI 2847:2019.

Novel Ductile Enhancement in the Structural Characteristics of External Beam Column Joint with Potassium-Activated Green Concrete Technology

Ductility and energy dissipation capacity of the beam column joints are the two prominent characteristics which govern the stability of the entire structure constructed in the seismic prone areas. In this paper, the effect of potassium-activated geopolymer concrete in the exterior beam column joint application is investigated under low frequency cyclic loading. Numerical analysis has been done by using the finite element software Abaqus and compared with the experimental work. From the load deformation relationship, parametric studies are carried out in the aspects of ductility, stiffness degradation, energy dissipation capacity, drift ratio and cracking pattern. The use of potassium-activated geopolymer technology in the exterior beam column joint application resulted in the improved ductility, energy dissipation capacity with superior ultimate load carrying capacity of 1.05% over conventional cement reinforced concrete beam column joints with special confining reinforcement confirmed by IS 13920 due to the enormous polymerization activated by high molecular potassium ions. There is an improved energy dissipation capacity of 2.78% of potassium-based geopolymer specimen resulting in lesser number of non-structural cracks and 11.26% more deformation under 11.96% enlarged drift ratio than the conventional reinforced concrete specimen. From the observed results, it is clearly noted that the implementation of potassium-activated green polymer technology in the beam column joints possessed enhanced ductility characteristics to protect the structure susceptible to seismic environment and resulted in innovative, economical and sustainable mode of seismic-resistant building construction.

Seismic response of various sites of the territory of Kyiv to seismic loads

The research presented in the work aims to assess the seismic response of three different taxonometric sites, identified by the method of engineering and geological analogies within the territory of Kyiv, to seismic loads with different spectral content and peak amplitude from 0.01 g to 0.06 g. Assessment of the influence of local soil conditions on the intensity of earthquakes is an important task of earthquake-resistant design and construction. The soil layer at the base of the study site acts as a filter on seismic vibrations. It amplifies or attenuates the amplitude of the seismic wave propagating from the bedrock to the free surface. The paper considers the mechanisms of the possible amplification of seismic motions by various soil complexes and methods for calculating the seismic response to seismic loads of various intensities. As an analytical tool for analyzing the response of the taxonometric areas to seismic vibrations (seismic response), an equivalent linear analysis was used, which is comprehensively studied and widely used in engineering seismology. For the selected sites, models of soil strata were built, and graphs of changes with depth of peak shear strain and peak ground acceleration (PGA) were calculated, as well as predicted (expected with a given probability of non-exceeding) amplitude Fourier spectra of seismic motions in the upper layer and the response spectra of single oscillators with 5 % attenuation to seismic effects with a maximum amplitude from 0.01 g to 0.06 g. A comparative analysis of the change in the value of these parameters in individual sections of Kyiv is presented. It is shown that to assess the potential hazard from seismic ground motions during earthquakes, it is necessary to use the maximum number of design parameters that characterize the seismic hazard of specific areas and which are used to determine the seismic resistance of buildings and structures. The most complete seismic hazard for calculating the seismic stability of objects is set by the full vector of seismic motions deployed in time: calculated accelerograms, seismograms and velocigrams. The presented calculation results are planned to be used in solving methodological and practical problems of earthquake protection, which can be realized in different parts of the territory of Kyiv.

Prototyping of a Novel Rammed Earth Technology

Buildings of the future are called to meet increasingly high-performance requirements and to ensure adequate environmental sustainability of the production and construction chain. This issue has stimulated a keen interest in the use of natural materials in construction. Among these, raw earth has proved to be particularly interesting for its intrinsic availability, sustainability, and recyclability. In Europe, the spread of raw earth building technologies has often been hindered by the lack of specific legislation regulating its use for load-bearing structures, even if in many countries, it can be noticed a widespread and well-established constructive tradition. Some transoceanic research experiences attest that unfired earth can be used, together with different types of reinforcements, to create seismic-resistant buildings. After presenting a review of the main raw earth reinforced technologies, the present study focuses on a novel reinforced and modular rammed earth construction made with natural or recycled materials, developing a technology with low energy consumption and low environmental impact, specifically designed for areas with high seismic risk. In particular, the work presents the results of a prototyping procedure aiming at developing a new seismic-resistant construction system that combines rammed earth with timber reinforcement elements and nylon/polyester ropes. These elements have a dual function: (1) they are fundamental components of the construction process (as they integrate the formwork system), and (2) they act as seismic-resistant devices once the structure is completed. In line with the performance-based approach required by the construction sector, the study aims at defining a controlled and standardised supply chain for rammed earth construction.

Probabilistic methods for calculating seismic resistance of buildings

The article aims to assess possibilities of using probabilistic methods for calculating seismic resistan of buildings based on the laws of structural mechanics. The design schemes and models of buildings rigidly embedded in the base and with a seismic isolation device are described. Formulas developed on the basis of the law of energy conservation, namely the seismodynamic law, which allow to estimate the coefficient of dynamism, are presented. It is proposed to abandon the main modes of vibration in the calculations, i.e. the coefficient ηir of the waveform and the vibration frequency of the residential building and the foundation during earthquakes. Shear and bending calculations of a residential building are based on the design model developed. The values of seismic force are determined by the first and last modes of vibration. Based on these values, it is proposed to calculate internal forces and deformations in the bearing structures of buildings using the methods of structural mechanics.

High Strength Steel and Fuse Dissipative Solutions for Seismic Resistant Building Structures

AbstractThe robustness of structures against severe seismic action is ensured by their global performance, in terms of ductility stiffness and strength, properly calibrated. The “plastic“ members of ductile Mild Carbon Steel ‐ MCS – (S235 to S355) will dissipate the seismic energy, acting as “structural fuses“, while the “elastic“ members, must be provided of adequate overstrength, to have the capacity to carry the supplementary stresses after the plastic hinges have been formed and the redistribution forces were occurred. For these elastic members, High Strength Steels (HSS), such as S460 to S690, might be used, provide them the necessary overstrength, without enhancing the stiffness, because that could unbalance the structural system. These structures, which combine HSS with MCS, are termed Dual‐Steel (DS). The braced frames can be equipped with detachable dissipative MCS members, which are acting as seismic fuses. In case of CBF, the fuses might be the Buckling Restrained Braces (BRB), while for EBF, the links could take this role. In case of MRF, Steel Plate Shear Walls (SW) can be used as fuses. To make possibly to replace the used fuses, the HSS elastic part of the structure, has the mission to re‐centring the structure after the earthquake. This is the subject of present paper.

On the Use of Cloud Analysis for Structural Glass Members under Seismic Events

Current standards for seismic-resistant buildings provide recommendations for various structural systems, but no specific provisions are given for structural glass. As such, the seismic design of joints and members could result in improper sizing and non-efficient solutions, or even non-efficient calculation procedures. An open issue is represented by the lack of reliable and generalized performance limit indicators (or “engineering demand parameters”, EDPs) for glass structures, which represent the basic input for seismic analyses or q-factor estimates. In this paper, special care is given to the q-factor assessment for glass frames under in-plane seismic loads. Major advantage is taken from efficient finite element (FE) numerical simulations to support the local/global analysis of mechanical behaviors. From extensive non-linear dynamic parametric calculations, numerical outcomes are discussed based on three different approaches that are deeply consolidated for ordinary structural systems. Among others, the cloud analysis is characterized by high computational efficiency, but requires the definition of specific EDPs, as well as the choice of reliable input seismic signals. In this regard, a comparative parametric study is carried out with the support of the incremental dynamic analysis (IDA) approach for the herein called “dynamic” (M1) and “mixed” (M2) procedures, towards the linear regression of cloud analysis data (M3). Potential and limits of selected calculation methods are hence discussed, with a focus on sample size, computational cost, estimated mechanical phenomena, and predicted q-factor estimates for a case study glass frame.

Evaluation on Seismic Performance of Dual Steel Moment-Resisting Frame with Zipper Bracing System Compared to Chevron Bracing System against Near - Fault Earthquakes

In order to design seismic-resistant buildings, it is necessary to get comprehensive information about their behavior against the forces induced by earthquakes. Seismic design codes have been developed to meet the requirements of a safe and economical structure. According to the structural codes, the designed structures should not be damaged against light or moderate earthquakes so that the members should be had sufficient strength and safety while they should be a ductile complex with a proper structural configuration against severe earthquakes to dissipate the forces caused by ground motions. In the design of steel buildings, the use of moment-resisting frames in combination with braces is a seismic-resistant system. One of these systems is the dual steel moment-resisting frames with zipper braces. In this research, the seismic performance of the moment-resisting frame with the zipper brace system has been studied and its performance has been compared to the performance when the chevron bracing system is used. Three 4-story, 8-story, and 12-story buildings have been selected then they have been modeled by SAP2000 software, and finally, their seismic performances have been evaluated using time history analysis. The structural responses have been compared as comparing the relative displacement of the stories (story drift), the maximum displacement of the roof, and the formation of plastic hinges in the members. The results of the current study have been shown that using a zipper member has been decreased both overall displacement of the structure by about 10 to 30 percent, and also has been reduced the damage index of 4, 8, and 12-story structures by 27, 11, and 12 percent, respectively. The formation of plastic hinges has been directed from horizontal and vertical members toward diagonal members.

Increasing the seismic resistance of operated buildings using special seismic protection methods

The change in the level of seismicity of buildings and structures occurs as a result of
 updating the maps of general seismic zoning. Ensuring the seismic resistance of buildings and
 structures is a factor that must be taken into account, especially during construction in
 seismically active regions. Nowadays, one of the main approaches to increasing seismic
 resistance is the use of various seismic isolation systems. It is not always profitable and rational to increase the seismic resistance of building structures or foundations for equipment by simply increasing the strength. A classification of seismic reinforcement systems is given, among which the most sparing are special methods of seismic protection in the form of seismic isolation.
 Practical examples of the use of seismic isolation systems to improve the seismic resistance of existing buildings are given. A computational study was carried out, the result of which showed
 the effectiveness of using rubber-metal supports for hanging the seismic resistance of buildings.

Pembandingan Perancangan Bangunan Tahan Gempa Menggunakan SNI 1726:2012 Dan SNI 1726:2019

Indonesia has a code for designing a seismic-resistant building, which has always improved year after year. Start from Peraturan Perencanaan Tahan Gempa Indonesia Untuk Gedung (PPTI-UG) 1983, SNI 1726:2002, SNI 1726:2012, and the latest one is SNI 1726:2019. SNI 1726:2019 experienced some renewal on designing a seismic-resistant building. This research aims to compare spectrum response design and the structural behavior between seismic-resistant building design using SNI 1726:2012 and SNI 1726:2019. The reviewed structure behaviors are base shear force (V), drift (δmax), and story drift (Δ). The study compares the detail of the structural components as well as using SNI 2847:2013 and SNI 2847:2019. The research uses a 10-story building modeling that serves as an apartment building and located in the city of Banda Aceh. Seismic analysis using a spectrum response analysis with Special Moment Resisting Frame (SMRF) structure. The result showed that the peak acceleration (Sa) for the class sites of Medium Land (SD) and Hard Land (SC) were 11% and 26%, respectively, while for Soft Land (SE), there was no increase. The shear force in SNI 1726: 2019 has increased by 19.75% for the X direction and 19.97% for the Y direction. The increase in the shear force is directly proportional to the increase in drift and story drift. In the beam detailing and beam-column connection, there were no significant changes. While in the column detailing, there are additional provisions that cause the transverse reinforcement to be tighter.

Analytical Investigation of MR Damper for Vibration Control: A Review

Abstract In this paper, a vibration control system with magnetorheological (MR) damper investigation is reviewed. At first a MR damper is investigated analytically using various finite element method software and the performance is investigated using experimental. The MR Dampers are designed and modelled for a scaled down setup. The application is in seismic resistance of buildings, automobile, physical and biological. Finally, the damper is investigated using various technique and methods used to study the performance is reviewed. This device reduces the vibration in both active and semi active control system effectively.

Experimental and numerical investigation of mechanical properties on novel modular connections with superimposed beams

The use of lightweight modular construction becomes increasing popular all around the world today. The benefits of off-site prefabrication include consistent quality, shorter construction time, eco-friendly function which are being realized in both residential and commercial building construction. The connection of modular building plays a critical role in ensuring the stability, robustness and seismic resistance of buildings. However, conventional connection design for modular buildings (e.g. blind flange gaskets, on-site welding or open large access holes) ignores the potentiation of composite effect on the stability of the modular buildings. This study presents a novel modular connection configuration (i.e. Type A modular connection) for connecting modular units to columns in both vertical and horizontal directions by an in-build component. The proposed connection can bring the floor beam of upper units and ceiling beam of bottom units into an integrated system with the advantages of easy installation without on-site welding. The mechanical behavior of modular connection was firstly experimentally investigated. An experimentally validated numerical model was then developed to further investigate the mechanical and deformation behavior of the joint. The results show that the proposed novel connection could allow the twins beam to rotate identically. In addition, they demonstrate that the twin beams’ flexural stiffness ratio and gap between in-build component and column are two critical factors that govern the continuity of the overall joint.

Economic performance analysis of seismic isolation, energy dissipation, and traditional seismic structures

The construction of a new countryside requires a compr hensive improvement in the building standards of villages and towns, and the seismic resistance of buildings in earthquake-prone areas has attracted much attention. Due to the backward economic development of villages and towns, the development of seismic isolation structure and energy dissipation structure is hindered. To build houses with better seismic performance, the economic efficiency of seismic isolation and energy dissipation structures has become a matter of close concern to the local people and the government. This article compares the economic differences between the original seismic structure, the base isolation structure, and the seismic damping structure from the costs incurred during the entire life cycle of the building, and provides economic reference for the new rural seismic isolation building.

ОБЕСПЕЧЕНИЕ ЭКСПЛУАТАЦИОННЫХ ХАРАКТЕРИСТИК ЖЕЛЕЗОБЕТОННЫХ ЭЛЕМЕНТОВ КАРКАСОВ ЗДАНИЙ, ПОДВЕРГШИХСЯ СЕЙСМИЧЕСКИМ ВОЗДЕЙСТВИЯМ

The objectives of the study were to improve the operational characteristics of buildings with a bearing reinforced concrete framework located in seismic areas of the Russian Federation. The article presents the results of analysis of previous studies of stress-strain state of the framework elements of a multi-storey building under seismic impacts. It has been established that despite a more optimal solution of load-bearing systems of buildings in the form of reinforced concrete frames in seismic areas as a result of periodic actions of background earthquakes, inevitable accumulation of temporary fatigue and damage to structures during operation there is a significant reduction of dynamic resistance of the building as a whole. It is noted, that throughout all term of life of an object except design seismic load, the crucial role is played also by physical wear which development leads to structural modifications of properties of materials and inevitable deformation of technical characteristics of bearing structures. It has been found, that the most dangerous failures associated with the reduction of strength of columns, assemblies, the mating of bearing elements and, as a result, the loss of their stability, leading to the progressive destruction of the building as a whole. Three groups of possible methods of strengthening and increasing seismic resistance of buildings and structures are considered.

Comparability of estimates of the impact of gunpowder and gas-dynamic explosions on the stability of buildings and structures

A brief description of natural and artificial influences influencing the stability of buildings and structures is presented. Studying the seismic resistance of buildings and structures designed, under construction, erected, and in operation requires time to wait for seismic activity, which is not permissible; costs of manpower and resources, which is inappropriate. In this regard, a working hypothesis has been put forward that by artificially acting on soils with the help of detonation wave energy, it will be possible to induce vibrations, with the help of which it will be possible to study the behavior of building structures put into operation, the entire building and structure as a whole. The goal is set: - to investigate the behavior of structures under construction and in the operation of buildings and structures that perceive artificial vibrations caused by the detonation unit by acting on soils. To achieve this goal, tasks have been identified. A detonation (blast) wave is taken as a "tool" for force action. The theoretical foundations of the experiment are briefly presented and the developed scheme of a detonation tube and a shock wave with a general view of the installation causing detonation wave energy. A brief technique for carrying out field experiments is presented.