Performance Of Building Structures Research Articles

A model to support the decision-making in urban regeneration

Urban regeneration represents an opportunity for sustainable development and smart growth of towns. The European best practices of urban regeneration demonstrate its effectiveness to valorize obsolete existing buildings, through integrated design of energy and structural upgrade. In countries of southern Europe, characterized by medium to high seismic risk, programs of urban regeneration, would make it possible to reduce buildings vulnerability, through seismic upgrade/retrofit interventions, or alternatively, through demolition and reconstruction interventions, when the previous ones do not allow the improvement of seismic performance of building structures in order to ensure adequate levels of safety. The research work sets out a real case for a possible process of urban regeneration, of a residential neighborhood located in the city of Matera, through demolition of existing buildings and then their reconstruction in the same volume size or, eventually, increased in relation to the premiums of volume required by current regulations. The process involves three different categories of stakeholders: residents, public sector and private investor responsible for executing and financing of the entire processing. Each of them with different and contrasting needs. At the end of the process, the new surfaces should be redistributed between residents and private investor. These shares, with the volumetric premium, constitute the unknown variables of the problem and, their possible combinations represent the different possible options of intervention. The problem is solved through the construction of the model based on the objective functions, expressed by utility functions, defined for each stakeholder. The search for the optimum solution, which is able to balance the different utilities, is carried out with Multi-objective linear programming.

The Structure System of Bugis Traditional House in Disasters Perspective

The existence of traditional house until now could be believed as proof of a good human protector. Bugis traditional house is one of them. The research problem is how Bugis behavior and building structure performance to struggle in flood. The goal is to reveal the performance of house structure and Bugis ancestor behavior to survive after disasters. The methods are logical argumentation to explain the architectural knowledge, and modeling simulation to explain building structural performance. The results are Bugis ancestor has been leave inheritance a good behavior in survive after disasters through they architectural space arrangement. They prepare space in a safe area at their house for food storage, so when disasters happen they still have food stock without waiting for aids. The structure system as the stilt house its find in safe for the occupant because of space for human living lifted more than two meters above the ground surface. The structural performance indicates the displacement in early dangerous occur when flood loads higher than human living space. The best knowledge can be adopted in this research is the availability of food stock at own house. The better construction method to apply in flood area is the stilt house.

Experimental investigation on the temperature decay beneath a horizontal projection of spilled plumes from a compartment window

Since the horizontal projection upon the building facade are widely used in vertical fire-induced thermal protection, this paper is focused on the temperature decay beneath a horizontal projection of spilled plumes from a compartment window. A series of 1:8 reduced scale experiments were carried out in a cubic compartment. The window dimensions as well as the total heat release rates were variable, whilst the temperature was measured by thermocouples installed beneath a horizontal projection, which was located right attached to the facade wall at the top of the compartment window. The temperature field beneath the horizontal projection was found to be singular to a naturally formed ceiling jet. The elongation of temperature field in the longitudinal direction was observed, which should be attributed to the extra horizontal velocity provided by the window spilled plume, and meanwhile, the horizontal velocity started to take advantage as the flow spreads. Finally, the temperature decay in both longitudinal and transversal directions are well correlated by dimensionless functions. The results would provide crucial references in the realistic interpretation on the thermal and strength performance of building structure in building fire scenarios.

Analisis Perpindahan Lateral Struktur Beton Bertulang Pada Bangunan Bertingkat Beraturan dan Ketidak Beraturan Horizontal

The effect of earthquake forces on buildings will certainly be different if applied to regular and irregular buildings. The performance of structures produced in irregular buildings will be different from the performance of irregular building structures for the same load intensity. In the earthquake resistant structure planning regulations, SNI 1726-2012 concerning structural irregularities. Where in this regulation there are two types of structural irregularities namely horizontal structural irregularities and vertical structural irregularities which are then subdivided into several types of irregularity. The study was carried out to compare the results of building structure performance with horizontal irregularity compared to regular buildings as seen from displacement, drift ratio, base shear, performance level based on ATC-40, differences in reinforcement weight. This research resulted in the largest displacement for the x-direction, namely the type A irregular building where it experiences a deviation of 0,49 m difference and for the y-direction of 0,44 m in the type A irregular building Type A. The biggest drift ratio of the x-direction and direction y is a Type B irregular building that is equal to 0,64 m for the x-direction and 0.57 m for the y-direction. The largest base shear occurs in regular buildings with Type B irregular buildings at 16.34%. the level of performance based on ATC-40 for all building models is immidiate occupancy, the biggest reinforcement need is the irregular building model B with a percentage difference of 11,20%.

Performance evaluation of outrigger location on the seismic load distribution of high-rise building structure

Various structural systems have been developed to be able to accept the lateral force of the earthquake with an optimum and economical. One of these structural systems is the outrigger system. Outrigger is one of the structural stiffening systems that can be used on building structures, especially in high-rise buildings. Structural systems such as outriggers are used for earthquake-resistant buildings, so the performance of building structures can be increased by producing minimum displacement. This research will design the building as high as 40 and 50 floors, with the calculation of earthquake based on Indonesia Earthquake Design Code SNI 1726-2012. This study will be compared the calculation of seismic loads in the building structure with and without using outrigger, so that it can be seen the difference in the seismic loads and the performance of the structure. From this research, it is found that the outrigger system can reduce the seismic loads in the structure, and also is able to reduce the lateral displacement of the structure. The inter-story lateral displacement of 50 storey and 40 storey structure can be reduce up to 2.06% and 7.84% with one outrigger and 3.76% and 12, 49% with two outrigger.

Comparison of heat gain values obtained for building structures with real and constant properties

The magnitude of energy consumption due to heating and cooling of buildings has led to the demand for increasing the thermal performance of building structures. Many investigations are presented in literature arguing to find the effect of each thermophysical property on the thermal characteristics of building components, while the properties have been assumed as independent of each other. In this context, this paper focuses on the effect of each property on heat gain value utilizing relationships between the measurement values of thermophysical properties of building structures. In previous study, 102 new wall samples were produced, their thermophysical properties were tested and expressions among these properties are obtained. In this study, the heat gain values through the structures are computed using solution of transient heat transfer problem by using both the obtained expressions between the thermophysical properties and assumptions proposed from the literature. Results obtained for varying and constant thermophysical properties have been compared with those values presented in literature. The results show that the assumptions are not realistic in a significant number of cases. Moreover, if one of the thermophysical properties of a material is known, heat gain values can be calculated easily for the selected wall or roof types.

DESIGN AND ANALYSIS OF CONNECTION TYPES FOR ULTRA-HIGH-RISE TWIN-TOWER STRUCTURE LEARNING

One of key issues of designing connected structure is the design of the connecting body between towers. This paper presents the analysis of different connecting body design schemes based on a 202.15 m (663 ft) twin-tower ultra-high-rise structure connected by a connecting truss. The influence of height and type of connection on the entire building structure was studied by comparing storey shear forces and drift of structure. The results indicated that the connection type between the connecting body and main structure has little influence on the building structure performance. Finite element analysis of the connecting body indicated that the internal force characteristic of rigid connection type is better compared to the hinge connection type. Furthermore, the connecting truss design based on inclined braces connected by hinge joint is superior compared to the rigid joints.

Effect of R, µ and T on the Fragility Curves for Two Spans Reinforced Concrete Highway Bridges

Abstract Fragility curves are useful tools for evaluating the probability of structural damage due to earthquakes as a function of ground motion indices. The force reduction factor (R) is one of the seismic design parameters that determine the nonlinear performance of building structures during strong earthquakes. R factor itself is mostly a function of displacement ductility (µ), natural period of a structure, and soil conditions. A statistical method (Path Analysis) is proposed for the first time to determine the effect of R, µ and T on the column fragility curve parameters of typical box girder, two spans reinforced concrete highway bridge class. An analytical approach was adopted to develop the fragility curves based on numerical simulation. The R, µ and fundamental period T have been used to characterize different bridge configurations. The total, direct, and indirect effects of the variables as having significant effect on fragility curve parameters were identified.

Response modification factor - Review paper

Response modification factor (R) has a main function in the seismic design of new construction materials and is a seismic design parameter in equivalent static analysis. It determines the nonlinear performance of building structures during strong earthquakes. R is based on experimental test and engineering judgment, and no uniform technique exists to determine such a value for different conditions. The development in the reliability of modern earthquake-resistant buildings requires systematic assessment of building response characteristics that mainly affect the rates allocated to R, which is formulated based on three aspects, namely, strength, ductility, and redundancy factors. Response modification is affected by the height of structures. This review paper aims to summarize relevant information from different experimental and analytical studies on overstrength, ductility, and R.

Analysis of structural performance of existing rc building designated as tsunami evacuation shelter in case of earthquake-tsunami scenarios in lima city

In 1746, Lima Region was hit by a severe earthquake and a consecutive tsunami in Callao City caused 96% of casualties in the Callao City population. Under SATREPS Project [1], several studies were realized, and they concluded that a severe earthquake (Mw8.6~8.9) may occur in Lima City [2], following by tsunami which may hit a large coastal area. In that sense, harmful scenarios can occur. Based on last studies, and historical earthquake consequences in Callao City; Local government in La Punta, the most tsunami prone district in Callao, has designated 19 reinforced concrete (RC) buildings as tsunami shelters. Nevertheless, the lack of the structural vulnerability studies of these buildings in front of an earthquake and consecutive tsunami scenario, makes uncertain the good performance of the buildings. Guidelines of other countries such as Japan, The United States and Chile, are oriented to calculate the tsunami forces; nevertheless, these guidelines lack information about structural performance of buildings in front of earthquake-tsunami scenarios. This paper describes a methodology to assess the sequential action of the earthquake and the consecutive tsunami to evaluate the structural performance and the damage level to ensure the safety of buildings and their inhabitants.

Strengthening of RC Structures by Using Engineered Cementitious Composites: A Review

This paper presents a review of the recent work assessing the performance of building structures strengthened with engineered cementitious composite (ECC). ECC characterizes tensile strain hardening and multiple cracking properties, as well as strong interfacial bonding performance with substrate concrete, which makes it a promising retrofitting material. A lot of researches have been conducted on reinforced concrete (RC) structures, including beams, columns, beam–column joints, and fire-damaged slabs, strengthened with ECC material, and an extensive collection of valuable conclusions were obtained. These strengthening systems usually combine ECC with FRP textiles or steel bars to form a composite strengthening layer. The review demonstrates that ECC strengthening can greatly improve the performance of RC structures.

KONTRIBUSI DINDING BATA TERHADAP KINERJA STRUKTUR SPACE FRAME DENGAN METODE PUSHOVER (STUDI KASUS PADA GEDUNG IKATAN ALUMNI UNIVERSITAS SYIAH KUALA)

The influence of brick walls to performance of space frame is often being ignored, even though in this condition walls are participating in strengthen the building. Contribution of brick walls to performance of space frame structure with push over method goal is to know how the impact of walls in building structure performance which is being ignored all this time. Building of alumnus association was being modeled in two condition, first condition with the walls were being ignored and second condition with brick walls were modeled as a strut force. Modeling brick walls as strut alumnus association building Syiah Kuala university increased structure performance at this building. Modelling with brick walls as strut in pushover analysis x direction at MTS model minimize the displacement 6,36% from MTS model and increased building ability to accept base shear 301,71% from MTS model. Modelling with brick walls as strut in analysis displacement at Y direction increase 4,38% from MTS model. This thing showed that walls impacted building performance in bearing base shear. Plastification condition structure element at X direction without strut modeling, there is 54 element which had already collapsed (greater than collapse prevention) whereas at building with strut modelling has 6 element which already collapsed (greater than collapsed prevention). Plastification condition element structure at Y direction in building without strut modelling has 14 element which already collapsed (greater than collapsed prevention).

Nonlinear Performance Evaluation of High Rise Building Structure

Performance evaluation can provide information on how far an earthquake will affect building structure. This is important for evaluating the seismic behavior of post-yield building structures. The purposes of this study were to evaluate the story shear force that occurred, evaluate the distribution of plastic hinge, and evaluate the high rise building structure performance level during an earthquake. This research was conducted using static nonlinear analysis and calculated using capacity spectrum method. The plastic hinges that formed in the global-x and global-y direction were 1 and 52. Several elements are in collapse prevention level. This shows the element behavior and performance on performance point were not good. The performance level of building structure based on the calculation was damage control. The results show that the building structure was not efficient enough, because for a return period of 2500 years based on SNI 1726-2012, building performance was expected at damage control level.

Analysis of controllers in suppressing the structural building vibration

Two degree of freedom (2 DOF) mass spring damper system is used in representing as building structure that dealing with the earthquake vibration. The real analytical input is used to the system that taken at El Centro earthquake that occurred in May 1940 with magnitude of 7.1 Mw. Two types of controller are presented in controlling the vibration which are fuzzy logic (FL) and sliding mode controller (SMC). The paper was aimed to improve the performance of building structure towards vibration based on proposed controllers. Fuzzy logic and sliding mode controller are widely known with robustness character. The mathematical model of two degree of freedom mass spring damper wasis derived to obtain the relationship between mass, spring, damper, force and actuator. Fuzzy logic and sliding mode controllers were implemented to 2 DOF system to suppress the earthquake vibration of two storeys building. Matlab/Simulink was used in designing the system and controllers to present the result of two storeys displacement time response and input control voltage for uncontrolled and controlled system. Then the data of earthquake disturbance was taken based on real seismic occurred at El Centro to make it as the force disturbance input to the building structure system. The controllers proposed would minimize the vibration that used in sample earthquake disturbance data. The simulation result was carried out by using Matlab/Simulink. The simulation result showed sliding mode controller was better controller than fuzzy logic. In specific, by using the controller, earthquake vibration can be reduced.

Fling-step ground motions simulation using theoretical-based Green's function technique for structural analysis

The article aims to a. introduce a technique to generate long-period waveforms having fling-step effect at near fault and b. study the effect of fling-step on the structural performance of buildings. The study focuses on the fling-step effect which is related to large co-seismic displacement. For this purpose, seismological parameters of Kocaeli 1999 earthquake have been computed through an evolutionary multi objective approach (MO-GA) and Theoretical-based Green's Function (TGF) method with regard to specific objectives such as permanent displacement, response spectra, and multi-taper spectra. Thereafter many accelerograms were generated at desired near stations and the fling-step effects were removed from the accelerograms by a specific technique. Subsequently, three3-, 9- and 20-story steel frames were modeled in Opensees and the structural responses were obtained using nonlinear time history analyses. Findings from this study demonstrate that fling-step would affect the seismic demand fairly high when the ratio of the fundamental period of the structure to fling rise time (pulse duration) varies from 0.5 to 1.1. Also a good agreement between the responses of the structures subjected to generated ground motions and as-recorded ground motions was observed when this ratio equals 0.5. In most cases, an increase in seismic demand was observed in the absence of fling-step pulse.

Técnicas de refuerzo sísmico para la recuperación estructural del patrimonio arquitectónico chileno construido en adobe

El terremoto del Maule del año 2010 de magnitud 8.8Mw, dejó severamente dañadas las estructuras de adobe que conforman gran parte del patrimonio colonial rural chileno. En ese contexto, y como parte de un programa gubernamental de reconstrucción patrimonial, se desarrollaron una serie de intervenciones destinadas a la recuperación estructural y arquitectónica de las obras dañadas, pese a la inexistencia en ese entonces, de una normativa específica que regulara dichas intervenciones. Así, las actuaciones de reconstrucción, refuerzo y consolidación estructural, se realizaron teniendo como referentes investigaciones internacionales, adaptándolas a la realidad de las tipologías locales, en una suerte de laboratorio real donde el desempeño estructural de los inmuebles será puesto a prueba en futuros sismos. En este artículo se caracterizan y analizan comparativamente los sistemas de refuerzo empleados en edificios religiosos y viviendas de adobe, en función de las características tipológicas y de los daños sufridos.

The Influence of Accidental Torsion on the Inelastic Dynamic Response of Buildings during Earthquakes

Nonlinear dynamic analysis is becoming an accepted procedure to assess the performance of building structures during earthquakes. Several documents have emerged to provide guidance in terms of mathematical modeling, ground motion selection and scaling, and acceptability of results. While there are some significant differences in these documents, one feature in common is that explicit inclusion of accidental torsion in the nonlinear response history analysis is generally not required. One notable exception is ASCE/SEI 7-16 (2017) , which requires performing nonlinear analyses, including accidental torsion when the building has a torsional irregularity. The analysis presented in this paper supports this requirement, but also shows that neglecting accidental torsion in the analysis of torsionally regular buildings can be problematic. Failure to include accidental torsion in nonlinear analysis of torsionally irregular buildings may indicate stable response instead of dynamic instability, or may significantly underpredict deformations and thereby falsely indicate that deformation-based acceptance criteria have been met. Additionally, it is shown that simultaneous application of ground shaking in orthogonal directions is essential, and that the spatial distribution of geometric nonlinearities related to global torsional response must be included directly in the analysis.

Influence of ground motion duration on damage index-based fragility assessment of a plan-asymmetric non-ductile reinforced concrete building

The role of ground motion duration on the seismic performance of building structures remains unclear. This paper presents results on the effects of ground motion duration on the seismic behaviour of a 3-D plan-asymmetric reinforced concrete building. A three-story reinforced concrete building tested in Europe is used asa case study. A nonlinear model of the building with fibre-section distributed inelasticity displacement-based beam-column elements is subjected to two ground motion sets: (1) long-duration bi-directional earthquake ground motions, and (2) short-duration bi-directional earthquake ground motions. A new ground motion selection procedure is proposed to isolate the effect of duration on the structural response and on damage assessment. For comparative studies, long- and short-duration ground motions are selected so that they have similar response spectra. The damage assessment is performed analysing global and local responses. Global responses of the structure are evaluated in terms of peak roof drift ratios, peak interstory drift ratios (IDRs), IDR envelopes, normalized roof displacements relative to motion of the centre of gravity of the roof, and dissipated energy. Local responses assessed include moment-curvature or moment-rotation response in beams and columns as well as the hysteretic energy dissipated at selected sections of the structure. Two damage indices available in the literature are used to characterize the level of damage that the structure experiences, through damage index-based fragility curves that are developed as part of the work. For the short-duration motions, fragility curves developed independently from interstory responses and from the damage indices are similar, thus providing confidence into the use of the damages indices for fragility curve development. In addition, results indicate that for the vintage plan-asymmetric building analysed, the ground motion duration plays a role in the damage predicted using the two damage indices.

Response Modification Factors for Reinforced Concrete Structures Equipped with Viscous Damper Devices

The response modification factor is one of the seismic design parameters that determine the nonlinear performance of building structures during strong earthquakes. Most seismic design codes lead to reduced loads. Nevertheless, an extensive review of related literature indicates that the effect of viscous dampers on the response modification factor is no longer considered. In this study, the effect of implementing viscous damper devices in reinforced concrete structures on the response modification factor was investigated. Reinforced concrete structures with different stories were considered to evaluate the values of the response modification factors. A nonlinear statistic analysis was performed with finite element software. The values of the response modification factors were evaluated and formulated on the basis of three factors: strength, ductility, and redundancy. Results revealed that the response modification factors for reinforced concrete structures equipped with viscous damper devices are higher than those for structures without viscous damper devices. The number of damper devices and the height of buildings have significant effects on response modification factors. In view of the analytical results across different cases, we proposed an equation according to the values of damping coefficients to determine the response modification factors for reinforced concrete structures furnished with viscous damper devices.

Minimum life-cycle cost-based optimal design of yielding metallic devices for seismic loads

The yielding metallic devices have been used to improve the performance of building structures at design level intensities. They dissipate large levels of vibration energy through yielding of disposable steel plate elements but they may also enhance acceleration response related damage of mechanical and electrical components. This paper addresses the optimal design of these devices that minimizes the expected life-cycle object cost considering the story drift and acceleration related damages over the entire spectrum of seismic intensities that can occur on a building site. Genetic algorithm is used to calculate the optimal design parameters of the devices. The uncertainties associated with the frequency of occurrence of earthquakes of different intensities and random characteristics of the structural response are included in the life-cycle failure cost and the object cost calculations. It shown that these devices can be used effectively to reduce the overall life-cycle object cost and can be considered as good protective investment for structural designs in seismic regions.