Structural Performance Levels Research Articles

Reconstruction as Deterioration Indicator for Operational Structural Performances of Bridge Materials

This article presents analysis of deterioration indicators for a comparative quantification of the operational structural performances of bridge inventories. The analysis considers the various kinds of material in the entire database of the US National Bridge Inventory. The multi-criteria approach integrates the indicators of deterioration, considering diagnostic condition and life cycle to determine the equivalent operational structural performances. This study also uses reconstruction data to determine an additional deterioration indicator for performance. The proportional effort for reconstruction reflects the practical need to counter deterioration and preserve a required level of structural performance, under all circumstances. The presented addition of reconstruction performance provides a more comprehensive assessment of bridge performance. The results reveal the continuous efforts to maintain a relatively balanced performance adequacy at the national level within the prevailing funding constraints. Reconstruction performances are generally higher than deterioration trends (rate and pattern) performances, revealing that the constrained reconstruction efforts have difficulty to keep pace with the actual deterioration.

Rapid Safety Assement and Experimental Derivation of Damage Indexes for In-Service Glass Slabs

The mechanical performance of pedestrian structures attracts the attention of several studies, especially with respect to unfavourable operational conditions or possible damage scenarios. In terms of vibrations, for example, specific customer comfort levels must be satisfied, depending on the class of use, the structural typology, the involved materials, in addition to basic safety requirements. A special consideration should be given to in-service systems that are possibly affected by degradation or even damage, and thus potentially unsafe for pedestrians. In this regard, the availability of standardized non-destructive protocols for a reliable and rapid structural safety assessment may result in efficient support for diagnostic analyses. In this paper, 3 different laminated glass (LG) modular units belonging to 2 different indoor in-service pedestrian systems located in Italy are investigated. Operational Modal Analysis (OMA) procedures and dynamic identification techniques are used to quantify the residual capacity of the examined systems, including damage and material degradation, based on a single triaxial Micro Electro-Mechanical System (MEMS) accelerometer. The experimentally derived performance indicators and calibrated mechanical parameters for the examined structural system are assessed towards traditional design procedures, and further quantified with the support of Finite Element (FE) numerical model updating. A comparative analysis is carried out to explore the structural performance and safety levels of in-service LG slabs in regards to vibration comfort, deflection control and stress analysis.

Seismic performance evaluation of unconfined dry stacked block masonry structure

Dry stacked block masonry is getting popularity and has auspicious future both in developed and developing countries. In this research work, it was aimed to appraise the seismic performance of unconfined dry stacked block masonry structure built with Hydraform blocks. The experimental work included the construction of a full-scale typical building and testing by using quasi-static reverse cyclic loading. The seismic parameters and behavior studied in this research work, include the force–deformation relationship, ultimate ductility factor, response modification factor, displacement amplification factor, energy dissipation, stiffness degradation, and structural performance levels. The visual assessment and analyses of the test data was scrutinized to construe and elucidate the damage patterns, and local and global behavior of the structure. Based on the results, the unconfined dry stacked block masonry structures can easily withstand against low to moderate seismic actions. The tolerance of self-interlocking blocks, in sliding and rotation in out-of-plane direction, enables it to act as energy dissipating devices and mitigates the chances of brittle shear failure.

Study comparison P-Delta Effect analysis depends on height variation of the building

Indonesia is an area where three active plates meet, so many areas are prone to earthquakes. To anticipate this and minimize casualties due to earthquakes, earthquake-resistant buildings are needed. Earthquake resistant buildings are the most important thing that needs to be considered, a building structure must be designed to be able to withstand lateral loads such as earthquakes within the limits set by the code/standard. The result of the earthquake load will produce an additional effect on the multi-storey building, namely the P-Delta effect. In this study, the effect of these effects will be analyzed on non-rise buildings and high-rise buildings. Analysis of the P-Delta effect will be calculated on the modeling of three buildings for non-rise buildings (Building models A, B and C) and three highrise building models (Building models D, E and F) and get the results that the P-Delta Effect has an impact on changes structural performance level in Model E Building (56 meters) from Immediate Occupancy to Life Safety

Analisis Perbandingan Kinerja Seismik dari Struktur Gedung dengan Pelat Konvensional, Waffle Slab, dan Flat Slab

Indonesia is a country with high earthquake risk because it is located in the path of the most active earthquake in the world. It makes Indonesia situated in a region with a high earthquake intensity. The study aimed to determine the seismic performance levels of building structures with conventional slabs, waffle slabs, and flat slabs with the time history analysis method. There are three models of structures studied, namely building structures with conventional plates, building structures with waffle slabs, and building structures with flat slabs, with a 5-story structure system, where the longest and shortest span has the same size of 20 m and the height of each level 4 m. This study showed the largest displacement was 235.82 mm in building structures with waffle slabs and the smallest displacement was 146.49 mm in building structures with flat slabs. The largest drift is 0.012 on a building structure with a waffle slab, and the smallest drift is 0.007 on a building structure with a flat slab. The level of seismic performance produced from all three types of structures varies from immediate occupancy (IO) to damage control (DC).

Seismic performance indicator and seismic performance levels of rectangular underground structures

The classification of structural performance levels and quantitative definition of performance indicators of underground structures are important parts of performance-based structural seismic design. Four typical underground rectangular reinforced concrete frame structures with different cross sections are taken as the research object, and their seismic performance is analyzed through the pushover method in this study. According to the seismic response characteristics and the failure law, it is determined that the central column is the control section in the seismic performance. Then, based on the capacity curves of these control sections, the performance indicator and the performance levels are determined. Subsequently, through a series of seismic capacity analyses considering the variations in structure type, site condition, structural material property and burial depth, the limits of the structural performance indicator under different performance states are analyzed, and a quantitative division plan of structural performance levels is proposed.

Structural performance of 1 way and 2 way setback with the soft first story using ddbd

Irregular building structures increasingly varied, such as setback buildings and buildings with soft level stiffness irregularity on the first floor of the building (soft first story). High-rise buildings are at risk of collapse due to earthquakes. Designing efficiency requires a Direct Displacement Based Design (DDBD) method. In this study, the DDBD method uses pushover analysis on soft first-story buildings without a setback,1-way setback, and 2-way setback. This study aims to obtain the value software's value of displacement, story drift, ductility, plastic hinge response, and performance levels study indicates that the displacement value of the soft first-story building without setback is smaller than the setback building. In addition, the value of displacement and story drift in the setback building with a soft first story is influenced by the small setback area ratio. The highest displacement and story drift values in the X direction are 1-way setback buildings, which are 0.422 m and 0.0147 m, while in the Y-direction, the 2-way setback buildings are 0.44 m and 0.0167 m. The most significant value of actual ductility is a building without setbacks with a soft first-story. The plastic hinge response in all three buildings shows a strong column weak beam. The level of structural performance in all three buildings is at the level of Immediate Occupancy, where the value of the performance level of the FEMA 356 method is greater than the ATC 40 method.

Experimental and numerical study on seismic response of RC frames strengthened by shotcrete sandwich panel infills and CFRP strips

The present study evaluates the utilization of shotcrete sandwich panel (SSP) infill and CFRP strips to strengthen reinforced concrete (RC) frames. To this end, a CFRP diagonal strip-infilled RC frame, an SSP-infilled RC frame, and a control specimen (a bare RC frame) were examined as single-story specimens in terms of the in-plane seismic response. This work compared the specimens in the stiffness degradation, damping, and cyclic lateral response. Also, the available empirical techniques were subjected to performance comparison in the stiffness and capacity calculation of masonry infills for the SSP infill system. The structural performance levels of the system were calculated and compared to the ASCE 41 code. Eventually, numerical analyses were carried out in order to examine the specimens in nonlinear behavior. It was found that the SSP-infill led to a two-fold rise in RC frame strength, even though system stiffness increased. Moreover, the ductility of the infilled frame experienced a 42% improvement in light of the CFRP diagonal strips.

Assessment of damage index and seismic performance of steel plate shear wall (SPSW) system

Nowadays, the discussion of prevention and reduction of earthquake hazards and the introduction of methods to assess the vulnerability of structures has become very important. This study aims to investigate the failure distribution and assess the seismic behavior of a steel shear wall (SPSW) system quantitatively. Therefore, to assess the failure distribution of SPSW structures in the 4, 8, and 12-floors has been designed and analyzed. The studied structures have been analyzed under 24 far-field earthquakes in the time history analysis section. Three damage indicators of Park and Ang, Iemura and Mikami, and relative displacement were used to investigate the failure's extent and location. The average failures of all three indicators are examined to evaluate the performance levels of structures. The results show that a significant part of the floors for the relative displacement index is limited to life safety. Also, Park and Ang's and Iemura and Mikami's indices are limited to damage control. According to the results, the most damage is observed in 4-story frames. There is also damage to 8- and 12-story frames, but the amount is small. On the other hand, the evaluation of failure indices and performance levels estimates the structure's safety in terms of seismic design. Also, examining the seismic behavior of structures based on damage indices Park and Ang and Iemura and Mikami provides a more realistic amount of damage and performance levels of structures for designers.

Retrofitting technique effectiveness and seismic performance of multi-rise RC buildings: A case study

This study aims to determine the effectiveness of a retrofitting technique based on the seismic performance analysis results comparison between two inactive multi-storey reinforced concrete (RC) buildings for a long period. Their seismic performance is determined according to the latest Turkish Building Earthquake Code (TBEC-2018) recommendations. The main difference between the examined buildings is the reinforcement (retrofit) technique applied to one of them with additional new shear walls. The whole process was demonstrated with a code-based approach, and the results were compared after the performance evaluation. The structural system geometry, member dimensions and plan layout of the buildings are checked with the original design projects by making on-site measurements. The material properties of the buildings are determined by field studies and laboratory studies. Buildings are modelled with finite element software, and numerical simulations are performed to determine the seismic performance levels according to existing code. As a result of the analysis, the effectiveness of the retrofit approach was examined by comparing the structural behaviour and seismic performance levels of both buildings. The results showed the importance of some parameters that should be taken into account in the retrofitting process with the addition of new shear walls to RC structures. While the applied retrofit process increased the stiffness of the structure and decreased the displacements, the results indicated a failure with a shear-critical condition.

Evaluasi Struktur Bangunan Pasar Inpress Blok IV Gedung B dengan Metode Pushover

AbstractInpres market block IV Pasar Raya Padang is not designed as a shelter building, but is designated as a vertical evacuation site when a tsunami occurs. This study aims to evaluate the structural performance of Inpress market block IV zone B. The method used for this research is the pushover analysis method. According to FEMA P-646/2019, vertical evacuation refuge structures are included in tsunami risk category IV, based on the risk category the maximum performance level is at the Immediate Occupancy (IO). For loads on buildings, refer to SNI 1727:2020 and SNI 1726:2019 for earthquake loads. For the calculation of the capacity of concrete structural elements, refer to SNI 2847:2019. Structural analysis was carried out using the SAP2000 version 16. After analysis, based on performance points, drift ratio that occur due to earthquake loading in X-direction and Y-direction are 0,05875% and 0,0067%. The maximum total drift that occurs is smaller than that required by ATC-40 for the Immediate Occupancy performance level, which is 1%. Thus, the structure performance level is Immediate Occupancy. This means that the Inpress market block IV building is still strong enough against earthquake loads.

Effectiveness of Damping Devices on Coupling Beams of 15-story Building Based on Nonlinear Analysis Procedures

In recent years, damping device has been experimentally studied to replace diagonally reinforced coupling beams, to mitigate rebar congestion problem. This study focuses on evaluating the effectiveness of various damping devices in a high-rise building. Type of damping devices evaluated are Viscoelastic Damper (VCD) and Rotational Friction Damper (RFD), with study case of a 15-story reinforced concrete apartment building with a dual system (column-beam and shear walls). The analysis used is a nonlinear time history analysis with 11 pairs of ground motions matched to the Indonesian response spectrum based on ASCE 41-17 and ASCE 7-16. In this analysis, each damper will be varied with a different position, namely the first model, the damper will be installed on the entire floor and in the second model, the damper will be installed on the 5th floor to the 9th floor, which is the floor with the largest drift. The results show that the model using both dampers increase the level of structural performance globally and locally in the building, reducing the level of damage to the structural elements. But between the two dampers, the coupling beam that uses RFD is more effective than using VCD in improving building performance. The damper on the coupling beam has a good role in dissipating earthquakes and in terms of ease of installation.

Numerical study of reliability index of structure rehabilitated with steel shear wall

Uncertainties in seismic demand and structural capacity create conservatism in the acceptance criteria of structural performance levels. This conservatism can be reduced and designs optimised by considering and reducing uncertainties. In seismic rehabilitation, a secondary system added to an existing structure has probabilistic parameters that can lead to changes in existing uncertainties. In this work, a steel moment frame was rehabilitated with a steel shear wall (SSW). Structural uncertainties were investigated by considering probabilistic variables of the force–deformation relationship of the SSW. The results showed that structural uncertainty increased the total uncertainty by 2.0–9.3%. Previous studies that have not considered structural uncertainty due to the force–deformation relationship and may not provide results with appropriate conservatism. As a result, the dispersion of the total uncertainties of a structure rehabilitated with a SSW is close to the dispersion value of a moment frame equipped with a brace, but is more than the dispersion value of the moment frame structure. A parametric study of the reliability index was performed based on probabilistic variables. Based on the results, the structural uncertainty reduced the reliability index by 0.57–1.28%.

A simplified design procedure for seismic upgrade of frame structures equipped with hysteretic dampers

This paper presents a simple and affordable design procedure for the seismic upgrade of frame structures equipped with hysteretic dampers. The proposed framework is aimed at leading the designer to proportion the damper device(s)) in order to achieve a desired structural performance level. According to the method, the structural system composed by frame and dampers is replaced by an equivalent Single Degree of Freedom (SDOF) system, characterized through its secant stiffness and equivalent viscous damping, both defined in relation to a “performance point” which is assigned on the basis of the allowable damage of the frame and on the first mode deformation of the main structure. The global stiffness and strength of the equivalent SDOF system are then distributed along the height of the frame according to a stiffness-proportionality criterion, and the properties of the damper units are calculated depending on the chosen layout. Two case-studies relevant to as many reinforced concrete frames are provided to demonstrate the effectiveness of the suggested procedure, obtaining a satisfactory agreement between the design target and numerical capacity curves. Non-linear dynamic analyses are further performed to assess the reliability of the methodology.

Perilaku Seismik Struktur Rangka Komposit RCS dengan Variasi Rigidity Zone Factor Pertemuan Balok-Kolom

This research evaluated the effect of connection’s rigidity zone factors of RCS frame’s connections on the seismic behavior of regular RCS frames of a five-story office building located at seismic design category (SDC) of D. The variations on rigidity zone factors were 0, 0.25, 0.50, 0.75, and 1.0, respectively for Model MS, MSR025, MSR05 MSR075, and MR with the same elements’ dimension. A 3-D finite element modeling was conducted to do a linear elastic analysis for structural design and nonlinear static pushover analysis for evaluating the structural seismic performance. The results show that all models have met the strength and serviceability design limits. The seismic performances in terms of base shear, elastic stiffness, and ductility of all RCS models increased with an increase in the values of the rigidity zone factor. The structural performance level according to FEMA 440 was life safety (LS) for the Model MSR05, MSR075, and MR, while for the Model MS and MSR025 was collapse prevention (CP). The seismic energy dissipation for all RCS frames was an intermediate category indicated by the numbers of developed plastic hinges less than 20% of the total potential plastic hinges

Studi Perbandingan Kinerja Sistem Struktur Setback berdasarkan Metode ATC 40, FEMA 356 dan SNI 1726:2012

The aim of this study was to compare the performance level of the setback structure system and the non-setback structural system using the ATC-40, FEMA 356 and SNI 1726-2012 methods. The non-setback structure have the shortest span of 15 m, the longest span of 20 m and the level of each floor was 3.5 m but the setback structure have setback system on the longest span of 10 m at the 5th and 6th floor level. The results showed that the performance level based on all methods of the sectback structure system is at the immediate occupancy level while the non-setback structure system, based on SNI 1726-2012, the performance level is immediate occupancy for the longest span and the shortest span is damage control. On the other hand, based on the ATC-40 and FEMA 356 methods, the performance level of the non-setback structure is at the immediate occupancy level. Drift on non-setback buildings based on the SNI 1726-2012 method is 0.011, based on the ATC-40 method is 0.007, and based on FEMA 356 is 0.005. Drift on the setback building based on the SNI 1726-2012 method is 0.010, based on the ATC-40 method is 0.006, and based on FEMA 356 is 0.004.

Influence of buried depth on seismic capacity of underground subway stations through performance-based evaluation

Buried depth is an important physical factor that affects the seismic performance of underground structures yet remains scarcely considered in existing seismic design. This paper aims to determine the influence of buried depth variation on the seismic capacity of underground subway stations in the framework of performance-based seismic design with particular focus on the influence on the inter-storey drift ratio limit. A brief introduction is presented to determine the performance level of subway station structures based on the pushover method. The influence of buried depth on the seismic performance index (inter-storey drift ratio) of subway station structures is investigated, as well as its influence on the shear distribution and failure mode of the key structural component, that is the middle column. It is found that the inter-storey drift ratio limit generally decreases with increasing buried depth and the station ductility worsens. The failure mode of the middle column changes from large eccentric compression to small eccentric compression with increasing buried depth owing to increased axial compression. The results are applied to estimate an optimum buried depth that improves the overall safety of subway station structures.

Evaluation of Structure Performance under Seismic Load with Non-Liner Time History on High-Rise Building Affected by Kendeng Fault Earthquake Simulation

Indonesia is a country located in the convergence of small plates and large plates. Furthermore, this causes Indonesia to be high potentially to earthquake hazards. The newest geological research published by Geophysical Research Letter (2016) shows the existence of Fault Kendeng, a fault stretches along 300 km from South Semarang, Central Java, to East Java with a movement of 0,05 millimeter per year [1]. As a result of its research, an evaluation using a non-linear time history analysis for structural buildings is necessary. The objective of this study is to evaluate structural buildings using a non-linear time history analysis. This study applies DSHA (Deterministic Seismic Hazard Analysis) method to obtain acceleration time history on bedrocks. Since the record of ground movement in Indonesia is limited, the attenuation function equation used to scale and match other country’s time acceleration history data. SSA (Site-Specific Analysis) is used to propagate earthquake acceleration from bedrocks to the surface. The earthquake acceleration on the surface generates as the earthquake load on the buildings. The results of Kendeng fault earthquake simulation using non-linear time history analysis shows that column members capacity is more robust than beam members capacity which the beam collapse mechanism occurs initially. From the maximum total drift ratio result, when the Kendeng fault earthquake occurs, the building structure performance level is at collapse prevention level Based on ATC-40 [2]. This research result shows that 96,7% of plastic hinge has not yielded. However, some elements are already damaged. Since most damage members are column, then it may require column strengthening to enhance maximum performance level at life safety condition category.

Seismic Performance Evaluation of Two-story Dhajji-dewari Traditional Structure

ABSTRACT Experimental and numerical studies performed on traditional timber-frame masonry buildings have confirmed excellent deformability of timber structure; however, observations from dynamic shake table tests and earthquakes have revealed the potential hazard of stone falls poses a risk for occupants to get injured. This research presents a seismic performance evaluation study carried out on a traditional two-story Dhajji-Dewari structure having reduced diagonal braces for economizing construction. Moreover, one in-plane wall and one out-of-plane wall were retrofitted with typical steel wire mesh to control dislodging and fall of infill stones. Shake table tests were performed on a representative 1:3 reduced scale test model. The testing was performed using natural acceleration time history with multi-level excitations. The structure damage mechanism was observed with increasing intensity of base motion. The fundamental dynamic properties like frequency, damping, and acceleration amplification factors were obtained. The structure lateral force-deformation capacity curve was derived and bi-linearized to compute the structure ductility, overstrength, response modification factors (approximated to 3.0), and to develop structural global performance levels (i.e. roof drift limits, the corresponding base shear coefficients, and the wall damage states). A simplified procedure was also presented for the global seismic performance assessment of the Dhajji-Dewari structure in various seismic zones. The overall behavior of the model was observed to be good; however, the Immediate Occupancy and Life Safety limit states were primarily governed by the falling of infill rubbles from walls without steel wire mesh. The proposed steel wire mesh negligibly contributes to the lateral stiffness and strength of the structure and primarily prevented the dislodging and fall of stones. The proposed response modification factor can be used for the seismic analysis of structures using an elastic model to compute design forces for timber members and connection fasteners.

Evaluasi Level Kinerja Bangunan Gedung Kayu Bertingkat Rendah Akibat Beban Gelombang

Several coastal areas in Indonesia are at risk of moderate to high tsunami disasters, this is related to the condition that Indonesia is located in an earthquake high risk area. At this time there are many buildings located on the coast with a low-rise stilt house system with the main structural system, namely beams and columns using timber materials. The building structure design includes the performance evaluation process, namely strength, stiffness and structural stability. The purpose of this research is to study the evaluation behavior of performance levels, especially the strength and stiffness of low-rise timber buildings, namely the level of structural performance due to gravity and lateral loads, namely sea waves. The research scope is a three-story building with a beam and column frame structure system. Columns are circular and beams have a square cross section. The loads taken into account are gravity and lateral. The strengths discussed are the bending capacity of the beam and the compressive capacity of the column. In order to obtain building behavior that is closer to real conditions, especially in beam-column joints, secondary data is used, namely empirical data on the envelope load-deformation curve of the beam-column joint test results in the laboratory (modeled as link property). Evaluation of structural performance begins with structural analysis using SAP2000 software, to obtain internal forces and building drift. The results show that the use of link properties in beam-column joint joints in the timber building structures shows greater deformation results compared to rigid joint models, this indicates that modeling the structure with beam-column joint joints modeled as link property has an impact on building stiffness. Lower and represents the condition of a timber building with beam-column joint characteristics closer to the actual condition. The existence of a hole size in the column (to insert the beam) which is larger than the cross-sectional size of the beam results in the rotation of the joint not being zero and a slip occurs when the joint works to transmit internal forces.