Performance-based Seismic Design Research Articles

Substructure Mass Participation Effect on the Performance-Based Seismic Design Method for Isolated Bridges

Substructure Mass Participation Effect on the Performance-Based Seismic Design Method for Isolated Bridges

Study on the Seismic Optimization Scheme of Steel Bundled-Tube Structure with Vertical Setback

In order to improve the seismic performance of vertical setback steel bundled-tube structure and meet the dynamic multi-objective requirements of seismic performance-based design, the optimization effects under rare earthquakes on the zone of fortification intensity 7 and 8 in China are researched by improving members stiffness and adding dampers in the weak parts of structure, based on dynamic elastic-plastic analysis. The results show that: 1) Under rare earthquakes on the zone of fortification intensity 7, increasing the stiffness of weak skirt beam can improve the seismic performance of spiral and symmetrical setback structure; 2) For the spiral setback structure, under rare earthquakes on the zone of fortification intensity 7, the damper can only be arranged at the junction of the first layer of the setback frame unit and the frame unit without setback. However, under rare earthquakes on the zone of fortification intensity 8, it is not advisable to install dampers at the weak areas; 3) After incorporating dampers at the weak areas of symmetrical setback structure, the optimized members experienced a reduction in stress levels, significantly decreased the inter-layer displacement angles with a maximum reduction of 43%, and the optimization effect is significant.

Estimation and analysis of the cumulative energy damage model for precast concrete nonrectangular column frame structures

A detailed characterization of structural damage progress is essential to performance-based seismic design for precast concrete nonrectangular column (PCNC) frame structures. The paper presents an experimental investigation into the damage behavior of the PCNC frame structures under reverse cyclic loading, including specimens PCFS1 and PCFS2 in bay and specimen PCFS3 in depth of a new precast residential building. Based on the experimental results, the damage mechanism of the PCNC frame structures was further discussed with the cumulative energy damage model proposed in this paper, and the influence of key structural parameters on the damage of the PCNC frame structures was examined, including energy dissipation adjusted factor, the residual deformation rate and the stiffness degradation rate. Available results indicated that the experimental damage curves of test specimens increased with the loading progress and acted with nonlinear damage characteristics, and PCNC frame structural damage behavior was sensitive to the axial compression ratio. For the proposed damage model, the calculation results were in good agreement with the experimental results. On the basis, the damage degree of the PCNC frame structures was divided into five performance levels including normal use, temporary use, use after repair, life safety and prevent collapse in the defined damage range of (0, 1). Elastic layer drift ratio limit was suggested to relax for PCNC frame structures. Final test results could provide a basis for the aseismic design and damage assessment of such structures after earthquake.

Probabilistic seismic capacity models for circular tunnels at different performance levels

This paper presents a systematic study to develop the probabilistic seismic capacity models for circular tunnel linings. The uncertainties of lining parameters, soil properties, and ground motions are all considered. The Bayesian approach is used to estimate the model parameters based on the capacity samples simulated by a large number of refined dynamical numerical analyses. Finally, probabilistic capacity models are separately constructed for circular tunnels at three performance levels. To demonstrate the properties of the proposed method, the capacity models are used to estimate the capacities and the fragility curves of a typical tunnel. It is concluded that (1) the probabilistic model can quickly estimate the probability distribution of capacity based on existing parameters, with the estimated median value closely approximating the numerical result; (2) the proposed probabilistic capacity models can be used to quickly derive fragility curves for specific tunnels, which facilitates safety evaluation and performance-based seismic design of tunnels.

Performance-Based Seismic Assessment and Design of Long-Span Concrete Deck Arch Bridges

Performance-Based Seismic Assessment and Design of Long-Span Concrete Deck Arch Bridges

Economic Seismic Performance of Buildings with Peer Methodology and Fema P-58

The performance-based seismic design pretends to take care of the lives of the occupants and reduce the cost of damage caused by earthquakes. Several ways of estimating damage and economic losses have been developed, but most of them lack objectivity and have great dispersion in the results. In the last decade, the advancement of technology has allowed the appearance of new methodologies, such as the one developed by the Pacific Earthquake Engineering Research Center (PEER methodology). However, the information regarding application and scope is scarce. In the present investigation, the economic seismic performance for a steel building was determined by applying the PEER methodology with different levels of seismic intensity. A multi-family residential model of special moment frames (SMF) was used, and the structure was designed by means of modal analysis. Spectral, incremental dynamic non-linear analysis was performed where the structural response was determined, with the help of the PACT software. The seismic performance, expressed as the repair costs, repair times, deaths, and injuries, was defined. The results obtained indicate that buildings designed with traditional structural standards can be demolished after the action of an earthquake because the repair costs exceed 40% of the replacement cost. Rare and very rare seismic events can cause the total suspension of the service and a considerable number of deaths and injuries.

An Overview of Performance-Based Seismic Design Framework for Reinforced Concrete Frame Buildings

An Overview of Performance-Based Seismic Design Framework for Reinforced Concrete Frame Buildings

Performance-based seismic design and vulnerability assessment of concrete frame retrofitted by metallic dampers

Concrete frame has been one of the most widely employed structural types in engineering practice and would also have widespread application in the future. However, severe failure even collapse behavior were also detected for the pure concrete frame in strong earthquakes. So it is necessary to improve the seismic performance of pure concrete frame. This paper aims to analyze the seismic performance of metallic damper retrofitted concrete frame. Three concrete frames with metallic damper were selected as the research objects. The performance-based seismic design using the equivalent energy method was employed to design the prototype buildings, in which the multi performance objectives were considered. The concrete beam and column was designed taking the additional forces caused by the metallic damper into consideration. Further, the numerical model of the concrete frame with metallic damper was developed and verified by the test results. Time-history analyses were performed under frequently-occurred, design-based and maximum considered earthquakes to validate that the seismic performance of prototype buildings complied with the design objectives. Subsequently, seismic vulnerability of three prototype buildings were evaluated in terms of non-collapse and collapse fragilities. The analytical results indicated the performance-based design method is suitable to design the concrete frame with metallic dampers and the metallic damper could significantly improve the seismic vulnerability of pure concrete frame. This paper is beneficial for the design and application of metallic damper in concrete frames.

Studi Kinerja Struktur Beton Bertulang Beraturan Yang Didisain Dengan Performance Based Plastic Design

Indonesia is a country that has a very high level of seismicity. It is necessary to plan a building structure that can withstand the earthquake load. Indonesia has adopted guidelines on earthquake resistance planning procedures for buildings and non-buildings. This guideline uses the Performance-Based Seismic Design (PBSD) concept. Performance-Based Plastic Design (PBPD) is a structural analysis with the concept of energy methods which was initially used on steel structures. For reinforced concrete structures this method can also be used using the C2 coefficient. To determine the performance level of structures designed using the Performance-Based Plastic Design method, an analysis of the five-story reinforced concrete structure was carried out. Next, the structure will be analyzed using pushover loads. From the structural performance analysis, the structural ductility value based on Performance-Based Plastic Design (PBPD) was 3.014. The performance level is based on the capacity spectrum at the immediate occupancy level.

Reliability of steel structures with Chevron bracing systems considering the performance-based seismic design philosophy

In this paper, the seismic performance and reliability of steel buildings with Chevron-Braced frames are studied integrating a novel probabilistic approach and the performance-based seismic design concept. The seismic response of models is extracted using response history analyses with the help the commercial software SAP2000. In this sense, three variables associated with the seismic response of the structure are studied: overall lateral displacement, rotation of connections, and inter-story drift. Those responses are evaluated by exciting the structure with eleven characteristic ground motions of the zone with respect to three performance levels: immediate occupancy, life safety, and collapse prevention. Once the seismic response is extracted for every performance level, the reliability of the models is calculated with respect to inter-story drift as described next. First, considering the seismic response in terms of inter-story drift for every ground motion, the associated histogram is constructed. Then, using 13 Probability Density Functions (PDFs), a Chi-square test is performed to identify the best-fitted PDF associated to the histogram of inter-story drift. Afterwards, with the best-fitted PDF of inter-story drift, the probability of failure and reliability index are extracted considering serviceability limits for every performance level. This represents a unique approach to extract the risk of structures subjected to ground motions associated to different performance levels. In addition to the structural reliability, a study about the cost of the structures with and without Chevron braces is developed, and then, it is documented the best option. Finally, based on the results reported in this paper, it is demonstrated that steel buildings with Chevron-braced frames present a better seismic performance than steel moment resisting frames without any bracing system. In summary, overall lateral drifts are reduced between 40 and 60% when Chevron braces are implemented in comparison to steel moment resisting frames without braces. On the other hand, if Chevron bracing systems are not used, i.e., in steel moment resisting frames, the inter-story drifts are about 300% higher than those of steel structures with Chevron braces. Hence, structural damages can be considerably reduced if Chevron-braced frames are implemented in steel structures that may be excited by characteristic ground motions of the zone where they are located.

Monotonic and Cyclic Modelling of Structural Steel for Finite Element Analysis

Nowadays, as a response to the promoted concept of performance-based seismic design, the finite element method (FEM) has become an omnipresent practice that supports the simulation of structural elements. This approach requires constitutive numerical models, which could reproduce both elastic and plastic behaviour of steel. Looking forward to a reliable FEM simulation, the modelling and calibration of steel undergoing monotonic and cyclic loading tests is investigated in this paper. With respect to monotonic tensile test, a sensitivity analysis regarding mesh refinement and finite element type is developed. Another inspected issue, such as high-strength steel modelling, taking into consideration low ductility and absence of yield plateau, is also presented. And finally, a model for structural steel, using the combined isotropic-kinematic hardening model, is introduced to simulate metal non-linear behaviour under ultra-low-cycle fatigue regime. All these numerical simulations are processed via Abaqus software package, and are validated by a set of experimental tests.

On the performance-based seismic design of yielding retaining structures

This work summarises recent research on the seismic behaviour of displacing or yielding retaining structures, i.e., structures that can undergo permanent displacements during strong earthquakes without failing. For these systems, energy dissipation on shaking, leading to reduced inertia forces, can be achieved by allowing the activation of ductile plastic mechanisms. These must be correctly identified to guarantee the desired strength hierarchy, and depend on the specific retaining structure under examination. It is shown that the critical acceleration, or the smallest value of acceleration corresponding to the activation of the critical plastic mechanism, is the key ingredient for the performance-based design of yielding retaining structures. In fact, the critical acceleration controls both the maximum internal forces in the structural elements and the magnitude and trend of post-seismic permanent displacements and rotations, required for quantitative serviceability and post-earthquake operability assessment of infrastructures. Based on a clear understanding of the physical mechanisms governing the dynamic behaviour of these systems, pseudostatic limit equilibrium solutions and simplified dynamic methods can be developed for their seismic design. Theoretical predictions are validated against data from reduced scale centrifuge models and results of pseudo-static and fully dynamic numerical analyses. Finally, all the results presented in the paper, including experimental, numerical and theoretical findings, are used to provide suggestions for the performance-based design of retaining structures.

In-plane seismic fragility models for clay masonry infills in reinforced concrete frames

This study aims at deriving multi-damage state fragility functions/curves for clay masonry infills in low-to-medium-rise reinforced concrete frames designed according to a performance-based seismic design methodology. Different structural archetypes were identified and modelled numerically by means of distributed plasticity approaches in order to undertake multi-stripe nonlinear dynamic analysis and derive seismic lognormal fragility models through regression analysis. Both infilled and bare frame configurations were simulated and compared together, providing fragility curves corresponding to immediate occupancy, damage prevention, and, ultimately, life safety limit states, all of which can be integrated in general frameworks for seismic risk/loss assessment and management. To this end, fragility models are given in terms of three different intensity measures, namely peak ground acceleration, peak floor acceleration, and peak floor spectral acceleration, considering also two different methods for the calculation of the probability of occurrence/exceedance of a certain damage state, namely building-wise and storey-wise approaches.

A Review of Studies on the Seismic Vulnerability of Structures in China

The performance-based seismic vulnerability analysis is the basis for evaluating the seismic reliability of structures, which is of great significance to the prediction of seismic damage and the establishment of seismic design codes based on the reliability theory. In this paper, a comprehensive review of the methods of seismic vulnerability analysis, the current research status, and the remaining problems in this field is presented. Firstly, the methods of structural seismic vulnerability analysis are categorized, and the advantages and disadvantages of each method are summarized, and the research progress in this field is discussed in detail; Finally, it is concluded that the research on the seismic vulnerability of structures in China has not yet produced research results of practical engineering significance. A set of more effective seismic vulnerability analysis theories should be established to directly guide the performance-based seismic design of structures by reasonably and accurately quantifying relevant factors such as ground shaking input parameters and performance level damage indicators.

Seismic Failure Risk Assessment of Post Electrical Equipment on Supporting Structures

To assess the seismic failure risk of post electrical equipment, an assessment method considering different sorts of uncertainty of the post electrical equipment was proposed. The aleatory and epistemic uncertainties were considered in the assessment, and the parameters in seismic hazard function of different sites were fitted. To investigate the effects of the supporting structure on the seismic fragility and risk of post electrical equipment, case studies on ultra-high-voltage gas insulated switchgear bushings mounted on two different supporting frames were conducted. The results indicated that both the maximum tensile stress of the bushing and the maximum displacement of the supporting frames should be considered as the limit statuses of the post electrical equipment. The different sorts of uncertainty increase the seismic failure risk of the post electrical equipment, and should be considered in the assessment. Besides, for the pillar-type porcelain element equipment, the supporting frames with lower lateral stiffness generated higher seismic failure risk. In constrast to the case of retrofitting the supporting frame to increase the lateral stiffness, the annual seismic failure risk of the GIS bushing mounted on the retrofitted supporting frame decreased 101%. Besides, the seismic failure risk of the post electrical equipment is not positive correlated with the peak ground acceleration. In the performance-based seismic design of the electrical substation, the seismic failure risk of the electrical equipment should be considered.

Structural reliability of steel buildings with X‐bracing systems considering the performance‐based seismic design philosophy

AbstractThe main objective of this paper is to study and compare the structural reliability of steel moment resisting frames (SMRFs) and steel frames with X‐bracing systems considering the performance‐based seismic design (PBSD) philosophy. In this sense, to accomplish such a study, nonlinear response history analysis is implemented. The buildings under consideration are designed to be located in Culiacan, Mexico. The results are presented in terms of overall displacements, rotations of connections, and interstory drifts, for three performance levels: (1) immediate occupancy, (2) life safety, and (3) collapse prevention, respectively. For each performance level, 11 ground motions were selected to study the response of the structures. Such responses were extracted by using the SAP2000 commercial software to perform structural analysis. It was demonstrated that the steel frame with X‐bracing systems developed a better seismic performance than SMRFs for all three variables under consideration. In addition, it was found that a reduction up to 70% in overall displacements and interstory drifts can be achieved when X‐bracing systems are used in steel structures. The risk of the structures was extracted in terms of reliability index and probability of failure considering probability density functions of interstory drifts. It was demonstrated that reliability index increased for structures with X‐bracing systems in comparison with SMRFs. Finally, in terms of costs, steel structures with X‐bracing systems are more expensive than SMRFs. However, its use is justified because serviceability conditions as overall displacement and interstory drift are considerably reduced.

Machine learning-based design of a seismic retrofit frame with spring-rotational friction dampers

In this study a machine learning-based design procedure for a new seismic retrofit system is presented and its seismic retrofit capability is validated by intensive seismic analyses. The retrofit system consists of a steel frame with rotational friction dampers (RFD) at beam-column joints and linear springs at the corners providing both energy dissipation and self-centering capabilities to existing structures. The performance-based seismic design procedure of the spring-rotational friction damper (SRFD) retrofit system is developed using a genetic algorithm (GA) and an artificial neural network (ANN). The performance of the presented retrofit system and its optimum design procedure is evaluated using case study models for multi-limit states by investigating seismic fragilities, life-cycle cost (LCC), and seismic Resilience Index (RI) before and after the retrofit. According to the analysis results, the SRFD retrofit system proved to be effective in decreasing story drifts, seismic fragility, and LCC of the retrofitted structures significantly. The retrofitted models turn out to be more resilient and recover better than the un-retrofitted models after earthquakes. The developed performance based design procedure is proved to be effective in seismic retrofit of case study structures to satisfy multi-level design objectives.

Response modification factor of high strength steel frame with D-eccentric brace using improved pushover analysis method

The high-strength steel frame with D-eccentric brace presents a novel structural system that demonstrates exceptional plastic deformation capabilities when exposed to high levels of earthquake hazards. This system employs ordinary steel links with a yield strength below 345 MPa, while the frame beam and column utilize high-strength steel (yield strength above 460 MPa, such as Q460 or Q690 steel) to reduce cross-sectional dimensions while ensuring elasticity of non-energy consuming components. The resulting structure exhibits outstanding ductility and energy-dissipating capacity. The response modification factor (R), a crucial parameter in performance-based seismic design, plays a significant role in achieving appropriate and cost-effective seismic designs. Unfortunately, the 2016 edition of China's code for Seismic Design of Buildings (GB50011-2010) did not consider the concept of R and instead employed a constant value for all structural systems, which is unreasonable. Therefore, a comprehensive investigation of the R value for the high-strength steel frame with D-eccentric brace is imperative to enhance structural performance design, provide guidance for future designs, and promote the widespread implementation of this structure in seismic regions, where it exhibits superior seismic performance. This study utilizes the performance-based seismic design approach to design structures with varying numbers of stories (4, 8, and 12), link lengths (900, 1000, and 1100 mm), and different steel strengths (Q460 and Q690). An improved pushover analysis method is employed to calculate the R values for each prototype, considering the number of structural stories (N) and the link length (e). The derived values of each performance coefficient serve as valuable references for future performance designs of novel structural systems.

Framework for Risk-Targeted Performance-Based Seismic Design of Ordinary Standard Bridges

Framework for Risk-Targeted Performance-Based Seismic Design of Ordinary Standard Bridges

A stochastic CSM-based displacement-oriented design strategy for the novel precast SRC-UHPC composite braced-frame in the externally attached seismic retrofitting

With the development of performance based earthquake engineering, the recognition of performance based seismic design (PBSD) is continuously growing in academia and industry. Meanwhile, with the gradual awareness of earthquake threat to the existing aged buildings, researchers are focusing more on the novel retrofitting technologies to enhance the structural capacity. Based on this background, a novel precast steel-reinforced-concrete and ultra-high-performance-concrete composite braced-frame is developed for the externally attached seismic retrofitting, and a stochastic capacity spectrum method (CSM) based displacement-oriented design strategy is proposed and well validated via a case study. In general, the novel external composite substructure combines the superiority of substructure technology, precast technology, energy-dissipation technology and high-performance material technology, and is a promising structural form in the seismic retrofitting. The proposed design strategy derives from the classic CSM, and its procedure is in alignment with the PBSD to make the designed building to satisfy various predetermined functional requirements during use. The incorporation of probability factors makes evaluation results more comprehensive and objective, and the control of displacement targets makes structural systems more performant under different demand levels. The case study indicates that the stochastic CSM-based design strategy can be well coupled with the novel external composite substructure during the whole retrofitting process (i.e., three design parts), which demonstrates the superior applicability and stupendous potentials of the proposed design strategy for the subsequent in-depth research.