Performance-based Design Method Research Articles

Improved PBPD method for dual steel system considering the global effect of space frames

Performance-based plastic design (PBPD) method has been proposed to design single bay planar frames for twenty years. For a dual steel system, such as an eccentrically braced frame (EBF) structure, there will be both EBF bays and moment resisting frame (MRF) bays. So, the global effect between different frame bays cannot be considered when designing the global structure using the traditional PBPD method. In this paper, a ten-story high-strength steel composite K-shaped eccentrically braced frame (HSS-K-EBF) structure was firstly used for performance design and analysis based on a single bay EBF. The results show that the global structural model obtained by direct performance design of the single bay model cannot achieve the desired performance objectives. To this end, an improved PBPD method for the dual steel system was proposed considering the global effects of space frames. The elastic and elastic–plastic shear distribution relations were calculated for different bays of the frames including EBFs and MRFs. The performance objectives of the global structure were designed and evaluated more accurately by considering the over-strength contribution of shear links and the plastic development rate index ξ of energy dissipation members. The improved PBPD method was used to design the ten-story global HSS-K-EBF structure. The results of nonlinear dynamic time history analysis show that the improved PBPD method can ensure that the plastic damage distribution of energy dissipation members of different bays is more uniform and the plastic damage degree is more consistent with expectations.

Strength reduction factor for inelastic-displacement estimation and design of self-centering viscous-hysteretic systems

This study focuses on developing strength reduction factor Rμ spectrum, a maximum inelastic displacement (MID) estimation method and a displacement-based design method for single-degree-of-freedom (SDOF) bilinear structures with self-centering viscous-hysteretic devices (SC-VHDs). The effects of design parameters on Rμ spectrum are statistically investigated under near-fault pulse-like ground motions (NFPG) and far-field ground motions (FFG), and its prediction formula is fitted according to the statistical data. Following proposed Rμ spectrum, a MID estimation method and a performance-based design method are proposed, respectively. Next, three SC-VHD frames are designed step-by-step to verify the proposed design method, and then their MIDs are calculated step-by-step to validate the MID estimation method. Finally, a risk assessment is conducted on a SC-VHD frame and a conventional frame to compare their collapse performance and the performance exceeding 0.2% residual drift in the probability framework. The results indicate that Rμ spectrum is primarily affected by the ductility ratio, period and viscous damping ratio, while the parameters of ring springs have little effect on it. Rμ spectrum under the NFPE is significantly lower than that under the FFE except for periods from 0.2 s to 0.6 s. The Rμ spectrum formula and the MID estimation method both have errors that are typically less than 10%. The designed SC-VHD frame can achieve the target performance, and its probability of collapse and exceeding 0.2% residual drift in a period of 50-year is significantly smaller than that of the conventional frame.

Seismic Performance Evaluation of a Chilean RC Building Damaged during the Mw8.8 Chile Earthquake

Chile, recognized as one of the world’s most earthquake-prone nations, has gained valuable insights from significant earthquakes, such as those in 1985 and 2010, which have influenced updates to the nation’s design codes. Although Chile’s seismic design approach has been largely effective in recent earthquakes and demonstrated an “operational” performance level in most structures, performance-based design (PBD) methods have not yet been officially incorporated as valid approaches in the Chilean seismic design codes for buildings. However, in 2017, the Chilean Association on Seismology and Earthquake Engineering (ACHISINA) introduced a PBD approach, primarily for verification purposes, based on the Los Angeles Tall Buildings Structural Design Council (LATBSDC) framework. In this work, firstly, we provide an overview of Chile’s PBD methodology, focusing on the thresholds for various performance levels. These levels are established through experimental and numerical analysis, correlating performance with permissible damage levels. The second part of the paper examines the seismic performance of a residential building, designed before the 2010 Maule earthquake and subsequently damaged, using Chile’s PBD guidelines. This case study highlights the implementation and effectiveness of PBD for assessing seismic resilience in Chilean structures.

Evaluating the Fatigue-Cracking Resistance of North Dakota’s Asphalt Mixtures

Fatigue cracking is a critical pavement distress caused by extreme environmental conditions and heavy repeated cyclic loading. Performance-based design methods that use mechanistic models focus on material performance properties, creating an opportunity to use engineered and recycled materials such as reclaimed asphalt pavement (RAP). The primary goal of this study was to use the simplified viscoelastic continuum damage (S-VECD) model to assess the fatigue behavior of North Dakota’s asphalt mixtures. Eight mixtures typically used in North Dakota were sampled and underwent | E*| testing to determine their linear viscoelastic (LVE) properties. The S-VECD tests were conducted on the same mixtures to determine their damage characteristics. The outputs from the two tests were exported to the FlexMATTM software to obtain their damage characteristic curves, DR failure criterion parameters, and Sapp-index values. CT-index values for the same mixtures were obtained from the North Dakota Department of Transportation (NDDOT). The results revealed that the mixture used for HWY 52, which does not contain RAP, was least susceptible to fatigue cracking. The mixture used for HWY 6, which contains the highest RAP content (25%), had the lowest fatigue resistance, revealing RAP’s stiffening effect on asphalt mixtures. The mixture used for HWY 1, which used the performance grade (PG) 58S-34 binder, had the second-highest fatigue-cracking resistance despite containing 15% RAP, indicating that binder grade affects an asphalt mixture’s fatigue behavior. A relatively low correlation was observed between the CT-index and Sapp-index.

Determination of response modification coefficient of SPSW in RC frame using plastic design method

ABSTRACT In the last few decades, the idea of using thin steel plate shear walls (SPSW) as a resistant system against lateral loads in designing and reinforcing buildings has been of concern to researchers and designers. In this research, we studied the response modification coefficient (R), the overstrength factor (Ω0), and the deflection amplification factor (C d ) in a reinforced concrete special moment frame (RC-SMF) with thin SPSW. We used the performance-based plastic design (PBPD) method. For this purpose, we consider frames with SPSW systems with different story numbers. Static pushover analysis is performed on these frames using the strip model in OpenSees software. OpenSees software is the Open System for Earthquake Engineering Simulation located at http://opensees.berkeley.edu. Simulation results were compared with experimental results, and acceptable matching was observed between the two. Finally, the values of response modification coefficient (R), overstrength factor (Ω0), and deflection amplification factor (C d ) for RC-SMF with thin SPSW were calculated based on the Uang method. The ultimate limit design method proposed them as 9.37, 2.21, and 11.06.

Methodology to generate earthquake-tsunami fragility surfaces for community resilience modeling

Community resilience analysis and performance-based tsunami design methods typically use separate fragility curves for earthquake and near-field tsunami hazards to predict damage, neglecting the direct cascading effects of the earthquake damage on the subsequent tsunami damage analysis for coastal communities. This paper presents an improved two-phase successive analysis that can incorporate the most significant sources of uncertainties in structural modeling and hazards. However, generating multi-hazard 3D fragility surfaces that fully incorporate uncertainties through Monte Carlo Simulation requires millions of successive nonlinear analyses, which can be computationally intensive. To address this issue, a multi-distributed and parallel processing architecture was used and summarized herein. This methodology has been applied to a 4-story RC building as an illustrative example and demonstrated to be highly efficient and scalable in generating near-continuous fragility surfaces for earthquake and tsunami hazards, reducing the expected computational time by over 98%. Due to their near-continuous characteristic, these surfaces are easier to implement in resilience frameworks and applications. The fragility surfaces also feature earthquake-only and tsunami-only 2D fragility curves along the intensity measure axis boundaries, making them versatile for use in resilience frameworks that focus on a single hazard or both earthquake and tsunami hazards. Therefore, the proposed method is scalable making it helpful in developing fragility models for building portfolios to be used at the community resilience modeling of full coastal cities.

Analysis of Bridge Tests on Sandy Overburden Site with Fault Dislocating

Performance-based seismic design methods for bridges are advancing, yet limited research has explored the damage mechanisms of bridges subjected to extreme seismic effects, such as those near or across faults. To investigate the damage mechanisms under bedrock dislocation and bridge rupture resistance, providing essential insights for the standardized design and construction of bridges in close proximity to seismic rupture sites, we developed a large-scale device to model bridges in the immediate vicinity of tilted-slip strong seismic rupture sites. This included a synchronous bedrock dislocation loading system. Four sets of typical sandy soil modeling tests were concurrently conducted. The results indicate: (1) The overall shear deformation zone of the foundation and surface uneven deformation primarily concentrate the overburdened soil body along the fault dip. The damaged area under the low-dip reverse fault is lighter on the surface and inside the soil body compared to the high-dip-positive fault. (2) The presence of bridges reduces the width of the main rupture zone and avoidance distance to some extent. However, this reduction is not as significant as anticipated. The damage to the bridge pile foundation along the fault dislocation tendency notably leads to the bending damage of the bridge deck. (3) Input parameters for fracture-resistant bridge design (surface rupture zone location, extent, maximum deformation, etc.) can be deduced from the free site. Within the rupture zone, a “fuse” design can be implemented using simply supported girders. Additionally, combining the “fuse” design with simple supported girders on both sides and utilizing simple support beams for “fuse” design within the rupture zone, along with structural “disconnection”, allows for reinforcing measures on the bridge structure’s foundation platform and pile in the soil body.

Development of a Performance-Based Design Technique for an Axial-Flow Fan Unit Using Airfoil Cascades Based on the Blade Strip Theory

Axial-flow fans are widely used as cooling fans in the outdoor units of split-type air conditioners. The design of an axial-flow fan blade involves stacking several airfoils that can be differently designed for each spanwise section. However, the complex flow field around the fan blade, including circumferential and axial flows, presents challenges when applying the single airfoil theory. This study proposed a systematic performance-based design method for axial-flow fans using a cascade of airfoils based on the blade strip theory. The theory characterized the complex three-dimensional flow field driven by an axial-flow fan in terms of a two-dimensional cascade of airfoil flows. Computational fluid dynamics based on finite volume methods were used to predict the flow field and aerodynamic sound sources of an existing low-pressure axial-flow fan partially covered by a fan shroud, and the results were validated against experimental measurements. Three radial locations in the spanwise region from the hub to the blade tip that have a significant impact on aerodynamic performance were selected, and the two-dimensional flow field on a cylindrical surface with a constant radius was extracted from the three-dimensional flow field to characterize the performance of an axial fan. Then, the airfoils at the targeted span locations were optimized for a higher flow rate and greater efficiency via two-dimensional simulations using the cascades of the airfoil, and the selected optimized airfoils were applied to existing fan blades. The effectiveness of the proposed performance-based design method for low-pressure axial-flow fans was validated by the results, which showed that the redesigned fan blades with cascades of airfoils performed as predicted, increasing the intended higher flow rate by about 1%, improving power consumption by 8%, and lowering the overall sound pressure level by 1.5 dBA.

A two-level performance-based plastic design method for multi-story steel frames with double-yielding systems

The performance-based seismic design (PBSD) is usually conducted under design basis earthquakes (DBE), and then, the performance of the designed structures is examined under maximum considered earthquakes (MCE). As a result, it is challenging to simultaneously satisfy the performance targets associated with the DBE and MCE levels. To this end, this study proposes a two-level performance-based plastic design (PBPD) method. The fused steel frames exhibiting trilinear capacity curves are selected as the example structures. The peak interstory drift ratios under the DBE and MCE levels are defined as the performance targets and they are explicitly utilized at the beginning of the design procedure. The expressions of two energy modification factors are first obtained by establishing energy balance equations for single-degree-of-freedom (SDOF) systems under the DBE and MCE levels, respectively. Nonlinear time history analyses (NLTHA) for SDOF systems with various trilinear capacity curves are conducted to derive necessary design parameters. The versatility and flexibility of this design method are achieved by enabling both the primary and secondary yielding systems to yield under the DBE level. To demonstrate and validate the proposed design method, a six-story benchmark steel frame equipped with idealized metallic yielding damping braces is selected and designed with two sets of performance targets. The nonlinear static and NLTHA results proved that the designed structures can simultaneously meet the prescribed performance targets under both DBE and MCE levels.

Performance-based seismic design method for disc spring-based self-centering viscous dissipative braced steel frame

Disc spring-based self-centering viscous damper (SCVD) has emerged as a novel technology, offering velocity-dependent energy dissipation and exceptional self-centering capabilities. Integrating this damper in structural bracing systems can effectively enhance passive control over critical structural demands such as peak deformation, residual displacement, and floor acceleration. Nevertheless, a seismic design method specifically tailored for self-centering viscous dissipative braced steel frames (SCVDFs) needs further refinement. This study proposes a performance-based seismic design (PBSD) method for SCVDFs, which is grounded in the performance-based plastic design (PBPD) approach. The proposed procedure primarily considers the effects of two critical hysteresis parameters: the post-activation stiffness ratio and the viscous damping ratio. To verify the effectiveness of the design method, a set of SCVDFs was designed, each utilizing different combinations of design parameters. Nonlinear static and dynamic analyses were performed on these archetypes to evaluate their seismic performance. The evaluation findings demonstrated that the properly designed SCVDFs can achieve the expected design performance and effectively suppress the peak inter-story drift, residual inter-story drift, and peak absolute floor acceleration of the structure, thereby achieving a favorable trade-off in the design outcome and maximizing the advantages of the SCVDF in seismic resilience.

Performance-based plastic design and seismic fragility assessment for chevron braced steel frames considering aftershock effects

Observations from past earthquakes demonstrated that buildings in high seismic regions might be exposed to several aftershocks following the mainshock which can significantly increase the damage level. Since aftershocks have the potential to increase the vulnerability of buildings damaged under mainshocks, it is crucial to consider aftershock effects in the structural design phase. Performance-based Plastic Design (PBPD) method is an innovative seismic design method in which the building designed by this method shows a desirable performance under severe ground motions. PBPD allows the designer to avoid time-consuming trial and error process of analyses that are usually done in Performance-based Design method to reach a desirable performance. However, this efficient method is only valid for mainshocks only and does not consider aftershock effects in the structural design process. In this study, initially, the seismic performance (interstory drift and plastic hinges distribution) of the three 3-, 6-, and 9- story PBPD designed Chevron-braced Steel frames (CBSF) are compared under mainshocks (MS) and mainshock-aftershock (MS-AS) sequences. Subsequently, a PBPD method is developed for CBSFs considering the aftershock effects in the structural design process. Incremental dynamic analysis (IDA) has been performed using a suite of mainshocks and aftershock ground motions to develop a design base shear modification factor. Using the developed method, the performance of CBSFs under MS and MS-AS sequences is evaluated and compared with the existing PBPD method. Fragility curves are developed to compare the seismic vulnerability of the frames designed based on PBPD and proposed PBPD methods under MS-AS sequences. The outcomes of this study provide a practical design approach for CBSFs under MS-AS sequences and shows that the structures designed using developed PBPD method show more desirable behavior under MS-AS sequences compared with the structures designed using the conventional PBPD method.

Experimental Study on Effect of Temperature Characteristics on Upper Rack According to Type and Arrangement of Combustibles in Logistics Facilities

As part of a study to establish a performance-based fire-response design and evaluation method for logistics facilities, an experimental rack was manufactured, and the temperatures at the top of the combustible material during a rack fire were measured. The temperature time and temperature flame length relationships were established. Based on the variation in – – temperature with the arrangement of the combustibles, the rate of increase in heat flow through the vertical flue was higher when the combustibles were doubled than when they were single, indicating that the increased rate of the flame and flume was more than twice that of a single combustible. Based on the type of combustible, CEP exhibited a significantly higher rate of temperature increase than CUP. In the case of the CUP, when arranged in one stage and one row, the fire intensity was weak in the early stage of the fire; therefore, it was possible that the upper sprinkler head did not respond. In addition, the correlation between the flame length and temperature during the initial fire was relatively high (R<sup>2</sup> = 0.93).

The role of bio-based additives in achieving sustainability in asphalt pavements

Increased service demands from asphalt pavements due to ever-increasing volumes, coupled with the aging of highway networks, and calls for improved sustainability across the industry, have rendered the need for smart and sustainable pavement material and design more important than ever. While chemical warm mix additives and rejuvenating technologies have been utilized in pavement materials at various scales of research and practice in the past, in recent years bio-based additives have emerged as increasingly practical solutions for potentially achieving more sustainable pavements, offering the prospect for high performance combined with environmental and economic sustainability. Adaptation of chemical warm mix additives and rejuvenators in practice requires a working knowledge on the definitions, relevant evaluation criteria available to the practitioner, and, perhaps most importantly, demonstrated experience of successful application in practice. The present study will review current efforts underway in the industry to incorporate bio-based chemical warm mix additives and rejuvenators in performance-based design methods for HMA and WMA, using real world Balanced Mix design (BMD). Examples including comprehensive research being carried out in conjunction with NCAT and MnROAD research and test facilities will be reviewed to illustrate the utilization of such concepts in practice today.

Research on seismic design methods for high-rise building structures

In recent years, with the increase of the number of high-rise buildings and the increase of the frequency of earthquakes, the requirement of seismic design of high-rise buildings is getting higher and higher. Therefore, this paper mainly studies the requirements of the existing seismic design code and the basis of designing the seismic performance of high-rise buildings. The results of this paper show that the performance-based seismic design method is the most popular and practical seismic design method at present. It also concluded that the seismic capacity of high-rise buildings can be improved by changing the calculation method of bearing capacity and adopting stable lightweight materials. In addition, this paper also introduces the new seismic methods such as preset yield mode, so as to improve the seismic ability of tall buildings as a whole. In the future, more new and innovative technologies will be applied to the seismic design of high-rise buildings to provide a stable and safe environment for peoples production and life.

Seismic Design of Large-Span, Heavy-Load Transfer Truss for Zhanjiang Bay R&D Building

The Zhanjiang Bay Laboratory R&D Building project aims to create a favorable working, research, and living environment. Zone II of the Zhanjiang Bay Laboratory R&D Building is equipped with a large-span, heavy-load transfer truss to obtain a large space on the ground floor. The overall structure adopts a steel frame-core tube structure system. In order to reduce the deflection of the large-span, heavy-load transfer truss, eight diagonal pull rods are installed between the large-span, heavy-load transfer truss and the core tube. The Q235 cross-shaped replacement section can consume construction load energy. Adopting replacement methods can reduce the stress and damage of diagonal pull rods caused by construction loads. The structure adopts a performance-based seismic design method for seismic calculation and analysis. In addition, a special analysis was conducted on the single frame structure. The major results can be summarized as follows: during small earthquakes, all structural components are in the elastic stage; during large earthquakes, frame beams yield first, but frame columns and core tubes do not yield; even without considering out-of-plane constraints, the structure can still meet the requirements.

Seismic design and performance evaluation of hybrid braced frames having buckling-restrained braces and self-centering viscous energy-dissipative braces

Hybrid braced frames (HBFs) emerge as an innovative seismic-resilient system, synergizing the strengths of buckling-restrained braces (BRBs) and self-centering viscous energy-dissipative braces (SCVDBs). This novel system has the potential to simultaneously manage three key seismic demand parameters: peak inter-story drift (PID), residual inter-story drift (RID), and peak absolute floor acceleration (PFA). Nevertheless, a dedicated seismic design method for HBFs is yet to be developed. This research proposes a performance-based seismic design (PBSD) method specifically tailored for HBFs. The method's core relies on energy decoupling in the HBFs using a proposed energy distribution factor (η). To validate the proposed design method, sets of 4-, 8-, and 12-story braced frames are designed using varied η. A comprehensive seismic performance evaluation is conducted, utilizing nonlinear static and nonlinear time-history analyses. The findings indicate that the HBFs, designed utilizing different values of η, consistently meet predefined performance objectives. Within the scope of this study, the η value of 0.5 is shown to be optimal, enhancing the structural resilience of HBFs against PIDs and PFAs while exhibiting excellent self-centering performance comparable to the self-centering viscous energy-dissipative braced frame (SCVDF). Additionally, the HBFs demonstrate superior control over PFA compared to pure buckling-restrained braced frame (BRBF) and SCVDF.

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

Modified performance-based plastic design for self-centering structures

The Performance-Based Plastic Design method (PBPD), developed on the energy concept, has been frequently used in technical literature as a performance-based design method for various structures. However, implementing the method for self-centering (SC) structures, which can concentrate damage in replaceable members and reduce residual deformation, encounters difficulties due to selecting an overall energy modification factor regardless of structural geometry, ductility, and energy absorption capacity. In this study, considering the behavior of self-centering structures, the PBPD method is modified to implement any SC structure with a specific energy modification factor. The proposed method was then implemented to design two braced SC structures with different height, cable, and damper configurations. For comparison, the designed structures and similar structures designed by force method under identical conditions were subjected to nonlinear dynamic and pushover analysis employing eleven far-field earthquake records. The results show that the structures designed by the energy method with different heights and configurations exhibit average seismic response close to the target performance response while maintaining cable linearity. While in the force method, the cables did not remain linear in some cases, and the structures were designed with about 20 % deviation of mean response to the target performance. Furthermore, assessing the proposed approach with analytical results in terms of absorbed energy reveals that the accuracy of the proposed method in forecasting the structures' input energy was more than 87 %. The results indicated that the modified energy method is simple, accurate, straightforward, and efficient for the PBPD of SC structures.

Performance-based plastic design of high-strength steel framed-tube structures fused with replaceable shear links

This study proposes high-strength steel framed-tube structures fused with replaceable shear links (HSS-FTSLs) to improve the seismic performance and post-earthquake reparability of traditional steel framed-tube structures. The conventional seismic design commonly uses the capacity design method, which primarily focuses on the ductility of the structures, resulting in localized damage concentrated on individual floors. An improved performance-based plastic design (I-PBPD) method is proposed for HSS-FTSLs based on the energy balance concept, target drifts, and preselected failure mechanisms. The proposed I-PBPD method considers the influence of post-yield stiffness of the structures. The seismic performance objectives for HSS-FTSLs are categorized into four levels, accompanied by the interstory drifts and residual interstory drifts corresponding to these objectives. The capacity curve for HSS-FTSLs is assumed as a tri-linear form to correspond with the failure modes. Three HSS-FTSL prototype structures with various heights are designed through the I-PBPD method. Nonlinear pushover and dynamic analyses were carried out to investigate their seismic performance. The results indicate that the HSS-FTSL structures designed using the I-PBPD method can achieve the expected failure modes and performance objectives under earthquakes of varying intensities, exhibiting exceptional seismic performance.

Corrosion Rate-Based Adjustment of Plastic Hinge Parameters of Corroded RC Elements

In line with the trend towards predictive seismic codes adopting the performance-based design method, this paper presents an integrated protocol to determine the degraded hysteresis parameters of corroded RC hinges based on relationships developed for this purpose together with a calibration procedure using the random-mutation hill-climbing algorithm. The adjustment procedure is integrated into the material library of the OpenSees software and used to perform nonlinear dynamic analyses to investigate the seismic performance of a typical bridge with affected piers at different corrosion levels. In practice the proposed procedure permits to assess the seismic performance of existing or new structures for a given corrosion rate distribution.