Journal of Structural Engineering

Abstract

The scotch yoke inerter (SYI) is a new geometrically nonlinear vibration isolator with a smaller maximum transmissibility than linear inerter systems. The influence of internal friction and the damping effect on the response of the SYI system for seismic isolation can be significant and needs to be studied. In this study, a small-scale SYI is designed and tested, and an accurate model of SYI is developed for describing its dynamic behavior. Then, the motion equation of the coupled structure-SYI system is established, and several dynamic analyses are studied, including the amplitude-frequency response, the critical excitation amplitude, the backbone curve, the peak response, the starting frequency, and the linearization design, and many fitting expressions for engineering applications are proposed. Finally, the vibration isolation performance of SYI is investigated when friction and damping effects are considered or not, using a single-degree-of-freedom system and a building structure as examples. For harmonic excitations, the maximum transmissibility of the SYI system is superior to that of the linear inerter system, and its advantage becomes more obvious as the excitation amplitude increases. Its seismic isolation effect is slightly better than that of a linear inerter for seismic excitations, where the SYI considering friction and damping effects is better.

Practical Applications

A scotch yoke inerter is a geometrically nonlinear inerter that is simple to construct, easy to implement, and has the advantage of variable inertance. The variation of inertance is reflected in two aspects: first, its nominal inertance can be changed by adjusting the location of the pin; second, its dynamic inertance is related to its deformation, which can provide greater negative stiffness effects for larger external excitations. The precise and simplified output force model of the scotch yoke inerter is provided, which can be applied to the calculation and verification of the output force in the design of scotch yoke inerters. Fitting expressions for the critical excitation amplitude, starting frequency, and linearization design are proposed, which can provide a theoretical basis for the application of scotch yoke inerters in base-isolated structures. Compared with traditional linear inerters, scotch yoke inerters have a better isolation control effect, and this control effect can be further improved by making reasonable use of the internal friction and the damping in SYI.

This paper introduces a retrofit design procedure for reinforced concrete (RC) frame buildings using alternative steel bracing systems based on the simple lateral mechanism analysis (SLaMA). Employing a displacement-based design approach, the procedure captures the actual behavior of existing buildings and the contribution of the bracing system. The retrofit design process and seismic assessment procedures are outlined, followed by the proposed SLaMA-based retrofit design procedure. The design procedure is demonstrated on pre-1970 four-story and eight-story RC case study frames, targeting maximum displacements informed by the expected failure mechanisms identified using a detailed seismic assessment (DSA). The New Zealand Society of Earthquake Engineering 2016/017 Seismic Assessment Guidelines’ SLaMA method is utilized for DSA, revealing that the frames are potentially earthquake-prone with specific failure mechanisms and seismic capacities. After retrofitting with a concentric braced frame (CBF), buckling-restrained brace (BRB), and CBF with friction dampers, the failure mechanisms are modified, resulting in seismic capacities exceeding 100% New Building Standard (NBS). Evaluation of local and global behavior post-retrofit enables the determination of the advantages and disadvantages of alternative brace systems. Nonlinear time-history (NLTH) analyses using a lumped plasticity model verify the results, affirming the viability and practicality of the SLaMA-based retrofit design procedure for selecting and designing appropriate interventions in concrete frame buildings.

Failure mode identification in unreinforced masonry (URM) walls is a challenging task because of the presence of multiple damage mechanisms, including so-called hybrid modes. This paper employed a novel application of supervised and unsupervised learning to link URM wall design and mechanical properties to the failure mode. We used a database with 330 backbone curves from cyclically loaded URM walls as well as the associated images captured during the experiments. Based on the observations documented during the experiments, information on the cyclic curves, and the associated images, the walls were first manually classified into four failure modes: bed-joint sliding, diagonal tension, rocking, and toe crushing. Then $k$-means clustering was used to group the damaged walls into four classes based on critical points along the backbone curves. A hybridity index was introduced to quantify the contribution of each failure mode based on the distance from the centroid of the clusters. The design and mechanical properties of the URM walls were then used to predict the hybridity index using a multioutput regression model. The hybridity prediction model determines the contribution of the various failure modes to the ultimate behavior of a damaged URM wall. The proposed framework provides a robust approach to quantifying the relative contribution of each failure mechanism to the overall performance of the URM wall.

A practical strengthening strategy for nonseismically designed exterior beam–column joints (BCJs) has been proposed by installing an unsymmetrical chamfer on the soffit of the beam. Its feasibility and effectiveness have been validated by extensive experimental studies. In this study, the load transfer mechanism of an exterior BCJ with chamfer is further analyzed to establish an analytical model for joint shear strength. An additional strut is identified in the chamfer based on finite element analysis results, which serves as the secondary load transfer path in addition to the diagonal strut within the joint area. Furthermore, a parametric study was performed to correlate chamfer size with joint shear strength of a strengthened joint. Width of the diagonal strut is enlarged with increasing chamfer size, whereas the effective width of compression zone in the chamfer is limited. With identified load path of BCJ with chamfer, an analytical model is established based on softened strut-and-tie model (STM) which provides clear load transfer mechanism for rational conception design and reasonable join shear estimation, especially for unreinforced BCJs. Width of the diagonal strut, which is the main parameter in a STM, is redefined accounting for contribution of chamfer. Finally, design procedures and recommendations are provided for application of the strengthening strategy in practice.

A large number of structures in the United States and worldwide include nonductile reinforced concrete (RC) frames with columns and beams that are prone to shear failure. Due to the brittle nature of shear failures, accurate simulation of RC structures with shear-critical members is essential to predicting their overall capacity under severe loading scenarios (e.g., earthquakes) and designing effective retrofits and upgrades. In this paper, a previously developed gradient inelastic (GI) force-based (FB) beam-column element formulation capable of capturing axial-flexural interaction and predicting flexural failures is extended to account for axial-flexural-shear interactions in RC members in order to predict shear failures. The proposed shear-enhanced GI FB element formulation advances the original GI FB element formulation by developing higher-order cross section kinematics, i.e., beyond the plane sections assumption, and by developing a 3D concrete constitutive model. The higher-order cross section kinematics can simulate strain distribution of the cross section more accurately while using 3D concrete constitutive models at the element’s cross sections permits simulation of axial-flexural-shear interactions. To incorporate the confinement effects of transverse steel reinforcement, through-the-depth stress equilibrium is strictly enforced in the transverse directions of the member’s cross section. To eliminate strain localization phenomena, new gradient nonlocality relationships are introduced in addition to those of the original GI FB formulation. The proposed element formulation is implemented in the OpenSees structural analysis software and is shown to maintain continuous macroscopic section strain distributions over the element length during softening and discretization convergent responses, thereby eliminating the strain localization phenomena. In addition, the predictions of the shear-enhanced GI FB element formulation are compared with data available from experiments on RC beams and columns.

An experimental program and numerical study on the structural performance of cold-formed steel unstiffened and edge-stiffened channel section members under major axis bending are presented in this paper. Channel sections with plain flanges and single-fold lips as well as double-fold inward and outward return lips were investigated. In total, 16 four-point bending tests were conducted on channel section specimens of steel grades G450, G500, and G550. The experimental results, including moment–curvature responses, failure modes, and bending capacities, were obtained and used for the calibration of a nonlinear finite-element model. Subsequently, based upon the validated finite-element model, a parametric study was carried out to examine the flexural behavior of thin-walled channel section beams. Underpinned by the results of 16 experiments and 222 numerical analyses obtained from this study together with 19 test data reported in the literature, it was revealed that the strength predictions determined by the direct strength method (DSM) in AISI S100 were overall conservative for the plain channel section beams, while generally unconservative for the edge-stiffened channel section beams. Additionally, the DSM-based approaches with consideration of local–distortional interaction were found to underestimate the nominal flexural strengths of the thin-walled channel section members with edge stiffeners. Hence, modified DSM formulas were recommended in this study to accurately predict bending capacities of the cold-formed steel unstiffened and edge-stiffened channel section beams under major axis bending.

Abstract

Cold-rolled ribbed steel bar welded mesh (CRWM) is used to speed construction and improve the quality of the reinforcing. However, the seismic performance of such RC walls is uncertain. The current study assessed the seismic efficacy of these walls by analyzing the effects of different combinations of axial and cyclic lateral loading in a large-scale experimental program. The walls were built with boundary elements at the ends and two layers of mesh placed into the web of the walls. The seismic parameters comprise a force-displacement hysteresis curve, concrete and rebar strains, dissipated energy, and stiffness. The experimental findings show that the axial load had a significant effect on the deformation capacity, strength, and failure mode of the wall. Except for walls with flexural failure, the study revealed that the use of such mesh had a detrimental effect on the cyclic performance of other specimens. In walls exhibiting flexural failure modes, such as C15, the use of CRWM slightly improves ductility compared to the ASCE 41-17 proposed model. The use of such mesh in walls with any type of shear failure mode had a significantly negative influence on the seismic performance of the walls. Among shear failure modes, sliding shear failure is particularly adverse. In such failures, the vertical rebars are subjected to deformation perpendicular to their direction. Because of their brittle nature, they cannot accommodate this deformation and are prone to fracture. Moreover, a comparison of the experimental backbone curve of the walls and the numerical model proposed by ASCE 41-17 revealed that the ASCE model tended to overestimate the effective stiffness of walls with axial loads of less than 10% $f_c^{\prime }{A}_g$.

Practical Applications

The structural integrity of buildings is critical in seismically active areas. This study looks into the use of cold-rolled ribbed steel bar welded mesh (CRWM) in the web of reinforced concrete special structural walls, a technique used in Turkey and China that is also being considered in Iran. Because of a lack of performance data, current building codes, such as ACI 318-19, do not include provisions for CRWM in seismic systems. Our research attempts to fill this gap, which provides empirical data from large-scale experimental tests to evaluate the cyclic performance of walls with CRWM under various axial loads. The findings provide important insights into the behavior, strength, and ductility of such walls, allowing for a better understanding of their use in earthquake-prone areas. The findings are intended to inform and potentially influence building codes and practices, advocating for the use of CRWM where it can improve construction efficiency and seismic resilience. This research not only helps to optimize structural designs but also helps to develop safer, more cost-effective building strategies in seismically active areas.

Strongback braced frames (SBFs) are a relatively new structural system intended to reduce structural damage during seismic events and improve resilience. SBFs combine buckling-restrained braces, which provide the primary lateral resistance and energy dissipation, with a stiff elastic spine to distribute demands across the height of the structure and prevent the formation of weak- and soft-story mechanisms. Designing the spine is challenging, as higher mode effects and partial nonlinear mechanisms have been shown to be significant. These effects, and their interaction, are not fully accounted for by standardized design methods. It is also unclear how stiff and strong the spine must be in order to achieve the desired behaviors. There are proposed procedures for designing SBFs; however, they have not been broadly evaluated, and they have not been compared. This work evaluates two proposed design procedures, the simplified modal pushover analysis (SMPA) and generalized modified modal superposition (GMMS), with a “control” procedure based on current standardized capacity design procedures. A total of nine frames were designed for three buildings using the three procedures. Nonlinear response history analyses were performed to evaluate the differences in behavior resulting from the different design methods. To determine the effect of the strength and stiffness of the strongback, the yield strength and elastic modulus of the strongback members were varied and the analyses repeated. The results of this work show that the GMMS and SMPA design procedures are generally well-calibrated and provide benefits over current standardized procedures in several ways: collapse performance is improved, and yielding in the strongback and residual drifts is reduced. The GMMS procedure results in larger members, but provides similar outcomes to the more-complicated-to-implement SMPA. The insights from this work will assist engineers when implementing these design methods and support the codification of strongback braced frames in design standards.

Beam–column joints are critical in reinforced concrete moment-resisting frames. Adequately designed beam–column joints support the plastic hinging of the adjoining beams under seismic actions and transfer gravity loads, both of which are critical for the energy dissipation and survival of buildings during earthquakes. Beam–column joints in exterior frames of buildings are occasionally eccentric such that the axes of the beam and column are offset from one another. Previous work on eccentric joints indicates an inferior seismic behavior compared to concentric joints. Beams flush with the concrete column represent the maximum eccentricity considered in previous studies. However, beam–column joints with higher eccentricity where the beam section only partially intersects with the column exist in some buildings. The impact of this notably high beam eccentricity on the seismic performance of joints has not been documented in studies published in open literature to the knowledge of the authors. This paper presents an experimental study focused on a joint geometry characterized by a beam eccentricity exceeding half the column width. The objective is to lay the groundwork for understanding how such eccentricity affects the seismic performance of reinforced concrete beam–column joints. The experiments involved reversed cyclic testing of four large-scale beam–column cruciform assemblages. The results indicate that the joints had sufficient core capacity to develop plastic hinges in the beams. In addition, the tested assemblies exhibited highly ductile behavior and considerable postpeak energy dissipation. The inadequacies of the design documents on such joints are discussed in detail. Based on the findings, a suggestion was made to evaluate the shear strength of such joints. Finally, a strengthening scheme using fiber-reinforced polymer patching was evaluated to improve the seismic performance with minimal work on the joint. The strengthened joint showed similar behavior with a higher energy dissipation compared to the unstrengthened joints.

High-strength steels (HSSs) have been gaining increasing attention in recent years because of their potential application for lightweight structures. Hybrid structural steel I-sections, featured by dissimilar strength grades for constitutive plates, provide a more economical solution to suit bending loading scenario. This study conducted experiments on nine I-sections with Q690 flange plates under four-point loads, incorporating three different web strength grades including Q690, Q460, and Q355. Furthermore, the local buckling behavior of representative I-sections with various section geometries was analyzed using a validated numerical method to understand the role of web strength grade. Test and numerical analysis results revealed that the section with web steel in the strain hardening stage exhibited different levels of ductility among specimens with different strength webs. It was also observed that earlier yielding or inelastic buckling of the lower strength web plate in hybrid I-sections affects the local buckling behavior of I-girders, in terms of moment resistance and rotation capacity. In addition, the initial local imperfection mode used in numerical analysis was found to affect the rotation capacity of I-girders, but the effect of web strength grade remains consistent among I-sections with the same local buckling deformation mode. This study provides further insights into the local buckling behavior of hybrid I-sections subjected to uniform bending, laying the foundation for further development of design methods.

Tornadoes are intense localized convective windstorms that are among the most devastating natural hazards that occur in the United States. Although the probability of any tornado striking one particular building in any given year is quite low because of its small footprint, when strong tornadoes strike densely populated areas, the results can be catastrophic; the Joplin, MO tornado of 2011 caused 161 fatalities and nearly $3 billion in damages. Such losses are projected to increase in the future as a result of urbanization and economic development. ASCE Standard 7-22 on Minimum Design Loads has, for the first time, included new reliability-based design criteria for tornado loads. The objective of this paper is to provide archival documentation of the basis for these tornado-resistant load provisions in Chapter 32 of ASCE 7-22. This paper summarizes the significant challenges that were overcome in addressing the fundamental differences between effects of tornado and nontornadic winds and the higher uncertainties associated with tornado wind pressures that must be accommodated in the risk-informed framework of ASCE 7-22. These challenges were addressed through reliability analyses that led to new tornado load criteria that provide reasonable consistency with the reliability delivered by existing criteria for nontornadic winds.

An extensive experimental program was performed to evaluate the structural behavior of a novel fully prefabricated noise barrier wall system. The experimental investigation entailed the fabrication and testing of two full-scale prototypes, which was the foundation for implementing a systematic parametric nonlinear finite-element analysis (NLFEA) study. The intent was to assess the impact of four critical parameters on the overall structural behavior of the noise barrier wall system for further optimization and improvement. These critical parameters include the integral column size, the presence of a gap, the type of steel section utilized, and the embedment length of the steel section. Therefore, the parent nonlinear finite-element analysis model was created, calibrated, and verified against the experimental results of the full-scale prototypes in terms of the load–deflection curves, load–strain curves, cracking patterns, and failure modes. Then, various nonlinear finite-element analysis models were created by expanding the parent model to allow for evaluating various possibilities from each parameter. For a preidentified performance acceptance criterion, the findings of the study revealed that the integral column size could be reduced from the size used in the prototypes, the embedment length of the steel section was already at an optimum length, the existence of a gap would result in the prevention of any sliding, and a circular hollow steel section (HSS) $14\times 15.875\mathrm{m}\mathrm{m}(5/8\mathrm{in.})$ or $\mathrm{W}8\times 48$ would represent the most advantageous selection for the steel column section.

Compressive strength models for ordinary portland cement composites are typically deterministic and rely on parameters such as water-to-cement ratio, porosity, and chemical composition. While these models can estimate compressive strength, they often lack the ability to quantify uncertainty in their predictions. Various factors contribute to this uncertainty, including diverse testing protocols, limited data, overly complex mathematical formulations, and constraints in capturing the variability of the phenomenon through model parameters. This study introduces a comparative evaluation of representative compressive strength–porosity models for cement paste, adopting a probabilistic perspective and using data from various testing protocols found in the literature. Experimental data encompassing compressive strength and porosity, spanning porosity values from 1% to 30%, were gathered from hot-pressed and conventionally cast specimens. Results were obtained following the Bayesian Analysis Reporting Guidelines (BARG) with combined decision criteria using a 95% High Posterior Density (HPD) interval and the Range of Practical Equivalence (ROPE). A probabilistic version of Ryshkewitch’s model emerges as the most plausible based on porosity data. These results hold promise for integration into risk analysis and decision-making tailored for structural analysis and design. Ultimately, this research contributes insights into enhancing the reliability of compressive strength predictions for cement composites by accounting for the inherent uncertainty of the underlying models.

This paper reports an experimental and analytical investigation on a novel self-centering damper. The damper is characterized by a multistage energy-dissipation mechanism, which is desirable for multiperformance-based seismic designs. The conceptual design, working mechanism, assembling process and hysteretic performance of the proposed damper are presented. The fundamental mechanical behavior of each component of the damper was examined experimentally. Then a series of cyclic tests of damper specimens was conducted, focusing on the influence of the preload of the shape-memory alloy (SMA) bolts, the SMA bolt type, and the sloping angle of the wedge-shaped friction plates on the damper performance. An analytical model is proposed for quantification of the hysteretic behavior of the damper. The test results showed that the damper specimens exhibited the expected multistage energy-dissipation characteristics and stable flag-shaped hysteretic curves with full self-centering behavior. A good energy dissipation capacity with an equivalent viscous damping (EVD) of about 20% was observed, which basically was consistent over the entire loading stages. The overall behavior of the damper was related closely to the aforementioned test parameters, indicating that the damper performance can be adjusted flexibly according to various seismic design requirements. The analytical predictions and the test results of the damper were in good agreement, indicating that the developed analytical model can be used confidently by engineers for the design of the developed damper.

The structural behavior of fully grouted reinforced concrete masonry (RM) walls subjected to either pure in-plane (IP) or pure out-of-plane (OOP) loading has been thoroughly examined in the literature. However, in certain circumstances (e.g., seismic loading), RM walls could be subjected to combined IP and OOP loads. This study conducts a comprehensive numerical investigation into the structural behaviors of RM walls under combined IP and OOP loading, focusing on the influence of geometric parameters (aspect ratio and height-to-thickness ratio) and precompression load. To capture the possible failure modes of RM walls under bidirectional loading scenarios, a simplified micromodeling approach is employed in this study. The numerical simulations were performed in the general-purpose finite element software package ABAQUS. The simulation results indicated that the presence of OOP loads can induce substantial IP capacity reductions, especially for flexural-governed walls characterized by a larger aspect ratio and a low level of precompression load. For flexural-governed walls, IP and OOP capacity interactions were found to be less sensitive to geometrical parameters and precompression load than shear-governed walls. The most interaction was observed for highly slender walls without precompression loads, indicating a reduction in IP capacity by 45% when OOP loading is at 80% of its corresponding capacity. A further comparison between the RM walls and their counterparts, unreinforced masonry (URM) walls, suggested that the IP capacity reduction of RM walls could be 11.6% less than that in URM walls, indicating the positive effects of reinforcements in mitigating the IP–OOP interaction effects.

Double-skin tubular columns (DSTCs) represent one of the most novel column systems for future structures, such as bridges, flyovers, high-rise buildings, and towers, due to their higher axial compressive strength and improved ductility characteristics. The enhanced confinement of the concrete is the primary reason for the improved axial compressive strength and superior ductility in DSTCs. However, the steel in DSTCs is localized to the outer and inner layers only, without any connecting element in-between inner and outer steel tubes. As a result, a significant sudden drop in the load-carrying capacity has been observed in DSTCs as soon as the outer or inner steel tube fails. However, the failure in inner and outer steel tubes can be significantly delayed or prevented if they are connected through stiffeners. The present study, through an extensive experimental investigation, focused on effectively strengthening and connecting both the outer and inner tubes in DSTCs by adopting various stiffener schemes. Additionally, the stiffeners split the concrete core into discrete concrete cells. Accordingly, in the current study, these columns have been referred to as multicell double-skin tubular columns (MC-DSTCs). From the experimental observations, axial compressive strengths in MC-DSTCs were higher than that in the unstiffened DSTCs by up to 62%. Further, MC-DSTCs exhibited larger axial deformations compared with the unstiffened DSTCs, improving their ductility index by up to 253%. The increased axial strengths and ductility in MC-DSTCs have been attributed to delayed and controlled failure of steel and concrete components because of the improved participation of inner and outer tubes through stiffener connections. Finally, a design model has been proposed based on the concept of concrete confinement in MC-DSTCs to accurately predict their axial compressive strength, which has been verified through a regression analysis. A good correlation (with ${\mathrm{R}}^2=0.986$) between the predicted and experimental axial compressive strengths of MC-DSTC was observed.

Buckling and critical temperatures of steel columns are crucial parameters for structural fire safety design. However, the existing simplified design methods for buckling or critical temperature are based on column models with either pin ends or with large rotational restraints. Their applications on steel columns with limited rotational restraint stiffness ratios—the ones smaller than the critical rotational restraint stiffness ratio—is questionable. In this paper, parametric analyses on a validated numerical column model with rotational restraint stiffness ratio varying from 0.0001 to 10.0 were conducted. The effects of slenderness ratio, load ratio, and axial restraint stiffness ratio were also considered. Results show that for steel columns with limited rotational restraint stiffness ratios, prediction errors of existing simplified design methods were significant. Following the parametric analyses, new prediction formulas of buckling temperature and critical temperature are proposed for H-section steel columns. Results of proposed formulas aligned closely with those of parametric analyses in the full range of considered parameters. Furthermore, the proposed formulas were also validated by test results in the literature.

The paper introduces a new model of compressive membrane action (CMA) for a conical fan failure mechanism around a patch load in a reinforced concrete plate with in-plane restraint. The new model is based on a concept of 3-dimensional wedging and it is fundamentally different from conventional arching models of CMA. The new model accounts for the effects of CMA on the bending resistance at yield lines and the complementary wedging effect of compressive membrane forces at the yield lines, considering the interaction between the radial and tangential forces acting on the wedgelike segments in a restrained fan. The model was developed in the context of an investigation of the strength of fiber reinforced shotcrete (FRS) tunnel linings, but it is readily adaptable for conventional reinforced concrete plates and slabs. The paper compares the wedging model results (predicted load-deflection curves) with field test results for FRS tunnel linings. It is shown that the wedging model provides a good approximation to the available test results.

This paper proposes an innovative hybrid timber beam-to-steel column connection for seismic design of multistory buildings. This innovative connection consists of a set of two U-shaped steel fuses connecting a glulam beam to a steel column. U-shaped fuses are designed to dissipate seismic-induced energy and can be replaced after a moderate or potentially strong seismic event. Eight full-scale experiments were conducted, involving four glulam beam specimens with varying thicknesses and eight pairs of fuses with two U-shaped plate configurations (open-fuse and closed-fuse). The key connection performance metrics, including the flexural stiffness and strength, hysteresis response, ductility, and energy dissipation capacity, were investigated using the test results. A set of mechanics-based equations is proposed to estimate flexural stiffness and strength of the connection. The results of the experimental program confirmed that the proposed hybrid connection exhibits a stable hysteresis response without noticeable strength degradation and possesses excellent ductility and energy dissipation capacities. Furthermore, the proposed mechanics-based equations can predict the moment capacity of the connection with sufficient accuracy.

This study examines the seismic force modification factors related to overstrength and ductility of wood light-frame shearwalls. Several archetypes were developed to meet different design criteria. Nonlinear static procedure, nonlinear time-history analysis, and nonlinear incremental dynamic analysis were performed. The numerical analyses were based on 2D representations of the designed archetypes. The nonlinear static analysis results revealed an overstrength factor of 2.2, which is greater than the current value of 1.7 for wood light-frame shearwalls. The findings also indicated that existing design requirements for hold-downs and the overcapacity requirement for the first and second stories may not always ensure satisfactory performance. The archetype detailed screening step proved valuable as a preliminary assessment prior to the incremental dynamic analysis in identifying critical archetypes. The results of the performance margin ratios indicated that the archetypes marginally met the life safety performance level. Overall, this study suggests a need for potential adjustments in design standards and considerations for a more comprehensive evaluation of the seismic performance of wood light-frame shearwalls. This study also found that adhering to design requirements related to certain irregularities decreased the probability of collapse in those archetypes.