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Seismic collapse risk of RCtimber hybrid building with different energy dissipation connections considering NBCC 2020 hazard
Journal of Infrastructure Preservation and Resilience volumeÂ 3, ArticleÂ number:Â 14 (2022)
Abstract
The 2020 National Building Code of Canada (NBCC) seismic hazard model (SHM) marks a comprehensive update over its predecessor (NBCC 2015). For different regions in Canada, this will have an impact on the design of new buildings and performance assessment of existing ones. In the present study, a recently developed hybrid building system with reinforced concrete (RC) momentresisting frames and crosslaminated timber (CLT) infills is assessed for its seismic performance against the latest SHM. The sixstory RCCLT hybrid system, designed using the direct displacementbased method, is located in Vancouver, Canada. Along with very high seismicity, southwestern British Columbia is characterized by complex seismotectonics, consisting of subduction, shallow crustal, and inslab faulting mechanisms. A hazardconsistent set of 40 ground motion pairs is selected from the PEER and KiKnet databases, and used to estimate the buildingâ€™s seismic performance. The effects of using steel slit dampers (associated with large hysteresis loops) and flagshaped energy dissipators (associated with the recentering capability) are investigated. The results indicate that the hybrid system has good seismic performance with a probability of collapse of 2â€“3% at the 2475year return period shaking intensity. The hybrid building with steel slit dampers exhibits a collapse margin ratio of 2.8, which increases to 3.5â€“3.6 when flagshaped dissipators are used. The flagshaped dissipators are found to significantly reduce the residual drift of the hybrid building. Additionally, the seismic performance of the hybrid building equipped with flagshaped dissipators is found to improve marginally when the recentering ratio is increased.
Introduction
Buildings have become a key point of focus in establishing sustainable development goals meant to address the growing challenge of climate change [1]. With rapid population growth in urban areas, nontraditional buildings such as those with hybrid structural systems are central to the development of sustainable infrastructure. Over the past couple of decades, concrete and steel have become the materials of choice for the construction of civil infrastructure. With a robust design methodology, traditional concrete and steel structures have dominated the construction market. However, with the focus shifting to environmentally friendly and lightweight structures, timber is fast becoming a viable construction material [2]. One of the benefits of timber construction in seismic zones is its light weight, which attracts smaller inertial forces when compared to concrete or steel structures with the same size and complexity. Aside from being used as a standalone material for building structural systems as permitted by the various design codes, several hybridstructural systems using timber have been investigated, e.g. [3,4,5,6,7,8,9].
Prescriptive design standards, based on a forcebased methodology, utilize reduction factors to account for inherent nonlinearity in the structural systems [10]. Several researchers have worked to develop the reduction factors for different hybridstructural systems [11, 12]. However, existing design codes do not provide the reduction factors for emerging hybridstructural systems, consequently, forcebased design cannot readily be implemented. In an attempt to provide a more robust, accurate, and reliable design approach, the performancebased design methodology was developed [13,14,15]. One variation of that methodology is direct displacementbased design (DDBD) [16]. Starting with the design of simple concrete multispan bridges and building frames [17], the DDBD has been extensively applied to traditional and novel systems. Examples include structures with passive energy dissipating devices [18], steeltimber hybrid buildings [6], framewall structures [19, 20], framewall structures with dissipators [21], structures with seismic isolation systems [22], steel and RC momentresisting frames [23,24,25], traditional lightframe timber structures [26], structures with flexible bases [27], tall hybrid timber buildings [26], selfcentering bucklingrestrained braced frame structures [25, 28], baseisolated building structures [29], dual systems [30], and structures with viscoelastic dampers [31]. Recent developments have paved the way for highrise building design using the DDBD by addressing issues of the displacement profile [32], higher modes, and PDelta effects [24, 25].
An integral part of the DDBD method is estimating the equivalent viscous damping (EVD) for different structural systems [33, 34]. Over the years, different researchers have sought to establish expressions for determining the EVD of different structural systems, e.g., TableÂ 1. This was generally achieved by using results from a physical experiment to calibrate a numerical model, and then EVDductility relationships are developed for a large number of numerical models using an areabased approach. The ductility, \(\mu\), is defined as the ratio of the maximum displacement to the yield displacement. In recent years, EVD expressions for hybrid buildings using timber and different dissipation mechanisms have been developed [6, 35,36,37,38,39,40]. These studies will facilitate the design and widespread acceptance of hybrid timber buildings. The present study adopts an RCtimber hybrid building designed using the DDBD approach [8]. A maximum story drift ratio (\(IDR_{max}\)) of 2.5% that corresponds to the collapse prevention limit state is targeted. The EVD for the RCtimber hybrid system was developed by Nielsen and Imbeault [41]. The hybrid building system utilizes the high strength and stiffness characteristics of the CLT to reduce the induced displacement of the structure and the energy dissipating characteristics of the hysteretic connectors [8, 42].
While it is important that sustainable alternatives to traditional structural systems be developed, attention must be paid to their seismic collapse risk to ensure adequate life safety performance. As such, seismic collapse risk assessment of buildings has gained attention [48]. In the present study, the collapse capacity of the RCCLT building reported in [8] is assessed using nonlinear timehistory analysis. The effects of the energy dissipation devices have been studied by considering an alternative flagshaped dissipator which has gained widespread interest in the last two decades [49,50,51,52,53,54]. The hybrid building reported in Tesfamariam et al. [8] was designed with the NBCC 2015 [55] seismic hazard. With the newly released updated NBCC 2020 [56] hazard model, it is postulated that substantial changes in the seismic hazard will have an impact on the design of new buildings and assessment of existing ones, especially in regions with very high seismicity, such as southwestern British Columbia. The seismic hazard of the selected Vancouver, British Columbia site, is affected by the interaction of three tectonic regimes, viz., Subduction, Shallow Crustal, and Inslab. A hazardconsistent 40paired ground motion records, representing the complex seismicity of Vancouver, is selected for nonlinear response history analysis of the hybrid building system.
The present study has three primary contributionsâ€”(i) a rigorous ground motion record selection consistent with the complex seismicity of Southwestern British Columbia is performed. The record selection follows the latest seismic hazard model per NBCC 2020 [56]. (ii) The seismic collapse assessment of an innovative RCCLT building system designed using DDBD is assessed, and (iii) the effects of alternative energy dissipators on collapse capacity and residual deformation are investigated.
Design details of the RCCLT hybrid building with steel slit dampers
A regular 6story, 3bay RC moment resisting frame with CLT infill designed by Tesfamariam et al. [8] has been considered for the seismic performance assessment. The building is 24 m \(\times\) 42 m in plan with the longer direction having 7 bays each with a length of 6 m. FigureÂ 2 shows the elevation along the shorter and more critical direction. The CLT infill is a threeply panel that is 99 mm thick, comprised of three 33 mm thick laminae that are fused together. The CLT infill was designed with some clearance to the RC frame to avoid shear (brittle) failure in the RC columns due to their interaction [57]. Slit dampers [42] at the top of the CLT infill were provided as an additional energy dissipation mechanism. The steel slit dampers are associated with large hysteretic loops leading to high energydissipation capacity. Given the novel structural system, the RCCLT building was designed using the DDBD. The target was set to a maximum interstory drift \(IDR_{max}\) of 2.5% corresponding to 2% probability of exceedance in 50 years, for the NBCC 2015 hazard level [55].
Figure 1 summarizes the DDBD procedure as follows:

1
Develop the design displacement profile.

2
Determine the characteristics of the equivalent single degree of freedom system.

3
Determine the design ductility.

4
Estimate the Equivalent Viscous Damping

5
Determine the effective period, stiffness and base shear.

6
Perform structural analysis and member design.

7
Calculate the stiffness of each story.

8
Calculate the equivalent stiffness of the CLT and dampers.

9
Calculate the number of dampers required for each story.

10
Design and validate the structure.
A more detailed DDBD procedure for the RCtimber hybrid building is described in Tesfamariam et al. [8]. The elevation of the hybrid building is shown in Fig.Â 2. It is noted that the length of the CLT infill and the number of slit dissipators are optimized during the design. A summary of the results from the design is given in TableÂ 2. All beams are 450 mm \(\times\) 350 mm in size. The design is governed by the connection with the slit damper and gravity loads on each floor.
Nonlinear structural modeling of the RCCLT hybrid building
A twodimensional nonlinear model was considered to be appropriate due to the regularity of the hybrid building. FigureÂ 3 provides a schematic representation of the key elements of the analytical model. A concentrated plasticity model is used to capture the nonlinearity in the RC frame. MarkerÂ 1 shows the modeling details of the RC frame whereas MarkerÂ 2 describes the details of the RCCLT dissipator connections. Different structural components are provided in the following subsections. The PDelta effects are captured using a leaning column [58]. 5% Rayleigh damping has been considered in the first and the third fundamental mode for all linear elastic elements. Damping in the nonlinear elements has not been modeled as recommended in the literature [59,60,61]. The eigenvalue analysis of the frame resulted in first, second, and third mode periods of 1.17, 0.40, and 0.25 seconds, respectively.
CLT modeling
The threeply 99 mm thick CLT infill panel is modeled using quad elements with a bilinear isoparametric finite element formulation. The CLT infill is formulated assuming a plane stress condition due to the minimal outoftheplane stresses. Because of the connection detail and design of the hybrid building, the assigned nDMaterial for the CLT elements are elastic with a modulus E, of 9.5 kN/mm^{2}, and a Poissonâ€™s ratio of 0.16. The CLT and RC frame are connected using steelslit dampers. The stiffness of the CLT, \(K_{CLT}\), is approximated as follows [62]:
where h, E, A, L, G, d, and f represent the CLT height, elastic modulus, crosssectional area, wall length, shear modulus, thickness, and bearing capacity factor per CSA O86 [63], respectively.
RC frame modeling
The modeling details of a typical RC beamcolumn joint are shown with MarkerÂ 1 in Fig.Â 3. The RC beamcolumn joints are designed and detailed to conform with the highest ductility class specified in the Canadian standard [55]. Thus, flexural yielding is expected to precede shear failure. The RC members are modeled using the hysteretic rules defined by the IbarraMedinaKrawinkler (IMK) model [64], which captures strength and stiffness degradation. The key points on the backbone curve and cyclic deterioration constants are based on the semiempirical expressions developed in the literature [65, 66]. The multipoint constraints for the RC joints are modeled using the joint2D element that incorporates a diagonal compression strut mechanism [67] and a shear panel is used for the joint deformation.
RCCLTDamper modeling
The modeling details of the RCCLT joint including the slit dampers on top of the CLT infill are shown with MarkerÂ 2 in Fig.Â 3. The beamcolumn elements have 3 degrees of freedom (\(u_x\), \(u_y\), \(r_z\)) and the quad element has two (\(u_x\), \(u_y\)). The two elements with different numbers of degrees of freedom are linked using connector nodes which are constrained using the equalDOF command. A twoNodeLink element is used between the connector and RC beam nodes. The bottom of the CLT infill is anchored to the RC beam by constraining the quad elements at the base of each floor. Due to the dominance of flexural behavior (\(r_z\)), the chord rotation is used as the deformation measure for the RC members, whereas the displacement is used as the deformation measure for the energy dissipators due to their point action along the translational direction (\(u_x\)).
FigureÂ 4a shows an example calibration of the hysteretic response of the slit damper using OpenSees [68], which is modeled using the RambergOsgoodSteel uniaxial material. The experimental data are taken from Lee et al. [42]. The calibrated parameters for the RambergOsgoodSteel material are: the yield strength \(F_y= 140\) kN, initial elastic modulus \(E_0 = 70\) kN/mm, yield offset \(a = 0.002\), and the parameter to control the transition from elastic to plastic response \(n= 13\). Similarly, Fig.Â 4bâ€“c show the numerical response of the flagshaped dampers. Two recentering ratio values, \(\beta _F = 0.8\) and \(\beta _F = 0.6\), have been considered. These values are based on relevant experimental studies [39]. The flagshaped dampers are modeled using the SelfCentering uniaxial material in OpenSees. In the absence of experimental results for the flagshaped dampers of equivalent strength, their key parameters are selected such that the peak strength and deformation capacity closely resemble that of the steel slit dampers. Nonlinear static analyses of these systems are used to confirm this design choice. The adopted parameters for flagshaped dissipators are: the forward activation strength \(F_{a} = 130\) kN, initial stiffness \(k_1 = 61.9\) kN/mm (corresponding to 2.1 mm of deformation at activation strength), and postactivation stiffness \(k_2 = 0.03 k_1\).
Seismic hazard and GM selection per NBCC 2020
Seismic hazard
The 6th generation seismic hazard model (SHM6) described in the NBCC 2020 [56] represents a comprehensive change over the NBCC 2015 [55]. FigureÂ 5a shows the change in short period seismic hazard for several locations in Canada, from East to West. Such an increment of 25â€“50% is expected to impact the design and performance assessment of Canadian buildings, especially in regions with very high seismicity such as southwestern British Columbia. FigureÂ 5b shows the response spectrum for Vancouver corresponding to the 2% in 50 year return period. However, it is noted that for the period of interest in the present study (first natural period of the CLTRC hybrid building, \(T_1 = 1.17 \text{ s}\)), the two hazard models incidentally have approximately the same spectral acceleration value. FigureÂ 6a shows the hazard hazard curve for the Vancouver site (\(49^\circ 15' 00''\) N, \(123^\circ 7' 12''\) W) with an average shear wave velocity to 30 m depth, \(V_{s30} =\) 450 m/s. The hazard curve is shown for the intensity measure, \(Sa(1.17 \text { s})\) i.e., the spectral acceleration corresponding to the first mode. The deaggregation results for \(Sa(1.17 \text { s})\) corresponding to a 2475 year return period is shown in Fig.Â 6b. Three contributing tectonic regimes are considered for southwestern British Columbia [69, 70]. For the present hazard, their contributions are 41% for Active Shallow Crust, 32% for Subduction Interface, and 27% for InSlab (source id IntraSlab55).
Hazardconsistent ground motion selection
The ground motion selection is conducted to represent the complex tectonic feature of southwestern British Columbia. A series of site and structurespecific conditional spectra (CS) is considered. Specific to a tectonic regime, the CS includes the mean (known as, conditional mean spectrum, CMS) and covariance between different spectral ordinates [71]. The CMS accounts for the conditionality of spectral ordinates by defining the parameter \(\varepsilon\), as follows:
where \(S{a}(\cdot )\) is the spectral acceleration; \(T^*\) is the conditioning period; and \(\mu _{\ln Sa(\cdot )}\) and \(\sigma _{\ln Sa(\cdot )}\) are obtained from a suitable ground motion model for deaggaregted magnitudedistance \((\overline{M}, \overline{R})\). Further, the CMS is expressed as:
where \(\rho _{\varepsilon (T),\varepsilon (T^*)}\) is the correlation coefficient between Sa(T) and \(Sa(T^*)\).
TableÂ 3 shows the modal earthquake tuples \((\overline{M}, \overline{R})\) with the highest contribution for each tectonic regime using SHM6. The corresponding deaggregation was shown earlier in Fig.Â 6b. The table also lists the spectral shape at 1.17 s for each tectonic regime. The ground motion models for each tectonic regime is selected from the corresponding logic tree of the tectonic regime used during Probabilistic Seismic Hazard Analysis (PSHA).
FigureÂ 7 shows the results of the ground motion selection based on the target CS. The number of records from each tectonic regime is proportional to its contribution to the site hazard. Thus, there are 16 Shallow Crustal, 13 Subduction Interface, and 11 InSlab records. The NGA West2 database [75] has been used for crustal and inslab records, whereas the KiKnet database [76] has been used for the subduction records. Site classification and flatfiles for each database are available in the literature [77, 78]. The period range of interest is based on the NBCC guidelines [69, 79]. The upper bound of the period range, \(T_{max}\) is defined as \(\max (2T_1, 1.5\text { s})\), where \(T_1\) is the period of vibration in the first mode. The lower bound of the period range, \(T_{min}\) is defined as \(\min (0.15T_1, T_{90\%})\), where \(T_{90\%}\) is the lowest period of vibration that achieves a cumulative mass participation of 90%. For the RCCLT building, the 0.25 second period corresponds to the third mode. Thus, the period range of interest is [0.18, 2.34]. A computationallyefficient algorithm is employed to select the ground motion suite [80]. The scaling factor is limited to 5 [69]. Further, a restriction of \(R_{JB} > 20 \text { km}\) is imposed to exclude nearfield records. A maximum magnitude difference of 1.5 from the modal magnitude is allowed. The \(V_{s30}\) values are between 300 and 600 m/s. FigureÂ 7bâ€“c show the target and achieved mean and dispersion of the three conditional spectra. An excellent match reflects the versatility of the considered database and selection algorithm.
Results
Pushover analysis
FiguresÂ 8bâ€“c show the pushover curves for the RCCLT hybrid frame with slit and flagshaped dampers, respectively. The pushover curves for the latter with \(\beta _F = 0.8\) and \(\beta _F = 0.6\) are identical due to the common backbone curve of both flagshaped dissipators. The effect of the recentering ratio is captured in the dynamic analysis, which is presented in the subsequent sections. The pushover curves of hybrid frames are compared with the bare RC frame (Fig.Â 8a) to observe the effects of the CLT infill and energy dissipators on the nonlinear static response. For both types of dissipators, a significant increase of \(\approx~70\%\) is observed in the maximum base shear. While the yield displacements of the hybrid buildings are smaller than that for the bare frame, the maximum deformation capacity (corresponding to a base shear reduction to 80% of the maximum) increases. Thus, a combination of CLT infill with energy dissipators enhances the strength as well as the drift capacity of the building. The reduction in yield drift is attributed to the presence of the stiffer CLT infills, whereas the higher ultimate deformation is attributed to the high deformability of steel slit and flagshaped dampers. The nonlinear static capacity of the hybrid frame with flagshaped dissipators is similar to the frame with slit dampers. Since the design of frames is based on static analysis, this similarity confirms the equivalence of the design using both types of dissipators. The marginal difference in the inelastic capacity of the two dissipators is attributed to the discrete nature of the design process.
Incremental dynamic analysis
The seismic performance of the RCCLT hybrid system with different energy dissipators is assessed using incremental dynamic analysis (IDA) [81]. Under IDA, increasingly scaled ground motion records are applied to the building until its collapse. The statistical distribution of the intensity measure values for each ground motion record in the suite is used to derive the seismic fragility function. Due to the unique seismicity of Southwestern British Columbia, a rigorous ground motion selection method is adopted. As discussed earlier, a suite of 40 pairs of ground motion records is selected to represent the three tectonic regimes that affect Vancouver, British Columbia. FigureÂ 9 shows the IDA curves for RCCLT buildings with three design configurations of energy dissipators, viz., one slit damper and two flagshaped dissipators with recentering ratio, \(\beta _F = 0.8\) and \(\beta _F = 0.6\). The figure also shows the 84th and 16th percentile IDA curves. The median collapse capacity of buildings with flagshaped dissipators is observed to be the highest. This may be attributed to the recentering capacity of flagshaped dissipators, which result in relatively smaller nonlinear deformations. It is noted that the scaling of the ground motion records for IDA maintains the same spectral shape at different intensities, which may not be a true representation of the hazard. Multiple stripe analysis targeting conditional spectra at different intensities can alleviate this issue [82, 83].
Fragility assessment
Using the empirical data from the IDA curves, a lognormal distribution is fitted to produce a collapse fragility for each building. FigureÂ 10 shows the collapse fragility of three RCCLT hybrid building designs. The spectral acceleration corresponding to the first mode \(Sa(1.17 \text { s})\) is chosen as the intensity measure. TableÂ 4 presents the fragility parameters. The fragility functions reaffirm the better seismic performance of buildings with flagshaped dissipators, whose median collapse capacity is 25â€“30% more than those with slit dampers. Accordingly, the collapse margin ratio (CMR) defined as the ratio of median collapse capacity to the MCE level spectral acceleration is found to be 2.8 in the case of slit dampers, whereas it increases to 3.6 and 3.5 for buildings with flagshaped dissipators. It is noted that an increase in the recentering ratio \(\beta _F\) results in higher collapse capacity. This can be attributed to the larger hysteresis loops for \(\beta _F=0.8\) compared to that for \(\beta _F=0.6\), as shown earlier in Fig.Â 4. Thus, the flagshaped dissipator with a higher recentering ratio provides higher energy dissipation and thus less deformation.
Residual deformation
While the maximum interstory drift ratio (\(IDR_{max}\)) is a useful measure for the collapse assessment of structures, the postearthquake safety of a structure is largely determined based on the residual drift ratio (\(IDR_{res}\)). The literature is rich with studies on \(IDR_{res}\) for single and multidegreeoffreedom systems (e.g., [7, 84,85,86]). FigureÂ 11 shows a plot of the residual drift ratio versus maximum drift ratio for all three energy dissipators. It is observed that flagshaped dissipators significantly reduce the residual drift. Thus, the recentering capacity of flagshaped dissipators improves the building performance by reducing residual drift.
Collapse risk assessment
The fragility functions developed in the previous section capture recordtorecord uncertainty (\(\beta _{RTR}\)) in the buildingsâ€™ seismic performance. Additional sources of uncertainty were approximated based on the literature [87]. These include (a) uncertainty in design requirements, \(\beta _{DR} = 0.10\): Superior rating on account of capacitybased RC frame obtained using DDBD, (b) uncertainty in test data, \(\beta _{TD} = 0.20\): Good rating due to wellcalibrated material and damper properties, and (c) modeling uncertainty, \(\beta _{MDL} = 0.35\): Fair rating due to modest confidence in the representation of the collapse characteristics. Different uncertainty components are combined using the square root of the sum of their squares. TableÂ 4 summarizes different measures of collapse for the RCCLT hybrid building with energy dissipators. The probability of collapse at MCE, P(collMCE), for the building with slit dampers is found to be 2.7%. As anticipated from the fragility, the value of P(collMCE) for buildings with flagshaped dissipators is smaller and equals to 1.7% and 1.9% for \(\beta _F = 0.8\) and \(\beta _F = 0.6\), respectively. These values are favorably compared to the target of 10% in codecompliant ordinary buildings based on ASCE 7 [88]. The collapse rate, \(\lambda _{coll}\) is estimated using the total probability theorem considering all possible intensity levels. The value of \(\lambda _{coll}\) is assessed as \(0.65 \times 10^{4}\) for the hybrid building with slit dampers, whereas \(\lambda _{coll}\) for buildings with flagshaped dissipators is found to be \(0.42 \times 10^{4}\) and \(0.46 \times 10^{4}\). These values again compare favorably to the collapse risk target of \(2\times 10^{4}\) in ASCE 7 [88]. Assuming a Poissonâ€™s distribution for collapse, the probability of collapse in 50 years \(P(coll)_{50y}\) is determined as 0.32% for the slit damper case; \(P(coll)_{50y}\) takes the value of 0.21% and 0.23% for the cases with flagshaped dissipators. These values again comfortably meet the conventional target of 1% for ordinary buildings [88].
Conclusions
A global call for environmentallysustainable construction is making timber an attractive material for building structural systems. The seismic performance of a hybrid timber building located in Vancouver, Canada is studied in this paper. The latest 6th generation seismic hazard model described in the NBCC 2020 coupled with the complex seismotectonic features of southwestern British Columbia make a compelling case for the present investigation. The sixstory RCCLT hybrid building contains steel slit dampers that enhance its energy dissipation mechanism. A hazardconsistent suite of 40 ground motion records representing three tectonic regimes (Subduction, Shallow Crustal, and Inslab) is selected for nonlinear response history analysis. The effectiveness of the energy dissipation mechanism using slit dampers is compared to a modern flagshaped dissipator. Two flagshaped dissipators are considered to observe the effect of different recentering ratios. The seismic performance of three building configurations is compared in terms of residual drift ratio. Flagshaped dissipators are shown to outperform the slit dampers. The following conclusions are drawn from the study:

The CLT infill and steel slit dampers in the building enhance its maximum base shear capacity by \(\approx\) 70% compared to the bare RC frame. While the yield displacement of the hybrid building is marginally smaller due to the stiffer CLT infills, the maximum deformation capacity is enhanced by steel slit dampers. Thus, a combination of CLT infills and steel slit dampers increased both the lateral strength and drift capacity of the building.

Comparable nonlinear static performance is obtained for the hybrid buildings with flagshaped dissipators and steel slit dampers. However, when the nonlinear response history is compared, the buildings with flagshaped dissipators outperform the ones with slit dampers.

The median collapse capacity of the buildings with flagshaped dissipators is 25â€“30% more than those with slit dampers. Correspondingly, the collapse margin ratio (CMR) is found to be 2.8 in the case of slit dampers, whereas it increases to 3.5â€“3.6 for buildings with flagshaped dissipators.

With an increase in the \(\beta _F\) value, the flagshaped hysteresis provides a better energy dissipation mechanism.

Compared to the steel slit damper, the flagshaped dissipators significantly reduce the residual drift under seismic excitation.

The probability of collapse at the MCE for the hybrid building with slit and flagshaped dissipators (\(\beta _F=0.8\) and \(\beta _F=0.6\)) was found to be 2.7%, 1.7%, and 1.9%, respectively. These values are deemed favorable when compared to the 10% target for codecompliant ordinary buildings in ASCE 7 [88]. Further, the probability of collapse of the hybrid building in 50 years was computed as 0.32%, 0.21%, and 0.23%. These values again outperform the conventional target of 1% for ordinary buildings.
Availability of data and materials
The analysis models used in the current study are available from the corresponding author on reasonable request.
Abbreviations
 CLT:

CrossLaminated Timber
 CMS:

Conditional Mean Spectrum
 CS:

Conditional Spectrum
 DDBD:

Direct DisplacementBased Design
 EVD:

Equivalent Viscous Damping
 IDA:

Incremental Dynamic Analysis
 IDR:

InterStory Drift Ratio
 IM:

Intensity measure
 NBCC:

National Building Code of Canada
 PSHA:

Probabilistic Seismic Hazard Analysis
 SHM6:

6th Generation Seismic Hazard Model
 RC:

Reinforced Concrete
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Acknowledgements
The funding from British Columbia Forestry Innovation Investmentâ€™s (FII) Wood First Program and Natural Science and Engineering Research Council of Canada (Grant/Award Number: RGPIN 201905013) is greatly acknowledged.
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British Columbia Forestry Innovation Investmentâ€™s (FII) Wood First Program and Natural Science and Engineering Research Council of Canada, Grant/Award Number: RGPIN 201905013.
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IO: Modeling, Analysis, Writing  original draft. PSB: Conceptualization, Methodology, Modeling, Formal analysis, Writing  original draft, Review. HVB: Conceptualization, Methodology, Review & Editing. ST: Conceptualization, Methodology, Review & Editing, Supervision, Funding Acquisition. All authors read and approved the final manuscript.
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Odikamnoro, I., Badal, P.S., Burton, H. et al. Seismic collapse risk of RCtimber hybrid building with different energy dissipation connections considering NBCC 2020 hazard. J Infrastruct Preserv Resil 3, 14 (2022). https://doi.org/10.1186/s43065022000616
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DOI: https://doi.org/10.1186/s43065022000616