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The cross-laminated timber (CLT) shear-wall and glulam moment-resisting frame (CLTW–GMRF) dual system is a recently completed research prepared for the British Columbia (BC) Forestry Innovation Investment Ltd. With the introduction of new structural systems, the need to update existing building code becomes evident. Accordingly, this study evaluates the ductility-related force modification factor (Rd) of the CLTW–GMRF system for the National Building Code of Canada, utilizing the FEMA P-695 procedure. In two performance groups, 16 archetype buildings are designed considering different building storey heights, CLT shear-wall locations, and wall-frame moment proportions. Numerical model of the systems is developed in OpenSees and incremental dynamic analyses are conducted using 30 bi-directional ground motion records that represent the seismicity of Vancouver, BC, Canada. Collapse margin ratios are calculated to assess the adequacy of the trial Rd factors. The research determined that with an over-strength factor of 1.5, an Rd of 3 is found to be acceptable for the system. [ABSTRACT FROM AUTHOR]

The desire of using sustainable materials has reignited the interest in timber-based construction. Researchers and practitioners are developing novel timber-based structural solutions. Cross-laminated timber (CLT)-coupled wall is a recently proposed system for potential use in mid- and high-rise timber construction. The National Building Code of Canada, however, does not include this system and, consequently, the seismic force modification factors are not available. This study evaluated the ductility-related force modification factor (Rd) using the FEMA P-695 procedure. Nine archetype buildings were designed considering different design parameters: building storey height, CLT wall configuration, and coupling ratios. Using 30 ground motion records (bi-directional), rigorously selected for seismicity of Vancouver, BC, Canada, incremental dynamic analyses were performed. Collapse margin ratios were calculated to assess the adequacy of the trial Rd factors. Using an over-strength factor of 1.5, Rd = 4 is found to be acceptable for this system. [ABSTRACT FROM AUTHOR]

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) moment-resisting frames and cross-laminated timber (CLT) infills is assessed for its seismic performance against the latest SHM. The six-story RC-CLT hybrid system, designed using the direct displacement-based 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 in-slab faulting mechanisms. A hazard-consistent set of 40 ground motion pairs is selected from the PEER and KiK-net databases, and used to estimate the building's seismic performance. The effects of using steel slit dampers (associated with large hysteresis loops) and flag-shaped 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 2–3% at the 2475-year return period shaking intensity. The hybrid building with steel slit dampers exhibits a collapse margin ratio of 2.8, which increases to 3.5–3.6 when flag-shaped dissipators are used. The flag-shaped dissipators are found to significantly reduce the residual drift of the hybrid building. Additionally, the seismic performance of the hybrid building equipped with flag-shaped dissipators is found to improve marginally when the recentering ratio is increased. [ABSTRACT FROM AUTHOR]

The lateral strength and stiffness requirements due to wind loads usually govern the design of tall buildings. The current building codes in the US, Canada, and Europe recognize the first significant yield point as an ultimate limit state. Consequently, the current design practices ignore the plastic capacity of structural systems in the nonlinear range, which could result in overdesigned buildings. Thus, the classical linear-elastic design arguments shall be reexamined with consideration of performance-based wind design (PBWD) approaches, innovative technologies, and materials. We are presenting two companion papers to demonstrate the benefits of considering the nonlinear capacity of structural systems in the design of wind-excited buildings. In this paper, Part I, we have postulated and then proved the capability of self-centering systems in controlling the possible damage accumulation in structural systems subjected to along-wind loads. Our arguments are based on an extensive parametric study through nonlinear time history analyses considering peak and residual ductility-demands, normalized hysteretic energy dissipation, and the rate of damage accumulation as performance indicators. Overall, the results of the parametric study revealed that self-centering systems could benefit the most from the ductility-based design due to their inherent recentering capability, higher energy dissipation, and lower sensitivity to wind duration. Consistent with the notion of PBWD, for self-centering systems, the companion Part II paper demonstrates the benefits of the ductility-based wind design in terms of economics and safety through structural reliability analysis. [ABSTRACT FROM AUTHOR]

This study presents a city‐wide seismic risk assessment of single‐family wooden houses in Victoria, British Columbia, and Canada. The novelty and uniqueness of this study include considerations of detailed building‐by‐building exposure model for residential houses, current national seismic hazard model for Canada, and rigorous seismic fragility modeling of wooden houses based on nonlinear dynamic analysis of structures subjected to mainshock‐aftershock sequences. A full consideration of stochastic event scenarios in probabilistic seismic risk analysis allows the identification of critical scenarios from overall regional seismic risk perspectives and provides valuable insights in informing earthquake disaster risk management actions. Outputs from the developed catastrophe model for Victoria are compared with the empirical model that was developed based on insurance claim data from the 1994 Northridge earthquake. Results of the seismic loss calculations highlight the importance of seismic resistance of the existing houses and of aftershock effects. The integrated use of the outputs from the advanced catastrophe model facilitates risk‐based identification of critical earthquake scenarios, which are useful for different stakeholders for earthquake risk management purposes. [ABSTRACT FROM AUTHOR]

Summary: Megathrust earthquake sequences, comprising mainshocks and triggered aftershocks along the subduction interface and in the overriding crust, can impact multiple buildings and infrastructure in a city. The time between the mainshocks and aftershocks usually is too short to retrofit the structures; therefore, moderate‐size aftershocks can cause additional damage. To have a better understanding of the impact of aftershocks on city‐wide seismic risk assessment, a new simulation framework of spatiotemporal seismic hazard and risk assessment of future M9.0 sequences in the Cascadia subduction zone is developed. The simulation framework consists of an epidemic‐type aftershock sequence (ETAS) model, ground‐motion model, and state‐dependent seismic fragility model. The spatiotemporal ETAS model is modified to characterise aftershocks of large and anisotropic M9.0 mainshock ruptures. To account for damage accumulation of wood‐frame houses due to aftershocks in Victoria, British Columbia, Canada, state‐dependent fragility curves are implemented. The new simulation framework can be used for quasi‐real‐time aftershock hazard and risk assessments and city‐wide post‐event risk management. [ABSTRACT FROM AUTHOR]

The use of timber panels to construct the lateral and gravity load resisting systems of tall mass-timber buildings makes them lightweight and less stiff than buildings made from conventional construction materials. As a result, frequent exposure to wind-induced oscillations could cause discomfort to the occupants. This study examines the dynamic response and serviceability-performance of five case study tall mass-timber buildings varying in height (10-, 15-, 20-, 30-, and 40-story). In the assessment, the case study buildings are structurally designed according to the 2015 National Building Code of Canada and CSA O86-14 standard. High-frequency pressure integration wind tunnel tests are conducted to obtain floor-by-floor aerodynamic wind load time histories. Dynamic structural analyses in the frequency domain are performed to calculate the peak floor accelerations for various levels of critical damping ratios, wind directions, and exposure conditions. For validation and to include the possible motion-dependent effects, such as aerodynamic damping, aeroelastic wind tunnel tests are also carried out on the model of the 40-story tall mass-timber building. A base-pivoted two-degrees-of-freedom stick type aeroelastic model is designed and built to simulate the dynamic response of the prototype building in its two fundamental sway modes of vibration. Overall, it is shown that the dynamic response of tall mass-timber buildings under wind excitation is strongly dependent on the height, structural damping, local turbulence intensity, and wind direction. Based on the case studies, recommendations regarding the habitability of mass-timber buildings, critical height limit, and mitigation strategies for wind-induced excessive motions are forwarded. [ABSTRACT FROM AUTHOR]

Water utilities often rely on water main failure prediction models for developing preventive or proactive repair and replacement action programs. Due to inherent uncertainties in modeling, it is challenging to understand the water main failure processes and to predict the failure effectively. In this study, Bayesian model averaging (BMA) method is presented to identify the influential covariates and to predict the failure rates of water mains considering model uncertainties. To accredit the proposed model, it is implemented to predict the failure of pipes of the water distribution network of the City of Kelowna, BC and Greater Vernon Water, BC, Canada. Results indicate that the proposed BMA approach captures the effect of the potential explanatory variables more effectively through the posterior probabilities in contrast to that of the p-value given by the classical regression analysis. Moreover, BMA approach performs better compared to classical regression analysis when limited pipe failure data are available. [ABSTRACT FROM AUTHOR]

About 95% of the water supply systems in Canada are being operated by small-to-medium-sized water utilities (SMWU) serving populations less than 50,000. The representation of these utilities in National Water and Wastewater Benchmarking Initiative (NWWBI) is almost negligible due to less awareness, issues related to data availability, and financial constraints. In the present work, an inter-utility performance benchmarking model (IU-PBM) is developed, which entails consideration of 47 performance indicators (PIs) for different functional components of SMWU, such as water resources and environment, personnel, physical assets, quality of service, water quality and public health, and financial aspects. For performance benchmarking, 47 (linear, exponential, logarithmic, and polynomial) transformation functions have been established to translate the calculated PIs into performance levels between 10 and 100, which is based on literature, NWWBI reports, and expert judgment. The weights are estimated using a specific method from the literature for ranking of PIs by different water utilities in the Okanagan basin, British Columbia, Canada, and opinions of experts working in water infrastructure management. Finally, performance indices have been established by aggregating the transformed performance levels using the technique for order preference by similarity to ideal solution (TOPSIS) (i.e., based on the concept of relative closeness to the most desirable performance and remoteness from the least desirable performance). The IU-PBM results presented in the form of a web diagram demonstrate the utility's performance to the top management for pragmatic decision making. The proposed model has also been implemented for two SMWU operating in Okanagan Basin to evaluate its practicality. [ABSTRACT FROM AUTHOR]

Joint probabilistic characteristics of key structural demand variables due to intense ground shaking are important for quantitative seismic loss estimation. Current damage–loss models require inputs of multiple seismic demand parameters, such as maximum/residual inter-storey drift ratio (ISDR) and peak floor acceleration (PFA). This study extends current seismic demand estimation methods based on incremental dynamic analysis (IDA) by characterising dependence among different engineering demand parameters (EDP) using copulas explicitly. The developed method is applied to a 4-storey non-ductile reinforced concrete (RC) frame in Victoria, British Columbia, Canada. The developed multi-variate seismic demand model is integrated with a storey-based damage–loss model to assess the economic consequences due to different earthquake loss generation modes (i.e. non-collapse repairs, collapse, and demolition). Results obtained from this study indicate that the effects of multi-variate seismic demand modelling on the expected seismic loss ratios are significant. The critical information is the limit state threshold for demolition. In addition, consideration of a realistic dependence structure of maximum and residual inter-storey drift ratios can be important for seismic loss estimation as well as for multi-criteria seismic performance evaluation. [ABSTRACT FROM AUTHOR]

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Life-cycle cost (LCC) analysis entails consideration of building performance throughout the structures’ life. The impact and interaction of topology irregularities and construction quality (CQ) on LCC, however, are often ignored and require a more detailed evaluation. In this article, different levels and interaction of soft story (SS) andCQare analytically modeled to quantify corresponding fragility curves and LCC (by considering hazard level, limit state cost, and probability of being in different damage states). The proposed method is illustrated with a three-, six-, and nine-story reinforced concrete building located in Vancouver (located in west coast of Canada). [ABSTRACT FROM PUBLISHER]

Devastation observed from global earthquakes highlights the need for a decision-making tool to aid in prioritisation and resource allocation for seismic risk management. In this paper, a seismic risk index assessment tool is developed using Bayesian belief network (BBN) that considers geological, engineering, economic, social, political and cultural factors. Previously proposed hierarchical structure is modified and modelled using a BBN. The subjective probabilities of the BBN are derived using expert knowledge. Furthermore, to illustrate versatility of the proposed model, a case study is undertaken for 11 Canadian cities. [ABSTRACT FROM PUBLISHER]

Over 50 years of design life, buildings are exposed to different magnitudes and frequencies of earthquakes that require consideration of life-cycle cost (LCC). The LCC entails quantifying the building performance under seismic hazard and investments throughout the life of the structures. Traditional LCC utilises probabilities of being in different damage states. However, for buildings with inherent irregularities (e.g. vertical irregularity and plan irregularity), these probabilities are not readily available. In this paper, a system-based approach, utilising fuzzy set theory, is used to quantify the possibility of being in different damage states. The analysis is limited to study the effect of seismic exposure on the building LCC. The proposed method is illustrated with two case studies, a six-storey reinforced concrete (RC) building located in Vancouver, Canada, and vulnerability of an urban centre with 1000 RC buildings. Furthermore, sensitivity analysis is carried out to highlight the impact of different building performance modifiers on the LCC. [ABSTRACT FROM AUTHOR]

• The main considerations in stormwater infrastructure management are discussed. • A model is developed to investigate sustainable funding strategies. • Stormwater fee-based funding strategy is explored for Canadian municipalities. Most cities in Canada do not charge a stormwater fee; consequently, stormwater programs may need to compete with other funding priorities in public works. This often leads to a lack of dedicated and predictable cash flow, which can limit municipalities' capacity to sustain stormwater services. In such situations, it is useful to identify available revenue sources and expected expenditures, so that sustainable funding strategies can be determined. In this paper, we explore a novel system dynamics model to investigate sustainable funding strategies. The model consists of a qualitative assessment that uses causal loop diagrams to provide a conceptual system representation and a mathematical formulation for a quantitative assessment. The model is used to explore the potential of introducing stormwater fees in the city of Vernon, Canada. It is shown that the model is helpful in strategic asset management decision making, and can be used to build arguments for implementing proactive asset management programs. [ABSTRACT FROM AUTHOR]

Abstract Introduction : The safety of oil and gas pipelines is an increasing concern for the public, government regulators, and the industry. A safety management system cannot be efficient without having an effective integrity management program (IMP) and a strong safety culture. IMP is a formal document (policies, planning, scheduling, and technical processes) while safety culture is a measure of views, beliefs, and traditions about safety. For regulatory authorities and O&G companies, assessing the effectiveness of both the IMP and safety culture through regulatory audits is a daunting task with indistinct findings. Method : An integrated framework based on regulatory audits is developed to assess the maturity of safety culture based on IMP efficacy through risk-based approach by using failure mode and effect analysis (FMEA). The framework focuses on three distinct aspects, the probability of failure occurrence in case of the non-compliance of regulatory and program requirements, severity of non-compliance, and effectiveness of the corrective actions. Results : Program requirements and performance indicators are translated into assessment questions which are grouped into 18 IMP components. Subsequently, these components are linked with four safety culture attributes. Sensitivity analysis revealed that four IMP components, i.e., organizational roles and responsibilities, policy and commitment, risk assessment, and training and competency, significantly affect the safety culture maturity level. Conclusions : Individual assessment of IMP and safety culture in O&G sector consumes extensive time and efforts in the auditing process. The framework facilitates the process by pursuing common criteria between IMP and safety culture. The O&G companies and regulator can prioritize the improvement plans and guidelines using the framework's findings. Practical applications : The integrated framework developed in this research will improve the existing assessment mechanism in O&G companies. The framework has been effectively implemented on a case of 17 upstream O&G pipeline-operating companies in the province of British Columbia, Canada. [ABSTRACT FROM AUTHOR]