Risk-Informed and Life-Cycle Analyses of Structures and Infrastructures

The special collection on Risk-Informed and Life-Cycle Analyses of Structures and Infrastructures is available in the ASCE Library (https://ascelibrary.org/jsendh/risk_informed_life_cycle_structures_infrastructures).

The structural engineering community is increasingly interested in the derivation of new techniques and approaches for risk-informed decision-making in the design of structures and infrastructures, and for the management and retrofitting of aging ones.

Traditional design approaches are being replaced by life-cycle analyses of structures, which permit the consideration of a broader set of performance metrics throughout a system’s lifetime. Life-cycle analysis allows accounting for uncertainties involved in the design, considering the effects of multiple concurrent or interacting hazards, and addressing potential deterioration and progressive damage. In the perspective of life-cycle analysis, the advantage of structural health monitoring systems can also be properly evaluated.

This special collection contains 14 technical papers. The collection provides an overview of recent advancements in the fields of risk assessment and life-cycle analysis of structural and infrastructure systems subjected to various hazards, like wind, earthquake, scouring, sand accumulation, degradation, or any combinations of the above.

Athanasiou et al. (2022) present a multihazard performance-based design framework for steel buildings. Structural and nonstructural damage is examined in terms of interstory drifts and floor acceleration thresholds. Repair costs are employed to assess the performance of selected buildings subjected to wind and earthquake hazards. The study combines simulations with data from wind tunnel experiments to study wind loads and response and to evaluate economic losses. Controlled inelastic deformations of the vertical bracing systems are allowed under wind excitation in moderate seismic regions.

Billah and Iqbal (2022) study the effects of joint seismic and scour on bridge fragility, but uniquely for the case of isolated structures that incorporate either friction pendulum or lead rubber bearings. For the case study structure considered, the results reveal the effect that isolation can have in reducing the seismic fragility of bridges and countering the heightened column demands imposed as a result of combined scour at the foundations.

Chu et al. (2022) examine life-cycle wind-resistant performance of an existing suspension bridge in the coastal region of China. The paper quantifies various sources of input uncertainties, such as random modal frequencies, damping ratios, and identification of Scanlan derivatives, the variability of which is postulated by Wishart probability distribution. First, the team investigates flutter probability in the context of bridge reliability. Second, buffeting deck response is studied under the effect of tropical cyclones and warming climate scenarios. Information on the bridge deck modal behavior is extracted from the Bayesian fast Fourier transform method using structural health monitoring data. Uncertainty propagation is quantified by Markov chain Monte Carlo sampling.

The paper by Darestani et al. (2022) focuses on risk analysis of wood utility poles considering the two major failure modes: the rupture of the pole and the overturning due to foundation failure. Indeed, in coastal regions, in addition to wind load, the impact of high-level groundwater that saturates the soil and the effect of surge and wave-induced loads are not negligible. The paper derives a set of parameterized fragility models for combined wind, surge, and wave effects. The results of this study indicate that depending on the type of soil, both modes of failure could be significant, and therefore they are crucial for risk and resilience assessment of coastal distribution systems.

Ferro et al. (2022) presents a forensic investigation into the collapse of one of the spans of the La Reale viaduct in the Piedmont region in Italy. The paper sheds light on issues surrounding cable injection and subsequent deterioration. Along the way, it offers insights on visible evidence that could be used in future inspections and also explores partial safety coefficients for variable traffic loads.

González-Dueñas and Padgett (2022) study critical coastal infrastructures, such as coastal buildings vulnerable to tropical cyclone in the Atlantic Ocean and along the coast of the United States. The authors expand the performance-based coastal engineering framework that allows for consideration of depreciation, aging, or deterioration of coastal structures and infrastructure systems. Using as an example the residential building stock of Galveston, Texas, a Bayesian network framework is employed to evaluate damage and subsequent recovery of the portfolio between the years 2030 and 2050. Correlation analysis between immediate damage and social vulnerability factors, as well as between the recovery index and social vulnerability factors, is employed to expose potential disparities among different communities. Changing climate conditions are simulated, exacerbating the probability of failure of the building stock and associated housing recovery. Furthermore, correlation analysis demonstrates that the elderly and women might be most at risk in future hurricane events.

Kim et al. (2022) examine vehicle accident risk over sea-crossing bridges under wind hazards. The annual frequency of car accidents is evaluated as a risk index, using information on daily traffic volumes, the percentage of trucks, and the probability distribution of the speed and direction of the wind at the bridge site. The approach considers various factors affecting vehicle stability. The risk index is derived and estimated by examining all road sections of the bridge deck. The proposed method identifies the vulnerable sections along the bridge deck axis and the vehicle types. A case study is used for illustration purposes.

Mahdavipour and Vysochinskiy (2022) evaluate fracture-based fragility curves for steel components located in corrosive environments. The curves were developed at the component level by micromechanical modeling to consider uncertainties of pitting morphologies and to extract the probability of failure of components. The proposed method coupled with corrosion data and risk management procedures can be used for the life-cycle evaluation of new or existing steel structures under excessive plastic deformations and corrosive environments.

Marasco et al. (2022) focus on damage detection in beam structures, including localization and severity assessment, by proposing a hybrid method that combines insights from influence lines with computational exploration using genetic algorithms. The method is illustrated with a simply supported railway bridge superstructure along with parameter analyses.

The paper by Lan and Huang (2022) focuses on life-cycle risk analysis of roofs of low-rise buildings subjected to typhoons, based on the extremum probability density evolution method (EPDEM). The EPDEM combined with wind tunnel test results are used to generate the probability density curve of typhoon wind loads. The proposed approach is compared with the Monte Carlo method to show its effectiveness and accuracy for practical applications. Based on this result, a methodology is proposed to predict the vulnerability curves for a new structure at different service times.

Ning and Xie (2022) develop a risk-based optimization strategy that relates the expected annual repair cost ratio (ARCR) of the bridge to the design parameters of base isolators and fluid dampers. This strategy is achieved through a multistep workflow that integrates a seismic hazard model, an experimental design of bearings and dampers, a logistic regression toward parameterized component-level fragility models, and a bridge system-level seismic loss assessment. It is shown that optimal design parameters can significantly reduce the expected ARCR of the bridge and combining optimally designed bearings and dampers can provide the minimum seismic risk.

Torti et al. (2022) address challenges relevant to management of bridges located in multihazard environments with earthquakes and a corrosive environment. Specifically, this paper proposes a framework to illustrate the potential influence of knowledge regarding corrosion conditions (e.g., via a structural health monitoring system) on the fragility and subsequent life-cycle cost analysis of reinforced concrete bridges in seismic zones.

Raffaele et al. (2022) examine the windblown sand action effects on civil infrastructures in deserted and coastal areas. The wind interacts with built structures and affects their serviceability and safety. The study utilizes sand mitigation measures applied to a railway example, in which windblown sand action is quantified to design the sand mitigation measures. In this study, the authors propose a practical approach for structural design and mitigation of windborne sand effects using specialized wind-sand tunnel tests and computational simulations. The simulations determine windblown sand action and frequencies of sand removal maintenance.

Wang et al. (2022) pose a multihazard optimal design problem leveraging a life-cycle cost (LCC)–driven objective function with Bayesian optimization. This problem is illustrated in the context of optimal design of a tuned liquid wall damper (TLWD) within case study buildings subjected to nonconcurrent wind and seismic loads. The outcomes reveal the superior LCC performance relative to traditional tuned liquid column dampers installed at the top of buildings.