David Y. Yang

• PhD
• Professor (Assistant) at Portland State University

This chapter addresses the challenges posed by climate change in structural engineering practice to advance the performance of infrastructure systems through guidelines for recommended code and standard provisions and for best engineering practices for design, rehabilitation and risk management of future climate extremes. Many climate effects in in...

Risk-informed life-cycle engineering provides a viable approach for addressing the challenges posed by climate change for developing appropriate design and management criteria for structures and infrastructure systems. The basic mathematical formulations are first presented and followed by a discussion of important factors that must be considered d...

Corrosion is a major deterioration mechanism of carbon steel bridges. Multiple maintenance actions have been proposed to meet the safety requirements for bridges subjected to corrosion, including preventive maintenance, such as repainting, and essential maintenance, such as girder replacement. Recently, corrosion-resistant steel has been adopted fo...

Reliable and continuous operation of ships is vitally important to the decision-makers. Driven by the rising cost of newbuilding ships, maintenance actions are needed on existing ships to ensure safe and enduring service beyond their initial design life. Extending ship service life can provide economic operating profit and promote sustainability. M...

Social dimensions, as one of the three pillars of sustainability, are commonly not fully considered in the planning, bidding, and design processes of construction projects, primarily due to a lack of standardized estimation methods. Despite the potential economic and social benefits of these projects, they may lead to various negative social impact...

Structural deterioration due to environmental and mechanical stressors is a major concern for civil and marine structures. Inspection actions can reduce uncertainties, facilitate decision-making on maintenance, and in general assist life-cycle management. Risk-based inspection (RBI) planning is a useful tool to minimize life-cycle cost while preser...

Life-cycle management under uncertainty relies on the determination of life-cycle failure probability and risk. Usually, both life-cycle failure probability and risk are approximated by adding up the annual quantities during the service life of a structure. This approximation is based on the assumptions of (a) low annual failure probabilities and (...

The target reliability index is pivotal to the design, assessment, inspection, and maintenance of structures. It is commonly determined by cost optimization. However, depending on the method of quantifying fatality cost, cost optimization may lead to inconsistent target reliability indices, causing inadequate or unnecessary investment for safety im...

Corrosion-induced material loss can reduce the load-carrying capacity of structures, resulting in an increase of the probability and risk of failure. Currently, carbon steel is predominantly used in steel bridges due to its relatively low material cost, ease of fabrication at large scale and excellent material strength. However, low corrosion resis...

Corrosion and hurricanes pose substantial risk to coastal bridges. This risk is compounded by future climatic and socioeconomic changes due to the increasing temperature and humidity, rising sea level, changing frequency and intensity of hurricanes, and amplifying exposure and consequences to adverse events. These future conditions, however, involv...

Service life extension through proactive maintenance has become increasingly important for ships due to significant cost associated with new ship acquisition and adequate remaining load-carrying capacity. While continuous operation beyond design service life can offer economic profits to ship owners, it may also incur significant costs associated w...

Civil infrastructure systems have two essential characteristics: long service life and low probability of failure. Under these circumstances , life-cycle management (LCM) of civil infrastructure involves time preference of decision-makers on potential gains associated with maintenance actions and the perception of low probability (i.e., risk percep...

Structural deterioration poses a substantial threat to the safety, serviceability, and functionality of bridges. Since bridges are connected in transportation networks, their failure can dramatically alter traffic flow, causing immense social consequences such as large-scale traffic delay and additional vehicle operating cost. In this paper, a nove...

Transportation networks, as an essential ingredient of civil infrastructure, are subjected to various natural hazards over their service life. Failure of bridges may severely disrupt the serviceability of transportation networks, causing considerable economic and social losses. Recently, climate change has been found to be liable for the increasing...

Managers of civil infrastructure systems are facing the challenge to effectively and efficiently manage the ageing and deteriorating asset portfolio while accommodating ever increasing demand resulting from socioeconomic development and climate change. In this article, a novel approach using robust optimisation is proposed for risk-based portfolio...

Corrosion is a severe threat to the integrity of ships and other steel structures in marine environments due to material loss and the associated reduction in their load-carrying capacities. Most existing studies on corrosion of steel plates in marine environments dealt only with general corrosion. However, laboratory experiments and field tests hav...

Climate change poses a substantial threat to civil infrastructure systems. This paper proposes a systematic approach to evaluate the climate change impact on risk of bridge scour. The proposed approach pivots on global climate models and their downscaled simulation data for future climate prediction. For scour hazard analysis, the climate simulatio...

The large number of deteriorating bridges and the goal of sustainable development mean that maintenance actions should not only effectively improve the current condition of bridges but also enhance post-maintenance durability. In this paper, a probabilistic life-cycle optimization method is proposed for the planning of this type of maintenance acti...

Civil engineering structures can induce various environmental problems during their lifetime. In this paper, the life-cycle environmental impacts of structures, including the emissions to air, water and land, are quantified by environmental cost, and are considered as a part of indirect cost in the life-cycle cost (LCC) model. The computation of en...

Climate change and population growth can affect the supply and the demand sides of transportation networks, respectively. Rational assessment of societal risk of transportation networks should consider these effects, both of which are uncertain in nature. In this paper, a novel method is proposed to assess societal risk of transportation networks s...

Civil infrastructure during its service life is subject to progressive deterioration due to aggressive environments and sudden deterioration due to natural and/or manmade hazards. This paper presents a general approach to perform life-cycle management considering both types of deterioration. As an important aspect of life-cycle asset management und...

Flooding and the resultant scour damage to bridges may lead to immense economic losses and significant social and environmental impacts. Currently, bridge management decisions are developed on a bridge-by-bridge basis to prevent bridge failure due to scour, i.e., these decisions are made irrespective of other bridges in the regional transportation...

A novel method is proposed to rank bridges for maintenance priorities based on the risk posed by structural deterioration. The proposed method integrates structural reliability analysis, public datasets, and traffic flow theory to provide more accurate estimates of (1) probabilities of bridge failure, and (2) failure consequences. For the former, f...

Bridges, ships, and other civil and marine structures are subjected to fatigue damage due to repeated load fluctuations. Fatigue damage is likely to jeopardize the functionality and even structural safety of these structures. Therefore, inspections and timely repair actions are needed to ensure adequate structural performance throughout their lifet...

Ship structures are subjected to repetitive wave loads that can lead to fatigue damage. Accumulation of fatigue damage may eventually result in structural failure. In order to mitigate fatigue hazard to ship structures, timely inspections and maintenance actions must be planned during their life-span. As delays in the process of decision-making cou...

This paper presents a lifetime reliability-based approach for the optimization of post-tensioned concrete box-girder bridges under corrosion attack. The proposed approach is illustrated by determining the optimal life-cycle cost and CO 2 emissions of several initial designs of post-tensioned box-girder bridges with different objectives, i.e. the lo...

Time-dependent reliability analysis of deteriorating structures is important in their performance evaluation and maintenance. Various definitions and methods have been used by researchers to predict the time-dependent reliability of structures. In the present study, these methods are first critically reviewed and examined. Among these methods, the...

Time-dependent reliability analysis has been used for the performance evaluation and maintenance planning of deteriorating reinforced concrete (RC) structures during their life-cycle. This paper presents an improved threshold-based approach for the rational scheduling and selection of maintenance actions for RC structures based on time-dependent re...