Civil and Environmental Engineering Commons^™

Functionality Risk Assessment And Risk-Based Management For Critical Infrastructure Systems, Anteneh Zewdu Deriba

Dissertations and Theses

Critical infrastructure systems such as transportation networks serve as the lifelines of modern society, supporting economic activity and ensuring access to critical services. Their disruption under extreme events can produce consequences extending far beyond physical damage to individual assets. In transportation networks for instance, failures of critical assets such as bridges and tunnels can reduce accessibility of communities, limit freight capabilities for commerce, and increase travel distance and travel time of road users. These consequences associated with the system functionality loss are tied not only to the physical vulnerability and failure of individual assets, but also to the system configuration …

Storm Surge And Tides In Convergent Estuaries: The Case Of Extratropical Storm Merbok In Alaska, Steven Dykstra, Stefan Talke, David A. Jay, Matthew Lobo, Silvia Innocenti, Pascal Matte

Civil and Environmental Engineering Faculty Publications and Presentations

Coastal floods are composed of multiple drivers that interact with coastline geometries and are difficult to differentiate. To investigate the effects of basin shapes on storm surge and tides, we study the landfall of ex-Typhoon Merbok in the east Bering Sea, Alaska. Water levels at 34 stations are detided with a new tide wavelet tool, CWT_Multi (Lobo et al., 2024), and the spatial and temporal shifts in tides and surge are interpreted via long-wave theory. Results show nonstationary semiannual trends in tidal constituents due to ice effects and large interannual variability in mean-sea level (20-40 cm). After removing non-stationary tidal …

Theoretical Model To Predict The Flexural Response Of Concrete Beams Pre-Tensioned With Cfrp Rods Considering Cfrp Slippage Effects, Yasir Saeed, Karrar Al-Lami, Franz Rad

Civil and Environmental Engineering Faculty Publications and Presentations

The overwhelming costs of maintenance for reinforced concrete structures due to steel corrosion have motivated researchers to look for alternatives. One of the promising alternatives is Fiber Reinforced Polymer (FRP). Among FRP materials, Carbon FRP (CFRP) is the most attractive material for prestressed concrete members due to its high tensile strength and modulus of elasticity. Previous studies investigated the use of CFRP in prestressed concrete through experimental tests and theoretical analysis. However, there is a significant need for more experimental data to develop an accurate model that can accurately predict the behavior of CFRP prestressed concrete beams. In the current …

Understanding Structural Risk: Seismic Demand For Low-Fill Slender Fuel Tanks, David Yang, Sam Anderson

Civil and Environmental Engineering Faculty Publications and Presentations

Older fuel storage tanks, such as those in Oregon's CEI Hub, present significant seismic vulnerabilities, prompting proposals to limit storage capacity as a transitional risk mitigation measure before more permanent retrofitting actions. However, a critical knowledge gap exists regarding the applicability of standard analysis methods, like API 650, to low-fill conditions. This study utilizes the Veletsos-Yang iterative fluid-tank interaction procedure to evaluate the seismic demand of low-fill slender tanks. The analysis reveals that low-fill slender tanks exhibit slightly longer impulsive periods compared to fully-filled tanks with identical fill-height to radius ratios. Furthermore, the fixed roof mass of a low-fill tank …

Fuel Tank Seismic Stability Program-Informed Displacement Maps Of Portland's Critical Energy Infrastructure Hub, Ana Tijerina Esquino

Dissertations and Theses

Oregon's Critical Energy Infrastructure (CEI) Hub in northwest Portland contains a large portion of the state's liquid fuel storage and distribution capacity and is located in an area susceptible to liquefaction and earthquake-induced permanent ground deformation during a Cascadia Subduction Zone earthquake. Initial Seismic Vulnerability Assessments submitted under Oregon's Fuel Tank Seismic Stability program provide valuable facility-specific information, but the assessments vary in subsurface characterization, treatment of fine-grained soils, ground motion selection, and deformation estimation methods. This variability complicates interpretation of regional seismic risk and motivates a consistent corridor-scale analysis.

This thesis develops CPT-informed displacement estimates for representative cross sections …

Project Prioritization For Near-Optimal Functionality Risk Reduction In Bridge Networks, David Y. Yang, Anteneh Deriba

Civil and Environmental Engineering Faculty Publications and Presentations

Bridge retrofit prioritization is commonly guided by structural vulnerability, traffic conditions, or indirect consequences following a single bridge failure. However, these metrics often fail to identify retrofit projects that maximally reduce system-level functionality risk, because they do not account for the consequences of joint failures among multiple bridges. This presentation develops a mathematically rigorous, gradient-based approach to bridge retrofit prioritization for achieving a near-optimal reduction in functionality risk. This risk is formulated as the expected increase in total travel time given probabilistic bridge survival or failure under external stressors such as earthquakes. By reinterpreting risk as the evidence term in …

Interpretable Deep Reinforcement Learning For Element-Level Bridge Life-Cycle Optimization, David Y. Yang, Seyyed Amirhossein Moayyedi

Civil and Environmental Engineering Faculty Publications and Presentations

The new Specifications for the National Bridge Inventory (SNBI), in effect from 2022, emphasize the use of element-level condition states (CS) for risk-based bridge management. Instead of a general component rating, element-level condition data use an array of relative CS quantities (i.e., CS proportions) to represent the condition of a bridge. Although this greatly increases the granularity of bridge condition data, it introduces challenges to set up optimal life-cycle policies due to the expanded state space from one single categorical integer to four-dimensional probability arrays. This study proposes a new interpretable reinforcement learning (RL) approach to seek optimal life-cycle policies …

Tidal River Flood Risk Highest During Intermediate Rather Than Peak River Discharge, Leicheng Guo, Adam T. Devlin, Ton Hoitink, Ian Townend, David A. Jay, Zheng Bing Wang, Chunyan Zhu, Hamed R. Moftakhari, Qing He, Fan Xu, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Tidal rivers are defined as the tide‐influenced, salinity‐free inland reaches of estuaries. Understanding the occurrence of peak water levels (PWLs) is critical for flood risk management, yet the timing and magnitude of PWLs in tidal rivers have been little studied. We address this gap by investigating PWLs during two catastrophic floods (1954 and 2020) in the tidal Yangtze River, which reveals that PWLs are higher during perigean spring tides under intermediate discharges following peak flow. Three factors modulate the PWLs in tidal rivers: river‐enhanced tidal damping, flow‐elevation hysteresis that raises the falling flow limb of the hydrograph, and low‐frequency subharmonics. …

Investigation Of The Lower Block Rows In The King’S Chamber Of The Great Pyramid Using Ultrasonic Testing With Shear Wave Arrays, Benedikt Maier, Amr G. Hamza, Alejandro Ramirez-Pinero, Khaled Taie, Thomas Schumacher, Olga Popovych, Mohamed Elkarmoty, Mehdi Tayoubi, Hany Helal, Christian U. Grosse

Civil and Environmental Engineering Faculty Publications and Presentations

This study investigates the internal geometry of the granite block rows in the King’s Chamber (KC) of the Great Pyramid of Giza using Non-destructive testing (NDT) with ultrasonic testing (UST) using shear wave echo arrays. As part of the ScanPyramids (SP) project measurement campaigns in 2022, the lower two block rows of all four walls were examined using ultrasonic shear-wave echo arrays (PD8000, Screening Eagle Technologies). The measurement strategy initially included rapid overview acquisitions using an 8-channel UST device to identify potential areas of interest. High-resolution, detailed measurements were then performed at these locations, particularly along the north wall (NW) …

Methylglyoxal And Glyoxal In High-Puff Disposable Electronic Cigarette Liquids: Unexpected Accumulation And Enhanced Cytotoxicity, Esther E. Omaiye, Wentai Luo, Kevin J. Mcwhirter, Man Wong, Prue Talbot

Civil and Environmental Engineering Faculty Publications and Presentations

Despite concerns regarding the potential health risks associated with EC use, their design, puff count, and e-liquid formulations have continued to evolve. Aldehydes are a key class of thermal degradation byproducts generated during the vaporization of EC fluids. This study tested the hypothesis that aldehyde concentrations would be elevated in used ECs with high puff numbers. Devices from multiple brands were analyzed to assess the impact of extended use on aldehyde formation. E-fluids were extracted from field-collected and user-donated devices and analyzed using gas chromatography/mass spectrometry to quantify 178 flavor chemicals, two synthetic coolants, nicotine, solvents, and aldehydes (methylglyoxal (MGO), …

An Exploratory Latent Segmentation Approach To Account For Temporally Shifting Parameters In Driver Injury-Severity Models, Tanmoy Bhowmik, Shahrior Pervaz, Fred Mannering, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

Temporally shifting parameters in crash severity modeling is a well-documented phenomenon, with growing evidence suggesting that the influence of explanatory variables changes over time due to shifts in driver behavior, vehicle technology, and roadway conditions. Many studies have examined this issue by comparing the temporal stability of adjacent-year data using a variety of modeling frameworks that have often assumed a homogenous effect of explanatory variables across the entire crash population. The current research effort departs from past work in two ways. First, it compares data separated by multiple years (instead of comparing adjacent years), and second, it tests the homogeneous …

Water Velocity And Discharge From Tidal Freshwater Creeks In Forested And Herbaceous Wetlands, Austin S. Hudson, G. Curtis Roegner, Gary E. Johnson, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Acoustic Doppler Current Profilers were deployed in four tidal creeks within forested swamps and herbaceous marshes in the lower Columbia River. Measurements were collected over 12 to 20-day periods during high and low river stage, and then analyzed using wavelet tidal analysis software (CWT_Multi) to characterize temporal variability of water elevation, velocity, and discharge. While subject to similar fluvial and tidal forcing, nuances in creek geometry led to large differences in their hydraulic response. Most obviously, creeks in the higher elevation forested swamps were hydraulically isolated, which limited subtidal discharge but increased tidal monthly variability of discharge in comparison to …

Scale-Dependent Particle Transport Over Urban-Like Roughness In Turbulent Flow, Rae Riddle

Dissertations and Theses

This study employs direct numerical simulation (DNS) to investigate the dispersion of inertial particles in turbulent flow over three-dimensional urban-like roughness at Reτ = 200. Particles with Stokes numbers St = 5, 25, and 100 are tracked over cubic arrays with spanwise spacings Sy from 2h to 32h, where h = δ/8 and δ is the half-channel height, alongside a smooth-wall reference case. The results reveal scale-dependent particle responses characterized by three distinct regimes. First, high-inertia particles (St = 100) align strongly with mean secondary flows, exhibiting organized plumes above roughness elements. Their vertical transport peaks at intermediate spacing …

Quantitative Comparison Of Different Ultrasound Simulation Approaches For Civil Engineering Applications, Fabian Dethof, Simon Schmid, Jean-Marie Henault, Thomas Schumacher, Sylvia Kessler, Salvador Villalobos

Civil and Environmental Engineering Faculty Publications and Presentations

Interpreting ultrasonic waveforms is often challenging, especially in the presence of tilted boundaries that introduce multiple reflections, mode conversions, and echoes. To analyze such complex signal patterns, wavefield simulations provide a valuable tool. To ensure confidence in the simulation results, the accuracy of the numerical method is crucial. Another consideration when using simulations is their computational expense. Especially in civil engineering applications, large structures need to be investigated, which may not be feasible given the available resources. In this study, different numerical methods and software implementations commonly used for simulations in civil engineering are compared, including the Elastodynamic Finite Integration …

Effect Of Degree Of Saturation On The Liquefaction Resistance Of Non-Plastic And Low-Plastic Soils, Kayla Rae Sorenson

Dissertations and Theses

Liquefaction and cyclic softening of fine-grained soils pose a significant hazard during earthquakes, yet the cyclic behavior of transitional soils such as silts remains poorly understood. Existing empirical liquefaction evaluation frameworks and ground improvement techniques are largely developed for sands and are not directly applicable to silts, particularly beneath existing infrastructure where conventional mitigation methods are often impractical or cost prohibitive. This knowledge gap is critical in regions such as the Pacific Northwest, where young, loosely deposited silts are prevalent and susceptible to seismic loading.

Microbially induced desaturation (MID) has emerged in recent years as a promising, minimally invasive ground …

A Comprehensive Review Of Food Waste Management In Attaining Sdg 12.3 Goals: Insights From Asian Countries, Ping Hu, Lotifa Tamanna Toma, Ashraful Alam, Md. Tanvir Ahmmed, Md. Jahidul Islam, Kazi Farhana, Marjia Sultana, Miraj Ahmed Bhuiyan

Civil and Environmental Engineering Faculty Publications and Presentations

Food waste is one of the most important world-wide challenges whose environmental, economic and social impacts have far-reaching effects that include contributing to greenhouse gas emissions, resources depletion as well as the rising levels of food insecurity. These problems are further intensified in Asia due to high rate of urbanization, population growth, changing dietary habits, and lack of waste management facilities. These conditions complicate the fact that countries are increasingly struggling to achieve the United Nations Sustainable Development Goal (SDG) 12.3, which is to ensure that by 2030, half of the world has dropped per-capita food waste, and food losses …

Implementation Of Soil Improvement Techniques In The Dhaka Mass Rapid Transit Project A Comprehensive Case Study, Shoma Hore, Mosharof Al Alim, Maliha Farjana, Monir Hossain, Ripon Hore

Civil and Environmental Engineering Faculty Publications and Presentations

This paper evaluates Sand Compaction Pile (SCP) and Dynamic Compaction (DC) methods for enhancing soft soil in the Dhaka Mass Rapid Transit (MRT) project. Targeted interventions were required for the stratified soil profile, consisting of liquefiable sand (3–5 m thick) over soft clay (SPT ∼5): dynamic compaction for densifying the sand layer and soil-cement piles for stabilizing the underlying clay. Post-treatment Standard Penetration Test (SPT) values indicated that DC significantly improved the sand layer (SPT rose to 15–25) while SCP effectively strengthened the clay (SPT increased to 8–12). The Tongi-to-Uttara section (CP01) simultaneously addressed liquefaction concerns and settlement issues through …

Characterizing The Effect Of Plasticity Index On Monotonic And Cyclic Shear Behavior Of Natural Low-Plastic Silt Mixtures, Amir Barati-Nia

Dissertations and Theses

Low-plasticity silts are "transitional" soils prevalent in many seismically active regions, including the Pacific Northwest. Most research in the literature has historically focused on sand materials or clay materials, while low plastic silt does not fit either traditional "sand-like" or "clay-like" frameworks, resulting in a knowledge gap regarding this type of soil. Knowing the behavior of this type of soil is more important because it is susceptible to liquefaction or cyclic softening. Existing research on low-plastic silts is mostly based on either intact soil, where some parameters, such as the overconsolidation ratio (OCR) and plasticity index (PI), cannot be accurately …

Evaluating The Fate And Variability Of Soil Organic Carbon And Nitrogen Species Under Conservation Practices In The Raccoon River Watershed, Zhonglong Zhang, May Wu

Civil and Environmental Engineering Faculty Publications and Presentations

This study evaluates the fate and variability of soil organic carbon (SOC) stocks and nitrogen species using the latest version of the Soil and Water Assessment Tool– Carbon (SWAT-C) and assesses how conservation practices influence their dynamics in the Raccoon River Watershed (RRW). Dominated by intensive agricultural pro- duction, the RRW is a significant contributor of sediment and nutrient loads to local rivers and the Mississippi River. This SWAT-C model simulates the export of SOC and nitrogen species and evaluates their responses under varying management scenarios. Model calibration was performed for streamflow, sediment, nitrate, total nitrogen, and organic carbon with …

An Integrated Multivariate Econometric Modeling Framework For Risky Driving Behavior Related Crashes: Evaluating Crash Risk And Severity Across Zones, Pabitra Kumar Roy

Dissertations and Theses

Rapid advancements in crash modeling have yet to fully integrate multiple behavior-driven crash types and their severity outcomes within a single, scalable framework, specially in a way that captures the sequential nature of these behaviors where one risky action may amplify another. This study proposed an integrated multivariate econometric framework to jointly model crash frequency and severity outcomes for three major behaviorally driven crash types: alcohol-related, distraction-related, and aggressive-driving-related crashes. Specifically, using Oregon's 2022 census block group-level crash data, we propose an Integrated Multivariate Negative Binomial – Generalized Ordered Probit Fractional Split (IMNB–GOPFS) model to analyze these dimensions simultaneously while …

Framework And Methodology For Risk-Based Bridge And Tunnel Asset Management: Risk-Based Asset Ranking And Corridor Prioritization, David Y. Yang, Arash Khosravifar, Diane Moug, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents the results of Phase II of the project, "Framework and Methodology for Risk-based Bridge and Tunnel Asset Management". The research was carried out at Portland State University in collaboration with engineers and officials at the Oregon Department of Transportation (ODOT) and Federal Highway Administration (FHWA). Using the framework and methodology developed in Phase I of the project, the primary goal of Phase II is to showcase the practical application in risk-based asset management. In particular, the report includes the following two case studies: Case Study I — Weighted hazard scenarios for seismic risk assessment of Oregon Highway …

Coupling The Parflow Integrated Hydrology Model Within The Nasa Land Information System: A Case Study Over The Upper Colorado River Basin, P.Eyman Abbaszadeh, Fadji Zaouna Maina, Chen Yang, Dan Rosen, Sujay Kumar, Matthew Rodell, Reed Maxwell

Civil and Environmental Engineering Faculty Publications and Presentations

Understanding, observing, and simulating Earth's water cycle is imperative for effective water resource management in the face of a changing climate. While NASA's Land Information System (LIS)/Noah-MP is widely used for land surface modeling, its ability to represent groundwater processes is limited. In contrast, the ParFlow hydrologic model explicitly simulates subsurface water movement. This study explores the effectiveness and usefulness of the newly coupled modeling framework, ParFlow-LIS/Noah-MP (PF-LIS/Noah-MP) over the Upper Colorado River Basin (UCRB). The framework integrates the strengths of both models to provide a physically based representation of surface and subsurface processes and their interactions. Unlike standalone LIS/Noah-MP, …

Incorporating The Influence Of Vehicle Mix On Crash Frequency And Severity, Shahrior Pervaz, Manmohan Joshi, Tanmoy Bhowmik, Dewan Ashraful Parvez, Kai Wang, John N. Ivan, Naveen Eluru

Civil and Environmental Engineering Faculty Publications and Presentations

The current approaches for crash frequency and severity prediction in the Highway Safety Manual (HSM) do not employ vehicle mix information. In this research effort, we build advanced alternatives to HSM methods while incorporating vehicle mix information. Two model systems—(a) multivariate Poisson-lognormal model and (b) negative binomial-ordered probit fractional split model—are estimated by incorporating vehicle mix variables. The developed model systems can also capture the influence of observed and unobserved heterogeneity of different independent variables including vehicle mix variables. We estimate the models for three facility types including Urban Arterial 4-Lane Divided segments, Rural 3-Leg STOP-Controlled and Rural 4-Leg STOP-Controlled …

Detection Of Two Anomalies Behind The Eastern Face Of The Menkaure Pyramid Using A Combination Of Non-Destructive Testing Techniques, Khalid Helal, Polina Pugacheva, Hussien Allam, Mohamed Fath-Elbab, Mohamed Sholqamy, Olga Popovych, Simon Schmid, Benedikt Maier, Alejandro Ramirez, Johannes Rupfle, Thomas Schumacher, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

The Menkaure Pyramid is the smallest of the three main pyramids on the Giza Plateau. Recently, the possibility of a second entrance to the Pyramid has been hypothesized by Van den Hoven [1], based on similarities between the polished granite blocks covering the Eastern face and the blocks around the main entrance on the Northern face. To test this hypothesis, measurement campaigns using three non-destructive techniques, Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR), and Ultrasonic Testing (UST), were carried out on the Eastern face of Menkaure Pyramid. ERT data was obtained from measurements of four long parallel profiles using …

Recovery Of Daily Water Levels In The Sacramento-San Joaquin Delta, 1915–2023, Serena B. Lee, Steven Dykstra, Reyna Gomez‐Sanchez, Cole Wilkenson, Ricardo Estrada, Nick Mcguire, David A. Jay, Stefan A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

This manuscript documents the data rescue, digitization, and quality assurance of archival daily maximum and minimum water levels at twenty-five sites within the Sacramento-San Joaquin Delta. The records encompass 1846 total unique years, where 915 years are newly digitized from the 1915–1985 era. The period of record for each gauge location varies from 40 to 109years (median=80 years). Quality assurance procedures and datum corrections were applied to both archival and digital records to generate a time series referenced to a common geocentric datum. Both riverine and coastal influences on mean sea level and great diurnal range are evident in the …

Seismic Fragility Analysis Of Above-Ground Liquid Storage Tanks, Pooyan Khajeh Shahzanian

Dissertations and Theses

Liquid storage tanks are critical infrastructure, serving as key storage facilities for various products. As the contents in these tanks are usually highly toxic and flammable, damage to these structures under earthquakes can cause severe consequences, including energy shortage, fire and explosion, and spilling and long-term environmental damages.

Although new liquid storage tanks are designed according to the updated seismic design codes, large numbers of existing storage tanks were built before modern seismic design codes and did not undergo necessary seismic retrofitting. Observations and reports from past earthquakes demonstrate that these older tanks can be highly vulnerable to seismic excitation. …

Development Of A Water Temperature Modeling Platform To Support Short- And Long-Term Water Temperature Management In Reservoir-River Systems, Michael Deas, Yung-Hsin Sun, John Degeorge, Benjamin T. Saenz, Thomas A. Evans, Scott Burdick-Yahya, Stephen Andrews, Jeff Schuyler, William Candy, Lin Zheng, Scott Wells, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

The U.S. Department of the Interior, Bureau of Reclamation (Reclamation) supports water temperature management for fishery species protection in downstream river reaches below Central Valley Project (CVP) reservoirs in the Sacramento, American, and Stanislaus River systems. The Water Temperature Modeling Platform (WTMP) Project was initiated to modernize and enhance modeling capabilities to predict summer–fall water temperature through reservoir cold water pool management using temperature control facilities designed for temperature management. The WTMP supports forecasts, historical analyses, and long-term planning efforts and advances previous modeling approaches by using an integrated modeling platform. This platform includes a data management system that acquires …

Evaluation Of User Interactions And Preferences Of Shared Bicycle And Pedestrian Transit Platforms, Nathan Mcneil, Sirisha Kothuri, Jennifer Dill, Chris Monsere, Elizabeth Yates, Julia Plotts

Civil and Environmental Engineering Faculty Publications and Presentations

Shared bike and bus platforms have been deployed in an effort to minimize conflicts between bicycles and buses (and other motor vehicles) on streets with bike lanes and bus transit service. This paper assesses bicycle/micromobility user and pedestrian behavior in shared bicycle and transit platforms along a bus rapid transit corridor in Portland, OR. Research objectives include understanding interactions between these users and potential conflicts between people on foot (or wheelchair/mobility devices) who are waiting for, boarding, and/or alighting a bus and people on bicycles riding in the bike lane. The research also assessed how well the shared transit platforms …

Proceedings Of The 33rd United States – Japan Bridge Engineering Workshop, David Y. Yang

Civil and Environmental Engineering Faculty Publications and Presentations

This report summarizes the 33rd United States–Japan Bridge Engineering Workshop, an event that convenes bridge engineers from both countries. The workshop serves as a platform to exchange innovative ideas and technologies, as well as to share crucial knowledge and lessons learned, all with the aim of advancing bridge engineering. The 33rd workshop specifically addressed transportation asset management and seismic retrofitting, two subjects of increasing importance to both the United States and Japan. The report details the workshop's discussions on topics relevant to bridge engineers.

Combined Passive And Active Ultrasonic Stress Wave Monitoring Of A Full-Scale Laboratory Reinforced Concrete Bridge Column Subject To Reverse-Cyclic Lateral Loading, Niklas Epple, Thomas Schumacher, A. K. M. Golam Murtuz, Ernst Niederleithinger, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Effective monitoring of reinforced concrete structures requires techniques that detect early-stage material change and active, localized cracking. This study investigates a combined structural health monitoring approach using passive acoustic emission and active ultrasonic methods on a full-scale reinforced concrete bridge column subjected to reverse-cyclic lateral loading. Active monitoring, based on coda wave interferometry, was used to track changes in wave velocity and waveforms, while passive acoustic emission monitoring was used to detect crack activity. The instrumentation consisted of three embedded ultrasonic transducers and three surface-mounted acoustic emission sensors. The results show that active ultrasonic monitoring is most effective prior to …