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Opioid misuse risk may be similar in individuals with chronic cancer and noncancer pain. However, risk screening is not uniformly used for patients with cancer, so its prevalence is unknown.The primary aim of this study was to estimate the level of risk for opioid misuse among patients with cancer. Secondary aims were to compare opioid misuse risk across cancer types and specialties and to explore psychosocial factors that may contribute to opioid misuse risk.Clinicians were trained to administer the Opioid Risk Tool during ambulatory visits. Data were retrieved from electronic health records and analyzed using descriptive statistics.Five percent of patients seen in the cancer center during the data collection period were screened for opioid misuse risk. Of the 226 patients screened, 163 were at low risk, 34 were at moderate risk, and 29 were at high risk for future opioid misuse. The most frequent cancer diagnoses for patients at moderate or high risk were lung (n = 15), breast (n = 16), gastrointestinal (n = 10), and genitourinary (n = 8). Of the 63 patients at moderate or high risk, 50 had a family history of substance misuse, 45 had a personal history of substance misuse, and 29 had a history of psychological disease.

Mental health disorders are highly prevalent, yet few persons receive access to treatment; this is compounded in rural areas where mental health services are limited. The proliferation of online mental health screening tools are considered a key strategy to increase identification, diagnosis, and treatment of mental illness. However, research on real-world effectiveness, especially in hard to reach rural communities, is limited. Accordingly, the current work seeks to test the hypothesis that online screening use is greater in rural communities with limited mental health resources. The study utilized a national, online, population-based cohort consisting of Microsoft Bing search engine users across 18 months in the United States (representing approximately one-third of all internet searches), in conjunction with user-matched data of completed online mental health screens for anxiety, bipolar, depression, and psychosis (N = 4354) through Mental Health America, a leading non-profit mental health organization in the United States. Rank regression modeling was leveraged to characterize U.S. county-level screen completion rates as a function of rurality, health-care availability, and sociodemographic variables. County-level rurality and mental health care availability alone explained 42% of the variance in MHA screen completion rate (R

439 Background: Clinician emotion regulation (ER), self and the patient’s, likely moderates successful prognostic discussions with patients, yet challenges around its evaluation limit its investigation. We performed a pilot study to develop and assess an experimental framework that uses multimodal assessment (self-report, observer, and biometric data) to measure clinician ER during a simulated, serious illness conversation (SIC). Methods: We developed our experimental framework in four steps: 1) drafted a patient case and assessment framework; 2) refined the data collection strategy using a multidisciplinary research team; 3) trained our actor; and 4) iteratively piloted the case to optimize data collection. For the assessment, we conducted a cross-sectional, case series pilot study with physicians trained in SIC to assess its feasibility and acceptability, defined a priori as an enrollment rate >60% of approached clinicians, > 90% completion rate of survey items, < 20% missing data from wearable heart rate variability (HRV) sensors. To characterize clinician ER strategies, we analyzed the visit dialogue, physician interviews performed while watching the visit back, and physician SIC documentation generated post visit. We used a hybrid approach of inductive and deductive coding and theme development based on preexisting ER theory. Results: The development phase yielded two major modifications: 1) abandoned use of AppleWatch since it did not provide continuous HRV measurement; and 2) used telehealth with video given context of COVID-19 pandemic. We approached 12 physicians and 11 enrolled, of which 5 were female and 10 white, 5 were medical oncologists, and 6 specialty palliative care physicians. All participants completed all study survey items. The results of our three HRV sensors were as follows: Empatica E4 and Polar H10 met our pre-specified HRV collection in all 11 resting tasks and SIC encounters, and the Scoche R24 the benchmark in 7/11 resting tasks and 4/11 of simulated encounters. Preliminary qualitative analysis suggests investigators can characterize clinician use of intrapersonal and interpersonal ER strategies. Conclusions: The use of multimodal assessment of clinician ER in a simulated, telehealth SIC visit was acceptable and feasible.

BACKGROUND Providing digital recordings of clinic visits to patients has emerged as a strategy to promote patient and family engagement in care. With advances in natural language processing, an opportunity exists to maximize the value of visit recordings for patients by automatically tagging key visit information (eg, medications, tests, and imaging) and linkages to trustworthy web-based resources curated in an audio-based personal health library. OBJECTIVE This study aims to report on the user-centered development of HealthPAL, an audio personal health library. METHODS Our user-centered design and usability evaluation approach incorporated iterative rounds of video-recorded sessions from 2016 to 2019. We recruited participants from a range of community settings to represent older patient and caregiver perspectives. In the first round, we used paper prototypes and focused on feature envisionment. We moved to low-fidelity and high-fidelity versions of the HealthPAL in later rounds, which focused on functionality and use; all sessions included a debriefing interview. Participants listened to a deidentified, standardized primary care visit recording before completing a series of tasks (eg, finding where a medication was discussed in the recording). In the final round, we recorded the patients’ primary care clinic visits for use in the session. Findings from each round informed the agile software development process. Task completion and critical incidents were recorded in each round, and the System Usability Scale was completed by participants using the digital prototype in later rounds. RESULTS We completed 5 rounds of usability sessions with 40 participants, of whom 25 (63%) were women with a median age of 68 years (range 23-89). Feedback from sessions resulted in color-coding and highlighting of information tags, a more prominent play button, clearer structure to move between one’s own recordings and others’ recordings, the ability to filter recording content by the topic discussed and descriptions, 10-second forward and rewind controls, and a help link and search bar. Perceived usability increased over the rounds, with a median System Usability Scale of 78.2 (range 20-100) in the final round. Participants were overwhelmingly positive about the concept of accessing a curated audio recording of a clinic visit. Some participants reported concerns about privacy and the computer-based skills necessary to access recordings. CONCLUSIONS To our knowledge, HealthPAL is the first patient-centered app designed to allow patients and their caregivers to access easy-to-navigate recordings of clinic visits, with key concepts tagged and hyperlinks to further information provided. The HealthPAL user interface has been rigorously co-designed with older adult patients and their caregivers and is now ready for further field testing. The successful development and use of HealthPAL may help improve the ability of patients to manage their own care, especially older adult patients who have to navigate complex treatment plans.

UNSTRUCTURED COVID-19 cases are exponentially increasing worldwide; however, its clinical phenotype remains unclear. Natural language processing (NLP) and machine learning approaches may yield key methods to rapidly identify individuals at a high risk of COVID-19 and to understand key symptoms upon clinical manifestation and presentation. Data on such symptoms may not be accurately synthesized into patient records owing to the pressing need to treat patients in overburdened health care settings. In this scenario, clinicians may focus on documenting widely reported symptoms that indicate a confirmed diagnosis of COVID-19, albeit at the expense of infrequently reported symptoms. While NLP solutions can play a key role in generating clinical phenotypes of COVID-19, they are limited by the resulting limitations in data from electronic health records (EHRs). A comprehensive record of clinic visits is required—audio recordings may be the answer. A recording of clinic visits represents a more comprehensive record of patient-reported symptoms. If done at scale, a combination of data from the EHR and recordings of clinic visits can be used to power NLP and machine learning models, thus rapidly generating a clinical phenotype of COVID-19. We propose the generation of a pipeline extending from audio or video recordings of clinic visits to establish a model that factors in clinical symptoms and predict COVID-19 incidence. With vast amounts of available data, we believe that a prediction model can be rapidly developed to promote the accurate screening of individuals at a high risk of COVID-19 and to identify patient characteristics that predict a greater risk of a more severe infection. If clinical encounters are recorded and our NLP model is adequately refined, benchtop virologic findings would be better informed. While clinic visit recordings are not the panacea for this pandemic, they are a low-cost option with many potential benefits, which have recently begun to be explored.

BACKGROUND The coronavirus disease (COVID-19) has led to dramatic changes worldwide in people’s everyday lives. To combat the pandemic, many governments have implemented social distancing, quarantine, and stay-at-home orders. There is limited research on the impact of such extreme measures on mental health. OBJECTIVE The goal of this study was to examine whether stay-at-home orders produced differential changes in mental health symptoms using internet search queries on a national scale. METHODS In the United States, individual states vary in their adoption of measures to reduce the spread of COVID-19; as of March 23, 2020, 11 of the 50 states had issued stay-at-home orders. The staggered rollout of stay-at-home measures across the United States allows us to investigate whether these measures impact mental health by exploring variations in mental health search queries across the states. This paper examines the changes in mental health search queries on Google between March 16-23, 2020, across each state and Washington, DC. Specifically, this paper examines differential changes in mental health searches based on patterns of search activity following issuance of stay-at-home orders in these states compared to all other states. The participants were all the people who searched mental health terms in Google between March 16-23. Between March 16-23, 11 states underwent stay-at-home orders to prevent the transmission of COVID-19. Outcomes included search terms measuring anxiety, depression, obsessive-compulsive, negative thoughts, irritability, fatigue, anhedonia, concentration, insomnia, and suicidal ideation. RESULTS Analyzing over 10 million search queries using generalized additive mixed models, the results suggested that the implementation of stay-at-home orders are associated with a significant flattening of the curve for searches for suicidal ideation, anxiety, negative thoughts, and sleep disturbances, with the most prominent flattening associated with suicidal ideation and anxiety. CONCLUSIONS These results suggest that, despite decreased social contact, mental health search queries increased rapidly prior to the issuance of stay-at-home orders, and these changes dissipated following the announcement and enactment of these orders. Although more research is needed to examine sustained effects, these results suggest mental health symptoms were associated with an immediate leveling off following the issuance of stay-at-home orders.

BACKGROUND Individuals often turn to the internet seeking answers to their mental health problems. In 2014, Mental Health America (MHA) began the online program MHA Screening, including the PHQ-9, and since then has collected data from nearly 2.5 million people. Among those who complete a depression screening online, 83% report moderate to severe depression. Despite a range of evidence-based treatments for depression, 60% of these individuals do not seek care. A lack of both knowledge of and access to treatment are major barriers to help-seeking. Decision aids (DAs) are tools that can increase treatment knowledge, yet it is unclear if individuals with depression symptoms would use such a tool online. OBJECTIVE The objective of this project was to determine the views of individuals with depression toward an online DA for depression, and to determine the characteristics those most likely to review a DA and are willing to seek care online. METHODS MHA offers web-based depression screening using the Patient Health Questionnaire (PHQ-9). For this pilot, MHA made a link to a depression DA available to all individuals completing PHQ-9 screening from October – November 2017. The DA consisted of information on frequently asked questions pertaining to three treatment approaches: watchful waiting, talk therapy and antidepressants. Respondents viewing the DA could complete a short survey assessing the perceived helpfulness of the DA, and whether they would be “willing to consult a doctor online” about symptoms. Descriptive statistics were calculated, while a multiple logistic regression model identified characteristics associated with viewing the DA. RESULTS Of 74,936 PHQ-9 screens completed, 599 (8%) proceeded to review the depression DA; 92% of these respondents screened positive for moderate to severe depression and 86% had never sought prior treatment. Of the 599, 527 (88%) completed the DA survey: 46% found the DA to be helpful, 45% were unsure, while only 8% said the DA was not helpful. Higher levels of depression severity, female sex and older age were associated with increased likelihood of viewing the DA, while higher income levels and Black/African Americans were less likely to view the DA. A majority of respondents (72%) stated they would be willing to discuss their symptoms with a doctor online. CONCLUSIONS Screening for depression and providing DA outside of traditional settings is viewed positively and holds significant potential for those seeking care online. This knowledge is timely given the rising interest in the use online therapies, and the detrimental impact on psychological health of social isolation measures in response to the Coronavirus pandemic. Future work will determine the best placement of such decision support tools to maximize DA access, and assess the potential for an online pathway to treatment facilitated by screening and decision support.

Very little data exists on the live-load behavior of twin-girder bridges despite their unique configuration and minimal redundancy. To investigate the live-load behavior of twin girder brid...

ObjectiveTo understand the perceptions of the impact of the COVID-19 pandemic on healthcare communication with family caregivers.DesignNationally representative survey.SettingUSA (national).Participants340 family caregivers, demographically representative of the US population by race/ethnicity.Primary outcome measuresCommunication outcomes (feeling involved by the provider, feeling involved by the care recipient, feeling more encouraged to be involved in care, feeling contributory to discussions, feeling questions are being answered), behavioural/wellness outcomes (feeling anxious, feeling isolated, feeling it is easier to attend the clinic visit), and desire to continue using telemedicine.ResultsHaving less than a college degree was associated with decreased odds of feeling involved by the provider (OR 0.46; 95% CI 0.26 to 0.83; p=0.01), feeling involved by the care recipient (OR 0.44; 95% CI 0.24 to 0.79; p=0.01), feeling more encouraged to be involved in care (OR 0.49; 95% CI 0.27 to 0.86; p=0.01), feeling like they contribute to discussions (OR 0.45; 95% CI 0.25 to 0.82; p=0.01) and feeling like their questions are being answered (OR 0.33; 95% CI 0.18 to 0.60; pConclusionIn our sample, the shift to telemedicine during COVID-19 was well received but caregivers of low educational attainment reported poorer health communication, and a greater proportion of black/African American and Hispanic caregivers reported a desire to return to in-person visits. There is an opportunity to improve health systems and increase equity as telemedicine becomes more widespread.

In this study, the Icy Springs Bridge, located in Coalville, Utah, was load-tested to quantify the effects of significant deterioration on its live-load behavior. Visual inspection and load...

A collection of condition and appraisal ratings of bridges prior to collapse is presented and analyzed to show commonalities among collapsed bridges in New York State. General observations ...

Contains fulltext : 174289.pdf (Publisher’s version ) (Open Access) INTRODUCTION: Shared decision making (SDM) is a goal of modern medicine; however, it is not currently embedded in routine care. Barriers include cliniciansaeuro attitudes, lack of knowledge and training and time constraints. Our goal is to support the development and delivery of a robust SDM curriculum in medical education. Our objective is to assess undergraduate medical studentsaeuro knowledge of and attitudes towards SDM in four countries. METHODS AND ANALYSIS: The first phase of the study involves a web-based cross-sectional survey of undergraduate medical students from all years in selected schools across the United States (US), Canada and undergraduate and graduate students in the Netherlands. In the United Kingdom (UK), the survey will be circulated to all medical schools through the UK Medical School Council. We will sample students equally in all years of training and assess attitudes towards SDM, knowledge of SDM and participation in related training. Medical students of ages 18 years and older in the four countries will be eligible. The second phase of the study will involve semistructured interviews with a subset of students from phase 1 and a convenience sample of medical school curriculum experts or stakeholders. Data will be analysed using multivariable analysis in phase 1 and thematic content analysis in phase 2. Method, data source and investigator triangulation will be performed. Online survey data will be reported according to the Checklist for Reporting the Results of Internet E-Surveys. We will use the COnsolidated criteria for REporting Qualitative research for all qualitative data. ETHICS AND DISSEMINATION: The study has been approved for dissemination in the US, the Netherlands, Canada and the UK. The study is voluntary with an informed consent process. The results will be published in a peer-reviewed journal and will help inform the inclusion of SDM-specific curriculum in medical education worldwide.

Accelerated bridge construction techniques have resulted in state-of-the-art options that save time and money during the construction of new or existing bridges. One such group of techniques that has generated considerable interest is the use of precast-concrete deck panels. Using precast-concrete deck panels allows for off-site curing, thus eliminating long delays from formwork construction and concrete curing time. Despite the benefits, problems can develop as a result of the inherent joints between the individual panels. These joints are locations for potential leakage, which can result in corrosion or inadequate long-term performance. Posttensioning the precast deck panels helps to eliminate leakage, but conventional longitudinal posttensioning systems require complete deck replacement in the event of a single faulty deck panel. The proposed posttensioned curved-strand connection presented in this paper allows for single-panel replacement. The capacity of the proposed curved-strand connection was investigated to compare its behavior with that of other systems currently in use. The curved-strand connection was found to be comparable to a standard posttensioning system. The ultimate capacity of the curved-strand connection in negative bending was found to be 97% of the standard posttensioning connection.

This paper presents a comparison of two live-load tests performed on a posttensioned, box-girder bridge. The initial live-load test was performed more than 20 years before the most recent test. Strain gauges were placed at the same location for both tests. In each case, the bridge was subjected to nearly identical loads so that changes in strain could be correlated as a heavy truck drove across the instrumented bridge. A comparison of the bridge behavior based on the two load tests is presented. The changes in recorded strain were also used to validate a detailed finite-element (FE) model using primarily shell elements. From this calibrated FE model, the live-load distribution factors for moment were obtained. These factors were used to calculate both the inventory and operating rating factors of the bridge. These values were compared with those calculated in accordance to the AASHTO LRFD specifications for distribution factors. It was found that the rating factors could be increased by 26% because of the partial fixity caused by the integral abutments.

This paper describes an investigation to quantify the behavior of a precast deck system. As part of this investigation, a live-load test was performed on a steel I-girder bridge made with accelerated bridge construction precast deck panels. It was found that the bridge was behaving compositely in some locations and noncompositely in others. When the bridge was decommissioned, a two-girder specimen was salvaged and transported to Utah State University for shear-capacity testing. The primary shear failure mechanism was found to be buckling of the girder web. A nonlinear finite-element analysis was conducted using ANSYS that was found to replicate the experimental behavior and reproduce the failure mechanism and magnitude. It was concluded that the effect of the noncomposite behavior on the ultimate shear capacity was a reduction of approximately 8.0%. The measured ultimate capacities were compared with estimates calculated according to procedures in the AASHTO LRFD specifications. When using the specified steel strength, the code predicted shear resistance ranging from 8.0% higher to 0.7% lower.

This study addresses the feasibility of using a single-span bridge as a weigh-in-motion (WIM) tool to quantify the gross vehicle weights (GVWs) of trucks inexpensively with a small number of sensors and without using axle detectors. Field testing was performed on an interstate without any lane closures. Four preweighed trucks with different axle configurations traveled over a bridge at three different speeds and in two separate lanes. Measured strain data were used to implement bridge weigh-in-motion (B-WIM) algorithms and calculate the corresponding velocities and GVWs. A comparison was made between calculated and actual measured static weights, and between the calculated and specified speeds of the trucks. In addition to field testing, a finite-element (FE) model of the tested bridge was created and calibrated based on the measured strains at different locations. This calibrated FE model enabled the acquisition of the influence values for the bridge at any location (influence surface). Ten diffe...

This paper describes the experimental testing of 48-year-old concrete bridge girders that were fabricated using lightweight concrete. After the bridge was decommissioned, three girders were transported to the Systems, Material, and Structural Health (SMASH) Laboratory at Utah State University (USU). The double-tee girders were tested to quantify the effective prestress, flexural capacity, and deck punching shear strength. The experimental results were compared with calculated values based on recommended procedures in the AASHTO LRFD bridge design specifications. The AASHTO refined method underestimated the loss of prestress of the three girders by an average of 17.6%. The calculated flexural capacities were overestimated by an average of 34.0% when compared with the measured values. This unconservative result is believed to be a result of the deck deterioration. The average calculated punching shear capacity was within 3.0% of the measured values. The experimental results were also compared with a...

Precast deck panels are increasingly being used to reduce construction times as part of a push for accelerated bridge construction by some state departments of transportation. Despite the short-term benefits, the connections between panels have a history of serviceability problems. To evaluate the service and ultimate behavior of current and newly proposed connections, 12 push-off tests were performed on precast bridge deck transverse connections for shear. These tests used an improved shear specimen geometry that allowed the connection to deform in more realistic shear. This new test setup included spaces that allowed diagonal cracks to form and reinforcement to pull out of the connection. The push-off tests established the cracking and ultimate shear strengths of each connection detail. These details included a welded connection, an unreinforced grouted connection, and a post-tensioned-type connection tested with and without an applied compression force. Results of each detail type are compared....

This paper presents an evaluation of flexural live-load distribution factors for cast-in-place box-girder bridges. The response of a typical box-girder bridge was recorded during a static live-load test. This test involved driving two heavily loaded trucks across the instrumented bridge on selected load paths. The instruments used to record the response of the bridge were strain gauges, displacement transducers, and tilt sensors. The measured data were then used to calibrate a finite-element modeling scheme using solid elements. From this finite-element model, the theoretical live-load distribution factors and load ratings for the test bridge were determined and compared with the factors and ratings predicted in the AASHTO LRFD specifications. A parametric study of cast-in-place, box-girder bridges using the calibrated finite-element modeling scheme was then used to investigate how various parameters such as span length, girder spacing, parapets, skew, and deck thickness affect the flexural live-load distribution factors. Based on the results of the parametric study, a new equation, which more accurately predicts the exterior girder distribution factor, is proposed.

Seven prestressed concrete bridge girders that had been in service for 42 years, and represented two span lengths and reinforcement designs, were tested to determine their effective prestress force and ultimate shear capacity. A cracking moment test was used to determine the effective prestress force in the girders. The measured effective prestress force was compared with calculated values according to the AASHTO LRFD prestress loss equations to investigate their adequacy. The AASHTO refined method was shown to provide the most accurate results to within 10% of the measured values. An ultimate shear test was also performed on two of the girders. An external load was applied near the support and increased until the girder failed in shear. The various procedures in the AASHTO LRFD specifications were compared with the measured results. The AASHTO simplified procedure predicted only 51% and 39% of the average measured shear capacity for the short and long span girders, respectively. The strut-and-tie models were found to estimate the shear capacity more accurately. The AASHTO refined method was shown to provide the most accurate results.

This study addressed delamination detection of concrete slabs by analyzing global dynamic responses of structures. Both numerical and experimental studies are presented. In the numerical examples, delaminations with different sizes and locations were introduced into a concrete slab; the effects of presence, sizes, and locations of delaminations on the modal frequencies and mode shapes of the concrete slab under various support conditions were studied. In the experimental study, four concrete deck specimens with different delamination sizes were constructed, and experimental tests were conducted. Traditional peak-picking, frequency domain decomposition, and stochastic subspace identification methods were applied to the modal identification from dynamic response measurements. The modal parameters identified by these three methods correlated well. The changes in modal frequencies, damping ratios, and mode shapes that were extracted from the dynamic measurements were investigated and correlated to the actual delaminations and can indicate presence and severity of delamination. Finite element (FE) models of reinforced concrete decks with different delamination sizes and locations were established. The modal parameters computed from the FE models were compared to those obtained from the laboratory specimens, and the FE models were validated. The delamination detection approach was proved to be effective for concrete decks on beams.

Sixteen shear capacity tests were performed on eight decommissioned AASHTO prestressed concrete girders that had been in service for over 42 years. These bridge members presented a unique opportunity to investigate carbon fiber-reinforced polymer (CFRP) retrofit schemes to enhance the shear capacity of underreinforced girders that were nonrectangular. Four destructive tests were performed to quantify the in-service strength of the girders and the remaining 12 tests were performed on CFRP retrofitted girders. In all, five configurations of the CFRP reinforcement were evaluated. Two anchoring techniques were investigated that either involved epoxying a horizontal CFRP strip over the vertical strips or a new methodology of epoxying a CFRP laminate into a groove over the vertical strips that was cut at the web-to-flange interface. Two methodologies that predicted the shear contribution of the carbon fiber reinforcement were compared with the test results. A carbon fiber-reinforcing scheme of vertical strips a...

In this paper, an experimental and analytical investigation of concrete-filled steel tubular (CFST) laced columns is presented. These columns consist of four concrete-filled steel tubes that are laced together. A total of 27 experimental tests were conducted to quantify the column failure mechanism at ultimate loads. The experiments were designed to obtain the load-deflection curves. These curves were subsequently used to quantify the structural behavior for each element of the hybrid column. Experimental results indicate that the compression force in the longitudinal members dominated the failure mechanism in the CFST columns. In-plane bending occurred when member segments reached the compression failure load. The forces in the lacing members (diagonal and horizontal bracing) were found to be small and remained in the elastic range through failure. The experimental study was used to validate an analytical parametric study. The analytical study showed that increasing slenderness ratios and eccentricities reduced the ultimate load capacity. Additionally, finite-element analyses of CFST columns based on four in situ structures were performed to determine the ultimate load-carrying capacity and were subsequently compared to several building codes. On the basis of the analytical results, a new methodology for calculating the ultimate load-carrying capacity is proposed. This purposed methodology is compared with five different building codes to quantify the increased accuracy.

Precast deck panels are increasingly being utilized to reduce construction times and traffic delays as many departments of transportation (DOTs) emphasize accelerated bridge construction. Despite the short-term benefits, the connections between panels have a history of service failure. This research focused on the evaluation of the service and ultimate capacities of five precast deck panel connections. Full-scale tests were developed to determine the cracking and ultimate flexural strengths of two welded connections, a conventionally posttensioned connection, and two newly proposed, posttensioned, curved bolt connections. The conventionally posttensioned specimens were shown to perform well with the highest cracking loads and 0.42 times the theoretical capacity of a continuously reinforced concrete deck panel. The proposed curved bolt connections were shown to be a promising connection detail with approximately 0.5 times the theoretical capacity of a continuously reinforced panel. Data from the welded specimens showed that some welded connection types perform significantly better than others. The experimental results also compared closely with values calculated on the basis of finite-element modeling, which can be used for future analytical studies.

The monitoring of five precast, prestressed bridge girders during fabrication and service provided the opportunity to observe changes in camber over time. These camber variations were compared with corresponding strain and temperature measurements. Each of the girders was cast outside during the winter. As a result, the cold ground acted as a heat sink, and a significant temperature gradient existed during curing of each of the instrumented girders. These temperature gradients are believed to have caused the wide range in the short- and long-term cambers. A procedure to calculate the effect that curing temperatures have on girder camber is presented. In addition, the measured camber values are compared with predicted values using the multiplier method, improved multiplier method, and a detailed time-step method. It was found for the long-span girders that the measured camber values were on average within 10% of the predicted values using the detailed time-step method, but ranged from 22% lower to 27% higher for the simpler methods.

This paper summarizes the measured properties of a three-layer model concrete tunnel lining using a newly proposed combined stress wave propagation (CSWP) method. The spectral analysis of surface waves (SASW) and impact echo (IE) methods were used in combination to determine the in-place dynamic properties of the tunnel lining and to locate embedded voids. Simultaneously, the free-free resonant column (FFRC) method was independently used to determine the dynamic properties of the materials used to construct the concrete tunnel lining. Finally, a direct P-wave (DPW) measurement was used to compare and verify measurements recorded using the CSWP method. Results indicate that the combination of the SASW and IE methods, along with FFRC measurements, provides a more efficient procedure that leads to the accurate determination of the P-wave and shear wave velocities, depths of layers, and locations of embedded voids without the need to make any assumptions of material properties. Thus, more physical properties can be found using this proposed procedure than by using the techniques independently, and the procedure is more efficient than performing each task separately.

Five prestressed concrete girders made with high-performance concrete were instrumented using vibrating-wire strain gages. Their behavior was monitored for three years from the time of casting. The measured change in concrete strain at the centroid of the prestressing strands was used to evaluate changes in prestress. The total measured prestress loss was as large as 28% of the total jacking stress. Due to the higher stresses, this loss is larger than would be expected for a girder made with conventional-strength concrete. The observed values of prestress losses were compared with values calculated using the recommended AASHTO LRFD and NCHRP 18-07 procedures. The AASHTO LRFD method overpredicted the average prestress losses for the highly stressed Span 2 girders by 20% while the NCHRP method underpredicted the average losses by 16%. The NCHRP method was found to be more inclusive and adaptable to regional construction. The calculated NCHRP Span 2 losses were found to be within 10% of the average measured losses when the elastic shortening losses were calculated based on measured data and differential shrinkage was calculated based on continuous beams.

Studies have shown that experimentally determined dynamic properties can be used to identify the characteristics of a structure. In this paper, a damage detection technique is developed and demonstrated using system identification, finite-element modeling, and a modal update process. The proposed approach, SFM, provides a rapid estimate of damage locations and magnitudes. The proposed methodology is applied to three case studies. The first is a numerical simulation using computer generated data. The second is an ASCE benchmark problem for structural health monitoring, where the results can be compared to other researchers. The third is a full-scale highway bridge that was field tested using a forced vibration shaking machine. In this case study, the bridge was shaken in several states of damage and the proposed methodology was utilized to detect and determine the location and extent of the damage. It was found that, using the collected data, the SFM approach was able to consistently predict the location of damage as well as estimate the magnitude of the damage.

Horizontally curved, steel girder bridges are often used in our modern infrastructural system. The curve in the bridge allows for a smother transition for traffic, which creates better road travel. However, some of the disadvantages of horizontally curved bridges are that they are more difficult to analyze, design, and sometimes construct in comparison to conventional straight bridges. This study focuses on a three-span, curved steel I-girder bridge which was tested under three boundary condition states to determine it's response to live load. The measured live-load strains were used to calibrate a finite-element model. The finite-element design moments and distribution factors for the three condition states were then compared with the results based on the V-load method. These different boundary conditions provided the researchers a unique opportunity to evaluate the impact that these changes had on the bridges behavior. It was found that while the V-load method produced positive bending moments that were close to the finite-element moments for some of the girders, this was a result of the V-load moment being unconservative and the distribution factor being conservative.

A curved, three-span continuous, steel I-girder bridge in Salt Lake City was tested in order to determine its dynamic and static load carrying properties for three boundary condition states. For each of the three boundary condition states, two dynamic forced vibration methods were applied to the bridge as well as a static live-load test. The first forced vibration method used an eccentric mass shaker. The second method involved striking the side of the bridge with an impact hammer. The live-load test was performed by slowly driving a truck at a crawl speed across the bridge. Velocity transducers, accelerometers, and strain gauges were utilized to record the response of the bridge. The analysis and compilation of recorded dynamic response of the bridge enabled the preparation of mode shapes and natural frequencies for each boundary condition. This paper discusses the resulting changes in relevant dynamic properties and compares them with the changes in the static properties that were determined from the bridge response recorded from the live-load tests.

The Kettle River Bridge is an arched, steel cantilevered deck, Pratt Truss bridge. To quantify the live-load performance of the bridge superstructure and provide a baseline for future comparisons, it was instrumented with 151 strain gauges on various beam, stringer, and truss members. In addition, 8 displacement gauges were attached along the truss. All gauges were simultaneously monitored while the bridge was subjected to a nondestructive, live-load test. The recorded bridge response was analyzed to quantify in situ behavior. The measured behavior was then used to validate a finite-element model using solid and frame elements, which was subsequently used to obtain an inventory- and operating-load rating of 2.03 and 2.64, respectively. Based on the results of the test, it was concluded that the large gusset plates added partial fixity to the truss members, as evident from the significant measured in-plane bending strains. However, the beam-and-stringer deck support system showed minimal rotational...

Integration of wireless power transfer (WPT) systems in roadways and vehicles represents a promising alternative to traditional internal combustion transportation systems. The economic feasibility and environmental impact of WPT applied to the transportation system is evaluated through the development of engineering system models. For a 20% penetration of the WPT technology in vehicles, results show a 20% reduction in air pollutants, 10% reduction in energy use and CO 2 emissions and a societal level payback (defined as total cost of ownership savings compared to a traditional vehicle equal to roadway infrastructure) of 3 years. The modeled system covers 86% of all traffic in the US, impacts 40% of all roadways and shifts $180 billion per year from oil production to jobs in local power generation and development, construction, and maintenance of electrified roadways and new electric vehicles. Results on model sensitivity to energy prices, payback as a function of penetration, and trucking vs light duty use are presented.

A regional bridge failure database was used to determine the bridge failure rate with associated causes. Using a sample population from one DOT over a 25-year period, the average number of bridge failures was approximately 1/4,700 annually with a 95% confidence interval from 1/6,900 to 1/2,700 annually. The number of bridge failures per year was modeled with a geometric distribution that requires a constant failure rate. Based on a validation analysis with bridge failures from six separate DOTs, other DOTs have bridge failure rates within the determined sample population 95% confidence interval. Analysis of the failed bridges by year of construction shows no apparent era of construction that is more susceptible than another to failure. Correspondingly, the determined constant failure rate ascertained in the model selection indicates that the changes in bridge design specifications and maintenance regulations do not appear to have significantly reduced bridge failure rates. Based on the data extrap...

Integration of wireless power transfer (WPT) systems in roadways and vehicles represents a promising alternative to traditional internal combustion transportation systems. The economic feasibility and environmental impact of WPT applied to the transportation system is evaluated through the development of engineering system models. For a 20% penetration, results show a 20% reduction in air pollutants, 10% reduction in energy use and CO 2 emissions and a societal level payback (defined as total cost of ownership savings compared to a traditional vehicle equal to roadway infrastructure) of 3 years. The modeled system covers 86% of all traffic in the US, impacts 40% of all roadways and shifts $180 billion per year from oil production to jobs in local power generation and development, construction, and maintenance of electrified roadways and new electric vehicles. Results on model sensitivity to energy prices, payback as a function of penetration, and trucking vs light duty use will be presented.