Download or read book A New Approach for Performance Evaluation of Bridge Infrastructure Using Terrestrial LiDAR and Advanced Mathematical Modeling written by Ali Shafikhani and published by . This book was released on 2020 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: High plastic expansive clays when subjected to different climatic conditions undergo large ground movements causing distress to infrastructures including bridges, pavements,buildings, retaining structures, and others. Performance assessment of these structures built on problematic soils such as expansive clays is important to reduce maintenance and extending the design life of infrastructure. Rapid developments in remote sensing technologies with precise evaluation have influenced the monitoring techniques for assessing the health condition of civil infrastructure projects. While these technologies have considerably aided in performance evaluation, cogent procedures for evaluating the ground movements are still required that integrates technologies, climatic factors, soil behavior models. This research study presents an integrated approach using the Three-Dimensional Terrestrial Laser Scanning (3D-TLS)technique and advanced mathematical modeling (system identification approach) for assessing the performance of the bridge infrastructure including highway embankment, bridge deck,bridge approach slab, bridge abutments, and columns. First, an optimized framework is developed to evaluate ground movements using 3D-TLS technique, which is an active-remote sensing Light Detection and Ranging (LiDAR) remote sensing technology that uses near infrared light to monitor physical characteristics of earth's surface. The ground movements from the processed scans, and climatic factor parameters including temperature and precipitation variations were used to develop advanced mathematical models of dynamic systems using collected time-series data. The validation of the developed integrated framework is illustrated on a test site built on high plastic expansive clay soils located in North Texas. Cost-Benefit Analysis (COA) is performed to compare 3D-TLS remote sensing and prevalent monitoring approaches. This research highlights the integration of latest technological developments with advanced mathematical models to predict the condition of a bridge infrastructure.

Download or read book Performance Evaluation of a Bridge Infrastructure Using Terrestrial Laser Scanning Technology written by Ali Shafikani and published by . This book was released on 2018 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Monitoring techniques, used to assess the condition of infrastructures, have been impacted by the rapid developments in remote sensing technology. While these technologies have improved performance evaluation, cogent procedures for evaluating ground movements have yet to be developed. This article presents an application of the three-dimensional terrestrial laser scanning (3D-TLS) technology for assessing the performance of bridge infrastructures, including highway embankments, bridge decks, approach slabs, abutments, and columns supported on drilled shafts. In this research study, a framework was developed, using 3D-TLS technology, to evaluate the ground movements. The survey process, variables, and analysis were demonstrated by performing the field operations at a rehabilitated bridge infrastructure located in North Texas. The analysis depicted vertical movements that were experienced by the approach slab during different time periods. The validation of 3D-TLS results was performed by comparing the vertical movements from the four horizontal inclinometers installed underneath the pavement. The comparison studies revealed similar movement patterns of both inclinometers and processed scans, while the latter provided detailed soil movements over a larger area.

Download or read book Laser Scanning Systems in Highway and Safety Assessment written by Biswajeet Pradhan and published by Springer. This book was released on 2019-04-02 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to promote the core understanding of a proper modelling of road traffic accidents by deep learning methods using traffic information and road geometry delineated from laser scanning data. The first two chapters of the book introduce the reader to laser scanning technology with creative explanation and graphical illustrations, review and recent methods of extracting geometric road parameters. The next three chapters present different machine learning and statistical techniques applied to extract road geometry information from laser scanning data. Chapters 6 and 7 present methods for modelling roadside features and automatic road geometry identification in vector data. After that, this book goes on reviewing methods used for road traffic accident modelling including accident frequency and injury severity of the traffic accident (Chapter 8). Then, the next chapter explores the details of neural networks and their performance in predicting the traffic accidents along with a comparison with common data mining models. Chapter 10 presents a novel hybrid model combining extreme gradient boosting and deep neural networks for predicting injury severity of road traffic accidents. This chapter is followed by deep learning applications in modelling accident data using feed-forward, convolutional, recurrent neural network models (Chapter 11). The final chapter (Chapter 12) presents a procedure for modelling traffic accident with little data based on the concept of transfer learning. This book aims to help graduate students, professionals, decision makers, and road planners in developing better traffic accident prediction models using advanced neural networks.

Download or read book Performance Evaluation of Bridge Approaches written by and published by . This book was released on 1983 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Terrestrial Laser Scanning Based Bridge Structural Condition Assessment written by Yelda Turkan and published by . This book was released on 2016 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objective, accurate, and fast assessment of a bridge's structural condition is critical to the timely assessment of safety risks. Current practices for bridge condition assessment rely on visual observations and manual interpretation of reports and sketches prepared by inspectors in the field. Visual observation, manual reporting, and interpretation have several drawbacks, such as being labor intensive, subject to personal judgment and experience, and prone to error. Terrestrial laser scanners (TLS) are promising sensors for automatically identifying structural condition indicators, such as cracks, displacements, and deflected shapes, because they are able to provide high coverage and accuracy at long ranges. However, limited research has been conducted on employing laser scanners to detect cracks for bridge condition assessment, and the research has mainly focused on manual detection and measurement of cracks, displacements, or shape deflections from the laser scan point clouds. This research project proposed to measure the performance of TLS for the automatic detection of cracks for bridge structural condition assessment. Laser scanning is an advanced imaging technology that is used to rapidly measure the three-dimensional (3D) coordinates of densely scanned points within a scene. The data gathered by a laser scanner are provided in the form of point clouds, with color and intensity data often associated with each point within the cloud. Point cloud data can be analyzed using computer vision algorithms to detect cracks for the condition assessment of reinforced concrete structures. In this research project, adaptive wavelet neural network (WNN) algorithms for detecting cracks from laser scan point clouds were developed based on the state-of-the-art condition assessment codes and standards. Using the proposed method for crack detection would enable automatic and remote assessment of a bridge's condition. This would, in turn, result in reducing the costs associated with infrastructure management and improving the overall quality of our infrastructure by enhancing maintenance operations.

Download or read book Development of a Robust Framework for Assessing Bridge Performance Using a Multiple Model Approach written by Jeffrey Weidner and published by . This book was released on 2019 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project presents a simple approach to multiple model deterioration modeling for bridges by identifying common points between deterioration model approaches and combining the results at these points. Inclusion of other data sources into this framework was explored, and an ontology of these sources and their relationships was developed. The results showed fairly close performance between individual models and combined models when considering a population of bridges in Texas using the National Bridge Inventory data--a resource that Texas would like to make better use of. This performance is a result of the bridges selected via identification of explanatory variables which are assumed through engineering judgment to drive deterioration - a practice that is common in nearly all of the literature. Future work includes exploring more robust ways of identifying explanatory variables.

Download or read book Laser Scanning written by Belén Riveiro and published by CRC Press. This book was released on 2019-10-18 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview on the evolution of laser scanning technology and its noticeable impact in the structural engineering domain. It provides an up-to-date synthesis of the state-of-the-art of the technology for the reverse engineering of built constructions, including terrestrial, mobile, and different portable solutions, for laser scanning. Data processing of large point clouds has experienced an important advance in the last years, and thus, an intense activity in the development of automated data processing algorithms has been noticed. Thus, this book aims to provide an overview of state-of-the-art algorithms, different best practices and most recent processing tools in connection to particular applications. Readers will find this a comprehensive book, that updates the practice of laser scanning for researchers and professionals not only from the geomatic domain, but also other fields such as structural and construction engineering. A set of successful applications to structural engineering are illustrated, including also synergies with other technologies, that can inspire professionals to adopt laser scanning in their day-to-day activity. This cutting-edge edited volume will be a valuable resource for students, researchers and professional engineers with an interest in laser scanning and its applications in the structural engineering domain.

Download or read book Understanding Bridge Performance Through Integrated Modeling and Monitoring written by Jian Liu and published by . This book was released on 2007 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first structure to be investigated, the Chesapeake City Bridge, is a 539 foot, tied arch that spans the C&D canal in Maryland. The objectives of the first case study presented were to (1) develop a numerical model, (2) characterize the physical condition of a tied arch bridge, and (3) determine the cause(s) of damage (fatigue cracking in this case) using multiple static diagnostic tests in conjunction with the developed model.

Download or read book Examination of Bridge Performance Through the Extension of Simulation Modeling and Structural Identification to Large Populations of Structures written by David Robert Masceri (Jr) and published by . This book was released on 2015 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt: The long-term strength and serviceability of common multi-girder bridges in the United States has been the subject of considerable inquiry in the modern era, in part due to the limited resources allocated to the preservation of large populations of bridges throughout the U.S. that are approaching the end of their originally envisioned design lives. While, the conservatism that has served the civil engineering profession well for over two centuries is still appropriate for new design, in the case of aging infrastructures it has proven ill-equipped with a resulting track record of "crying wolf.0́+ Current methods of population-scale evaluation are primarily qualitative and thus struggle to effectively support proper prioritization for preservation or replacement of the large numbers of bridges built during the infrastructure expansions of the 20th Century. The disparity between what is predicted through current methods of evaluation and what has been shown by refined quantitative testing indicates that concerns over safety are largely unfounded and hence provides little evidence for the need to drastically modify current design methodologies; therefore research in this area must concentrate on strategies for understanding this safety bias and the factors that influence its behavior on a quantifiable level so it may be used as factional information by infrastructure stakeholders. The overarching aim of the research reported herein is to establish a framework whereby realistic simulations and structural identification may be brought to bear on furthering the understanding of performance of large populations of bridges. The completed objectives outlined in this dissertation include: (1) Develop and validate an automated steel girder design/modeling tool capable of developing realistic estimates of the structural characteristics/responses for broad populations of bridges. (2) Using the tool developed in (1), establish the extent to which common design assumptions can result in deterministic trends of structural characteristics within populations of bridges. (3) Using the tool developed in (1), examine how the current practice of bridge design (inclusive of the conservatism introduced through common assumptions) may produce bridges that are capable of meeting demands that were not explicitly considered during member sizing. (4) Develop and validate a streamlined parameter identification tool capable of reliably improving the representative nature of simulation models through the use of field measurements. Key conclusions from this research include: (1) Design decisions such as diaphragm type and girder spacing that are made based on arbitrary criteria can have significant influence over the actual properties and reserve capacity of highway bridges. (2) Bias implicit in conventional design processes provides reserve capacity that is critical to accommodating limit states not explicitly considered during design. (3) When incorporating field measurements within structural assessment, it is crucial to perform model updating. The non-uniqueness associated with this inverse problem can be reduced through the updating and interpretation of both global and spatially varying deterministic parameters.

Download or read book Remote Continuous Evaluation of a Bridge Constructed Using High Performance Steel written by Terry J. Wipf and published by . This book was released on 2006 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the approximately 25,000 bridges in Iowa, 28% are classified as structurally deficient, functionally obsolete, or both. The state of Iowa thus follows the national trend of an aging infrastructure in dire need of repair or replacement with a relatively limited funding base. Therefore, there is a need to develop new materials with properties that may lead to longer life spans and reduced life-cycle costs. In addition, new methods for determining the condition of structures are needed to monitor the structures effectively and identify when the useful life of the structure has expired or other maintenance is needed. High-performance steel (HPS) has emerged as a material with enhanced weldability, weathering capabilities, and fracture toughness compared to conventional structural steels. In 2004, the Iowa Department of Transportation opened Iowa's first HPS girder bridge, the East 12th Street Bridge over I-235 in Des Moines, IA. The objective of this project was to evaluate HPS as a viable option for use in Iowa bridges with a continuous structural health monitoring (SHM) system. The scope of the project included documenting the construction of the East 12th Street Bridge and concurrently developing a remote, continuous SHM system using fiber-optic sensing technology to evaluate the structural performance of the bridge. The SHM system included bridge evaluation parameters, similar to design parameters used by bridge engineers, for evaluating the structure. Through the successful completion of this project, a baseline of bridge performance was established that can be used for continued long-term monitoring of the structure. In general, the structural performance of the HPS bridge exceeded the design parameters and is performing well. Although some problems were encountered with the SHM system, the system functions well and recommendations for improving the system have been made.

Download or read book Evaluation of Live load Distribution Factors LLDFs of Next Beam Bridges written by Abhijeet Kumar Singh and published by . This book was released on 2012 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new precast-prestressed cross section was recently developed by a consortium of engineers from the six New England states, New York and members of the northeast region of PCI. The northeast extreme Tee (NEXT) beam is efficient for medium Bridge spans (50 to 80 ft long). Field formwork savings are introduced by having a flange cast integrally during fabrication of the beams at the precasting plant. Job safety is increased because a working platform is created. The flange width of the NEXT Beams can be adjusted during fabrication to accommodate roadways of different widths and skew angles. Because the section is new with complexity in its shape, the present design guidance cannot be used to evaluate LLDFs for NEXT beams within the context of the AASHTO LRFD. In particular, the use of live-load distribution factors (LLDFs) equations in LRFD for NEXT beams is not straightforward. The distance between the beam webs is variable depending on whether it is measured within a beam module or between adjacent modules. In absence of detailed information a PCI technical committee evaluated LLDFs (through AASHTO 2010 Bridge specification) for the NEXT beams used in the Brimfield Bridge by two different approaches and found one of them conservative. The conservative approach was single stem which uses the average spacing (between webs ([S1+S3]/2)) for use in the LLDF equations. The committee expressed concerns about whether trends of LLDFs would be similar for other parametric sets, and would like to standardize the methodology for the Bridge projects in Massachusetts with NEXT beam as the girder. To verify the conservativeness of single stem methodology (for the evaluation of LLDFs) for other parameters this research project was initiated. LLDFs are evaluated based on the two approaches and compared with the LLDFs obtained through finite element modeling. The results of 40-3D finite element models have been used to compare the LLDFs obtained from AASHTO 2010 Bridge design specification. The results were also used to compare different parameters that affect LLDFs of NEXT beams including span, skew angle, and beam end fixity. The finite element models were created using a Bridge prototype that is being instrumented for future field verification of the analyses. The models were created using frame elements for the beams and shell elements for the cast in place deck. The integral abutment and foundation of the Bridges was included in the models in which piles are created using frame elements and abutments are created using shell elements. The results indicate that the approach taken for the design of NEXT beams is in general conservative for interior girders of the Bridge. On the contrary such the adopted approach was not yielding the higher value of LLDFs. The variation in strains due to losses are compared by two methods (strains variation obtained from field data and strain variation obtained based on AASHTO equation of losses) to verify the AASHTO equation of losses.

Download or read book Assessing Infrastructure Elements Using Automated Object Detection Technique in Smart City Applications written by Majid Mastali and published by . This book was released on 2019 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, road features are becoming more complex leading to more complicated complaints regarding urban environments. Point Cloud Data (PCD) processing is an essential element for detecting objects and analysing human driving behavior to identify the variables defining challenging objects and maneuvers in smart cities. PCDs include a range of processing, including indirect processing (e.g., data converting, cleaning process) and direct process (e.g., pass through elevation filter, statistical outlier removal, normal estimation as well as classification). Static and dynamic object detection and analysis are typically considered the most sophisticated options subsumed under PCDs. They involve direct evaluation of both static and dynamic objects of maneuvers variables for people who use the road with and without a vehicle in line with American with Disability Act (ADA) and trajectory variables of passing distance law for challenging scenarios. The results of point cloud data evaluations allow government agencies to provide communities with the information necessary to strategically plan transportation infrastructure improvements for people using roads and sidewalks. This two-part study identifies the essential components of sidewalk evaluation, and driver behaviors and reports the degree to which object and driver analysis are aligned with the expert recommended components of the ADA and passing distance law. The first study explores the feasibility of using both terrestrial laser scanner and open source processing algorithms to develop an approach to automate the evaluation of the alignment of transportation infrastructure with public rights of way. In the second study, a new approach of LIDAR data processing is developed to determine the speed and distance of vehicles approaching and entering the passing zone for bicycles. The model develops a technique for analysing the motorist passing behavior in the natural driving environment using the data collected from real vehicle and bicycle maneuvers.

Download or read book Lidar Assessment to Monitor Bridge Response Under Live and Dead Loads written by Daniel Watson and published by . This book was released on 2019 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding how a bridge structure responds to various loads in a time and resource-efficient approach is vital in characterizing bridge health. Bridge health monitoring is an evaluation of the structural condition and performance, which optimizes limited transportation budgets by prioritizing the bridges that are in the most need for retrofit or replacement. Identifying and remedying issues will mitigate long-term problems and ensure that the bridge remains open to service for all legal loads. In contrast, health monitoring and load rating will determine if a bridge can only carry traffic up to a certain weight or speed, requiring a bridge load restriction. Bridge response monitored in the field can calibrate a finite element method model to produce more reliable load ratings and distribution factors for bridges. Conventional methods utilizing discrete sensors can be time-consuming and provide a limited view of the bridge response that varies throughout the structure. Full-field data provided by lidar proves to be a viable tool to display the entire bridge response using less time and resources than conventional methods. This thesis evaluates the use of lidar to characterize bridge deflection response under changing live and dead loads. Two bridge structures were monitored while a loaded triaxial truck was placed on the deck and the other two were monitored during a phased construction concrete deck pour. The four assessed bridges represent a wide variety of bridges, where in each case lidar was able to provide high-fidelity and full-field deflection shapes. For one of these bridge structures, an inverted tee girder bridge of 19.81-meter length, a numerical model was constructed using the known parameters. Using traditional finite element modeling techniques, the numerical model fell short of the physical bridge response under live loads. The numerical model demonstrated the lack of uniform displacement, which was highlighted and characterized in the lidar point clouds. The use of lidar for this bridge structure demonstrates the benefit of the full-field response as well as the simplicity in the load test procedure.

Download or read book New ways to predict bridge performance written by and published by . This book was released on 2011 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Image Based Modeling of Bridges and Its Applications to Evaluating Resiliency of Transportation Networks written by Barbaros Cetiner and published by . This book was released on 2020 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern urban areas are heavily dependent on transportation networks to sustain their economic life. Hence, when vital components of a regional network are disrupted, economic losses are inevitable. As evidenced by 1989, Loma Prieta and 1994, Northridge earthquakes, the seismic damages experienced by bridges alone result in extensive traffic delays and rerouting, not only hindering emergency response but also causing indirect economic losses that far surpass the direct cost of damage to infrastructure. Nevertheless, in many areas of the U.S., transportation networks lack the resilience required to sustain the potential demands of natural hazards. Traditional hazard assessment methods, in theory, provide the tools required for predicting the vulnerabilities associated with natural hazards. Nonetheless, due to their abstractions of the complex infrastructure and the coupled regional behavior, they often fall short of that expectation. This study proposes a semi-automated image-based model generation framework for producing structure-specific models and fragility functions of bridges. The framework effectively fuses geometric and semantic information extracted from Google Street View images with centerline curve geometry, surface topology, and various relevant metadata to construct extremely accurate geometric representations of bridges. Then, using class statistics available in the literature for bridge structural properties, the framework generates structural models. Both the performance of the geometry extraction procedure and the structural modeling method proposed here are validated by comparison against the structural model of a real-life bridge developed based on as-built drawings. In principle, these models can be utilized to assess physical damage for any type of hazard, but in this study, the focus is limited to seismic applications. Thus to relate the damage resulting from seismic demands from ground shaking, bridge-specific fragility functions are developed for 100 bridge structures in the immediate surroundings of Ports of Los Angeles and Long Beach. Using these fragility curves, the physical damage resulting from a magnitude 7.3 scenario earthquake on Palos Verdes fault is predicted. Subsequently, the effects of the bridge infrastructure damage to the transportation patterns in the Los Angeles metropolitan area are investigated in terms of various resilience metrics.

Download or read book Automated and Enhanced Post processing of Multiple Reference Impact Test MRIT Data written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A significant amount of the nation's highway bridges are functionally obsolete or structurally deficient. The deficient structures represent significant impediments to safe and economical use of the highway system. This in turn results in safety hazards, higher user costs, and huge outlays for preservation and replacement. The complexities and costs associated with preserving the nation's bridge infrastructure demand innovative approaches to experimental and analytical studies, collection and analysis of data and prediction of current and future bridge preservation actions. These needs, coupled with the availability of modern analytical methods and high-speed computers, are leading to the development of new technologies and an interdisciplinary approach to the problem. Currently, bridge evaluation is done on an inspection basis, which is labor intensive considering the large number of bridges requiring inspection each year. A basic weakness in this current approach is bridges are rated based on a subjective condition assessment. Previous research by the University of Cincinnati Infrastructure Institute (UCII) has introduced a non-destructive testing and evaluation methodology to objectively assess the present bridge condition. Dynamic properties of the civil structure are identified to provide a modal flexibility, which has been shown to be condition sensitive. The present thesis is based on previous work provided by Dr. Michael Lenett and Dr. Necati Catbas. It focuses on reducing the amount of post-processing effort, to provide real-time condition assessment, and to incorporate system checks to validate the data and results achieved.

Download or read book Structural Performance Evaluation of Bridges written by Rolands Kromanis and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: