Civil Engineering Commons^™

Multimodal Imaging Of Structural Concrete Using Image Fusion And Deep Learning, Sina Mehdinia

Dissertations and Theses

Concrete structures may be exposed to a variety of loads and environments during their service life. Non-destructive testing (NDT) techniques can be helpful in evaluating the condition of a structure. Imaging provides a visual representation of the interior of concrete and its condition non-destructively. Ground penetrating radar (GPR) and ultrasonic echo array (UEA) using electromagnetic and stress waves, respectively, provide the data that can be used to reconstruct an image. In this PhD dissertation, image reconstruction and fusion algorithms, simulation, and a deep learning model were investigated with the goal to lay the foundation for enhanced imaging applications for concrete. …

Seismic Behavior Of Screen Grid Core Insulated Concrete Form Walls, Anwer Sabah Mohammed Mohammed

Dissertations and Theses

The use of the insulated concrete form (ICF) walls in residential buildings has increased over the past few decades. Much research has been conducted to evaluate the lateral strength of these walls by applying monotonic and cyclic loadings. In the current study, full-scale shake table experiments were employed to evaluate the in-plane behavior of four screen grid insulated concrete form (SGICF) walls. The first two wall specimens utilized dry fit insulated form blocks made from recycled expanded polystyrene granules that were bonded together with cement. When stacked, the cavities in the blocks formed a grid of cores that are evenly …

Advancing Bridge Technology, Task 10: Statistical Analysis And Modeling Of Us Concrete Highway Bridge Deck Performance -- Internal Final Report, Omar Ghonima, Thomas Schumacher, Avinash Unnikrishnan, Adam Fleischhacker

Civil and Environmental Engineering Faculty Publications and Presentations

Concrete highway bridge deck repairs represent the highest expense associated with bridge maintenance cost. In order to optimize such activities and use the available monies effectively, a solid understanding of the parameters that affect the performance of concrete bridge decks is critical. The National Bridge Inventory (NBI), perhaps the single-most comprehensive source of bridge information, gathers data on more than 600,000 bridges in all fifty states, the District of Columbia, and the Commonwealth of Puerto Rico. Focusing on concrete highway bridge deck performance, this research developed a nationwide database based on NBI data and other critical parameters that were computed …

A 3d Model For Earthquake-Induced Liquefaction Triggering And Post-Liquefaction Response, Arash Khosravifar, Ahmed Elgamal, Jinchi Lu, John Li

Civil and Environmental Engineering Faculty Publications and Presentations

A constitutive soil model that was originally developed to model liquefaction and cyclic mobility has been updated to comply with the established guidelines on the dependence of liquefaction triggering to the number of loading cycles, effective overburden stress (Kσ), and static shear stress (Kα). The model has been improved with new flow rules to better capture contraction and dilation in sands and has been implemented as PDMY03 in different computational platforms such as OpenSees finite-element, and FLAC and FLAC3D finite-difference frameworks. This paper presents the new modified framework of analysis and describes a guideline to calibrate the input parameters of …

Modified Design Procedures For Bridge Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading, Arash Khosravifar, Jonathan Nasr

Civil and Environmental Engineering Faculty Publications and Presentations

Effective-stress nonlinear dynamic analyses (NDA) were performed for piles in the liquefiable sloped ground to assess how inertia and liquefaction-induced lateral spreading combine in long- and short-duration motions. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of durations and amplitudes. The NDA results showed that the pile demands increased due to (a) longer duration shakings, and (b) liquefaction-induced lateral spreading compared to nonliquefied conditions. The NDA results were used to evaluate the accuracy of the equivalent static analysis (ESA) recommended by Caltrans/ODOT for estimating pile demands. Finally, the NDA results were …

Inertial And Liquefaction-Induced Kinematic Demands On A Pile-Supported Wharf: Physical Modeling, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Scott Schlechter, Nason Mccullough

Civil and Environmental Engineering Faculty Publications and Presentations

Results of a centrifuge test on a pile-supported wharf were used to investigate the time-, depth-, and row-dependent nature of kinematic and inertial loading on wharf piles in sloping rockfill. P-y models were calibrated against recorded bending moments in different piles and different depths. It was found that full kinematic demands and full superstructure inertia should be combined to estimate bending moments at pile head and shallow depths (less than 10 diameters below the ground surface). On the contrary, it was found that applying full kinematic demands alone was adequate to estimate pile bending moments at large depths (greater than …

The Effects Of Long-Duration Subduction Earthquakes On Inelastic Behavior Of Bridge Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading, Jonathan Nasr, Arash Khosravifar

Civil and Environmental Engineering Faculty Publications and Presentations

Effective-stress nonlinear dynamic analyses (NDA) were performed for a large-diameter reinforced concrete (RC) pile in multi-layered liquefiable sloped ground. The objective was to assess the effects of earthquake duration on the combination of inertia and liquefaction-induced lateral spreading. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of motion durations. The NDA results showed that the pile head displacements increased under liquefied conditions, compared to nonliquefied conditions, due to liquefaction-induced lateral spreading. The NDA results were used to develop a displacement-based equivalent static analysis (ESA) method that combines inertial and lateral spreading …

Behavior Of Prestressed Concrete Beams With Cfrp Strands, Yasir Matloob Saeed

Dissertations and Theses

The high cost of repairing reinforced or prestressed concrete structures due to steel corrosion has driven engineers to look for solutions. Much research has been conducted over the last two decades to evaluate the use of Fiber Reinforced Polymers (FRPs) in concrete structures. Structural engineering researchers have been testing FRP to determine their usability instead of steel for strengthening existing reinforced concrete structures, reinforcing new concrete members, and for prestressed concrete applications. The high strength-to-weight ratio of FRP materials, especially Carbon FRP (CFRP), and their non-corrosive nature are probably the most attractive features of FRPs.

In this study, an experimental …

Bridge Seismic Retrofit Measures Considering Subduction Zone Earthquakes, Peter Dusicka, Ramiro Bazaez, Sarah Knoles

Civil and Environmental Engineering Faculty Publications and Presentations

Over the years, earthquakes have exposed the vulnerability of reinforced concrete structures under seismic loads. The recent occurrence of highly devastating earthquakes near instrumented regions, e.g. 2010 Maule, Chile and 2011 Tohoku, Japan, has demonstrated the catastrophic impact of such natural force upon reinforced concrete structures. Research was conducted to investigate the effect of subduction zone earthquakes on structural damage. The study suggests that large magnitude ground motions of long duration have the potential of significantly increasing the number of inelastic excursions and consequently incur more extensive structural damage as compared to ground motions with similar elastic spectral demands but …

Seismic Retrofit Benefit Considering Statewide Transportation Assessment, Selamawit Tesfayesus Mehary, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

The purpose of this study was to identify and demonstrate a methodology to prioritize bridges for retrofit in the State of Oregon. Given the limited resources available, retrofitting all vulnerable bridges in the foreseeable future would not be practical. Instead, a retrofit strategy needs to be developed to prioritize the inventory and enumerate the retrofit cost. In this study, a prioritization methodology used a holistic assessment of overall roadway system to consider highway route segments, rather than individual bridges. The overall assessment was based on a cost-benefit analysis including retrofit cost, expected economic loss (with or without retrofit) and social …

Design Of Piles In Liquefied Soils For Combined Inertial And Kinematic Demands, Arash Khosravifar, J. Ugalde, T. Travasarou

Civil and Environmental Engineering Faculty Publications and Presentations

The design of piles penetrating liquefiable soils poses a number of challenges, including 1) accounting for the effects of liquefaction on lateral soil springs (p-y), 2) estimating liquefaction-induced kinematic demands (lateral spreading displacements) including pile-pinning effects, and 3) combining the effects of inertial demands from superstructure and kinematic demands from liquefied ground. This paper illustrates two approaches to address the above questions: A) a simplified decoupled approach adopting equivalent static analysis (ESA), and B) a detailed, coupled approach adopting nonlinear dynamic analyses (NDA). These approaches are presented through example projects showing the limitations and the potential conservatism associated with the …

Making Bridges Outlast Rising Waters, Daniel Cox

TREC Project Briefs

During Hurricanes Ivan in 2004 and Katrina in 2005, at least 11 highway and railroad bridges along the U.S. Gulf Coast were damaged by wave forces. The spans of these bridges typically rested on bent column supports, and were attached to the supports by a variety of connection methods. Failure of these connections caused bridge spans to be washed away when the water rose high enough to lift them off. To build bridges that can withstand such forces, engineers must be able to estimate the effects the forces will have.

Investigator Daniel Cox of Oregon State University has conducted wave …

Testing And Strengthening Bridge Connections, Christopher Higgins, Peter Dusicka, Michael Scott

TREC Project Briefs

Researchers evaluate and improve the strength of gusset plate connections, essential pieces in bridge design that can fail due to buckling.

Research Project Work Plan For Impact Of Cascadia Subduction Zone Earthquake On The Seismic Evaluation Criteria Of Bridges, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

The goal of this project is to provide ODOT with the best rational estimate of ground acceleration values for designing new and retrofitting existing bridges. The objectives are to:

• evaluate the hazard by contrasting the acceleration values from individual CSZ events to PSHA values
• provide experimental evidence of damage difference under longer duration shaking expected from CSZ event

Protecting Bridges From Earthquake Damage, Peter Dusicka

TREC Project Briefs

Earthquake damage to bridges can have serious effects on a transportation network. When a bridge is out, the damage can go well beyond what is immediately visible: in addition to the cost of repairing it, the state must deal with short-term and long-term interruptions to traffic. These interruptions can delay repair and construction, as well as impacting post earthquake emergency response and causing the loss of valuable time for commuters and freight. To prevent this situation, older bridges (ones that are past an average construction life of about 50 years) should be retrofitted with stronger materials, especially in earthquake- prone …

Laboratory Performance Of Highway Bridge Girder Anchorages Under Simulated Hurricane-Induced Wave Loading, Jora Lehrman, Christopher Higgins, Daniel Cox

TREC Final Reports

Many bridges along the Gulf Coast of the United States were damaged by recent hurricanes, and many more are susceptible to similar damage. This research examines the structural performance of common connection details used to anchor prestressed concrete girders to the substructure. Full-scale specimens were fabricated and tested under static and dynamic cyclic load histories. Dynamic load histories were developed from previously conducted hydraulic tests of a 1/5 scale model of a highway bridge under hurricane wave loads. The load effects considered included the pseudo-statically applied vertical uplift force, horizontal force, combined horizontal and vertical forces, and dynamically applied combined …

Seismic Hazard Assessment Of Oregon Highway Truck Routes, Peter Dusicka, Selamawit Tesfayesus Mehary

TREC Final Reports

This research project developed a seismic risk assessment model along the major truck routes in Oregon. The study had adopted federally developed software tools called Risk for Earthquake Damage to Roadway Systems (REDARS2) and HAZUS-MH. The model was the first time REDARS2 has been adopted and used in research outside of the original development team, presenting a number of unique challenges. The development of the model was a complex, intensive process that required a significant research effort, manipulation and adjustment of data. Furthermore, limitations of the software tools themselves had been identified that prevented the inclusion of important aspects such …

Strength And Fatigue Of Three Glass Fiber Reinforced Composite Bridge Decks With Mechanical Deck To Stringer Connections, Andrew Gleason, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Replacement of the steel grating deck on the lift span of the Morrison Bridge in Portland, OR, will utilize glass fiber reinforced polymer (FRP) panels to address ongoing maintenance issues of the deteriorated existing deck, improve driver safety and introduce bridge water runoff treatment. This report outlines the testing methods and results of an experimental program aimed primarily at evaluating a new open cell deck. While most FRP panels are connected via shear studs that are grouted within isolated pockets, the panels in this case were bolted directly to the steel stringers. Two different FRP deck options were evaluated for …

Development Of An Open Source Bridge Management System, Michael H. Scott

TREC Final Reports

A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing live load analysis through scripts and experimenting with emergent bridge rating methodologies. Since Tcl is an interpreted language, the application also has the important advantage that new bridge capacity models and rating factor calculations can be implemented on multiple platforms without compiling source code. The network programming features of Tcl give the system access to databases for conducting internet-based bridge rating. The system is demonstrated for rating a conventionally reinforced concrete …

Seismic Vulnerability Of Oregon State Highway Bridges: Mitigation Strategies To Reduce Major Mobility Risks, Albert Nako, Craig Shike, Jan Six, Bruce Johnson, Peter Dusicka, Selamawit Tesfayesus Mehary

Civil and Environmental Engineering Faculty Publications and Presentations

The Oregon Department of Transportation and Portland State University evaluated the seismic vulnerability of state highway bridges in western Oregon. The study used a computer program called REDARS2 that simulated the damage to bridges within a transportation network. It predicted ground motions for a specific location and magnitude of earthquake, resulting bridge damage and the cost of the damage, as well as the cost to the public for traffic delays due to detours around damaged bridges. Estimated damage and delay costs were presented for major highways in the region.

Secondary Stresses In Bowstring Timber Trusses, John F. Bradford

Dissertations and Theses

This study was undertaken in order to determine analytically the magnitude of the secondary (i.e., joint deflection induced) moments in the continuous glued-laminated chords of bowstring timber trusses. Traditionally, these moments have been assumed to be small and therefore neglected. The American Institute of Timber Construction makes no mention of these moments in their recommended design procedure.

A Study Of Single Angle Compression Members, James Robert Callaway

Dissertations and Theses

A study was undertaken to investigate the compressive capacity of a specific group of single angle members.

A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed.

Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, …

Response Of Orthotropic Bridge Decks To Highway Loadings, Harry Morris Rexin

Dissertations and Theses

This thesis documents the fabrication, testing techniques, and response of a plastic scale model of an orthotropic bridge deck. To economically investigate a two-lane steel bridge deck, plastic Acrylic^R was used as a modeling material. Welds were simulated with dichloromethane, a capillary action solvent, and PS-30, a polymerizable cement. Deflections were measured with laboratory dial guages while strains were monitored with strain guages mounted on the deck.

The response of the deck to AASHO vehicle axle loads was compared with a discrete element computer program used to analyze orthotropic bridge decks continuous over flexible supports. Results indicate good correlation …