Structural Engineering Commons^™

Effects Of Long Duration Earthquakes On The Interaction Of Inertial And Liquefaction-Induced Kinematic Demands On Pile-Supported Wharves, Milad Souri, Arash Khosravifar, Stephen E. Dickenson, Nason Mccullough, Scott Schlechter

Civil and Environmental Engineering Faculty Publications and Presentations

Nonlinear dynamic analyses were performed to evaluate the effects of ground motion duration on the dynamic response of a pile-supported wharf subjected to liquefaction-induced lateral ground deformations. The numerical model was first calibrated using recorded data from a well-instrumented centrifuge test, after which incremental dynamic analyses were conducted using a suite of spectrally matched motions with different durations. The nonlinear dynamic analyses were performed to evaluated three loading scenarios: combined effects of inertial loads from the wharf deck and kinematic loads from ground deformations, deck inertial loads only in the absence of liquefaction (with minimal kinematic loads), and kinematic loads …

Tensile Behavior Of Frp Anchors Made From Cfrp Ropes Epoxy-Bonded To Uncracked Concrete For Flexural Strengthening Of Rc Column, Yasir Saeed, Wisam Amer Aules, Franz N. Rad, Anis M. Raad

Civil and Environmental Engineering Faculty Publications and Presentations

One of the major problems with using fiber reinforced polymer (FRP) in strengthening reinforced concrete (RC) structures is FRP premature debonding. Anchoring FRP materials to concrete has become associated with most of the strengthening techniques. One of the anchoring techniques is using handmade anchors made from FRP materials. In previous studies, most FRP anchors were made from rolling pre-cut FRP sheets and had short embedment (mm) as they were used for flexural or shear strengthening of RC beams. In the present study, FRP anchors were made from carbon fiber reinforced polymer (CFRP) ropes and had long embedment to be used …

Rapid Repair Of Seismically Vulnerable Bridge Columns Following Earthquake Induced Damage, Gregory H. Norton

Civil and Environmental Engineering Master's Project Reports

The Cascadia Subduction Zone (CSZ) earthquake has a high probability of occurrence within our lifetime, threatening bridges across the Pacific Northwest. Damage is expected to be geographically spread throughout the region and will have a nearly simultaneous impact on transportation through several important corridors. While bridge repair and replacement will ultimately be needed, priority will be placed on resuming mobility such that repairs will need to be implemented quickly. In an effort to anticipate this need, a repair method is being developed for rapid repair with the goal of achieving semi-permanent installation that also considers the different bridge damage states …

Detailed Energy Efficiency Strategies For Converting An Existing Office Building To Nzeb: A Case Study In The Pacific Northwest, Ali Alajmi, Abby Short, Janna Ferguson, Kalina K. Vander Poel, Corey T. Griffin

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper is an attempt to identify a methodology for converting conventional energy consumption buildings to net-zero energy buildings (NZEB). The first step was rather different from the usual energy audit, which is to analyze a facility’s energy consumptions from both macro- and micro-scales. To implement such an approach, a governmental office building (Metro) in Portland, OR, was chosen as a case study. After a building model was validated against a real measurement, it was then used to evaluate different energy efficiency strategies (EESs) so as to reduce the energy consumption. The EESs showed a reduction in energy use intensity …

Evaluation Of A Novel Remote Displacement Sensor Prototype Using Video And Laser-Based Technology For Civil Infrastructure Applications, Nicholas J. Brown

Civil and Environmental Engineering Master's Project Reports

Deflection measurements on structures, especially with regards to long-term monitoring, continues to be a challenge with current sensor technologies. Material degradation and changes in the mechanical properties due to aging (for example, creep and shrinkage in concrete bridges) directly impact the deflections exhibited by a structure. In this article we introduce and discuss the evaluation of a novel laser and video-based displacement sensor prototype to monitor displacements and rotations in structures remotely. The sensor is both inexpensive, using off-the shelf components, but also accurate and practical for situations that do not allow the use of conventional displacement sensors, which require …

An Agent-Based Evacuation Model To Improve Safety In The Cascadia Subduction Zone, Haizhong Wang

PSU Transportation Seminars

This seminar will present ongoing research into how integrated social, natural, and engineered systems can improve life safety under threat of multi-hazards. The targeted scenario is a magnitude 9.0 earthquake and tsunami from the Cascadia Subduction Zone, threatening communities along 1,000 miles of the US Pacific Northwest coastline.

Since the mid-1980’s scientific evidence has underscored the possibility of such an extreme event, and it has taken at least another decade or more before public attitudes and policy have begun to adapt to this new hazard. Life safety is a pressing issue for the near-field CSZ tsunami hazard for several reasons. …

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 …

Webinar: Addressing Bicycle-Vehicle Conflicts With Alternate Signal Control Strategies, Sirisha Kothuri

TREC Webinar Series

There is nationwide interest in supporting sustainable and active transportation modes such as bicycling and walking due to the many benefits associated with them, including reduced congestion, lower emissions and improved health. Although the number of bicyclists is increasing, safety remains a top concern. In urban areas, a common crash type involving bicycles at intersections is the “right hook” where a right-turning vehicle collides with a through bicyclist. While geometric treatments and pavement markings have been studied, there is a lack of research on signal timing treatments to address right-hook bicycle-vehicle conflicts.

Addressing Bicycle-Vehicle Conflicts with Alternate Signal Control Strategies …

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 …

Non-Linear Deformation Analysis Of An Embankment Dam, Silas T. Sanderson

Civil and Environmental Engineering Master's Project Reports

Non-linear deformation analysis (NDA) of embankment dams is becoming more common as geotechnical engineers seek to better understand how critical infrastructure will perform under high seismic loading. In order to perform this type of analysis, site specific ground motions and engineering properties of the embankment dam are required. The NDA modeling effort consists of a static and seepage analysis to establish an initial stress state followed by a dynamic analysis to simulate the embankment response to ground motions. Using this approach, a two dimensional NDA was performed on an embankment dam using the NDA program FLAC. This report discusses the …

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 …

A Novel Laser And Video-Based Displacement Transducer To Monitor Bridge Deflections, Miguel A. Vicente, Dorys C. Gonzalez, Jesus Minquez, Thomas Schumacher

Civil and Environmental Engineering Faculty Publications and Presentations

The measurement of static vertical deflections on bridges continues to be a first-level technological challenge. These data are of great interest, especially for the case of long-term bridge monitoring; in fact, they are perhaps more valuable than any other measurable parameter. This is because material degradation processes and changes of the mechanical properties of the structure due to aging (for example creep and shrinkage in concrete bridges) have a direct impact on the exhibited static vertical deflections. This paper introduces and evaluates an approach to monitor displacements and rotations of structures using a novel laser and video-based displacement transducer (LVBDT). …

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 …

Achieving Operational Seismic Performance Of Rc Bridge Bents Retrofitted With Buckling-Restrained Braces, Ramiro Andrés Gabriel Bazáez Gallardo

Dissertations and Theses

Typical reinforced concrete (RC) bridges built prior to 1970 were designed with minimum seismic consideration, leaving numerous bridges highly susceptible to damage following an earthquake. In order to improve the seismic behavior of substandard RC bridges, this study presents the seismic performance of reinforced concrete bridge bents retrofitted and repaired using Buckling-Restrained Braces (BRBs) while considering subduction zone earthquake demands. In order to reflect displacement demands from subduction ground motions, research studies were conducted to develop quasi-static loading protocols and then investigate their effect on structural bridge damage. Results suggested that subduction loading protocols may reduce the displacement ductility capacity …

Torsional Strengthening Of Reinforced Concrete Beams Using Cfrp Composites, Ranj Rafeeq

Dissertations and Theses

Few decades ago, there were no guidelines for torsion design of reinforced concrete (RC) beams. Hence, many existing beams in older buildings have a lack of adequate torsional strength since they were not properly designed for torsion. One way to regain/rehabilitate adequate torsional strength is through application of externally bonded carbon fiber reinforced polymers (CFRP). To date, American Concrete Institute (ACI) code, as well as other building codes, do not have recommendations or provisions for strengthening RC beams for torsion using fiber-reinforced polymer (FRP) composites due to the inexistence of conclusive experimental and analytical data. Of the very limited works …

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 …

Experimental Investigation Of Fiber Reinforced Concrete Beams, Karrar Ali Al-Lami

Dissertations and Theses

Shear strength of fiber reinforced concrete beams was studied in this research project. Three types of fibers were examined: hooked-end steel fiber, crimped-steel fiber, and crimped-monofilament polypropylene fibers. The experimental program included five beam specimens. Two of the beams were control specimens in which one was reinforced with minimum shear reinforcement according to ACI 318, while the other one did not have any shear reinforcement. Each one of the other three specimens was reinforced with one of the above mentioned fibers by 1% volumetric ratio. In addition to the beam specimens, three prisms were also made for each type fiber …

Behavior Of Reinforced Concrete Beams Retrofitted In Flexure Using Cfrp-Nsm Technique, Salam Al-Obaidi

Dissertations and Theses

A variety of retrofitting methods are used to upgrade existing structures. For example, steel plates and Fiber Reinforced Polymer (FRP) jackets are externally bonded to members to increase their capacity in flexure and shear. However, due to the issue of corrosion these strengthening systems may lose their efficiency with time. FRP materials have been used to strengthen many structural components of different shapes and types. FRP jackets, FRP Strips, and FRP rods have commonly been used to rehabilitate existing structural components. The many advantages of using FRP as strengthening materials have made this material an attractive alternative: advantages such as …

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 …

Experimental Investigation Of Lateral Cyclic Behavior Of Wood-Based Screen-Grid Insulated Concrete Form Walls, John Stuart Garth

Dissertations and Theses

Insulated concrete forms (ICFs) are green building components that are primarily used for residential wall construction. Unlike most polystyrene based ICF variants, the Faswall ICFs used in these experiments were significantly denser because they were made from recycled wood particles and cement. The current design approach for structures constructed with this type of wall form only allows the designer to consider the contribution of the reinforced concrete cores. Previous research has shown that this approach may be conservative. This project experimentally evaluated the lateral structural response of these types of grid ICF walls under increasing amplitude of in-plane cyclic loading. …

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

The Effect Of Microencapsulated Phase-Change Material On The Compressive Strength Of Structural Concrete, Chad Norvell, David J. Sailor, Peter Dusicka

Mechanical and Materials Engineering Faculty Publications and Presentations

Latent heat energy storage through phase-change materials (PCMs) is one possible strategy to control interior temperatures in buildings, improve thermal comfort, and passively reduce building energy use associated with heating and cooling. While PCMs integrated into building structure elements have been studied since the 1970s, challenges of integrating PCMs into building materials while maintaining their heat storage benefits have limited their application in practice. The recent introduction of microencapsulated phase-change materials provides the energy storage capability of PCMs in micron-scale, chemically-inert capsules that can be easily integrated into composite materials such as gypsum wallboard and concrete. The size and physical …

Reducing Seismic Risk To Highway Mobility: Assessment And Design Examples For Pile Foundations Affected By Lateral Spreading, Scott A. Ashford, Michael H. Scott, Deepak Rayamajhi

TREC Final Reports

Damage in pile supported structures due to liquefaction and liquefaction induced deformation were reported in past earthquakes around the world (e.g., Ansal et al. 1999; Seed et al. 1990; EERI 2010, EERI 2011; GEER 2010a, GEER 2010b, GEER 2011). For example, a reconnaissance report from a recent subduction zone event, the 2010 Chile earthquake (Mw=8.8), showed the pervasive nature of liquefaction and liquefaction-induced lateral spreading damage to bridge foundations (GEER 2010a, Yen et al. 2011). In terms of seismic hazard, the Pacific Northwest shares similar conditions from a Cascadia Subduction Zone (CSZ) earthquake source with the expected earthquake magnitude of …

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 …