Structural Engineering Commons^™

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 …

A Proposed Data Qualification Procedure For The Connecticut Bridge Monitoring Network, Stephen R. Prusaczyk

Master's Theses

No abstract provided.

Motivating Technical Writing Through Study Of The Environment, J. Linsdell, Thalia Anagnos

Faculty Publications

No abstract provided.

A Parametric Study Of Pedestrian Vertical Force Models For Dynamic Analysis Of Footbridges, Paul Archbold, Joe Keogh, Colin C. Caprani, Paul Fanning

Conference papers

Footbridge vibration has received much attention in recent years. However, stochastic models for crowd loading are not common, and estimation of crowd-induced vibration is typically done through enhancement factors applied to single pedestrian loading models. This work compares two such models, a moving force model and a spring-mass-damper model (SMD). Typical ranges for various pedestrian parameters are examined, and it is found that the pacing frequency has by far the greatest influence on bridge vibration response. It is also found that the magnitude of the response for pacing frequencies near the bridge natural frequency is lower for the SMD model, …

Modelling Of Highway Bridge Traffic Loading: Some Recent Advances, Bernard Enright, Colin C. Caprani, Eugene J. Obrien

Conference papers

The accurate estimation of site-specific lifetime extreme traffic load effects is an important element in the cost-effective assessment of bridges. In recent years, the improved quality and increasing use of weigh-in-motion technology has meant that better quality and larger databases of vehicle weights are now available. This has enabled measurements of the regular occurrence of extremely heavy vehicles, with weights in excess of 100 t. The collected measurements have been used as the basis for building and calibrating a Monte Carlo simulation model for bridge loading. The computer programs written to implement this model generate simulated traffic in two lanes …

Characteristic Vertical Response Of A Footbridge Due To Crowd Loading, Colin C, Caprani, Joe Keogh, Paul Archbold, Paul Fanning

Conference papers

The characteristic vertical vibration of a flexible footbridge subject to crowd loading is examined in this paper. Typically, bridge vibrations produced from a crowd of pedestrians are estimated by using an enhancement factor applied to the effect caused by a single pedestrian. In this paper, a single pedestrian model, represented by a spring mass damper, which incorporates variables such as pedestrian mass and body stiffness, is used to calibrate a computationally efficient moving force model. This calibrated moving force model is further used in Monte Carlo simulations of non-homogenous crowds to estimate characteristic vertical vibration levels. Enhancement factors, which could …

Modeling Same-Direction Two-Lane Traffic For Bridge Loading, Eugene J. Obrien, Bernard Enright

Articles

Many highway bridges carry traffic in two same-direction lanes, and modeling the traffic loading on such bridges has been the subject of numerous studies. Different assumptions have been used to model multiple-presence loading events, particularly those featuring one truck in each lane. Using a database of weigh-in-motion measurements collected at two European sites for over 1 million trucks, this paper examines the relationships between adjacent vehicles in both lanes in terms of vehicle weights, speeds and inter-vehicle gaps. It is shown that there are various patterns of correlation, some of which are significant for bridge loading. A novel approach to …

Behaviour Of Unbonded Post- Tensioned Segmental Box Girders With Dry Joints, Michael Matson

Theses

The primary objective of this thesis is to examine the capacity of shear keys used in dry jointed precast post-tensioned segmental box girder bridge construction. The use of dry joints, in lieu of the more traditional glued joints, is becoming more popular in climatically suitable countries. The time and cost savings achieved using this construction form arc significant, due to the economies of scale involved.

The shear capacity of dry jointed keys is calculated using a number of available formulae. However, in previously published papers, significant differences have been noted in the results obtained from these formulae, deeming further investigation …

High-Strength Selfconsolidating Concrete Girders Subjected To Elevated Compressive Fiber Stresses, Part 2: Structural Behavior, Jared E. Brewe, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The design of prestressed concrete members is restricted by the requirement that the extreme compressive fiber stress at midspan be less than 60% of the concrete compressive strength at release of prestressing. the purported purpose of this limit is to provide serviceability performance, but it places unnecessary limits on the capability of the materials. for this research program, six prestressed concrete girders were produced with high-strength, self-consolidating concrete and subjected to elevated compressive fiber stress levels ranging from 65% to 84% of initial concrete compressive strength at release of prestressing. Part 1 of this series analyzed time-dependent prestress losses and …

Bond Behavior Of Fiber Reinforced Polymer Bars Under Hinged Beam Conditions, Ryan James Sandstrom

Master's Theses

The research provided in this report examines the behavior of fiber reinforced polymer (FRP) reinforcing bars, embedded in normal weight concrete (NWC) hinged beam-end specimens, tested in accordance with two laboratory conditions. Reinforcing bars of different diameter, material configuration, and finished surface preparation were tested for bond strength parameters determined in accordance with ACI Committee Report 440.3. Bond strength parameters under the first condition were tested within NWC beams at a relatively low compressive strength and minimum embedment length; the second condition allowed testing within NWC beams at twice the design compressive strength of the first condition and moderate embedment …

Modeling Extreme Traffic Loading On Bridges Using Kernel Density Estimators, Cathal Leahy, Eugene J. Obrien, Bernard Enright

Conference papers

Kernel density estimators are a non-parametric method of estimating the probability density function of sample data. In this paper, the method is applied to find characteristic maximum daily truck weights on highway bridges. The results are then compared with the conventional approach

Rubble-Mound Structure Design In The Coastal Environment, Jack Murphy

Theses

The main aims of this thesis were to investigate the main aspects of the design and implementation of rubble-mound structures as a form of shoreline stabilisation and coastal defence. An emphasis has been placed on the Irish context of how these structures have been implemented in the past. The intention was that this work would improve the understanding of the use of these structures for future projects both in Ireland and internationally.

This work required a literature review which investigated the general aspects of rubble-mound structures, the coastal environment, and the theory of designing the structures’ layout, cross-section and impact …

A Wireless System For Crack Monitoring In Concrete Structures, Souhail M. Saad

Dissertations and Theses @ UNI

The formation of cracks in concrete is a normal phenomenon. However, effective control and prevention of the formation of cracks is the key for successful life of concrete structures. Specifically, cracks represent a path of least resistance for moisture and corrosive ionic agents from de-icing salts to reach embedded steel in concrete. Commercial wireless sensor networks utilizing crack gauge sensors can be applied for crack monitoring in the common concrete structure. The crack sensors circuits' boards, which are used to stimulate the cracks, are currently unavailable for the SG-Link module platform.

The SG-Link module is an ultra-low-power module for use …

Investigating Wood Welding Parameters Using A Prototype Welding Machine, Timothy R. Melin

Master's Theses

Understanding how different processing variables influence wood welded bonds is vital if the technique will ever be used to create engineered lumber without using adhesives. A variation of vibration welding, wood welding uses pressure and friction to bond materials together. During welding, heat causes a softening in the wood, a naturally occurring composite material. This softening leads to fiber entanglement and a bond forms upon cooling.

The goal of this research was to investigate several processing aspects of the wood welding procedure. A prototype wood welding machine, designed and fabricated from the ground up, was used to investigate the effects …

Product Technical Information, Steel Stud Manufacturers Association

CCFSS Library (1939 - present)

No abstract provided.

Cold-Formed Steel Framing Seismic Design Optimization Phase 1a: Seismic Equivalency Parameter Evaluation, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

A Life-Cycle Assessment Of Cold-Formed Steel Enclosures Verses Alternative Enclosures In Commerical Buildings, K. J. Van, L. Xu

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

In North America, the operation of buildings accounts for approximately one third of the total energy use and greenhouse gas emissions each year. Over the life of a building, the total energy use is a combination of the embodied energy in the building materials and the operating energy of the building. Building enclosures (walls and roofs) have a huge impact on both the embodied energy and the operating energy of buildings. Historically, steel has been blacklisted as a material with a high embodied energy. This has led to a misconception that steel enclosures use significantly more energy than other enclosure …

Behavior And Design Of Axially Compressed Sheathed Wall Studs, L. C. M. Vieira Jr., B. W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The objective of this paper is to summarize efforts in a multi year project dedicated to developing a reliable design method for cold - formed steel wall studs that rely on sheathing for bracing. Testing on single columns with sheathing, and full - scale walls with sheathin g, are summarized. Particular emphasis is placed on the observed limit states given the different sheathing conditions. The sheathing supplies beneficial restraint to the wall studs and the stiffness of this sheathing - based restraint is characterized exper imentally and analytically. A unique application of the Direct Strength Method of design is explored …

Lateral Torsional Instability Of Single Channels Restrained By Angle Cleats, G. M. Bukasa, M. Dundu Masce

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

A series of experiments on the lateral tors ional instability of single channels is presented. The channels are restrained by a purlin – angle cleat connection and subjected to a two point loading system in order to simulate a distributed load. Failure of the channels occurred by local buckling of the compression zone of the flange and web and lateral torsional buckling of the channels between points of lateral support. Tests have shown the purlin–angle cleat connection to be capable of restraining the frames from failing due to lateral-torsional buckling. This eliminates the idea of having fly-bracings, which is normally …

Extending Direct Strength Design To Cold-Formed Steel Beams With Holes, Christopher D. Moen, Benjamin W. Schafer

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The extension of the American Iron and Steel Institute’s Direct Strength Method (DSM) to cold-formed steel beams with holes is nearly in place. DSM was first introduced to th e AISI specification in 2004 as an alternative to the effective width met hod, and is widely considered a major advancement in cold-formed steel component design. In DSM, the beam elastic buckling properties for a general cross-section are obtained with a computer analysis utilizing the finite strip method. A disadvantage of the finite strip method and DSM has been that discrete holes along the member length could not be easily accounted …