Structural Engineering Commons^™

Dynamic Vulnerability Assessment Of Highway And Railway Bridges, Mehdi Mohseni

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Dynamic loads can cause severe damage to bridges, and lead to malfunction of transportation networks. A comprehensive understanding of the nature of the dynamic loads and the structural response of bridges can prevent undesired failures while keeping the cost-safety balance. Dissimilar to the static behavior, the dynamic response of bridges depends on several structural parameters such as material properties, damping and mode shapes. Furthermore, dynamic load characteristics can significantly change the structural response. In most cases, complexity and involvement of numerous parameters require the designer to investigate the bridge response via a massive numerical study.

This dissertation targets three main …

Implementation And Validation Of Fault-Rupture Response Spectrum Analysis Procedure In Csibridge For Bridges Crossing Earthquake Fault Ruptures, Jennifer Evelyn Tures

Master's Theses

This thesis evaluates the application of a simplified analysis procedure as implemented in version 16 of CSiBridge^TM for design of bridges crossing earthquake fault ruptures. The fault-rupture response spectrum analysis (FR-RSA) approximation method has been proved adequate for both straight and curved ordinary bridges, but lacked a comfortable interface to accommodate the method users. Computers and Structure, Inc. has implemented the FR-RSA procedure into CSiBridge^TM, a user-friendly integrated 3-D bridge design software, as an added seismic design feature. By combining the response of the bridge due to the quasi-static displacement from the fault strike-slip rupture and the …

Structural Health Monitoring Of A Bridge Structure Using Wireless Sensor Network, Cheekian Teng

Masters Theses

Bridge Structural Health Monitoring (SHM) has rapidly become one of the main interests in civil engineering field. Inexpensive and efficient SHM method utilizing Wireless Sensor Network (WSN) is helping to facilitate the selection of the bridges that require maintenance. The changes to structural properties (i.e. stiffness) caused by damage (i.e. corrosion) will change the structural responses (i.e. acceleration responses) to ambient motions. Modal analysis algorithms applied to the vibration responses acquired through WSN provide the modal properties (i.e. natural frequency, modal shape and damping ratio) that will change with the changes in stiffness indicating possible existence of damage. Three output-only …

New Technologies In Short Span Bridges: A Study Of Three Innovative Systems, Andrew Lahovich

Masters Theses 1911 - February 2014

Short span bridges are commonly used throughout the United States to span small waterways and highway overpasses. New technologies in the civil engineering industry have aided in the creation of many unique designs of these short span highway bridges in efforts to decrease construction cost, decrease maintenance costs, increase efficiency, increase constructability, and increase safety. Three innovative systems, the Integral Abutment Bridge, “Bridge-in-a-Backpack”, and the Folded Plate Girder bridge will be analyzed to study how the bridges behave under various types of loading.

Detailed finite element models were created for integral abutment bridges of varying geometry. These models are used …

Monte Carlo Simulation Of Extreme Traffic Loading On Short And Medium Span Bridges, Bernard Enright, Eugene J. Obrien

Articles

The accurate estimation of site-specific lifetime extreme traffic load effects is an important element in the cost-effective assessment of bridges. A common approach is to use statistical distributions derived from weigh-in-motion measurements as the basis for Monte Carlo simulation of traffic loading. However, results are highly sensitive to the assumptions made, not just with regard to vehicle weights but also to axle configurations and gaps between vehicles. This paper presents a comprehensive model for Monte Carlo simulation of bridge loading for free-flowing traffic, and shows how the model matches results from measurements on five European highways. The model has been …

The Effect Of Clusters Within Crowds Of Pedestrians On The Vertical Response Of A Flexible Footbridge, Joe Keogh, Colin C. Caprani, Paul Archbold, Paul Fanning

Conference papers

The issue of excessive vibrations of footbridges due to the passage of pedestrians has been well documented in the past decade. Despite this there still remains great uncertainty as to how to predict the acceleration response of a footbridge due to crowd loading. This paper investigates the vibration response of a flexible footbridge subjected to crowd loading. Using a statistical model which caters for the variability of pedestrians, the vibration response of the footbridge is obtained. In this work, the effect of social groups or clusters of pedestrians in a crowd is investigated. Herein a cluster is defined as two …

The Response Of A Footbridge To Pedestrians Carrying Additional Mass, Darragh O'Sullivan, Colin Caprani, Joe Keogh

Conference papers

Footbridges with low natural frequency are susceptible to excessive vibration serviceability problems if the pedestrian pacing frequency matches the bridge natural frequency. Much research has been done into describing the response of a footbridge to single pedestrian loading. However, many pedestrians carry additional mass such as shopping bags and backpacks, and this has generally not been accounted for in previous research. This work examines this problem using an experimental bridge excited with many single pedestrian events, both with and without additional mass. The vertical acceleration response is measured and compared to moving force, moving mass, and moving spring-mass-damper models. The …

Estimating Characteristic Bridge Loads On A Non-Primary Road Network, Eugene J. Obrien, Bernard Enright, Brendan Williams, Cathal Leahy

Conference papers

When collecting truck loading data on a primary road network a common approach is to install a large network of permanent pavement-based Weigh-In-Motion systems. An alternative to this approach would be to use one or more portable Bridge Weigh-In-Motion systems which could be moved between bridges at regular intervals to determine the traffic loading throughout the network. A data collection strategy is needed to put such a system to best use. This paper details the data collection strategies which were examined for the National Roads Authority in Ireland. The use of urban economic concepts including Central Place Theory are discussed …

Portable Bridge Wim Data Collection Strategy For Secondary Roads, Bernard Enright, Cathal Leahy, Eugene J. Obrien, Jennifer Keenahan

Conference papers

A common method of collecting traffic loading data across a large road network is to use a network of permanent pavement-based WIM systems. An alternative is to use one or more portable Bridge Weigh-In-Motion systems which are moved periodically between bridges on the network. To make optimum use of such a system, a suitable data collection strategy is needed to choose locations for the system. This paper describes a number of possible strategies which the authors have investigated for the National Roads Authority in Ireland. The different strategies are examined and their advantages and disadvantages compared. Their effectiveness at detecting …