Experimental and Analytical Seismic Studies of a Four-span Bridge System with Composite Piers

Experimental and Analytical Seismic Studies of a Four-span Bridge System with Composite Piers
Author: Fatemeh Kavianipour
Publisher:
Total Pages: 1350
Release: 2013
Genre: Electronic books
ISBN:

Funded by the National Science Foundation through the Network for Earthquake Engineering Simulation (NEES) research program, a major multi-university research project has been in progress at the University of Nevada, Reno. This study describes the study of one of the three large-scale bridge models that were tested to failure on three shake tables system. This model was supported on fiber-reinforced polymer (FRP) composite piers implementing accelerated bridge construction (ABC) techniques. The bridge was a quarter scale model of a 4-span bridge with continuous reinforced concrete superstructure and a drop cap, two-column pier design. Each pier utilized different unconventional FRP details. The purpose of using these innovative details was to improve the seismic performance of the bridge. The first pier consisted of cast-in-place concrete-filled glass FRP tubes with ±55 degree fibers. The second pier consisted of two segmental reinforced concrete columns wrapped with layers of unidirectional carbon FRP sheets to provide confinement and shear reinforcement. Only nominal hoops were used to hold the longitudinal reinforcement, as FRP jacket and tube were sufficient in providing confinement and shear required reinforcement. The third pier had the same configuration as that of pier 1 but the columns and footing were precast. The top connections in piers 1 and 3 consisted of pipe-pin joints to facilitate ABC and provide hinge behavior. The objectives of the study presented in this document were to evaluate the biaxial seismic performance of this bridge system incorporating composite piers, investigate the performance of each detail and compared them to each other and to conventional ones, determine the influence of abutment-superstructure interaction on the response, assess the performance of a bridge model incorporating ABC techniques, evaluate sufficiency of analytical modeling of the performance of composite material and details, and to conduct parametric study of different variations of the bridge model to study the effect of several important factors such as near-fault earthquake effects and the variations in the configuration of the bridge model. large-scale 4-span bridge model was designed, constructed, and subjected to simulated earthquake loading on three shake tables. The simulated shake table motions were the modified 1994 Northridge, CA ground motion recorded in Century City and were applied to the bridge model in ten runs with increasing amplitudes. Over 380 channels of data were collected. Compared to conventional reinforced concrete bridges, experimental results showed superior performance under extreme seismic loading even under lateral drift ratios exceeding 9%. Extensive post-test analytical studies were conducted and it was determined that a computational model of the bridge that included bridge-abutment interaction using OpenSees was able to provide satisfactory estimations of key structural response parameters such as superstructure displacements. The analytical model was also used to conduct parametric studies on response of the bridge model and its variations under near-fault excitations. The effects of changing the column section properties were also explored. It was found that concrete-filled FRP tube piers and CFRP wrapped post-tensioned segmental piers reduce residual displacements compared to their conventional reinforced concrete counter parts even under impulsive near-fault motions.

Experimental and Analytical Seismic Studies of a Four-span Bridge System with Innovative Materials

Experimental and Analytical Seismic Studies of a Four-span Bridge System with Innovative Materials
Author: Carlos Alonso Cruz-Noguez
Publisher:
Total Pages: 1524
Release: 2010
Genre:
ISBN:

As part of a multi-university project utilizing the NSF Network for Earthquake Engineering Simulation (NEES), a quarter-scale model of a four-span bridge incorporating plastic hinges with different advanced materials was tested to failure on the three shake table system at the University of Nevada, Reno (UNR). The bridge was the second test model in a series of three 4-span bridges, with the first model being a conventional reinforced-concrete (RC) structure. The purpose of incorporating advanced materials was to improve the seismic performance of the bridge with respect to two damage indicators: (1) column damage and (2) permanent deformations. The goals of the study presented in this document were to (1) evaluate the seismic performance of a 4-span bridge system incorporating SMA/ECC and built-in rubber pad plastic hinges as well as post-tensioned piers, (2) quantify the relative merit of these advanced materials and details compared to each other and to conventional reinforced concrete plastic hinges, (3) determine the influence of abutment-superstructure interaction on the response, (4) examine the ability of available elaborate analytical modeling techniques to model the performance of advanced materials and details, and (5) conduct an extensive parametric study of different variations of the bridge model to study several important issues in bridge earthquake engineering. The bridge model included six columns, each pair of which utilized a different advanced detail at bottom plastic hinges: shape memory alloys (SMA), special engineered cementitious composites (ECC), elastomeric pads embedded into columns, and post-tensioning tendons. The design of the columns, location of the bents, and selection of the loading protocol were based on pre-test analyses conducted using computer program OpenSees. The bridge model was subjected to two-horizontal components of simulated earthquake records of the 1994 Northridge earthquake. Over 340 channels of data were collected. The test results showed the effectiveness of the advanced materials in reducing damage and permanent displacements. The damage was minimal in plastic hinges with SMA/ECC and those with built-in elastomeric pads. Conventional RC plastic hinges were severely damaged due to spalling of concrete and rupture of the longitudinal and transverse reinforcement. Extensive post-test analytical studies were conducted and it was determined that a computational model of the bridge that included bridge-abutment interaction using OpenSees was able to provide satisfactory estimations of key structural parameters such as superstructure displacements and base shears. The analytical model was also used to conduct parametric studies on single-column and bridge-system response under near-fault ground motions. The effects of vertical excitations and transverse shear-keys at the bridge abutments on the superstructure displacement and column drifts were also explored.

Experimental and Analytical Seismic Studies of Bridge Piers with Innovative Pipe Pin Column-footing Connections and Precast Cap Beams

Experimental and Analytical Seismic Studies of Bridge Piers with Innovative Pipe Pin Column-footing Connections and Precast Cap Beams
Author: Ali Mehrsoroush
Publisher:
Total Pages: 1518
Release: 2014
Genre: Electronic books
ISBN:

The use of prefabricated structural elements is an integral part of many accelerated bridge construction (ABC) efforts. Connections of these prefabricated elements to the rest of the structural system is critical to the performance of the structure under service loads and extreme events such as earthquakes. Two types of novel joints were developed in this study: 1) base pipe pin connections to substantially reduce the moment transfer between the column and footing, and 2) pocket connections to provide structural continuity at column-cap beam joints. The pipe pin consists of two steel pipes to transfer shear and a tension member to transfer uplift forces. Pocket connection is formed by extending the column into a pre-fabricated pocket in a precast cap beam and grouting the space between the column segment and the pocket. The primary objective of this research was to investigate the seismic performance, response, and behavior of base pipe pins for both cast-in-place (CIP) and precast construction, to study the performance of column-cap beam pocket connections to be utilized in ABC, and to develop a reliable design guideline for base pipe pins. This research was comprised of comprehensive experimental and analytical studies. The experimental portion of the study was conducted at the University of Nevada, Reno Large Scale Structural Laboratory including three sets of tests: 1) cyclic loading test of a large-scale two-column bent model, and 2) two direct pull tests of CIP and precast pipe pin connections. The bent model was composed of a precast engineered cementitious composite (ECC)-concrete column, a conventional CIP reinforced concrete column, a precast cap beam, and two single footings. The columns were connected to the footing and cap beam utilizing pipe pin and pocket connections, respectively. Direct pull tests were carried out to investigate the failure mode of the pipe pins under direct tension and determine the ultimate tensile capacity of the pins. The proposed pipe pin connections were found to be successful even under high drift ratios. Test results revealed that pipe pins needs to be designed for shear forces that exceed the column design shear due to reversed friction under large base rotations. Direct pull tests of the pipe pins showed that the dominant failure mode of the connection under pure tension was rupture of the tension member and all the other connection elements remained damage free. The pocket connection using corrugated steel pipes with a column embedment length of 1.2 times the column diameter performed well in forming the plastic hinge when conventional concrete was used in the embedded region. However, longitudinal bars in the precast column with embedded ECC debonded at 4% drift ratio. The analytical study consisted of 1) elaborate finite element (FE) modeling of the pipe pin connections and footings under direct tension, 2) FE study of the two-column bent, and 3) analytical modeling of pipe embedded in the footing (pipe shear key). ABAQUS and OpenSees were used in the analyses. The analytical models were evaluated based on correlation with experimental data, and were then used to investigate the effects of different parameters on the seismic performance of pipe pins. Results of the parametric studies along with the experimental observations led to an iterative procedure to determine seismic demands and methods for designing pipe pins. This was followed by development of design and detailing methods and illustrative examples.

Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones

Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones
Author: Mostafa Tazarv
Publisher:
Total Pages: 406
Release: 2014
Genre: Columns, Concrete
ISBN:

Longitudinal bar debonding allowed spread of yielding and prevented premature failure of reinforcements in UHPC-filled duct connections and grouted coupler column pedestal. The SMA-reinforced ECC column showed superior seismic performance compared to a conventional column in which the plastic hinge damage was limited to only ECC cover spalling even under 12% drift ratio cycles. The column residual displacements were 79% lower than CIP residual displacements on average due to the superelastic NiTi SMA longitudinal reinforcement, and higher base shear capacity and higher displacement capacity were observed. The analytical modeling methods were simple and sufficiently accurate for general design and analyses of precast components proposed in the present study. The proposed symmetrical material model for reinforcing NiTi superelastic SMA was found to be a viable alternative to the more complex asymmetrical model.

Risk-Based Bridge Engineering

Risk-Based Bridge Engineering
Author: Khaled Mahmoud
Publisher: CRC Press
Total Pages: 320
Release: 2019-08-20
Genre: Technology & Engineering
ISBN: 1000727513

Risk-based engineering is essential for the efficient asset management and safe operation of bridges. A risk-based asset management strategy couples risk management, standard work, reliability-based inspection and structural analysis, and condition-based maintenance to properly apply resources based on process criticality. This ensures that proper controls are put in place and reliability analysis is used to ensure continuous improvement. An effective risk-based management system includes an enterprise asset management or resource solution that properly catalogues asset attribute data, a functional hierarchy, criticality analysis, risk and failure analysis, control plans, reliability analysis and continuous improvement. Such efforts include periodic inspections, condition evaluations and prioritizing repairs accordingly. This book contains select papers that were presented at the 10th New York City Bridge Conference, held on August 26-27, 2019. The volume is a valuable contribution to the state-of-the-art in bridge engineering.

Seismic Performance of Reinforced Concrete Bridges Allowed to Uplift During Multi-Directional Excitation

Seismic Performance of Reinforced Concrete Bridges Allowed to Uplift During Multi-Directional Excitation
Author: Andres Oscar Espinoza
Publisher:
Total Pages: 666
Release: 2011
Genre:
ISBN:

Abstract Seismic Performance of Reinforced Concrete Bridges Allowed to Uplift During Multi-Directional Excitation by Andres Oscar Espinoza Doctor of Philosophy in Engineering - Civil and Environmental Engineering University of California, Berkeley Professor Stephen A. Mahin, Chair The behavior of bridges subjected to recent moderate and large earthquakes has led to bridge design detailed for better seismic performance, particularly through wider bridge foundations to handle larger expected design forces. Foundation uplift, which is not employed in conventional bridge design, has been identified as an important mechanism, in conjunction with structural yielding and soil-structure interaction that may dissipate energy during earthquakes. Preventing uplift through wider foundations looks past the technical and economical feasibility of allowing foundation uplift during seismic events. The research presented in this thesis is part of a larger experimental and analytical investigation to develop and validate design methods for bridge piers on shallow foundations allowed to uplift during seismic events. Several analytical and some experimental studies have been performed to assess rocking and or uplift of shallow foundation systems, however they have evaluated systems with a limited range of footing dimensions and seismic excitations. As such, there is an uncertainty in the information needed to base a performance evaluation and develop design methods. The purpose of this study is to investigate, through experimental and analytical studies, the seismic performance of uplifting bridge piers on shallow foundations when considering different ground motions and footing dimensions. As well as to identify key differences in performance evaluation criteria for conventional and uplifting bridge pier systems. The experimental study dynamically tested a single reinforced concrete bridge column specimen with three adjustable footing configurations grouped by footing dimension, and tested for various combinations of one, two, and three components of seismic excitation. Groups one and two evaluated uplifting systems where the column was limited to elastic loading levels while group three considered inelastic column loading levels. All test groups remained stable and exhibited some rocking and or uplift during testing. Analytical models were developed and validated using the experimental testing results to predict local and global footing and column response. Reliable estimates of forces and displacements during elastic and inelastic response were achieved. To assess the seismic performance of a range of bridge pier systems allowed to uplift a parametric investigation using the validated analytical models was performed in which the column was modeled per conventional design criteria to ensure adequate strength and flexural ductility. The parameters varied include footing width, ground motion excitation, and elastic or inelastic column response. Response of the uplifting bridge pier systems was found to be sensitive to the structural periods, magnitude of excitation, and footing width.

Structural Seismic Design Optimization and Earthquake Engineering: Formulations and Applications

Structural Seismic Design Optimization and Earthquake Engineering: Formulations and Applications
Author: Plevris, Vagelis
Publisher: IGI Global
Total Pages: 456
Release: 2012-05-31
Genre: Technology & Engineering
ISBN: 1466616415

Throughout the past few years, there has been extensive research done on structural design in terms of optimization methods or problem formulation. But, much of this attention has been on the linear elastic structural behavior, under static loading condition. Such a focus has left researchers scratching their heads as it has led to vulnerable structural configurations. What researchers have left out of the equation is the element of seismic loading. It is essential for researchers to take this into account in order to develop earthquake resistant real-world structures. Structural Seismic Design Optimization and Earthquake Engineering: Formulations and Applications focuses on the research around earthquake engineering, in particular, the field of implementation of optimization algorithms in earthquake engineering problems. Topics discussed within this book include, but are not limited to, simulation issues for the accurate prediction of the seismic response of structures, design optimization procedures, soft computing applications, and other important advancements in seismic analysis and design where optimization algorithms can be implemented. Readers will discover that this book provides relevant theoretical frameworks in order to enhance their learning on earthquake engineering as it deals with the latest research findings and their practical implementations, as well as new formulations and solutions.

Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations

Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations
Author: Hiroshi Yokota
Publisher: CRC Press
Total Pages: 8732
Release: 2021-04-20
Genre: Technology & Engineering
ISBN: 100017381X

Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations contains lectures and papers presented at the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), held in Sapporo, Hokkaido, Japan, April 11–15, 2021. This volume consists of a book of extended abstracts and a USB card containing the full papers of 571 contributions presented at IABMAS 2020, including the T.Y. Lin Lecture, 9 Keynote Lectures, and 561 technical papers from 40 countries. The contributions presented at IABMAS 2020 deal with the state of the art as well as emerging concepts and innovative applications related to the main aspects of maintenance, safety, management, life-cycle sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle sustainability, standardization, analytical models, bridge management systems, service life prediction, maintenance and management strategies, structural health monitoring, non-destructive testing and field testing, safety, resilience, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, and application of information and computer technology and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on maintenance, safety, management, life-cycle sustainability and technological innovations of bridges for the purpose of enhancing the welfare of society. The Editors hope that these Proceedings will serve as a valuable reference to all concerned with bridge structure and infrastructure systems, including engineers, researchers, academics and students from all areas of bridge engineering.

Reinforced Concrete Structures

Reinforced Concrete Structures
Author: Robert Park
Publisher: John Wiley & Sons
Total Pages: 794
Release: 1991-01-16
Genre: Technology & Engineering
ISBN: 9780471659174

Sets out basic theory for the behavior of reinforced concrete structural elements and structures in considerable depth. Emphasizes behavior at the ultimate load, and, in particular, aspects of the seismic design of reinforced concrete structures. Based on American practice, but also examines European practice.