Download or read book Effect of Structure Backfill on Stiffness and Capacity of Bridge Abutments written by Azadeh Bozorgzadeh and published by . This book was released on 2007 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge abutments provide resistance to deformation and earthquake induced inertial forces from the bridge superstructure. In order to limit the inertial forces transmitted into the abutment walls and piles, the abutment walls are designed to be sheared off in major seismic events. Therefore, the force-resistance mechanism of bridge abutments in the longitudinal direction is mainly provided by backwall-soil interaction. Current design practice in California makes use of bi-linear load-deformation curve and does not account for the structure backfill properties. An experimental and an analytical research program were conducted at UCSD to further investigate such structure backfill interaction characteristics. In order to meet the objectives of this research project, a field investigation was conducted to develop a proper characterization of the soil types used for abutment structure backfills. The experimental program included five large-scale tests. In the first phase of the experiment, an abutment wall (without a foundation) was built at 50% scale of a prototype diaphragm abutment. The second phase of this research program was performed on a backwall sheared off from wingwalls and stem in seat-type abutments. The specific aims of the experimental program were to examine the effect of structure backfill soil type, backfill height, vertical movement of the wall, and pre-existing cut slope in backfilling on stiffness and capacity of the abutments in the longitudinal direction. An analytical model was developed for evaluating the response of bridge abutments loaded longitudinally. The approach involves calculating maximum passive resistance of the structure backfill material, and creating p-y curves to predict the force-displacement relationship of longitudinally loaded bridge abutments. The finite element program Plaxis 2D was used to model the abutment wall experiments. The procedure was validated by comparing the finite element results with the experimental results. In conclusion, the study indicates that the response of bridge abutments in the longitudinal direction is nonlinear and a function of several factors which need to be considered. The passive resistance of the structure backfill is controlled by the soil shear strength and the interface friction angle. Finally, the vertical movement of the wall has a significant effect on post-peak behavior of abutments.

Download or read book Long Term Behavior of Integral Abutment Bridges written by Robert J. Frosch and published by Joint Transportation Research Program. This book was released on 2011-08-15 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral abutment (IA) construction has become the preferred method over conventional construction for use with typical highway bridges. However, the use of these structures is limited due to state mandated length and skew limitations. To expand their applicability, studies were implemented to define limitations supported by rational analysis rather than simply engineering judgment. Previous research investigations have resulted in larger length limits and an overall better understanding of these structures. However, questions still remain regarding IA behavior; specifically questions regarding long-term behavior and effects of skew. To better define the behavior of these structures, a study was implemented to specifically investigate the long term behavior of IA bridges. First, a field monitoring program was implemented to observe and understand the in-service behavior of three integral abutment bridges. The results of the field investigation were used to develop and calibrate analytical models that adequately capture the long-term behavior. Second, a single-span, quarter-scale integral abutment bridge was constructed and tested to provide insight on the behavior of highly skewed structures. From the acquired knowledge from both the field and laboratory investigations, a parametric analysis was conducted to characterize the effects of a broad range of parameters on the behavior of integral abutment bridges. This study develops an improved understanding of the overall behavior of IA bridges. Based on the results of this study, modified length and skew limitations for integral abutment bridge are proposed. In addition, modeling recommendations and guidelines have been developed to aid designers and facilitate the increased use of integral abutment bridges.

Download or read book Special Topics in Earthquake Geotechnical Engineering written by Mohamed A. Sakr and published by Springer Science & Business Media. This book was released on 2012-03-20 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geotechnical Earthquake Engineering and Soil Dynamics, as well as their interface with Engineering Seismology, Geophysics and Seismology, have all made remarkable progress over the past 15 years, mainly due to the development of instrumented large scale experimental facilities, to the increase in the quantity and quality of recorded earthquake data, to the numerous well-documented case studies from recent strong earthquakes as well as enhanced computer capabilities. One of the major factors contributing to the aforementioned progress is the increasing social need for a safe urban environment, large infrastructures and essential facilities. The main scope of our book is to provide the geotechnical engineers, geologists and seismologists, with the most recent advances and developments in the area of earthquake geotechnical engineering, seismology and soil dynamics.

Download or read book Large Scale Bridge Abutment Tests to Determine Stiffness and Ultimate Strength Under Seismic Loading written by Brian H. Maroney and published by . This book was released on 1995 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flowable Fill as Backfill for Bridge Abutments written by Joe R. Wilson and published by . This book was released on 1999 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Service Limit State Design and Analysis of Engineered Fills for Bridge Support written by Mahsa Khosrojerdi and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineered fills, including compacted granular fill and reinforced soil, are a cost-effective alternative to conventional bridge foundation systems. The Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS) is a fast, sustainable and cost-effective method for bridge support. The in-service performance of this innovative bridge support system is largely evaluated through the vertical and lateral deformations of the GRS abutments and the settlements of reinforced soil foundations (RSF) during their service life. While it is a common assumption that granular or engineered fills do not exhibit secondary deformation, it has been observed in in-service bridge abutment applications and large-scale laboratory tests. Evaluation of the secondary, or post-construction, deformation of engineered fills is therefore also needed. The aim of this study is to analyze and quantify the maximum deformations of GRS abutment and RSF under service loads, evaluate the stress distributions within the engineered fills of the GRS abutment and RSF, and investigate the time-dependent behavior of engineered fills for bridge support. The ultimate goal is to provide accurate yet easy-to-use analysis-based design tools that can be used in the performance assessment of GRS abutments and RSF under service loads. It is anticipated that the research performed within the scope of this dissertation will eventually help promote sustainable and efficient design practice of these structures.The research objective was achieved through development of numerical models that employed finite difference solution scheme and simulated the performance of granular backfill and reinforcement material. The backfill soil was simulated using three different constitutive models. Comparison of the simulation results with case studies showed that the behavior of GRS structures under service loads is accurately predicted by the Plastic Hardening model. The developed models were validated through comparison of model predictions with laboratory and field test data reported in the literature. A comprehensive parametric study was conducted to evaluate the effects of backfill soils properties (friction angle and cohesion), reinforcement characteristics (stiffness, spacing, and length), and structure geometry (abutment height and facing batter and foundation width) on the deformations of GRS abutments and RSF. The results of the parametric study were used to conduct a nonlinear regression analysis to develop equations for predicting the maximum lateral deformation and settlement of GRS abutments and maximum settlement of RSF under service loads. The accuracy of the proposed prediction equations was evaluated based on the results of experimental case studies. The developed prediction equations may contribute to better understanding and enable simple calculations in designing these structures. To investigate the time-dependent deformations of GRS abutment and RSF, a numerical model was developed. The time-dependent deformations are also known as secondary deformations and creep. To model the creep behavior of the backfill material, the Burgers creep viscoplastic model that combines the Burgers model and the Mohr-Coulomb model was used in the simulations. To model the creep behavior of geosynthetics, the model proposed by Karpurapu and Bathurst (1995) was used; this model uses a hyperbolic load-strain function to calculate the stiffness of the reinforcement. Results indicated that engineered fills can exhibit noticeable secondary deformation.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Expanded Polystyrene Flow Fill and Structure Fill for Bridge Abutment Backfill written by Shan-Tai Yeh and published by . This book was released on 1995 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three methods were tested in full-scale highway construction for their effectiveness at reducing the bump at the end of the bridge: expanded polystyrene, flowfill, and structural backfill. Vertical settlement, lateral movement, and soil pressure behind the abutments were monitored during and after construction. Based on findings of this study, flowfill material has the best performance among the three in controlling lateral pressure and movement behind the bridge abutments. Further flowfill shows the least post-construction compression and provides a better ride than the other two materials tested. Based on this study it is recommended that the Colorado Department of Transportation (CDOT) use flowfill for its bridge approaches to mitigate the bump at the end of bridges.

Download or read book Coupled Site and Soil Structure Interaction Effects with Application to Seismic Risk Mitigation written by Tom Schanz and published by Springer Science & Business Media. This book was released on 2009-06-18 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Research Workshop on Coupled Site and Soil-Structure Interaction Effects with Application to Seismic Risk Mitigation Borovets, Bulgaria 30 August - 3 September 2008

Download or read book Analytical Methods in Petroleum Upstream Applications written by Cesar Ovalles and published by CRC Press. This book was released on 2015-04-02 with total page 1351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effective measurement of the composition and properties of petroleum is essential for its exploration, production, and refining; however, new technologies and methodologies are not adequately documented in much of the current literature. Analytical Methods in Petroleum Upstream Applications explores advances in the analytical methods and instrumentation that allow more accurate determination of the components, classes of compounds, properties, and features of petroleum and its fractions. Recognized experts explore a host of topics, including: A petroleum molecular composition continuity model as a context for other analytical measurements A modern modular sampling system for use in the lab or the process area to collect and control samples for subsequent analysis The importance of oil-in-water measurements and monitoring The chemical and physical properties of heavy oils, their fractions, and products from their upgrading Analytical measurements using gas chromatography and nuclear magnetic resonance (NMR) applications Asphaltene and heavy ends analysis Chemometrics and modeling approaches for understanding petroleum composition and properties to improve upstream, midstream, and downstream operations Due to the renaissance of gas and oil production in North America, interest has grown in analytical methods for a wide range of applications. The understanding provided in this text is designed to help chemists, geologists, and chemical and petroleum engineers make more accurate estimates of the crude value to specific refinery configurations, providing insight into optimum development and extraction schemes.

Download or read book Soil Structure Interaction of Integral Abutment Bridges written by Ahmed Abdullah and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral abutment bridges (IABs) are monolithically rigid structures distinguished by eliminating the use of expansion and bearing joints. This leads to enhanced structural performance and reduced maintenance costs. However, the complex soil-structure interactions (SSI) of IABs in response to seasonal variations in ambient temperatures are not yet fully understood. This research aims to use comprehensive numerical models to expand the understanding related to the intricate SSIs of these structures in response to various conditions. The Middlesex bridge in Vermont, USA, was selected as a case study for this research. The thermal response of the bridge was monitored over a period of two years, in which the acting pressures, internal forces, and deformations were measured. The numerical research conducted in this study first involved the development of two- and three-dimensional finite element (FE) models using the software PLAXIS, where the corresponding findings were verified against field acquired measurements for a single case-study bridge. Parametric studies were then conducted to investigate the effects of varying the constitutive soil model, thermal loading, backfill stiffness, abutment stiffness, pile size and orientation, and span length on the resultant earth pressure distributions and pile bending moments. It was found that using a linear constitutive soil model resulted in significant inaccuracies in the results. It was also found that theoretically approximated abutment displacements obtained using the measured temperatures yielded similar results to the field measured deformations. They hence can be used for future performance predictions for climate change studies. The study also revealed that increasing the backfill stiffness was found to increase backfill stresses and decrease pile bending moments. It also showed that varying the abutment stiffness had no impact on the earth pressures and pile bending moments. Smaller pile sections oriented for weak-axis bending yielded smaller pile bending moments and larger earth pressures. Increasing the span length increased backfill stresses and pile bending moments.

Download or read book Numerical Simulations and Shaking Table Tests of Geosynthetic Reinforced Soil Bridge Abutments written by Yewei Zheng and published by . This book was released on 2017 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosynthetic reinforced soil (GRS) bridge abutments are becoming widely used in transportation infrastructure and provide many advantages over traditional pile-supported designs, including lower cost, faster and easier construction, and smoother transition between the bridge and approach roadway. Seismic events represent a severe loading condition and experimental testing and evaluation are needed to understand the potential issues and performance characteristics. This study involves a comprehensive evaluation of the performance of GRS bridge abutments for the service limit state, the strength limit state, and an extreme event limit state (i.e., seismic loading conditions) using both numerical simulations and physical modeling experiments. A numerical model was developed for GRS bridge abutments under service loading conditions and was validated using field measurements. Simulation results indicate that the horizontal restraining forces generated from the bridge structure can have an important effect on reducing lateral facing displacements and bridge seat settlements of GRS bridge abutments. Parametric studies were conducted to investigate the effects of various design parameters on the performance of GRS bridge abutments for service loading conditions, and the results indicate that reinforcement spacing, reinforcement stiffness, bridge load, and abutment height have the most significant effects on the lateral facing displacements and bridge seat settlements. The numerical model was enhanced by incorporating the strain softening behavior for backfill soil and the rate-dependent behavior for geosynthetic reinforcement to simulate the load-deformation behavior of GRS bridge abutments up to failure condition. A linearly elastic reinforcement model can capture the deformation behavior of GRS bridge abutments for service loads, but not for larger applied loads approaching failure. The geometry parameters for GRS bridge abutments have important effects on the internal failure surface of the GRS bridge abutments, and the internal failure surface manifests as a bilinear surface that starts at the heel of the bridge footing, moves vertically downward to mid-height of the GRS bridge abutment, and then linearly to the toe of the GRS bridge abutment. The seismic response of GRS bridge abutments was evaluated using an experimental testing program. Shaking table tests were conducted on six half-scale GRS bridge abutments by application of a series of shaking events in the directions longitudinal and transverse to the bridge beam. Experimental design of the model specimen followed established similitude relationships for shaking table testing of reduced-scale models in a 1g gravitational field, including scaling of model geometry, geosynthetic reinforcement stiffness, backfill soil modulus, bridge load, and characteristics of the earthquake motions. Experimental results indicate that the seismic facing displacements and bridge seat settlements for GRS bridge abutments are small and will likely not have a major effect on the bridge performance. Reinforcement spacing and stiffness have the most important effects on the seismic performance of GRS bridge abutments.

Download or read book Experimental and Analytical Investigation on Stiffness and Ultimate Capacity of Bridge Abutments written by and published by . This book was released on 2008 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridge Maintenance Safety Management Life Cycle Sustainability and Innovations written by Hiroshi Yokota and published by CRC Press. This book was released on 2021-04-20 with total page 8732 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book AASHTO Guide Specifications for LRFD Seismic Bridge Design written by and published by AASHTO. This book was released on 2011 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work offers guidance on bridge design for extreme events induced by human beings. This document provides the designer with information on the response of concrete bridge columns subjected to blast loads as well as blast-resistant design and detailing guidelines and analytical models of blast load distribution. The content of this guideline should be considered in situations where resisting blast loads is deemed warranted by the owner or designer.

Download or read book Development and Implementation of Improved Seismic Design and Retrofit Procedures for Bridge Abutments written by Geoffrey R. Martin and published by . This book was released on 1997 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Analysis of Integral Abutment Bridges Considering Soil Structure Interaction written by Reza Vasheghani Farahani and published by . This book was released on 2010 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral abutment bridges are jointless bridges in which the deck is continuous and connected monolithically with the abutment walls supported typically by a single row of piles. This thesis focuses on the effects of two major parameters on the seismic behavior of an integral abutment bridge in Tennessee by considering soil-structure interaction around the piles and in back of the abutments: (1) clay stiffness (medium vs. hard) around the piles, and (2) level of sand compaction (loose vs. dense) of the abutment wall backfilling. Modal and nonlinear time history analyses are performed on a three dimensional detailed bridge model using the commercial software SAP2000, which clearly show that (1) compacting the backfilling of the abutment wall will increase the bridge dominant longitudinal natural frequency considerably more than increasing the clay stiffness around the piles; (2) the maximum deflection and bending moment in the piles under seismic loading will happen at the pile-abutment interface; (3) under seismic loading, densely-compacted backfilling of the abutment wall is generally recommended since it will reduce the pile deflection, the abutment displacement, the moments in the steel girder, and particularly the pile moments; (4) under seismic loading, when the piles are located in firmer clay, although the pile deflection, the abutment displacement, and the maximum girder moment at the pier and the mid-span will decrease, the maximum pile moment and the maximum girder moment at the abutment will increase.