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Seismic Performance Of Bridge Column Pile Shaft Pin Connections For Application In Accelerated Bridge Construction
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Book Synopsis Seismic Performance of Bridge Column-pile-shaft Pin Connections for Application in Accelerated Bridge Construction by : Mehrdad Mehraein
Download or read book Seismic Performance of Bridge Column-pile-shaft Pin Connections for Application in Accelerated Bridge Construction written by Mehrdad Mehraein and published by . This book was released on 2016 with total page 1468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridges with integral superstructures are common in high-seismic regions. The superstructure and substructure are connected using rigid connections in these bridges. However, hinge or “pin” connections may be used to connect columns to pile-shafts to reduce the overall force demand in the integral bridges, leading to smaller and more economical foundations. Additionally, prefabrication of structural elements facilitates accelerated bridge construction (ABC), which could improve the quality and economy of project compared to cast-in-place (CIP). The primary objectives of this research were to investigate the seismic performance of three types of bridge bent connections: (1) pipe-pin connections at column-pile shaft joints for CIP and precast constructions (2) rebar-pin connections at column-pile shaft joint for CIP and precast constructions, and (3) pocket connections to develop rigid joints between precast columns and precast pier caps. This research was comprised of experimental and analytical studies. The experimental portion of the study was conducted on a shake table at the Earthquake Engineering Laboratory at the University of Nevada, Reno including two 1/3.75 scale, two-column bents subjected to seismic loadings. The cap beam in each bent was precast and connected to the columns using pocket details. The pin connections were used to connect the columns to pedestals, which simulated the pile-shafts. The column-pedestal joints were formed using pipe-pins in one bent and rebar-pin in the other bent. The available details of pin connections were modified for utilizing in the bents because the tensile force transfer mechanism and pile-shaft failure modes had not been accounted for in the current practices. A proposed ABC method for pin connections was investigated by constructing one column in each bent as a precast shell filled with self-consolidating concrete (SCC), whereas the other column was CIP. Furthermore, engineered cementitious composite (ECC) was incorporated in one column plastic hinge region of each bent to explore the effects of ECC on the seismic performance of the columns. The shake table experiments confirmed that the proposed design methods meet the safety and performance requirements of the codes under seismic loadings. The analytical studies consisted of: (1) simple stick models for the pin connections that were developed for the bents as design tools, (2) nonlinear finite element (FE) models for the pin connections in OpenSEES that can be utilized for global analysis of bridges with pin connections, and (3) elaborate nonlinear FE models of the bent with pipe-pins using ABAQUS to investigate the microscopic performance and interactions of the components. The analytical models were evaluated based on their correlation with experimental data and were subsequently used in focused parametric studies to address the gaps in the experimental results and provide more insight into the pin behavior under various conditions. Lastly, design procedures and detailing recommendations for column-pile-shaft connections using pipe-pins and rebar-pins were developed and proposed based on the results of the experimental and analytical parametric studies.
Book Synopsis Application of Accelerated Bridge Construction Connections in Moderate-to-High Seismic Regions by :
Download or read book Application of Accelerated Bridge Construction Connections in Moderate-to-High Seismic Regions written by and published by Transportation Research Board. This book was released on 2011 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB’s National Cooperative Highway Research Program (NCHRP) Report 698: Application of Accelerated Bridge Construction Connections in Moderate-to-High Seismic Regions evaluates the performance of connection details for bridge members in accelerated bridge construction in medium-to-high seismic regions and offers suggestions for further research.
Book Synopsis Drilled Shaft Socket Connections for Precast Columns in Seismic Regions by : Hung Viet Tran
Download or read book Drilled Shaft Socket Connections for Precast Columns in Seismic Regions written by Hung Viet Tran and published by . This book was released on 2015 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new type of connection between a precast concrete column and a drilled shaft has been developed for Accelerated Bridge Construction (ABC) in regions of moderate or high seismicity. This connection can be built quickly and allows generous placement tolerances. Three quasi-static tests of connections between a precast bridge column and a drilled shaft were performed (1) to investigate the seismic performance of this connection, and (2) to calibrate a new design methodology. The test specimens represented the most critical geometry in which the difference between the diameters of the shaft and column was minimized. Large-scale, lateral-load tests to a drift ratio of 10% showed that, if adequate confining steel is included in the splice zone, the plastic hinging mechanism forms in the column, without inducing damage in the splice or shaft. If the confinement is insufficient, the strength of the splice zone deteriorates rapidly with cyclic loading. A new design methodology, based on a strut-and-tie model of the transition region, allows the designer to proportion the connection to limit the strains in the connection transverse reinforcement.
Book Synopsis Experimental and Analytical Seismic Studies of Bridge Piers with Innovative Pipe Pin Column-footing Connections and Precast Cap Beams by : Ali Mehrsoroush
Download or read book Experimental and Analytical Seismic Studies of Bridge Piers with Innovative Pipe Pin Column-footing Connections and Precast Cap Beams written by Ali Mehrsoroush and published by . This book was released on 2014 with total page 1518 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones by : Mostafa Tazarv
Download or read book Next Generation of Bridge Columns for Accelerated Bridge Construction in High Seismic Zones written by Mostafa Tazarv and published by . This book was released on 2014 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Development of Earthquake-resistant Precast Pier Systems for Accelerated Bridge Construction in Nevada by :
Download or read book Development of Earthquake-resistant Precast Pier Systems for Accelerated Bridge Construction in Nevada written by and published by . This book was released on 2017 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Precast Column-footing Connections for Accelerated Bridge Construction in Seismic Zones by : Zachary Benjamin Haber
Download or read book Precast Column-footing Connections for Accelerated Bridge Construction in Seismic Zones written by Zachary Benjamin Haber and published by . This book was released on 2013 with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerated bridge construction (ABC) has become increasingly popular in the eyes of state and federal transportation agencies because of its numerous advantages. To effectively execute ABC projects, designers utilize prefabricated structural elements that can be quickly assembled to form functional structural systems. It is advantageous to the bridge designer if these systems emulate the design and behavior of conventional cast-in-place systems. If this can be achieved, typical analysis and design procedures can be used. The difficulty with developing emulative systems is usually encountered in the design and detailing of connections. Substructure connections are particularly critical in seismic zones because they must dissipate energy through significant cyclic nonlinear deformations while maintaining their capacity and the integrity of the structural system. The research presented in this dissertation focused on developing and evaluating earthquake resistant connections for use in accelerated bridge construction. The project was comprised of three main components; testing of five large-scale precast reinforced concrete column models, a series of individual component tests on mechanical reinforcing bar splices, and extensive analytical studies. Column studies included the design and construction of five half-scale bridge column models that were tested under reversed slow cyclic loading. Four new moment connections for precast column-footing joints were developed each utilizing mechanical reinforcing bar splices to create connectivity with reinforcing bars in a cast-in-place footing. Two different mechanical splices were studied: an upset headed coupler and grout-filled sleeve coupler. Along with the splice type, the location of splices within the plastic hinge zone was also a test variable. All column models were designed to emulate conventional cast-in-place construction thus were compared to a conventional cast-in-place test model. Results indicate that the new connections are promising and duplicate the behavior of conventional cast-in-place construction with respect to key response parameters. However, it was discovered that the plastic hinge mechanism can be significantly affected by the presence of splices and result in reduced displacement ductility capacity. In order to better understand the behavior of mechanical splices, a series of uniaxial tests were completed on mechanically-spliced reinforcing bars under different loading configurations: monotonic static tension, dynamic tension, and slow cyclic loading. Results from this portion of the project also aided the development of analytical models for the half- and prototype-scale column models. Results indicated that, regardless of loading configuration, specimens failed by bar rupture without damage to the splice itself. The analytical studies conducted using OpenSEES included development of microscope models for the two mechanical reinforcing bars splices and full analytical models of the five half-scale columns, which were both compared with respective experimental results to validate the modeling procedures and assumptions. Prototype-scale analytical models were also developed to conduct parametric studies investigating the sensitivity of the newly developed ABC connections to changes in design details. In general, the results of this study indicate that the newly develop ABC connections, which utilize mechanically-spliced connections, are suitable for moderate and high seismic regions. However, emulative design approaches are not suitable for all of the connections develop. A set of design recommendations are provided to guide bridge engineers in the analysis and design of these new connections.
Download or read book NCHRP Report 698 written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Seismic Performance of Column-to-drilled-shaft Connections in Reinforced Concrete Bridges by : Michelle Teng Chang
Download or read book Seismic Performance of Column-to-drilled-shaft Connections in Reinforced Concrete Bridges written by Michelle Teng Chang and published by . This book was released on 2021 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drilled shaft foundations are often used to support reinforced concrete bridge columns founded in soft soils or in locations where a small footprint is desired. Increasingly, the shaft is being built with a diameter larger than that of the column, to allow tolerance in the column placement and to facilitate plastic hinge formation in the column rather than in the shaft. The column-shaft connection, which involves a noncontact splice between the column and shaft bars, is a key component in this structural system. However, there is limited research on the behavior of these connections under seismic loads. In order to understand the force-transfer mechanism of column-shaft connections under seismic loading, one quasi-static cyclic experimental test was conducted on a column-shaft subassembly. Measured results were compared with those from three previous experiments performed at the University of Washington. The study found that the amount of shaft transverse reinforcement in the connection region was critical in determining the failure mode of the connection. In specimens with relatively low amounts of transverse reinforcement, including the specimen tested during this study and a previous specimen tested at the University of Washington, the connection failed through a shaft prying failure mode; the specimens developed large vertical cracks between the confined column core and the annular shaft transition region, and the shaft transverse reinforcement eventually fractured at large drift ratios. Therefore, three methodologies for detailing the shaft transverse reinforcement were evaluated, and a new analysis procedure using a strut-and-tie model was proposed. It is consistent with the measured and observed performance of the tested connections, and is applicable to shafts supporting either precast or cast-in-place columns. The new procedure allows engineers to more accurately predict the behavior of a column-shaft connection and prevent an undesirable below-ground failure in the shaft transition region. Lastly, a set of design equations based on the strut-and-tie findings and existing design models is proposed for use in practice.
Book Synopsis Seismic Performance of Precast Girder-to-cap Connections for Accelerated Bridge Construction of Integral Bridges by : Justin Vander Werff
Download or read book Seismic Performance of Precast Girder-to-cap Connections for Accelerated Bridge Construction of Integral Bridges written by Justin Vander Werff and published by . This book was released on 2015 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Simplifying Cast-in-place Joint Design Using ABC Pocket Connection Details in High Seismic Regions by :
Download or read book Simplifying Cast-in-place Joint Design Using ABC Pocket Connection Details in High Seismic Regions written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerated bridge construction (ABC) utilizes precast members to minimize on-site construction time, making it an appealing alternative to conventional cast-in-place (CIP) construction. The connections between these precast members are crucial as they must maintain structural integrity, and in regions of moderate and high seismic activity, ensure the ductile behavior of bridge columns. Recent research has demonstrated that pocket/socket connections meet these requirements while simplifying the construction of joints. Pocket connections allow precast members to be inserted into adjacent members. To form a pocket connection between a column and cap beam, the longitudinal reinforcement in the cap beam must be bundled outside the pocket to allow the precast column to extend into the pocket uninhibited. Earthquake-resistant CIP column-cap beam joints are difficult to construct because the column reinforcement must be threaded through the reinforcement of the cap beam. Additional reinforcement is also necessary within the joint, which can lead to rebar congestion. The primary goal of this study was to adapt ABC pocket connection details for use in CIP column-cap beam joint construction to avoid steel congestion and simplify construction. To achieve this goal, a CIP emulating ABC pocket connection detail was developed, implemented in a large-scale test model, and evaluated under seismic loading on a shake table. Summary design recommendations for the connection based on the results of the shake table testing were then developed. This project consisted of an experimental study, analytical studies, and development of detailing recommendations. The experimental study involved shake table testing of a 1/3 scale CIP model of a column and cap beam which incorporated a novel CIP pocket connection. The specimen was subjected to multiple runs of simulated, scaled versions of the 1994 Northridge earthquake event recorded at the Sylmar Converter Station. Results from the experimental study showed the column reached a drift ratio of 7.8 percent, and the connection was effective in forming the plastic hinge in the column while keeping the joint and cap beam free of damage. The cap beam behaved as a capacity-protected member and met the seismic performance objective of both CIP and ABC bridges. Analytical models were developed before testing to estimate the response of the specimen. After testing, the models were refined, and the calculated results were compared with the measured results. These studies revealed that relatively simple analytical models could estimate the global response of the specimen under dynamic loading with reasonable accuracy. Finally, design recommendations for CIP pocket column-cap beam connections emulating ABC were developed based on the performance of joint reinforcement during the testing.
Book Synopsis Seismic Performance of Precast Girder-to-cap Connections for Accelerated Bridge Construction of Integral Bridges by : Justin Vander Werff
Download or read book Seismic Performance of Precast Girder-to-cap Connections for Accelerated Bridge Construction of Integral Bridges written by Justin Vander Werff and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Rocking Connection Between a Precast Bridge Column and Cap Beam by : Bryan Kennedy
Download or read book Rocking Connection Between a Precast Bridge Column and Cap Beam written by Bryan Kennedy and published by . This book was released on 2015 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional cast-in-place, concrete bridge construction is often a lengthy undertaking, which is burdensome to the motoring public because of the traffic delays that it causes. Precast construction can accelerate the process by moving fabrication offsite, and then rapidly erecting and connecting bridge components onsite. However, designing connections that are both easy to complete and are robust under seismic loading is challenging. This thesis describes a connection that is intended to meet those criteria, and builds on previous work to do so. Experimental, precast, pre-tensioned specimens developed by Davis et al. (2012) showed good seismic performance, but had significant damage at low drift levels. Adding experimental, ductile materials resulted in less structural damage (Finnsson, 2013), but required unconventional construction materials and awkward fabrication. A new precast, pre-tensioned, column-to-cap beam connection has been developed. The design utilizes (1) unbonded prestressing strands to help the column re-center, (2) bonded reinforcing bars to dissipate energy, (3) a baseplate to permit rigid-body, rocking behavior of the column, and (4) a steel tube to confine the column concrete at the rocking interface. The strands are pre-tensioned when the column is cast, so the connection can be completed without any onsite stressing operations. The connection's seismic performance was evaluated with pseudo-static, cyclic testing of one subassembly. The test results showed that the specimen was stiff at low loads, re-centered well, dissipated energy, and was ductile and durable. Damage to the concrete was negligible and the peak moment strength was measured at drifts exceeding 10%. The system offers a method for achieving accelerated bridge construction that also provides excellent seismic performance and uses only conventional construction materials.
Book Synopsis Column and Footing Pocket Connections for Cast-in-place and Precast Construction by :
Download or read book Column and Footing Pocket Connections for Cast-in-place and Precast Construction written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerated bridge construction (ABC) may be preferable to conventional cast-in-place (CIP) construction because it can significantly expedite project delivery. The design of precast member connections is critical as the connections must maintain structural integrity and provide for ductile behavior under strong earthquakes. Pocket/socket connections are a type of ABC connection that eliminates the need to thread bars through the column cage which can be time consuming and cause rebar congestion. The primary goal of this study was to evaluate the performance and viability of a CIP column-cap joint that was detailed similar to ABC pocket/socket connections to reduce steel congestion. Another objective of the study was to explore the use of superelastic Copper-Aluminum-Manganese (CAM) shape memory alloy (SMA) bars at two-column base hinges. Superelastic SMA bars are known to have reduced permanent deformation of concrete bridges under seismic loads. To achieve the primary goal of the study, a CIP emulating ABC pocket connection design was developed and implemented in a 0.33-scale test model. The test model was a two-column bent, wherein one of the column-cap connections utilized the novel CIP pocket connection and the other utilized a traditional ABC pocket connection. Both connections were designed identically according to existing guidelines for ABC pocket connections. Auxiliary transverse cap beam reinforcement was placed around the connections to reduce joints stresses and address prying forces. The secondary objective of the study was achieved by implementing two-way hinges reinforced with CAM bars at the base of both columns. The test specimen was instrumented with strain gauges, displacement transducers, accelerometers, and cameras to measure local and global responses. The experimental study involved shake table testing of the test bent subjected to multiple runs of simulated, scaled versions of the 1940 Imperial Valley El Centro record. The bent reached a drift ratio of 11.2 percent, yet the connections were effective in forming the plastic hinge in the columns while the joints remained damage-free. Capacity-protected behavior was also observed in the cap beam for both connections as the cap beam reinforcement around the connection remained elastic. The CAM reinforced two-way hinges maintained the integrity of the column bases with substantial yielding and energy dissipation. Post-test analytical studies of the bent were conducted by using actual material properties and shake table motions. Comparison of the calculated and measured results showed that a relatively routine OpenSees model can be used to obtain an approximate response for moderate and strong earthquakes of up to approximately twice the design earthquake. Finally, the design of CIP pocket connections emulating ABC was evaluated in light of the measured seismic performance of the bent.
Book Synopsis Seismic Design of Pipe-pin Connections in Concrete Bridges by : Arash Esmaili Zaghi
Download or read book Seismic Design of Pipe-pin Connections in Concrete Bridges written by Arash Esmaili Zaghi and published by . This book was released on 2010 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Telescopic pipe-pin two-way hinges are used in concrete bridges to eliminate moments while transferring shear and axial loads from integral bridge bent caps to reinforced concrete columns. The hinges consist of a steel pipe that is anchored in column with a protruded segment that extends into the bent cap. In the absence of experimental and analytical studies, design of pipe-pin hinges has been based on pure shear capacity of the steel pipe. The primary objective of this research was two folds: (1) to investigate the seismic performance of the current detail of pipe-pin hinges and propose necessary modifications and (2) to develop a reliable design method for pipe-pin hinges that reflects their actual behavior. This research was comprised of comprehensive experimental and analytical studies of pipe-pin connections and their components including a shake table study of a two-column pier model. The experimental component of the study included three sets of test models: (1) six push-off specimens to evaluate the bearing strength of concrete against the steel pipe, (2) six pure shear specimens to determine the yielding and ultimate shear capacities, and (3) a two-column 0.2-scale bridge pier model incorporating pipe-pin hinges that were designed based on the proposed guideline. The pier model was used to evaluate the new design method under earthquake excitation. The experiments showed that the lateral failure mechanism is typically controlled by concrete diagonal tensile cracking of the column in combination with flexural yielding of the steel pipe as opposed to pure shear, although the pure shear failure mode should be considered when a large amount of lateral steel is used in the column. Another possible mode of failure is bearing failure of the concrete around the pipe in heavily reinforced columns. The shake table experiment of the pier model confirmed that the proposed design method meets the safety and performance requirements under seismic loading. The analytical studies consisted of (1) a stick model in SAP2000 that was developed for pipe shear key subassemblies, (2) detailed nonlinear FE models using ABAQUS that were used to performed an extensive parametric study in order to shed light on different aspects of the behavior and generate the required data for the design guideline, and (3) a model in OpenSees that utilized a macro model for the pipe-pin hinges. The experimental and analytical results helped identify the means to improve the performance of current pipe-pin hinge details. The pipe studs and spiral around the can proved to be unnecessary and were eliminated in the proposed standard detail. A thicker tapered hinge throat was suggested to solve the problem of local concrete damage to the throat and column edges. As a possible extension of pipe-pin application, a study was conducted on pipe-pins combined with isolation and damping systems. The analytical modeling of these details showed that modified connections can reduce the demands on the structure by dissipating a major portion of the earthquake energy.
Book Synopsis Seismic Performance of Precast Full-depth Decks in Accelerated Bridge Construction by : Grishma Shrestha
Download or read book Seismic Performance of Precast Full-depth Decks in Accelerated Bridge Construction written by Grishma Shrestha and published by . This book was released on 2018 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Repair and Testing of Out-of-Plane Seismic Response of Pocket Connection by :
Download or read book Repair and Testing of Out-of-Plane Seismic Response of Pocket Connection written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accelerated bridge construction (ABC) has been utilized in precast bridge structures because of its advantage to expedite onsite construction. In ABC, one of the main concerns is the joint connection as it needs to be well designed to maintain structural integrity. Several studies were able to demonstrate the effectiveness of ABC pocket connections for partial and fully precast columns. The pocket connections are designed to have the cap beam longitudinal reinforcements bundled outside the joint allowing the placement of the column uninhibited. On the contrary, this has been an issue for cast-in-place (CIP) construction where congestion of the reinforcements in the joint regions is typical. A recent study at the University of Nevada, Reno (UNR) was conducted by utilizing ABC pocket connection in CIP bridges. The specimen was tested at UNR Earthquake Engineering Laboratory on a shake table in an upside-down configuration using an increasing scaled ground motion. The specimen performed well under out-of-plane ground motion excitations and the ductility of the column was confirmed through typical plastic hinge behavior. In this study, the main objective is to further use the specimen from the recent UNR test to repair the damaged column and to test the repaired specimen using the same loading protocol as the original model. The objective was achieved by developing a repair method using flush cutting and coring of the damaged column. A new column was constructed using the exact reinforcements as the original model. However, the column was cast monolithically in the pocket joint as opposed to the original model where the column reinforcement sat in two different concrete casts with a cold joint at the column-cap beam interface. The repaired column was subjected to the same loading protocol as the original model using the scaled 1994 Northridge earthquake ground motion recorded at the Sylmar Converter Station. The repaired specimen performed well as the plastic hinge zone developed in the column outside the joint, close to the interface of the cap beam, as desired and required by design. The results were compared to the original specimen and the maximum drift ratio for 20% through 450% of the earthquake motion was relatively equal. However, for 550% and 650% of the earthquake motions, the drift ratio in the repaired specimen was significantly larger compared to the original specimen. The high drift ratios were attributed to the slippage of the column in the joint and were validated by an increase in the ratios between the rotations of the original and repaired column recorded at the base. The cap beam remained essentially elastic, i.e. capacity-protected as required, throughout the test which is similar to the performance of the original model. Lastly, recommendations for the repair of CIP cap beam-column emulating ABC pocket connection are provided with special attention to roughen the pocket joint connection to develop a sufficient bond between the two members.
