Energy Dissipation Bars Research Articles

Innovative Methods to Improve the Seismic Performance of Precast Segmental and Hybrid Bridge Columns under Cyclic Loading

This paper investigates the seismic performance of prefabricated segmental bridge columns (PSBCs) with hybrid post-tensioned tendons and energy dissipation (ED) bars under cyclic loading. PSBCs with unbonded and hybrid bonded prestressed tendons and columns incorporating ED bars are designed to improve the lateral strength, energy dissipation, and limit the residual drift. The PSBCs under cyclic loading were investigated using the three-dimensional finite element (FE) modeling platform ABAQUS. The FE model was calibrated against experimental results, with an overall error of less than 10%. The seismic performance of the proposed PSBCs was evaluated based on critical parameters, including lateral strength, residual plastic displacement, and the energy dissipation capacity. The results show that bonding the tendons in the plastic hinge region as opposed to the overall bonding along the column leads to a better cyclic performance. The lateral strength, and recentering abilities are further improved by bonding tendons up to 2/3 of the length in the plastic hinge region, along with 100–300 mm in the footing. It was also found that selecting a longitudinal length of ED bars crossing multiple precast segmental joints and having a circumferential spread of 70–90% of core concrete results in a higher bearing capacity and energy dissipation compared to ED bars crossing the single joint.

Structural design of self-centering socket precast post-tensioned segmental (SSPPS) bridge piers reinforced with BFRP tendons and stainless energy dissipation bars

In order to solve the construction and seismic problems of the existing precast pier connection methods, a self-centering socket precast post-tensioned segmental (SSPPS) bridge pier reinforced with basalt fiber reinforced polymer (BFRP) tendons and stainless energy dissipation (ED) bars is proposed. A detailed finite-element (FE) model is developed, validated with experimental results, and a parametric analysis of SSPPS is carried out. The bending performance, shear performance, anti-opening and closing and anti-overturning performance of the SSPPS pier are assessed through the simplified mechanical analysis. The findings demonstrate the SSPPS bridge pier is distinguished by its convenient construction and remarkable post-earthquake self-centering performance.

Seismic behavior of precast segmental bridge columns confined by grouted glass fiber reinforced plastic tubes

The application of precast segmental bridge columns (PSBCs) is still restricted in seismicity areas due to concerns such as lower lateral stiffness and column base bearing capacity. To enhance the applicability of PSBCs, this study proposed a novel approach of confining them with grouted GFRP tubes. Four novel and one reference specimens were tested under low cyclic loading to evaluate the effects of energy dissipation (ED) bars ratios, concrete interlayer strength, type of segment concrete, and concrete pouring methods within the outer GFRP tube (OGT) on the seismic behavior. Experimental results reveal that the failure modes of all specimens were triggered by the yielding of ED bars and the break of OGT at the top of ED bars. No crushed concrete at column bases or cracks at the segment joint were observed during the test due to the good confinement of GFRP tubes. All the specimens exhibited stable hysteretic behavior with small residual drift ratios and low strength degradation. Furthermore, finite element models (FEMs) were generated to predict the hysteretic behavior of novel specimens. The effects of some parameters such as OGT thickness, ED bars diameter, and concrete strength were further studied.

Self-Centering Precast Unit as Energy Dissipation Members in Precast Segmental Bridge Columns

This research aims to present a new generation of seismic-resisting systems designed for precast reinforced concrete (RC) bridge piers in modern sustainable cities to withstand moderate to high seismic activity. The proposed system consists of two self-centering (SC) systems operating in parallel to bring together all features of the required resiliency during a seismic action. The first/main system is a hollow core precast segmental bridge column, and the second is composed of an SC precast unit and energy dissipation (ED) steel reinforcements positioned in the main pier segment’s hollow core. To study the performance of the proposed system, a finite element model was first developed to capture the behavior of experimentally tested precast bridge columns. After validation, the created model was systematically studied to investigate the performance of the entire proposed system under cyclic loading. The effects of three parameters related to the ED system were investigated, including the reinforcement ratio, the unbonded length of ED bars, and the SC post-tensioned force ratio. Furthermore, the impact of FRP wrapping on the lower part of the core column of the ED system was also investigated. An analytical model predicting the characteristic points of the lateral response of the proposed system based on the superposition concept is also proposed. The FE results showed that the entire proposed system is a new design-based resilient system with the ability to dissipate energy without compromising the SC capacity of the main resisting system. Compared to the typical precast hollow core segmental column, a 6% reinforcement ratio of the ED unit can cause a 60% increase in lateral resistance and a 220% increase in the ED capacity. The analytical model can successfully be applied in the design of the proposed system to provide customized ED capabilities and controlled lateral resistance.

Segments arrangement effect on improvement of self‐centering precast post‐tensioned segmental piers seismic performance

AbstractIn bridge engineering, the use of precast post‐tensioned segmental (PPS) piers is increasingly expanding due to the Accelerated Bridge Construction viewpoint. Recent experimental and numerical researches have studied general seismic performance and nonlinear behavior of PPS piers without much attention to segment arrangements or joint openings. The aim of this paper is to utilize innovative segment arrangements to reduce the residual deformation, without reducing the energy dissipation capacity of PPS piers with internal energy dissipation (ED) bars. For this purpose, nonlinear rocking dynamics of a multiple‐block assembly of tied rigid rocking blocks equipped with ED bars at joints are firstly developed so that uplift moment for each joint is derived to obtain the threshold joint opening height (height above which no joint opens). Then, nonlinear static, quasi‐static, and dynamic analyses are conducted on different segment arrangements of finite element models of PPS piers. It is proposed to place more segments within the threshold joint opening height by using unequal segments so that the total rotation is shared among critical joints (joints that open), and the nonlinear extent of ED bars at the bottom joint is reduced, resulting in the reduced residual deformation. It is also proposed to place a lower ratio of ED bars at the critical intermediate joints or place ED bars of a lower yield stress there so that the intermediate joints can be more effective even with small rotations. Results indicate that using the proposed segment arrangement, enhances both seismic and post‐earthquake performance of PPS piers.

Cyclic loading test of self-centering precast segmental concrete high-speed railway bridge columns with UHPC-filled duct connections

Precast concrete high-speed railway (HSR) bridge columns are attractive for standardized HSR bridges, but their applications are rare partly due to a research gap in their lateral behavior. Traditional under-reinforced HSR bridge columns have huge lateral stiffness and poor drift capacity, which means that their prefabrication is not a simple separation-assembly process and requires special research. This study aims to develop a novel self-centering precast segmental concrete (SPSC) HSR bridge column, which is designed to have five major improvements including adopting large-diameter deformed bars as energy dissipation (ED) bars, inter-locking multi-hoops, unbonded post-tensioning (PT) tendons, a cast-in-situ ultra-high performance concrete (UHPC) layer at the bottom joint, and UHPC-filled duct connections. A 1/6 scaled cyclic loading test was conducted on three specimens to validate prefabrication feasibility and assess seismic behavior. The research results show that inter-locking multi-hoops can enable the developed bridge columns to have ductile flexural failure and a drift capacity of up to 5 %. The bridge columns have increased lateral stiffness and strength as well as decreased ductility. UHPC-filled duct connections can cause the strain amplification of ED bars at the bottom joint. The bottom joint opening dominates lateral deformation while the influence of joint sliding can be neglected. The bridge columns have good ED capacity and the equivalent hysteretic damping ratio of about 20 % at the drift ratio of 5 %. The bridge columns have the excellent self-centering capacity to control residual drift ratio in an allowable range before flexural failure. The acceptable drift ratios are suggested to be 3.5 % and 4.0 %, respectively, for the SPSC HSR bridge columns without and with PT force.

Performance of a seismic-resilient precast segmental column with UHPC segments and CFRP tendon

Precast segmental column has attracted a lot of research interests in recent years due to its numerous advantages. This study proposed a new seismic resilient precast segmental column with damage controllable and repairable designs. The special designs limited the damages of the column within a pre-determined plastic hinge region while keeping the other parts of the column damage-free. Also, internal energy dissipation (ED) bars were made to be replaceable so as to achieve quick post-earthquake retrofitting. UHPC was used in the damage-free parts to prevent these parts from damage. In addition, to address the potential corrosion problem of the unbonded steel tendons, CFRP tendons were used instead of steel tendons. One precast segmental column with traditional designs was also tested as a reference. Based on the cyclic test, it was found that the proposed new specimen had comparable performance to the reference column. The damages of the proposed column were limited in the pre-determined plastic hinge region. After replacing the ED bars and casting the concrete in the plastic hinge region, the seismic resilient column was tested again and it showed satisfying seismic performance. The test results demonstrated that the proposed seismic resilient designs in this study were feasible and could be used in earthquake-prone regions to keep the precast segmental column functionally restorable even after strong earthquakes.

Research on seismic absorption of high-speed railway segmental assembled round-end hollow pier with low yield point steel connection buckle

The research aims to enhance the seismic safety of the segmental assembled round end hollow pier (SAREHP) of high-speed railway in high intensity seismic regions and ensure the repairability of the pier after earthquake. A low yield point steel connection buckle (LYPSCB), which is easy to be installed and to be replaced after earthquake damage, was proposed as a new seismic absorption measure for the pier, and the seismic absorption effect of the LYPSCB was deeply studied. Firstly, the nonlinear numerical model of the SAREHP with energy dissipation bar (SAREHP-EDB) was established according to the pseudo-static test results of the pier completed. Based on the numerical model of the SAREHP-EDB, the SAREHP with the LYPSCB (SAREHP-LYPSCB) was established and corrected. Subsequently, the influence of the LYPSCB on the hysteretic behavior of the SAREHP was studied, and the hysteretic behavior of the SAREHP-LYPSCB was comprehensively compared with a reference to the SAREHP-EDB. Furthermore, considering the far-field seismic wave and the near-field seismic wave with or without pulse, the seismic absorption effect of the LYPSCB was revealed through dynamic time history analysis method. The research results indicated that, by increasing the section contribution rate of the LYPSCB, the horizontal resistance, loading and unloading stiffness as well as energy dissipation capacity of the SAREHP-LYPSCB are significantly improved. However, the residual displacement of the pier is also indirectly increased. Therefore, it is suggested that the section contribution rate of the LYPSCB is controlled and designed in combination with the seismic target displacement and self-centering capacity demand of pier. The hysteretic behavior of the SAREHP-LYPSCB is better than that of the SAREHP-EDB, which indicated that the LYPSCB possesses better seismic absorption effect. Note that the seismic absorption effect of the LYPSCB is more obvious in resisting strong earthquake, in which the seismic absorption rate can reach 80 %. The near-field pulse seismic wave has the greatest impact on the seismic response of the SAREHP-LYPSCB compared with other types of seismic wave, which should be paid special attention.

Single-side yielding precast concrete slotted beam-column connection with replaceable energy dissipation bars: Experimental investigation and finite element analysis

A new type of rebar coupler, non-slipping combined threaded sleeve (NCTS), is proposed, and based on this, replaceable energy dissipation (ED) connector is assembled. An innovative single-side yielding slotted beam-column connection with replaceable ED bars (SYSC-REDB) was developed by placing the ED connector in the beam end bottom of prefabricated concrete frame. Four quasi-static tests were conducted to evaluate the seismic behavior, such as the damage distribution, failure characteristics, hysteretic response, ED capacity, and deformation pattern. The hysteretic curves were stable and full without pinching, indicating excellent seismic performance. The deformation pattern of single-side yielding can enhance the ED capacity of connectors, concentrate damage and failure on the ED bars, and significantly reduce the deformation of the top beam and beam elongation. The joint could be repaired by replacing the ED bars via the inner space of the NCTS. The seismic behavior of the repaired specimens was similar to those of the original specimens. In addition, the finite element models of ED connector and SYSC-REDB joint were established by ABAQUS respectively, and their accuracy were verified by comparing with the test phenomena and results. Furthermore, parametric finite element analysis was executed for some key factors, including the top-hinge area depth, ED bar area, and top longitudinal reinforcement bar area. Theoretical and parametric study of bending moment capacity is also performed.

Parametric experimental investigation of unbonded post‐tensioned reinforced concrete bridge piers under cyclic loading

AbstractThe present paper investigates the cyclic performance of unbonded post‐tensioned reinforced concrete (PRC) rocking piers by a parametric experimental campaign. PRC rocking specimens are assembled by hybrid connections, containing an ungrouted post‐tensioned (PT) bar and grouted mild steel bars, that is, energy‐dissipation (ED) components. The properties of a benchmark PRC pier were defined according to a design procedure to control its strength, ductility, energy dissipation capacity, and self‐centering behavior. Five additional PRC piers with different ED bars amounts, initial PT force, and ED bars unbonded lengths were also tested to investigate the influence of these parameters on the cyclic performance. The test results show the superior cyclic performance of the PRC pier in limiting both damage and residual deformations. The parametric analysis highlighted that decreasing the initial PT force and/or ED bars amount enhances the PRC's ED capacity at the expense of the lateral force resistance and self‐centering behavior. Moreover, it has been observed that the influence of ED bars’ unbonded length only minimally affects the PRC pier's cyclic performance due to ED bars’ bond‐slip and concrete cover spalling of the pier shaft. Analytical models describing the PRC piers’ lateral force‐drift cyclic behavior were formulated and calibrated, showing a good agreement with test results for all specimens. The results and findings provide a valuable reference and solution for tailoring an efficient parameter recommendation of PRC rocking piers.

Numerical studies on the seismic responses of precast segmental columns-supported bridge structures subjected to near-fault ground motions

Precast segmental columns have attracted wide attentions in bridge construction industry recently due to its ability to accelerate construction speed, improve construction quality and reduce environmental impact. It is of great practical importance to study the seismic performances of segmental columns, and many experimental and numerical studies have been performed. However, most previous studies focused on segmental column itself, the research on the seismic performance of a whole bridge structure supported by precast segmental columns is very limited. In particular, no systematic studies have been performed to investigate the seismic performances of segmental columns-supported bridges subjected to near-fault (N-F) ground motions (GMs). To bridge this research gap, the seismic responses of three bridge structures (i.e. a segmental columns-supported bridge, a bridge supported by segmental columns with internal energy dissipation bars, and a conventional bridge supported by monolithic columns) subjected to four types of earthquake ground motions (i.e. a N-F GM with fling-step (F-S) effect, a N-F GM with forward-directivity (F-D) effect, a non-pulse-like N-F GM, and a typical far-field (F-F) GM are investigated and compared in the present study based on the validated numerical models developed in ABAQUS. The influences of permanent ground displacement in the F-S ground motion and pulse period are also systematically investigated. The numerical results demonstrate that the permanent ground displacement in the N-F ground motions has very different effects on the segmental-columns supported bridge and monolithic columns supported bridge.

Experimental investigation on hysteretic performance and deformation patterns of single-side yielding precast concrete beam–column connection with energy dissipation bars

With the aim of achieving high construction efficiency, satisfactory seismic performance, and rapid restoration of structural functionality after an earthquake, this study proposes an innovative single-side yielding beam–column connection with replaceable energy dissipation bars (REDB-SYBC) for precast concrete moment-resisting frames (PCMF). During assembly, the concrete beam is attached to a column via the connection function of a non-slipping threaded sleeve assembly (NSTSA) and the support action of the shear keys (SKs) in the REDB-SYBC. This reduces the need for temporary supports for the precast beams on site. Five large-scale tests on precast concrete connections considering the partial flange effect of a slab subjected to quasi-static cyclic loading were conducted to investigate the mechanical behavior, deformation patterns, and energy dissipation (ED) capacity. The primary experimental variables included different loading protocols, restrainer forms, ED segment areas, and whether to replace the ED bars. This paper presents the assembly construction and load-carrying mechanism, and the analysis of the experimental results, including the observations, hysteretic performance, and deformation patterns. The single-side yielding deformation pattern of the REDB-SYBC connection minimized the deformation of the adjacent floor slabs and magnified the deformation of the ED bars at the bottom of a beam, thus facilitating deformation compatibility with the floor system and causing the damage to be focused on the ED bars. Consequently, the five specimens exhibited similar failure patterns via the fracture of the ED bars due to low-cycle fatigue failure, which was attributed to extensive yielding in both tension and compression. The REDB-SYBC connections exhibited a distinct beam end yielding mechanism, which demonstrated a failure pattern that was consistent with the desired “strong column and weak beam” design philosophy. The test results indicated that the proposed REDB-SYBC connection exhibited a dependable decoupled moment and shear load transfer mechanism, stable hysteretic behavior, negligible beam elongation, and reduced floor damage. The performance of a repaired specimen was nearly the same as its counterpart before repair, indicating that replacement was effective. The impact on the REDB-SYBC connection in response to a strong aftershock was also estimated by reloading an unrepaired specimen.

Quasi-static and nonlinear time-history analyses of post-tensioned bridge rocking piers with internal ED bars

Post-tensioned (PT) rocking piers have been recently emphasized for satisfactory self-centering capacity and accelerated bridge construction (ABC) technique in high seismic regions. In this paper, quasi-static cyclic and nonlinear time-history analyses (NLTHAs) are conducted on the PT rocking piers incorporating internal energy-dissipation (ED) bars, based on two modeling techniques. The influences of three parameters consisting of the transverse reinforcement ratio, the area of ED bars and the initial total axial load on the hysteretic behavior of PT rocking piers are studied. The emphases of the quasi-static analyses are on the concrete strain and the neutral axis depth which are seldom referred in the previous researches. Furthermore, NLTHAs are conducted on a set of PT rocking piers under two suits of near-fault and far-fault ground motions (NFGMs and FFGMs) to compare the seismic behaviors of PT rocking piers with different design parameters. The results reveal that the area of ED bars and the initial total axial load are the key parameters that affect the seismic performance of PT rocking piers. In addition, pulse-like NFGMs with a high ratio (>0.2 s) between the peak ground velocity (PGV) and the peak ground acceleration (PGA) result in larger structural seismic responses than FFGMs, except for the acceleration response. The maximum displacement response subjected to FFGMs is almost unaffected by the area ratio of ED bars.

Cyclic tests of precast post-tensioned concrete filled steel tubular (PCFT) columns with internal energy-dissipating bars

In this paper, a promising construction option, which combines the concrete filled steel tubular (CFT) column and the self-centering rocking system, is introduced and its seismic behavior is experimentally investigated. In this hybrid system, named as post-tensioned concrete filled steel tubular (PCFT) column, the unbonded post-tensioned (PT) tendons and energy dissipation (ED) devices are employed to provide recentering and ED properties, respectively. The steel tube acts as a protective jacket, stay-in-place formwork, and transverse reinforcement. Six PCFT columns with different amounts of initial PT force and ED bars were tested. All columns failed due to the fracture of ED bars and the crushing of mortar bed which though was cast from ultra-high performance concrete (UHPC). The column shafts of specimens suffered little damage after testing. The amount of ED bars greatly affected the self-centering capacity and ED capacity of the PCFT columns when the ratio of ED bars was less than 1.2%. Beyond this ratio, its effect was negligible. Additionally, increasing initial PT force made only a little difference to the load-carrying capacity but significantly enhanced the self-centering capacity of the column.

Seismic behaviour of a precast prestressed beam–column joint with energy dissipation bars

A novel precast prestressed (PCPS) reinforced-concrete (RC) beam–column joint with unbonded energy dissipation (ED) bars was developed for a moment-resisting frame structure. Three full-size beam–column joints were designed and tested under reverse cyclic loading to investigate their seismic performance. The experimental results showed that the PCPS beam–column joints had competitive load-carrying capacities and larger initial stiffnesses than the RC beam–column joint. The post-tensioned joint with ED bars located at the column showed better ED capacity than the joint with ED bars located at the beam ends, which had an ED capacity that was comparable with the RC joint. Finite-element models of the three test specimens were established using OpenSees to replicate the experimental results. Analysis of the test and numerical simulation results showed that the proposed beam–column joints could have better seismic performance with the addition of devices to prevent the concrete in the beam ends from early cracking and spalling. The PCPS beam–column joints with ED bars demonstrated good seismic performance under reverse cyclic loading.

Feasible region of post-tensioning force for precast segmental post-tensioned UHPC bridge columns

This paper aims to establish an analytical method to determine the feasible region of post-tensioning (PT) force for precast segmental post-tensioned ultra-high performance concrete (UHPC) bridge columns. Three principles, i.e. no collapse after earthquake, good self-centering capacity, and no shear failure at joints, were put forward to define the feasible region of PT force according to the ultimate state. A calculation procedure was developed to determine the ultimate state and verified by a validated finite element model. With the ultimate state known, an analytical method was established to calculate the feasible region of PT force according to the three principles. Parametric analysis was conducted to quantitatively study the effects of eight common design parameters on the feasible region of PT force. A noniterative calculation method was further given to determine the feasible region of PT force for designers. The results show that the calculation procedure can accurately predict the characteristic values at the ultimate state. There are significant effects of the eight design parameters on the feasible region of PT force, which is actually controlled by the two former principles. The gravity loading can provide sufficient shear resistance at joints without shear keys in general. The feasible region of PT force is mainly distributed between 0.10 and 0.20 for precast segmental UHPC bridge columns with an area ratio of energy dissipation (ED) bars of more than 1.00%. The feasible region of PT force does not exist when the ED bar ratio is more than a critical value (i.e., 2.83% in this research). A noniterative and conservative calculation method to determine the feasible region of PT force can be obtained when the compression zone height of the bottom section at the ultimate state is equal to the wall thickness of the hollow section.

Energy dissipation and self‐centering capacities of posttensioning precast segmental ultra‐high performance concrete bridge columns

AbstractThe research aims to better balance energy dissipation (ED) and self‐centering capacities of posttensioning (PT) precast segmental ultra‐high performance concrete bridge columns by adjusting common design parameters. A numerical model is established based on the equivalent plastic hinge model and validated by the cyclic loading test. The validated model is used to conduct a parametric study to investigate the effects of seven common design parameters on ED and self‐centering capacities. The results show the proposed numerical model can accurately predict ED and self‐centering capacities of the proposed bridge columns. The effect of the strength‐yield ratio can be neglected when it is more than 1.2. The lower aspect ratio can first weaken and then improve the equivalent viscous damping ratio with drift ratio up, while the lower aspect ratio can reduce the residual drift ratio. With larger ED bar ratio, smaller unbonded length of ED bars and lower PT tendon ratio, the equivalent viscous damping ratio, and the residual drift ratio are significantly increased. It is not a perfect way to improve ED capacity by increasing the ED bar ratio, which can significantly magnify the residual drift ratio and limitedly enhance the equivalent viscous damping ratio, besides economical considering. Improving the gravity loading ratio and the initial PT stress are deemed to be effective ways to reduce the residual drift ratio because they not only have little influence on the equivalent viscous damping ratio but also result in no more costs.

Research on seismic resilience of prestressed precast segmental bridge piers reinforced with high-strength bars through experimental testing and numerical modelling

Precast segmental bridge piers are vigorously pursued, especially in low- and medium- seismicity regions, for their merits in accelerating construction, reducing environmental/traffic disturbances, enhancing quality control, etc. Recently, unbonded tendons are utilized to reduce the residual displacement and to facilitate fast rehabilitation of key bridges in the urban traffic system. To further enhance the resilience, prestressed precast segmentally-erected (PPC) piers were fabricated and tested, reinforced with a hybrid of unbonded tendons and high-strength (H) energy dissipation (ED) bars. In this study: (1) cyclic loading tests for the PPC piers with “H” ED bars were reported, and the seismic resilience was quantitatively evaluated and compared with the PPC piers with normal-strength (L) ED bars; (2) the computationally efficient fiber-based finite element (FE) model is developed for the tested PPC piers. Experimental results demonstrated that the “H” ED bars brought out apparent amelioration, in terms of load-carrying, ductility and self-centering capacities. In consideration of rising seismic resilience, “H” ED bars are recommended to replace currently large-scale adopted “L” ED bars in the PPC pier of vital bridges. Through validation with experimental results, the proposed fiber-based FE model is able to provide satisfactory predictions for seismic responses of the tested PPC piers.

Cyclic test and numerical study of precast segmental concrete columns with BFRP and TEED

Previous studies on the seismic behaviour of precast segmental concrete column revealed that concrete crushing and spalling damages may occur at the toes of the segments due to rocking between segments at the joints. In addition, the energy dissipation capacity of segmental column is smaller than the conventional monolithic column. Energy dissipation bars therefore have been proposed to increase its energy dissipation capability, which, unfortunately, at the cost of also increasing the residual displacement of the column, hence degrades the most advantageous characteristic of precast segmental column. To solve these problems, this paper proposes wrapping the segments with basalt fibre-reinforced polymer (BFRP) to reduce the concrete compressive damage and tension-only external energy dissipation (TEED) devices to dissipate energy without substantially increasing the residual displacement. Experimental cyclic tests and numerical simulations are carried out to examine the effectiveness of the proposed method. The results show that the damage of the segments could be effectively reduced by using BFRP, and the columns show good ductility and almost no strength degradation. The TEED devices are effective to increase the energy dissipation capacity of the column without significantly increasing the residual displacement.

Influencing factors of residual drifts of precast segmental bridge columns with energy dissipation bars

The energy dissipation bar has been proven to be an effective way to improve the lateral strength and the seismic capacity of the precast segmental bridge column. To date, however, investigations on how the main design parameters affect the residual drift of such bridge columns are quite limited. Focusing on this research gap, a novel numerical simulation method was proposed in this article to investigate the influencing factors of residual drift of precast segmental bridge columns with energy dissipation bars. First, the refined fiber element model was developed based on the OpenSees software package, considering the bond slip phenomenon at the column end and the boundary condition at the interface between the two adjacent segments. Then, the proposed numerical model was validated by comparing the simulated hysteretic behavior of the precast segmental bridge columns with available experimental data. After that, cyclic analyses were performed on 288 precast segmental bridge column models with different design parameters. Four important influencing factors were investigated, including the post-tensioning force, gravity load, energy dissipation bar ratio, and shear span ratio. According to the analysis results, some suggestions were provided for the practical design procedure of the energy dissipation bar reinforced precast segmental bridge columns.