工程科学与技术2025，Vol.57Issue(6)：93-103,11.DOI:10.12454/j.jsuese.202400013
新型预应力混凝土摇摆自复位桥墩抗震性能研究
Seismic Performance of the New Rocking Self-centering Prestressed Concrete Bridge Piers
摘要
Abstract
Objective A functionally recoverable rocking self-centering prestressed concrete(RSPC)pier with an expanded section in the plastic hinge zone is proposed to comply with the current requirements of the resilient seismic design concept and to enhance the seismic performance and rapid post-earthquake recovery of prefabricated assembled pier columns. Methods Based on the OpenSees software,the numerical calculation models of the RSPC piers were established.After verifying the reliability of the models,the seismic performance of the RSPC piers was studied,and the effects of parameters were analyzed,including the reinforcement ra-tio of energy-consuming rebars and the initial prestress values for prestressed tendons of the upper and bottom sections.The evaluation method for the resistance resilience of the rocking self-centering piers was proposed from the energy perspective,and the RSPC piers were analyzed un-der different design parameters. Results and Discussions Two-section prefabricated rocking self-centering piers,namely the prefabricated pier with unequal height(RSPC1)and the prefabricated pier with equal height(RSPC2),were designed.The hysteretic curves of the RSPC1 and RSPC2 piers exhibited an obvious flag shape,the pinching effect was significant,and both showed superior self-centering ability.The hysteresis curves of the energy-consuming steel bars of the RSPC piers were analyzed.When the energy-consuming steel bars entered the plastic stage,the hysteresis curves of the RSPC2 piers'energy-consuming steel bars were fuller than those of the RSPC1 piers.Before loading reached the ultimate displacement,the cumulative energy consumption of the monolithic reinforced concrete(RC)piers was always greater than that of the RSPC piers.However,the maximum cumulative energy consump-tion of the RSPC1 and RSPC2 piers was 57.1%and 76.6%higher than that of the RC piers,respectively.The energy dissipation capacity of the RSPC2 piers was greater than that of the RSPC1 piers,and the maximum cumulative energy dissipation was 12.4%higher than that of the RSPC1 piers.The equivalent viscous damping coefficient(ζeq)of the RC piers was significantly greater than that of the RSPC piers.After the piers entered the plastic stage,ζeq of the RSPC2 piers was greater than that of the RSPC1 piers,and the hysteretic curve fullness of the RSPC2 piers was higher than that of the RSPC1 piers.Compared to the RC piers,the peak bearing capacity of the RSPC piers increased by 83.7%and 94.9%,while the ductility co-efficient increased by 26.5%and 20.6%,respectively.The peak bearing capacity of the RSPC2 piers was 6%higher than that of the RSPC1 piers,and the displacement ductility coefficient was 4%lower.The residual displacement of the RSPC piers was significantly smaller than that of the RC piers,with the residual displacement deviation ratio being less than 1%.The maximum residual displacement of the RSPC1 and RSPC2 piers was only about 1/12 and 1/9 of that of the RC piers,respectively.Taking the RSPC2 piers as the benchmark model,the reinforcement ratio of the energy-consuming rebars and the effective prestress values for prestressed tendons of the upper and bottom sections were selected as the main influencing pa-rameters for the parameter analysis.The reinforcement ratio(ρED)of the energy-consuming steel bars was 0.34%,0.47%,0.57%,0.61%,and 0.69%.With the increase of ρED,the bearing capacity,cumulative energy consumption,and residual displacement deviation ratio of the RSPC2 piers gradually increased.When ρED=0.69%,the residual deviation ratio of the pier exceeded 1%.When ρED was less than 0.61%,the residual offset ratio was less than or equal to 1%,and the contribution rate of the lateral strength of the energy-consuming steel bars was less than 35%,which ensured that the piers maintained better self-centering ability and energy dissipation capacity.The effective prestress of the upper prestressed tendons(σST)was 162,323,484,and 581 Mpa.When σST=581 Mpa,the loading displacement reached 36 mm,the bearing capacity of the pier decreased significantly,and the loading was stopped.Under other working conditions,as σST increased,the bearing capacity of the RSPC2 piers decreased,while the cumulative en-ergy consumption and residual displacement increased.The maximum joint openings of the upper section were 1.17,0.68,and 0.36 mm,and their ra-tios to the joint openings of the bottom section were 16.7%,9.7%,and 4.9%,respectively.As σST increases,the joint opening of the upper section of the precast segment decreases significantly.When σST=484 Mpa,the ratio of the upper joint opening to the bottom joint opening was the smallest,and the prestressed tendons improved the integrity of the upper section,enhanced the rocking performance,and ensured that the RSPC2 piers main-tained better self-centering ability and energy dissipation capacity.The effective prestress of the bottom prestressed tendons(σSB)was 215,430,646,and 861 Mpa.As σSB increases,the bearing capacity of the RSPC2 piers rises,while the cumulative energy consumption and residual displacement de-crease.The stiffness after yielding increases,and the displacement ductility coefficient first increases and then decreases.The displacement ductility of the RSPC2 piers reached the optimal value when σSB=646 Mpa.The maximum difference in the ratio of the upper joint opening to the bottom joint opening was only 3%.The seismic resilience of the RSPC2 piers was analyzed from an energy perspective.The initial resistance resilience ratio(Rs)was greater than 1.00,and the residual resistance resilience ratios(R1,R2,Ru)were greater than those of the reference piers.The Rs,R1,R2,and Ru of the RSPC2 piers all increased with the increase of ρED.When ρED=0.53%and 0.61%,the comprehensive resistance resilience reached its optimal value.As σST increases,Rs decreases but remains greater than 2.0,while R1,R2,and Ru gradually increase.When σST=484 Mpa,the residual resis-tance resilience of the RSPC2 piers was superior.As σSB increases,Rs gradually improves,while R1,R2,and Ru decrease,but the changes remain within 0.004.When σSB=646 Mpa,the comprehensive resistance resilience reached its optimal state. Conclusions The hysteretic curves of the RSPC piers exhibited an evident flag-shaped pattern with a significant pinching effect,and the residual de-flection rate was less than 1%,indicating good self-centering ability and repairability.The lateral bearing capacity and displacement ductility of the RSPC piers increased by more than 80%and 20%,respectively,compared to RC piers,demonstrating superior seismic performance.Considering the comprehensive lateral bearing capacity,energy dissipation capacity,and self-centering capacity,the reasonable range of the reinforcement ratio of the energy-consuming rebars in the RSPC piers was determined to be 0.5%～0.6%.The seismic performance of the new piers was optimal when the ef-fective prestress values for the prestressed tendons in the upper and bottom sections were 484 and 646 Mpa,respectively.The proposed evaluation method for assessing the resistance resilience of the RSPC piers can accurately identify the resistance resilience of the piers at different stages.关键词
预应力混凝土桥墩/摇摆自复位/功能可恢复/抗震韧性Key words
prestressed concrete bridge columns/rocking self-centering/restorable function/seismic resilience分类
交通运输引用本文复制引用
彭涛,王军文,郝玉军,李春雨,李勇,郭进..新型预应力混凝土摇摆自复位桥墩抗震性能研究[J].工程科学与技术,2025,57(6):93-103,11.基金项目
国家自然科学基金项目(52578227 （）
52178493) （）
石家庄铁道大学研究生创新项目(YC2023007) （YC2023007）
