学术论文列表
汶川大地震简支梁桥落梁震害与设计对策
摘要：总结了5.12汶川大地震中简支梁桥落梁震害及主要影响因素,发现除地震山体滑坡等地质灾害外,断层地表破裂、近断层地震动效应、桥台胸墙冲切破坏、防落梁构造措施单一及桥梁体型复杂等因素都是引起简支梁桥落梁震害的重要原因。提出了简支梁桥防落梁设计的基本理念及相关技术方案要点为允许墩梁间发生滑移,以降低桥墩承受的地震惯性力,以及盖梁提供允许的最大滑移长度及支座支承宽度,再辅助挡块或拉索限位器等共同防止落梁发生。最后结合现行规范,以拉索限位器为例给出了简支梁桥防落梁设计方法。
Experiment on Shear Strength of Reinforced Concrete Bridge Column in Plastic Hinge Zone Under Seismic Effect
摘要：Aimed at problem of brittle shear failure occurred in the plastic hinge zone of reinforced concrete bridge columns under seismic effect,the shear strength of the column were studied.The pseudo-static tests of 12 reinforced concrete short bridge column were conducted.Existing calculated equations for shear strength of the bridge column around the world were also compared with each other based on experimental results.Using pseudo-static test database of PEER reinforced concrete column,statistical analysis for influencing factor of concrete shear strength in plastic hinge zone under seismic effect was carried out.Finally,according to relative code and research outcome,a calculated equation for shear strength of bridge column in the plastic hinge zone was proposed.Results show that the short bridge columns satisfied with minimum stirrup ratios of current seismic design code in China may suffer shear failure in plastic hinge zone which should pay more attention in the design.
基于纤维单元的钢筋混凝土桥墩地震损伤评价
摘要：基于纤维模型的梁柱单元特别是柔度法单元有着较高的计算精度,已被较多地用于评价钢筋混凝土桥墩的位移(延性)能力。随着基于性能/位移抗震设计理论的发展,相继提出了残余位移、极限曲率及曲率延性系数、纵筋和混凝土的最大应变、纵筋低周疲劳损伤等桥墩地震损伤量化指标。选用刚度法和柔度法纤维单元,考虑材料非线性、几何非线性和结点锚固钢筋粘结滑移的影响,通过数值分析和试验数据对比研究了利用纤维单元对上述损伤指标进行估计的准确程度及主要影响因素。结果表明,柔度法单元计算的损伤参数均大于刚度法;两种纤维单元计算的滞回曲线及残余位移和试验结果十分接近,刚度法单元计算的截面曲率和纵筋拉应变更接近试验值,当加载位移幅值或剪跨比较大时,两种单元有时会低估桥墩的截面曲率反应;两种单元都会高估桥墩纵筋的最大拉应变,低估核芯混凝土的最大压应变。
钢筋混凝土墩柱等效塑性铰长度研究
摘要：为研究钢筋混凝土墩柱等效塑性铰长度,整理了154根钢筋混凝土墩柱试验数据,研究了墩柱等效塑性铰长度随侧向位移的变化规律,通过试验对各国主要塑性铰长度计算公式进行了对比,讨论了影响墩柱等效塑性铰长度的主要因素,通过回归分析建议了等效塑性铰长度计算公式并进行了验证。结果表明:钢筋混凝土墩柱等效塑性铰长度随位移延性系数变化而变化,但未呈现一致变化规律;与试验结果相比,各公式计算的墩柱等效塑性铰长度离散性均较大,Priestley建议公式在平均意义上与试验结果最为接近,Paulay公式、Panagiotakos公式和欧洲Eurocode 8规范公式偏于不安全,中国《公路桥梁抗震设计细则》(JTG/T B02-01—2008)建议公式偏于保守,日本JRA规范建议公式最为保守;钢筋混凝土墩柱等效塑性铰长度主要与试件高度、截面宽度和纵筋直径有关,与纵筋屈服强度、试件轴压比、配箍等因素关系不大;建议的钢筋混凝土墩柱等效塑性铰长度计算公式在平均意义上与试验结果基本一致,适用于剪跨比在2.0~8.0之间且混凝土抗压强度在20~110 MPa之间的普通及高强钢筋混凝土墩柱。
钢筋混凝土桥墩地震弯剪破坏机理与震后快速修复技术研究
摘要：为研究钢筋混凝土桥墩的地震弯剪破坏机理与震后快速修复技术,首先进行了6个圆形截面桥墩试件的拟静力试验,试件均发生严重弯剪破坏,然后利用高流动性早强混凝土和CFRP布对其进行快速修复并在1周内重新进行加载试验,将原桥墩与修复后试件的破坏形态、承载力、延性与耗能能力、刚度退化等进行了对比分析。研究表明:塑性铰区配箍满足我国《公路桥梁抗震设计细则》(JTG/T B02-01—2008)及美国Caltrans规范要求的钢筋混凝土桥墩试件,最终仍有可能因塑性铰区抗剪强度不足发生弯剪破坏。由于初始损伤的存在,震后修复桥墩试件的初始刚度偏低、屈服位移偏大,但极限承载力较原试件均有不同程度的提高,延性与耗能能力达到或超过原试件,刚度可有效恢复至原桥墩试件水平,震后修复试件呈弯曲破坏形态,显示出修复方法的有效性。
Rapid repair of severely earthquake-damaged bridge piers with flexural-shear failure mode
摘要：An experimental study was conducted to investigate the feasibility of a proposed rapid repair technique for severely earthquake-damaged bridge piers with flexural-shear failure mode. Six circular pier specimens were first tested to severe damage in flexural-shear mode and repaired using early-strength concrete with high-fluidity and carbon fiber reinforced polymers (CFRP). After about four days, the repaired specimens were tested to failure again. The seismic behavior of the repaired specimens was evaluated and compared to the original specimens. Test results indicate that the proposed repair technique is highly effective. Both shear strength and lateral displacement of the repaired piers increased when compared to the original specimens, and the failure mechanism of the piers shifted from flexural-shear failure to ductile flexural failure. Finally, a simple design model based on the Seible formulation for post-earthquake repair design was compared to the experimental results. It is concluded that the design equation for bridge pier strengthening before an earthquake could be applicable to seismic repairs after an earthquake if the shear strength contribution of the spiral bars in the repaired piers is disregarded and 1.5 times more FRP sheets is provided
Research on Equivalent Plastic Hinge Length of Reinforced Concrete Bridge Column
摘要：钢筋与混凝土材料的高强化是工程结构发展的重要方向，为研究配置高强钢筋的高强混凝土桥墩等效塑性铰区长度，整理了 37 根高强钢筋高强混凝土桥墩试验数据，与 Priestley、Paulay、Telemachos 及我国《公路桥梁抗震设计细则》建议的塑性铰区长度计算公式进行了对比分析，并通过灰色关联方法分析了影响高强钢筋高强混凝土桥墩等效塑性铰区长度的主要因素。研究表明：与试验结果相比，各公式计算值离散性较大，Paulay 公式、Telemachos 公式偏于不安全，Priestley 公式和我国 JTG/TB 02—01—2008《公路桥梁抗震设计细则》建议公式偏于保守；在高强钢筋高强混凝土桥墩等效塑性铰长度的各影响因素中，纵筋直径影响最大，其次是试件高度和截面宽度，试件轴压比和力学含箍率影响最小，高强钢筋高强混凝土桥墩等效塑性铰区长度的主要影响因素基本符合目前的认识水平。
高强钢筋高强混凝土桥墩等效塑性铰区长度分析
摘要：钢筋与混凝土材料的高强化是工程结构发展的重要方向,为研究配置高强钢筋的高强混凝土桥墩等效塑性铰区长度,整理了37根高强钢筋高强混凝土桥墩试验数据,与Priestley、Paulay、Telemachos及我国《公路桥梁抗震设计细则》建议的塑性铰区长度计算公式进行了对比分析,并通过灰色关联方法分析了影响高强钢筋高强混凝土桥墩等效塑性铰区长度的主要因素。研究表明:与试验结果相比,各公式计算值离散性较大,Paulay公式、Telemachos公式偏于不安全,Priestley公式和我国JTG/TB 02—01—2008《公路桥梁抗震设计细则》建议公式偏于保守;在高强钢筋高强混凝土桥墩等效塑性铰长度的各影响因素中,纵筋直径影响最大,其次是试件高度和截面宽度,试件轴压比和力学含箍率影响最小,高强钢筋高强混凝土桥墩等效塑性铰区长度的主要影响因素基本符合目前的认识水平。
Lessons Learned from Wenchuan Seismic Damages and Recent Research on Seismic Design of Highway Bridges
摘要：The great Wenchuan earthquake,which measured as 8.0 Ms and occurred on May 12,2008 in Sichuan province of China,has caused severe damage to many highway bridges and also left us with valuable information that can be analyzed to reduce potential losses associated with future earthquakes.The Lessons learned from Wenchuan seismic damages of highway bridges were summarized.It is believed that special attention should be paid to(1) bridge seismic response and unseating damages subjected to near-fault ground motions;(2) preventive design of collapse damage of curved girder bridges with small radius;(3) ductility and seismic design,detailed reinforcement of bridges and seismic damage control of high-rise piers under deep water.The recent research progress of our research team on seismic performance of highway bridges was summarized.It includes design idea and method of unseating protection of highway bridges,deformation capacity and shear strength of PC bridge piers,numerical simulation of seismic damage mechanism of curved girder bridges,and countermeasures to prevent collapse of curved girder bridges with small radius.
汶川地震钢筋混凝土框架震害及震后修复建议
摘要：介绍了汶川大地震中几座典型钢筋混凝土框架结构的震害,重点总结了框架结构中梁、柱、节点以及楼梯间的震害情况,发现除较为常见的梁柱弯曲破坏、剪切破坏、弯剪破坏以及框架节点的破坏外,框架梁柱中的粘结破坏、施工缝处的破坏及楼梯间破坏也较为严重。部分新建结构尚未完工也遭到严重破坏,且表现为"强梁弱柱""强构件弱节点"的破坏形态。总结了国内外对损坏的钢筋混凝土框架结构进行震后修复和加固的研究进展,并对汶川地震后结构的震后修复和抗震加固工作提出了建议,强调应从结构整体角度进行震后修复和加固工作,考虑各种修复方案的优点和不足,重视结构整体和构件的相互关系,避免修复后的结构出现刚度不均,并注重形成多道抗震防线。
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