考虑冲刷和材料劣化耦合作用的钢筋混凝土桥梁桩基承载性能研究  

Coupling effect of scouring and material deterioration-considered study on bearing performanceof reinforced concrete bridge pile foundation

作　　者：祝彦知[1,2] 赵雅纯 田光辉 纠永志[1,2] 程学磊 ZHU Yanzhi;ZHAO Yachun;TIAN Guanghui;JIU Yongzhi;CHENG Xuelei(School of Civil Engineering,Zhongyuan Univercity of Technology,Zhengzhou 450007,Henan,China;Architectural Design and Research Institute,Zhongyuan University of Technology,Zhengzhou 450007,Henan,China)

机构地区：[1]中原工学院建筑工程学院,河南郑州450007 [2]中原工学院建筑设计研究院,河南郑州450007

出　　处：《水利水电技术（中英文）》2023年第3期116-125,共10页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金资助项目(51608548)。

摘　　要：桥梁桩基是桥梁承担荷载的重要组成部分,【目的】为研究钢筋混凝土桥梁在劣化和冲刷共同作用下的力学性能变化,【方法】结合工程实例,建立桥梁桩基模型。运用有限元软件模拟钢筋锈蚀,用Mander模型实现混凝土损伤本构模型随服役时间的变化情况,通过桩周土体钝化实现水流的冲刷作用。根据桥梁服役时间、钢筋混凝土劣化程度和冲刷深度的不同,分别模拟桥梁桩基在此基础上的承载性能变化。【结果】结果显示:桩基在竖向荷载作用下的位移随冲刷深度以及劣化程度的增大而增大;未考虑钢筋混凝土劣化时,极限承载力随着冲刷深度的增大呈减小的趋势,在服役初期,承载力受冲刷影响较大,下降的速度较快,到服役后期,冲刷深度逐渐稳定,承载力受冲刷影响逐渐变小,下降速度趋于平缓;考虑钢筋混凝土劣化时,钢筋锈蚀对冲刷后桩基承载力的影响不大,但核心混凝土劣化对桩基极限承载力有较大的影响。【结论】结果表明:钢筋混凝土桥梁在水流冲刷和材料劣化的共同作用下,桩基承载力较服役前下降较多,影响桥梁正常使用,甚至引发安全事故,因此对于冲刷劣化后桩基的加固工作应引起足够的重视。[Objective]Bridge pile foundation is an important part of the bridge to bear load,and then the change of its mechanical performance under the joint effect of both the material deterioration and scouring is studied herein.[Methods]A bridge pile foundation model is established based on an actual engineering case and the corrosion of reinforcement is simulated with the relevant finite element software,while the change with the service time of the concrete damage constitutive model is implemented through Mander model and the scoring effect of water flow is implemented through the passivation of the soil mass surrounding pile.In accordance with the service time of bridge,the deterioration degree of reinforced concrete and the difference of scouring depth,the changes of the bearing performance of the bridge pile foundation are respectively simulated on the basis of this.[Results]The study result shows that the pile foundation displacement under the vertical load is increased with the increases of both the scouring depth and the deterioration degree,while the ultimate bearing capacity exhibits a decreasing trend with the increase of the scouring depth when the deterioration of reinforced concrete is not considered.During the initial period of the service,the bearing capacity is largely impacted by scouring with a faster decreasing speed.During the later period of service,the scouring depth is gradually stable,the impact from scouring on the bearing capacity is gradually decreased and the decreasing speed tends to be flat.Under the consideration of the deterioration of concrete,the reinforcement corrosion has less impact on the bearing capacity of the pile foundation after scouring,but the deterioration of the core concrete has larger impact on the ultimate bearing capacity of the pile foundation.[Conclusion]The result indicates that under the joint effect from both the water flow scouring and the material deterioration,the bearing capacity of the pile foundation of the reinforced concrete bridge is to be largely decreas

关 键 词：桥梁桩基 冲刷 材料劣化 耦合 承载力 沉降 

分 类 号：TU997[建筑科学—市政工程]