考虑材料冻融劣化与多年冻土退化影响效应的桥梁桩基础抗震性能  

Seismic Performance of Bridge Pile Foundation Considering Effects of Material Freeze-Thaw Deterioration and Permafrost Degradation

作　　者：张熙胤[1] 于生生 王万平 文海荣 ZHANG Xiyin;YU Shengsheng;WANG Wanping;WEN Hairong(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《中外公路》2025年第1期20-30,共11页Journal of China & Foreign Highway

基　　金：国家自然科学基金资助项目(编号:52068045)。

摘　　要：以中国青藏高原为代表的高寒高烈度地区,由冻融循环作用导致的材料性能劣化和气候变暖导致的多年冻土退化问题日益严峻,给桥梁桩基础抗震性能评估带来巨大挑战。为系统研究多年冻土退化以及材料冻融劣化对桥梁桩基础抗震性能的影响,确保其合理的抗震设计,该文建立考虑多年冻土退化和材料冻融劣化的桩-冻土相互作用有限元模型,对比分析了不同因素对多年冻土区桥梁桩基础抗震性能的影响机制。研究结果表明:随着桥梁服役时间的增加,桩-冻土体系的水平承载力、等效刚度和耗能能力均呈下降趋势;多年冻土退化与材料冻融劣化的叠加效应对桩基础抗震性能的影响更显著,具体表现为在桥梁服役100年时,桩-冻土体系的水平承载力降至初始值的55%左右,但仅考虑多年冻土退化时,其水平承载力降至初始值的89%左右。因此,如果忽略材料冻融劣化的影响,会导致桥梁桩基础抗震性能评估结果偏不安全。在多年冻土区桥梁桩基础的抗震性能分析中,除了考虑多年冻土退化的影响,还必须充分考虑材料冻融劣化的影响。In cold and high-seismic regions,such as the Qinghai‒Xizang Plateau in China,the deterioration of material properties caused by freeze-thaw cycles and permafrost degradation due to climate change have become increasingly severe,posing significant challenges for the seismic performance assessment of bridge pile foundations.To systematically investigate the impact of permafrost degradation and material freeze-thaw deterioration on the seismic performance of bridge pile foundations and ensure proper seismic design,a finite element model was established,considering the dual effects of permafrost degradation and material freeze-thaw deterioration.A comparative analysis was conducted to evaluate the influence mechanisms of various factors on the seismic performance of bridge pile foundations in permafrost regions.The results indicate that as the bridge service life increases,the horizontal bearing capacity,equivalent stiffness,and energy dissipation capacity of the pile-permafrost system all show a decreasing trend.Notably,the combined effect of permafrost degradation and material freeze-thaw deterioration has a more significant impact on the seismic performance of the bridge pile foundations.Specifically,after 100 years of bridge service,the horizontal bearing capacity of the pile-permafrost system reduces to approximately 55%of its initial value,whereas when only permafrost degradation is considered,the horizontal bearing capacity drops to around 89%of its initial value.Therefore,neglecting the effect of material freeze-thaw deterioration will lead to an unsafe seismic performance assessment of the bridge pile foundation.In the seismic performance analysis of bridge pile foundations in permafrost regions,it is essential to consider not only the effect of permafrost degradation but also the impact of material freeze-thaw deterioration.

关 键 词：桥梁桩基础 抗震性能 多年冻土退化 材料冻融劣化 有限元模型 

分 类 号：U443[建筑科学—桥梁与隧道工程]