侧向堆土作用下桩柱式桥墩延性性能研究  

Study on Ductility Performance of Pile-type Piers under Action of Lateral Piled Soil

作　　者：王兵见[1] 贾延安 郭瑞 邓松 WANG Bing-jian;JIA Yan-an;GUO Rui;DENG Song(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;Anhui Highway Bridge Engineering Co.,Ltd.,Hefei Anhui 230031,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]安徽省公路桥梁工程有限公司,安徽合肥230031

出　　处：《公路交通科技》2023年第3期136-140,共5页Journal of Highway and Transportation Research and Development

摘　　要：为了研究建造在高陡坡位置上的桩柱式桥墩在堆土作用下的侧移性能及桩体关键截面的曲率延性,解决常规水平受力桩模型假设的局限性,采用土体应变楔模型半解析方法分析了侧向堆土作用下桩-土系统非线性行为。将桩柱式桥墩采用等效悬臂梁模型进行仿真,分析了天然状态和饱和状态的堆土楔形体对于桥墩的作用影响规律。比较了有堆土和无堆土两种工况下桩柱的变形特征。结合工程实例,研究了桥梁运营状态时,在温度变化、混凝土收缩、徐变影响力和汽车制动力作用组合下桩柱发生非弹性位移时的局部曲率延性能力。结果表明:根据堆土楔形体模型,堆土场形成的滑坡作用在桥墩上的侧向弯矩对其承载能力影响显著;有无堆土对桩身轴力影响不显著,但对剪力影响显著,剪力曲线特征转折点(最不利剪力位置)由于堆土的存在发生上移;采用土楔形体模型以及柱式桥墩等效悬臂梁模型可以成功估算柱式桥墩基础在侧向堆土作用下的塑性铰位置,以及桩柱的横向极限承载力。总结了桥下堆土在导致桥墩倾斜过程中的影响,并对桥下堆载的放置提出了建议。In order to study the lateral displacement performance of the pile-type bridge piers built on high and steep slopes under the action of piled soil and the curvature ductility of the key section of the pile body,and to solve the limitation of the assumption of the conventional horizontal stress pile model,the nonlinear behavior of pile-soil system under the action of lateral piled soil is analyzed by using the semi-analytical method of soil strain wedge model.The pile-type pier is simulated by using the equivalent cantilever beam model,and the influence of the natural and saturated soil wedges on the pier is analyzed.The deformation characteristics of piles with and without piled soil are compared.Combining with engineering examples,the local curvature ductility of piles with inelastic displacement under the combination of temperature change,concrete shrinkage,creep influence and vehicle braking force when the bridge is in operation is studied.The result shows that(1)according to the piled soil wedge model,the lateral bending moment on bridge pier caused by landslide formed by piled soil has significant impact on its bearing capacity;(2)the pile axial force is not significantly affected by the presence or absence of piled soil,but the shear force is significantly affected,the characteristic turning point(the most unfavorable shear position)of the shear curve moves upward due to the presence of piled soil;(3)using the soil wedge model and the equivalent cantilever beam model of the pile-type pier,the plastic hinge position of the pile-type pier foundation under the action of lateral piled soil and the lateral ultimate bearing capacity of the pile can be successfully estimated.The influence of piled soil under the bridge in the process of causing the pier to tilt is summarized,and some suggestions for the placement of piled load under the bridge are put forward.

关 键 词：桥梁工程 桩柱式桥墩 应变楔方法 等效悬臂梁 侧向堆土 塑性铰 

分 类 号：U448.2[建筑科学—桥梁与隧道工程]