边坡蠕滑影响下桥梁桩基力学特性分析

Analysis of Mechanical Characteristics of Bridge Pile Foundation Under the Influence of Slope Creeping

为了探究某蠕滑边坡上桥梁桩基的力学特性,采用有限元软件建立了考虑降雨影响的边坡数值分析模型,对边坡蠕滑导致的桥梁桩基力学特性变化进行了重点研究。结果表明,对于同一墩台下的各桩基:后排桩基弯矩极值大于前排桩基,后排桩基的边桩和内桩弯矩极值差值约为内桩弯矩极值的6.7%S(S为横向桩间距),中、前排桩基中边桩和内桩弯矩极值差值约为内桩弯矩极值的10%S;后排桩基的位移极值最大,中排次之,前排最小。在进行边坡上桥梁桩基础设计时,不仅要考虑坡体滑动产生的推力,还应考虑同一墩台不同位置桩基的差异配筋。

To explore the mechanical characteristics of the bridge pile foundation on a creeping slope,a numerical analysis model of the slope is established considering the effect of rainfall.And changes in the mechanical characteristics of the bridge pile foundation caused by slope creeping are studied.Results show that,for each pile foundation under the same pier,the extreme value of the bending moment of the rear row of pile foundations is greater than that of the front row of pile foundations,and the difference between the extreme value of the bending moment of the side pile and the inner pile of the rear row of piles is about 6.7S%that of the inner pile bending moment(S refers to the horizontal space between piles).The extreme value of the bending moment of the middle and front piles and the inner pile is about 10S%that of the inner pile bending moment.The displacement of the rear pile is the largest,the displacement of the middle row is the second,and the displacement of the front row is the smallest.Hence,not only the slope sliding thrust,but also the differential reinforcement of the pile foundation in different positions of the same pier should be taken into account in the bridge pile foundation design of the slope.