填方边坡变截面桩板墙桩身内力及变形数值分析

Numerical analysis of internal force and deformation of the variable cross-section pile-plank wall on fill slope

以变截面桩板墙加固某山区填方边坡为工程背景,对支护结构的水平位移、竖直位移进行了现场监测。结合工程实际建立有限元模型,通过对实测位移结果和数值模拟位移结果的对比分析,验证模型的正确性,根据数值模拟结果,分析变截面桩板墙桩身内力及变形规律。研究结果表明:桩身弯矩从桩顶处先递增后递减,变截面处突变,距桩顶13 m处最大;桩身剪力从桩顶处先递增后递减,在13 m处为0,13 m以下反向先递增后递减,在10 m处剪力最大;桩身水平位移随距桩底距离增加而增加,变截面处较小,桩顶处最大。针对其受力变形特性,提出在桩顶与截面变化处设置连系梁,变截面处设置过渡段、控制土体压实度等变形控制措施,为后续工程设计提供参考。

This paper takes the fill slope reinforcement of variable cross-section pile-plank wall in a mountainous area as the engineering background.The horizontal displacement and vertical displacement of the retaining structure are monitored on site.Combined with the engineering practice,a finite element model is established for analysis.The correctness of the model is verified by comparing the measured displacement results and the numerical simulation displacement results.At the same time,according to the numerical simulation results,the internal force and deformation law of variable cross-section pile-plank wall are analyzed.The results show that the moment of pile body increases first and then decreases from the top of pile,and it changes at variable cross-section suddenly.It has the maximum value at 13 m from the top of the pile.The shear force at the pile top increases first,then decreases,and is zero at 13 m.Under 13m,the shear of the pile increases first and then decreases,and the shear force has the maximum at 10 m.The horizontal displacement of the pile increases with the incensement of distance from the bottom of the pile.The horizontal displacement of the pile is a little small at the cross-section,and has the maximum at the top of the pile.Finally,according to the characteristics of its deformation,the deformation control measures such as setting the connecting beam at the top of the pile and the cross-section,setting the transition section at the variable cross-section,controlling the soil compaction degree.These can provide a reference for subsequent engineering design.