圆形抗滑桩-拱形挡土板支挡性能与参数分析

An analysis of the behaviors and sensitive parameters of circularantislide pile-arched retaining plates

为规避当前施工方法的不足,发展安全、高效和可靠的施工方法。依托东北地区某高速铁路路堑边坡工程,采用适于机械钻孔的圆形抗滑桩代替现行矩形抗滑桩,预制拱形挡土板,本文提出一种新型拱形板-桩墙支挡体系;并构建有限元模型,分析桩长、桩径、桩间距以及拱形挡土板矢跨比对新型拱形板-桩墙支挡体系支护性能的影响;揭示不同参数下桩顶水平位移与桩身内力的变化规律。研究结果表明:桩长与桩身弯矩和剪力大小呈正相关关系,与桩顶水平位移呈负相关关系。桩长超过14 m时,其对桩顶水平位移、桩身弯矩和剪力的影响效应明显减弱;随着桩间距增大,桩顶水平位移增大但变化幅度逐渐减小。拱形挡土板矢跨比增大时,桩顶水平位移、桩身弯矩和剪力均减小。影响拱形板-桩墙体系支挡性能的因素依次为桩间距、桩长、桩径和矢跨比。研究结果为圆形抗滑桩-拱形挡土板支挡体系在实际工程中的应用提供新思路。

In order to circumvent the shortwmings of the current construction methods,develop safe,efficient and reliable construction methods.Taking a high-speed railway cutting slope project in Northeast China as an instance,a new type of arched retaining plate and pile wall support system is proposed in this paper.This is achieved by using circular antislip piles that are suitable for mechanical drilling to replace the current rectangular antislip piles and prefabricating arched retaining plates.A finite element model was constructed to analyze the effects of pile length,pile spacing,pile diameter,and the rise-span ratio of the arched retaining plate on the support performance of the new arched plate and pile wall support system.The results reveal the change rule in the horizontal displacement of the pile top and the internal force of the pile stem under different parameters.Furthermore,the pile length is positively correlated with the bending moment and shear force of the pile stem but is negatively correlated with the horizontal displacement of the pile top.When the pile length exceeds 14 m,its influence on the horizontal displacement of the pile top,the bending moment of the pile body,and the shear force is significantly weakened.At the same time,as the spacing between piles increases,the horizontal displacement of the pile top increases,but the amplitude of change gradually decreases.As the span ratio of the arched retaining plate increases,the horizontal displacement of the pile top,the bending moment of the pile stem,and the shear force all decrease.The factors affecting the retaining performance of the arched plate pile wall system include successive pile spacing,pile diameter,pile length,and rise-span ratio.The research results provide a new idea for the application of circular antislip piles and arched retaining plate support systems in the field of practical engineering.