摘要
为反映多层加筋材料分布层位和应变差异对桩承式加筋路堤的影响,基于土拱形态和筋材应变分布的假设,推导桩土荷载分担比的计算公式。首先根据极限平衡理论和同心圆二维土拱模型假设,推导筋上桩体荷载分担比的计算公式;再假设帽间格栅变形为圆弧曲线,考虑帽上格栅变形对帽间格栅应变的贡献,推导更符合常用大桩帽疏桩结构特点的格栅应变计算公式;进一步以筋下填土产生的土压力和桩间土应力为附加应力计算底层格栅挠度,提出以底层格栅挠度为自变量的任意层格栅挠度表达式;最终依据格栅应变计算格栅拉力及其竖向分量,得到考虑格栅拉膜传荷作用的筋下桩体荷载分担比计算公式。该方法可适用于单层以及非单层加筋的桩承式加筋路堤,经工程实例验证,计算值与实测值吻合较好。
To address the influence of multiple layers of reinforcement on geosynthetics reinforced pile supported （GRPS） embankment, based on the hypothesis of soil arching and strain of geosynthetics, the formula was deduced for calculating the pile efficacy in this paper. Firstly, based on limit-stress equilibrium of soil arching and two-dimensional soil arching model with concentric arches, the theory formula was deduced for calculating the pile efficacy upon geosynthetics. Secondly, the shape of geosyntheticsdeformation between pile caps was assumed as arc, the contribution of deformation of geosynthetics upon pile caps to strain of geosynthetics between pile caps was considered, and then the calculation formula for strain of geosynthetics was deduced, which is well suited for GRPS embankment with sparse piles and large pile caps. Thirdly, the deformation of bottom geosynthetics induced by filling below geosynthetics and soil stress between piles was estimated, and then the mathematical relationship of deformation between the bottom geosynthetics and the others was proposed. Lastly, tensile forces and vertical components of geosyntheticswere calculated by aforementioned strains, and the formula was deduced for calculating the pile efficacy under geosynthetics. This method could be applied to plie supported embankment reinforced by single or multiple layers of geosynthetics. The calculation results were shown to provide satisfactory agreements with testing datum.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第A01期3587-3595,共9页
Chinese Journal of Rock Mechanics and Engineering
关键词
路基工程
桩承式加筋路堤
土拱效应
格栅应变
桩体荷载分担比
embankment engineering
geosynthetics reinforced pile supported embankment
soil arching effect： geosynthetics strain
pile efficacy
