中文摘要：

主要研究桩承式多层水平加筋复合地基中桩土应力比和桩土沉降。通过建立内外土柱受力变形模型和引入剪切位移法研究了水平加筋体的变形和应力传递规律，并基于内土柱微元体力平衡条件，推导出了桩土应力比n、差异沉降等计算公式。通过工程实例的分析计算，验证了公式的可靠性，分析了各影响因素与桩土应力比的关系。结果表明：随着桩土沉降差△s的增大，n也变大；随着内摩擦角P的增大，n是先增大后减小，且当φ=300时，n达到最大值；n与粘聚力c基本呈线性关系，与桩间距L近似呈双曲线关系。这与工程实例测试结果较为吻合。

英文摘要：

The pile-soil stress ratio and the settlements of soil and piles in multi-layer geosynthetic-reinforced and pile-supported composite ground were discussed. The transfer regularity of stress and deformation in reinforcement was studied by introducing shear displacement method and by developing a mechanical model for analyzing inner and outer soil columns.The formula of pile-soil stress ratio n and the differential settlement △s between the soil and piles were deduced from the previous method based on the force equilibrium of differential unit in inner soil columns. A practical example was given to verify the formulae and to analyze the relationship of the pile-soil stress ratio n with its influence factors. It is found that （1） the pile-soil stress ratio n grows with the increase of the differential settlement △s; （2） n first enhances and then reduces with the increase of angle of internal friction and the peak n is at φ = 30°; （3） n is still linear with cohesion c and approximately hyperbolic with the spacing of piles L. These findings agree with the observation of practical engineering.