基于薄板理论的刚性桩网复合地基桩土应力比计算

 桩土应力比是反映刚性桩网复合地基工作特性的重要指标。根据刚性桩网复合地基的荷载传递特点，对其在路堤填土荷载作用下的桩土应力分担比进行研究。根据加筋垫层–桩–桩间土应力和位移连续条件，将加固区视为整体进行研究。结合加筋垫层的应力–应变特点，选用大挠度薄板理论模拟加筋垫层的受力和变形。考虑加筋垫层的真实边界条件，首先假定加筋垫层四角点简支其余位置自由并进行桩土应力比求解。在该假定基础之上，考虑桩土相互作用影响，通过功能原理推导出真实情况下刚性桩网复合地基的桩土应力比计算方法。采用室内足尺试验对计算方法进行验证，并综合分析褥垫层模量、桩间距、土体基床系数和桩径对桩土应力比的影响。结果表明理论计算结果与试验结果较为吻合，可为工程实践提供参考。

Calculation of pile-soil stress ratio in composite foundation with rigid pile-net based on plate theory

The pile-soil stress ratio is an important indicator which reflects the characteristic of composite foundation with rigid pile-net. The pile-soil stress ratio of the composite foundation with rigid pile-net under the embankment loads was studied based on the load transfer characteristics. The reinforced area was considered as a whole body according to the stress and displacement continuity condition of cushion-piles-soil. The stress and deformation of reinforced cushion were simulated with the large deflection theory of thin plate. The real boundary conditions of the reinforced cushion were considered. The pile-soil stress ratio was solved with the assumption that the four corners were simple supported and the rest were free. The method for calculating the pile-soil stress ratio under normal conditions considering the effect of pile-soil interaction was deduced through the principle of energy. The method was validated through the indoor full scale tests. The influences of the modulus of mattress layer，pile spacing，soil bed coefficient and pile diameter on pile-soil stress ratio were systematically analyzed. The analytical solutions agree with the measured data.