关键词: 复合地基, 复合模量, 沉降, 摩阻力, 桩长, 桩土模量比

Abstract: Composite modulus is a key parameter of composite foundation, which is calculated in present by virtue of area ratio formula. Practically there is a big error between calculated value and measured value. Taking account of the pile length and the nature of pile-end soil, the bearing mechanics of composite foundation pile were used to correct the area ratio formula. Comparatively, the value calculated by the corrected formula is more accurate than by area ratio formula. With the increase of pile length, composite modulus increases linearly. The smaller the ratio of pile-soil modulus, the bigger the change. Similarly, with the increase of stiffness of pile-end soil, composite modulus increases. However, the bigger the ratio of pile-soil modulus, the bigger the change. So, the ratio of pile-soil modulus should be regarded as a criterion to differentiate the type of composite foundation.