微型桩芯搅拌桩工程实践与工作机理研究

Project practice and work mechanism about micropile-core cement mixing pile

微型桩芯水泥搅拌桩复合地基在江苏沿海、沿江地区广泛应用。结合实际工程简要介绍了该复合桩的施工工艺与构造、承载力设计方法。研究了桩芯、桩体与地基土三者之间的应力分布与荷载分担规律。结果表明,微型桩芯的打入提高了复合桩与桩周土之间的摩阻力,复合桩表现出摩擦桩工作特性。微型桩芯搅拌桩复合地基具有刚性桩复合地基的工作特点,荷载通过桩芯到桩体再到桩周土逐步向外有效地扩散到整个基础持力层。

Composite foundation composited of micropile-core cement mixing pile and foundation soil is widely used in coastal and riverside area of Jiangsu.Based on the actual project practice,the construction technology,details and design method of bearing capacity for this composited pile were introduced.Stress distribution and load share law were studied among pile core,mixing-pile body and foundation soil.The results show that piling core can enhance the friction force between piles and soil around pile.Composite pile shows the working characteristics of friction pile.This composited piled foundation is rigid,and the load can be transferred effectively from inside to outside through pile core,mixing-pile body and soil around pile.