中文摘要：

散体桩式复合地基的破坏形式主要为鼓胀破坏,而鼓胀破坏的主要原因是浅层桩间土对桩体的围护力不足,同时桩间土本身的承载能力也主要决定于浅层部位桩间土的力学特性。基于以上原理,提出散体桩复合地基工后浅层加固技术,即工后对浅层部位桩间土进行加固来提高复合地基承载力的方法;对比分析了加固前、后地基承载特性的变化,论证不同加固深度对地基承载力的影响,得出只要进行（0.5～1）倍散体桩桩径深度的浅层加固就可以大大提高地基承载力的结论,同时通过实际工程证明浅层加固技术合理性和有效性。

英文摘要：

The main destruction forms of granular-pile composite foundation is destruction of bulging,and bulging damage is mainly due to the inadequate maintenance of the shallow soil between piles,and the bearing capacity of the soil between piles itself depends also on the mechanical properties of shallow part of soil between piles.Based on the above principle,the after-work shallow reinforcement optimization technology of granular pile composite foundation that stabilized the site of shallow soil between piles to greatly improve the bearing capacity of the composite foundation was offered and the load-bearing characteristics changes of the foundation after and before the reinforcement were compared and analyzed,and the influences of different reinforcement depth on the bearing capacity were demonstrated.Through practical project,it is proved shallow reinforcement technology is reasonable and effective.The conclusion is：that as long as shallow depth of 0.5 ～ 1.0 times granular pile diameter would be reinforced,it could greatly improve the bearing capacity of granular-pile composite foundation.