基于沉降控制的端承型复合桩基工程实践

 针对端承桩无法满足桩、土变形协调的特点，通过专门研制的变形调节装置，协调桩、土变形差，提出在桩顶设置变形调节装置的端承型复合桩基，实现地基土承担上部结构大部分荷载，仅通过少量端承型桩来控制建筑物沉降的目的，并进行工程实践。该工程地基土承载性能良好，天然地基承载力可以满足要求，但建筑物沉降过大，通过采用该方法使地基土承担上部结构55%的荷载，且沉降控制效果良好，取得了显著的经济效益和社会效益。通过对一系列现场测试数据的分析，验证本工程基于沉降控制的端承型复合桩基方案的合理性和有效性。该工程端承型复合桩基的设计思路与方法可供同类工程借鉴和参考。

ENGINEERING PRACTICE OF COMPOSITE END-BEARING PILE FOUNDATION BASED ON SETTLEMENT CONTROL

The end-bearing piles do not meet normally the deformation compatibility between piles and soils. The deformation adjustors were thus designed to make the deformation of piles and soils compatible. The deformation adjustors were placed on top of the piles so that the end-bearing piles and soil layers together form a composite foundation. The foundation soil carried the most of the superstructure load and the purpose of the settlement control of the building was achieved with the end-bearing piles carrying the rest of the load. This method was applied in practice where the bearing capacity of natural foundation could meet the requirements but the settlement of the building was too large. Using the method presented in this paper，the foundation soil bore 55% of the superstructure load and the settlement was controlled well. A series of monitoring data showed that the scheme of the end-bearing composite pile foundation based on settlement control was reasonable and effective.