沉降控制复合桩基的工程应用

 以沉降控制复合桩基为对象，分析其受力机制、工作性态和变形特性，推导复合桩基桩数的计算公式；通过对沉降控制复合桩基沉降量的几种常规计算方法的讨论，建立计算复合桩基沉降量的实用新方法——修正实体深基础分层总和法；并用该方法计算2个沉降控制复合桩基工程的基础沉降量。结果表明：采用修正实体深基础分层总和法计算沉降控制复合桩基基础的沉降量要比天然地基浅基础的沉降量小；计算结果与现场跟踪检测沉降结果相吻合，比常规方法的计算结果更符合工程实际，满足现行地基基础设计规范要求；与常规桩基相比，更有利于充分发挥桩和桩间土的承载力，减少了用桩数量，在很大程度上降低了工程造价，并确保工程质量。

ENGINEERING APPLICATION OF SETTLEMENT-CONTROLLED COMPOSITE PILE FOUNDATIONS

The mechanical mechanism，working behavior and deformation property of settlement-controlled composite pile foundations are analyzed；and the expressions for the pile number of the composite pile foundations are deduced. A new method calculating the settlement of the composite pile foundations，i.e. modified deep foundation layer-wise summation method，is put forward. The foundation settlements of two engineering examples are calculated by the method. The results show that the foundation settlements obtained by the modified deep foundation layer-wise summation method are much less than those of shallow natural foundation. Furthermore，the composite pile foundation settlements accord with in-situ monitoring results，correspond to the practical situation and meet the requirement of current design code of building foundation. Under this condition，the number of the piles can be cut down，and the foundation¢s bearing capacity can exert fully. Consequently，the cost of construction can be saved and the quality of engineering can be more easily assured by the cooperation between the pile and soil.