李应保　 （上海林同炎李国豪土建工程咨询有限公司  200093）

[提要]  提出一种摩擦端承桩复合桩基设计方法，即在剪力墙或柱下集中布桩，桩顶与筏板（或承台）间设置一定厚度的软垫或专用变形器。通过迫使桩间土先于桩项发生沉降使其承担预定的荷载，随后增加的荷载则由桩、土共同承担。该法可充分发挥地基土的承载力，大幅度减少用桩量和筏板厚度及配筋，其经济效益明显优于常规桩基和复合地基。对其承载机理和变形特性进行了初步研究，得出了承载力和沉降近似计算公式，并成功应用于工程实践，取得了很好的经济效益。
[关键词]  摩擦端承桩  复合桩基  软垫  专用变形器  承载力  沉降

A design method has been put forward for composite pile foundation of friction and end-bearing piles that piles are located only under shear wall or column, and the cushion with thickness or special deforming device is installed between pile block and raft( or cushion cap). The soil between piles is settled earlier than pile block and carried the preload,after that the increasing load has been carried by piles and soil. It can make full use of foundation soil's bearing capacity, largely reduce the number of demanding piles,thickness of raft and distributed steels. Through elementary studies on the load-bearing mechanic and deforming characteristic of the composite foundation,we generalized the approximate formulas of bearing capacity and settlement,which has been successfully used in engineering practice.
Keywords:  frication&end-bearing piles; composite pile foundation; cushion; special deforming device; bearing capacity; settlement;design

   
    参  考  文  献
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