陈国杰    付赣清
    (广东工业大学  广州 510500)

[提要]  通过对软土地基桩土挤压变形的分析，导出桩土共同作用的桩压缩变形公式，式中的参数由软土打入单桩试验Q-s曲线确定。该公式能明确描述桩的三个工作阶段，同时得出了桩土弹性工作阶段的桩弹簧刚度k的理论公式；用于桩筏基础设计，可适当选择桩长，充分考虑地基土承载力，从而获得较好的经济效益。
[关键词]  桩筏基础  桩周土  附着层  弹簧刚度

The extruding deformation between pile and soil in soft soil base is analyzed. The formula of the compression deformation of pile in mutual action with soil is deduced. The parameters in the formula are determined according to the Q-s testing curve of single pile which is driven into soft soil. The formula may clearly describe the three working stages of the pile. Moreover, the theoretical expression of elastic rigidity k of pile is obtained in elastic stage and it may be used to give reference for designers. When the calculated elastic rigidity k is used in designing pile-raft foundation, the load-bearing capacity should be considered fully and the length of the pile is chosen properly. In this way, the better economic benefit may be realized.
Keywords: pile raft-foundation; soil around pile; adhesive layer; spring rigidity