[提要]  利用系统分析原理，从s域对桩土系统进行分析，得到系统传递函数、速度导纳响应函数。从缺陷桩的桩土系统参数模型出发，推导出缺陷桩速度导纳响应模型，研制了Matlab分析计算软件，得到缺陷桩的速度导纳曲线存在大峰夹小峰的特征，提出了一种直观的判断基桩完整性的方法。根据这一特征，得到小峰与大峰之比与缺陷程度之间的关系曲线，提出利用导纳曲线进行缺陷量化分析。
[关键词]  导纳响应  系统分析  传递函数  量化分析

With the system analysis theory, transfer function and velocity mobility response in s domain are　deduced. According to the pile-soil parameter model, the mobility of concrete defective pile is gained, and based on it,a program of Matlab language is worked out to simulate mobility response of a　defective pile.A simple method is provided to determine the integrity of the shaft. The relation between ratio of peaks and degree of defect is worked out, then a method of quantity analysis in frequency　domain is proposed.
Keywords:  conductance response; system analysis; transfer function; quantity analysis

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