基于动测法的基桩刚度验证试验研究

针对以往基桩刚度无法准确测得的情况,从基桩动力特性基本理论出发,重新梳理了桩顶受微小激励时所产生的动态响应,给出了通过速度导纳幅频曲线中振动固有频率的位置来计算基桩刚度值的基本公式。利用室内模型试验,通过静态加载法和瞬态机械阻抗法对比测定基桩刚度值,验证了瞬态机械阻抗法测试基桩刚度值的可行性。该结果进一步说明了通过瞬态机械阻抗速度幅频曲线拾取基桩振动固有频率来确定基桩刚度值是具有实际意义的。

Experimental research on verification test of the stiffness of foundation pile based on dynamic method

For the case of the stiffness of foundation pile low frequency cannot be accurately measured, form the analysis of basic theory of foundation pile dynamic properties, to comb the dynamic response of pile head when excited by small, given the basic formula for calculating foundation pile stiffness values by the position of natural vibration frequency in velocity admittance amplitude-frequency curve. Use of indoor model test, compared the foundation pile stiffness values through static loading method and transient mechanical impedance method, verified the feasibility of using transient mechanical impedance method to test foundation pile stiffness values. The results further illustrate that it is with practical significance to determine foundation pile stiffness values by pick natural vibration frequency from transient mechanical impedance velocity amplitude-frequency curve.