摘要
通过积分变换法,对考虑桩身材料阻尼条件下的桩基纵向振动问题进行求解,并得到了桩–土系统的传递函数以及脉冲响应函数。通过脉冲响应函数与外部激振函数在时域内卷积,可以得到任意激振条件下,桩顶位移(速度)响应的时域解析解,解决了分离变量法由于解法局限性只能对稳态正弦激振响应进行求解的不足,大大提升了解的适应性。并对工程测试中可能出现的测试信号高频干扰问题进行了波形分析,由于桩阻尼的存在,测试信号中的高频干扰成分所对应的响应会自动滤去,同时低频成分对应后继反射波趋于"宽扁"型。当桩阻尼较大时,反射波的起跳位置发生改变,不能作为一维弹性波速的测试依据。
The longitudinal vibration of a viscoelastic pile was derived by integral transformation method in this paper and the transfer and impulse response functions of pile-soil system were obtained as well. The analytical solution of displacement（velocity） at the pile top subjected to any form of excitation was derived by the convolution of impulse response function and excitation function. This method overcomes the limit of the method of separation of variables considering only the steady-sine excitation and extends the adaptability of the solution. Furthermore,a case study of low-strain integrity testing considering high-frequency disturbing signal was presented. Because of the existence of pile damping,the response to the high-frequency component of testing signal is filtered automatically,and the waveform of subsequently reflection corresponding to the low-frequency component is wide and flat at the same time. When the pile damping is very large,the location of the take-off point of reflection is shifted,and cannot be the basis for the test of one dimensional elastic wave velocity.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2017年第9期2305-2312,共8页
Chinese Journal of Rock Mechanics and Engineering
关键词
桩基础
黏弹性桩
积分变换法
低应变测试
foundation piles
viscoelastic pile
integral transformation method
low-strain test
