Timoshenko梁模型下完整桩瞬态横向振动半解析解

Semi-analytical solution for transient lateral vibration of integrate piles based on Timoshenko beam model

文章采用Timoshenko梁模型下桩-土系统横向振动的动力学模型和数学模型,通过Laplace变换,得到桩顶横向振动速度在频域内的解析解,进行快速Fourier逆变换,得到桩顶速度时域内的表达式;根据试验桩参数绘制出速度导纳曲线及桩顶速度曲线,分析Bernoulli-Euler梁模型和Timoshenko梁模型的速度导纳曲线的特点,对比2种模型桩的理论速度曲线与试验桩实测速度曲线的差异;分析不同参数对桩顶横向动力响应的影响。结果表明,Timoshenko梁模型的结果比Bernoulli-Euler梁模型更接近于工程实际中低应变横向测桩的结果,所得半解析解结果能在频域内进行分析,具有很好的适应性和准确性。

Using the dynamical and mathematical models of lateral vibration of pile-soil system under Timoshenko beam model, an analytical solution of the velocity of lateral vibration in frequency domain was derived by Laplace transforming, and the velocity of pile head in time domain was worked out through fast inverse Fourier transforming. According to the test pile parameters, the curves of velocity admittance and pile head velocity were plotted to show the features of velocity admittance curves of Timoshenko beam model and Bernoulli-Euler beam model. The theoretical velocity curves of the two model piles and the real velocity curves of test piles were also compared to analyze the impact of vari- ant parameters on the dynamical response of pile head. It is shown that the results of Timoshenko beam model are more approximate to the observation in low strain integrity testing than those of Ber- noulli-EuIer beam model. The semi-analysis method can solve the response of pile-soil system in fre- quency domain and has strong adaptability and high accuracy.