成层地基中单桩沉降的时间效应研究

为研究成层地基中静荷载作用下单桩沉降的时间效应,采用Voigt模型来考虑桩侧土对桩的作用,根据桩侧土的成层性,将桩土系统从下至上划分为若干层,对每层桩土系统建立控制方程。运用阻抗函数递推方法求得了频域内桩顶位移响应的解析解,进而利用Fourier逆变换和卷积定理求得了静荷载作用下考虑时间效应的单桩桩顶沉降半解析解。运用该解析解讨论了两层和三层桩侧土工况时桩土参数对单桩沉降性状的影响,并将计算结果与工程桩的实测数据进行了对比,验证了本文解的合理性。

A study on time effect of single pile settlement in layered foundation

In order to investigate the time effect on settlement of a single pile undergoing static loading in layered foundation,the Voigt model was used to simulate the viscoelasticity of soil surrounding the pile.Firstly,according to the stratification of soil surrounding the pile,the soil-pile system was divided into a number of layers and the governing equation of each layer was derived.Secondly,by the virtue of impedance function recursive method,the analytical solution of displacement response at the top of the pile in frequency domain was obtained.The semi-analytical solution in time domain under static loading at the top of the pile was also obtained by means of inverse Fourier transform and convolution theorem.Thirdly,based on these solutions,a parametric study was conducted to discuss the influence of the parameters on the settlement of the single pile when there were two and three soil layers surrounding the pile.Also,the calculated results based on the solutions presented in this paper were compared with the in-situ testing results,which proved that the solutions in this paper were reasonable.