考虑成层土剪切效应的相邻桩基动力相互作用

Dynamic interaction between adjacent piles considering soil shear effect in layered foundation

在Winkler模型中引入描述地基土剪切效应的第二地基参数,采用初参数法求解双参数地基模型中桩的水平振动微分方程,运用传递矩阵法得到层状地基中邻桩的动力相互作用因子。分析表明双参数地基模型的计算结果比Winkler模型的计算结果偏大,在低外载激振频率、小桩土弹模比、小桩间距和均质土的情况下差异更为明显。文中对影响动力相互作用因子的诸多因素(桩土弹模比、桩间距、桩间角、地基成层性、桩底边界条件、桩身长径比以及激振频率)进行了参数化分析。结果表明,桩间距和桩间角是影响邻桩相互作用因子最明显的参数,桩土弹模比对均质土的邻桩动力相互作用因子影响微小,而对层状土的邻桩动力相互作用因子影响较大。

Based on Winkler foundation model,the second soil elastic parameter was included in which the shear effect of layered foundation is included.The differential equation of the pile horizontal damped vibration in the two-parameter layer foundation was solved via the initial parameter method.The transfer matrix method was used to obtain the dynamic interaction factor between adjacent piles.The accuracy of theoretical derivation and calculation program was proved through comparing the numerical results with the published ones.The analysis shows that the interaction factor solved via the two-parameter model is larger than that by the Winkler model.There is more obvious difference between them especially in the homogeneous foundation with low pile-soil elastic modulus ratio,short piles distance and low frequency of exciting loads.The influence of factors on dynamic interaction factors such as the pile-soil elastic modulus ratio,distance and angle between piles,the layered property of the foundation,the aspect ratio and bottom conditions of piles and the dimensionless frequency was discussed.The parameters study demonstrates that distance and angle between piles are the most important factors affecting the dynamic interaction factors.The change of the pile-soil elastic modulus ratio has a little effect on dynamic interaction factors in the homogeneous foundation,while a greatly effect on that in the layered foundation.