层状地基中考虑土体剪切效应的单桩振动阻抗分析  

Vibration impedance analysis on single pile considering soil shear effect in layered foundation

作　　者：王珏[1] 周叮[1] 刘伟庆[1] 王曙光[1] 杜东升[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京211800

出　　处：《南京工业大学学报（自然科学版）》2013年第5期1-8,共8页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：土木工程防灾国家重点实验室开放课题(SLDRCE10-MB-06);江苏省自然科学基金(SBK201322459);江苏省研究生科研创新计划(CXZZ12_0429)

摘　　要：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(Pasternak)地基模型中单桩水平振动的微分方程,运用传递矩阵法得到层状地基中单桩水平和回转振动的阻抗。与实例比较验证了理论推导及程序编制的正确性。分析表明:随着桩土弹模比的减小,第二地基参数对桩顶阻抗的影响有增大的趋势,此时使用双参数地基模型进行分析是必要的。对桩顶振动阻抗的影响因素(桩土弹模比、地基成层性、桩底边界条件、桩身长径比、量纲为1的频率)进行了参数化分析,结果表明:表层土的桩土弹模比是桩水平振动最重要的影响因素,振动阻抗随桩土弹模比的增大而减小,而有效桩长则随弹模比的增大而增大。Based on Winkler foundation model, the second soil elastic parameter was introduced to con- sider the shear effect in the elastic foundation. The differential equation of the pile horizontal damped vi- bration in the two-parameter （Pasternak） layer foundation was solved by an initial parameter method. The transfer matrix method was used to obtain the horizontal and rotational impedances, as well as the dy- namic internal forces on different dimensionless frequencies. Compared the numerical results with the published data, the accuracy of the theoretical derivation and the calculation program was proved. The a- nalysis showed that the influence of the second soil elastic parameter became more obvious when pile-soil elastic modulus ratio decreased. It was necessary to build a two-parameter foundation model in that case. The influence of factors on impedance, such as the pile-soil elastic modulus ratio, the layered property of the foundation, the aspect ratio and bottom conditions of a pile and the dimensionless frequency was dis- cussed. The parameter study demonstrated that the pile-topsoil elastic modulus was the most important factor affecting the dynamic properties of a pile. Impedance values decreased fast with the increase of the ratio, while the effective pile length increased with the increase of the ratio.

关 键 词：桩 土与基础动力相互作用 双参数地基 阻抗函数 

分 类 号：TU470[建筑科学—结构工程] O347[建筑科学—土工工程]