粘弹性地基中考虑桩体剪切变形的单桩水平振动解析理论  

ANALYTICAL THEORY OF LATERAL VIBRATION OF SINGLE PILE IN VISCO-ELASTIC SUBGRADE CONSIDERING SHEAR DEFORMATION

作　　者：胡安峰[1] 谢康和[1] 应宏伟[1] 钱磊[2] 

机构地区：[1]浙江大学岩土工程研究所,杭州310027 [2]浙江大学建筑设计研究院,杭州310027

出　　处：《岩石力学与工程学报》2004年第9期1515-1520,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金(59895410)资助项目。

摘　　要：基于动力Winkler模型(BDWF)对粘弹性地基中单桩水平动力响应进行求解。采用与频率相关的刚度系数和阻尼系数来模拟动反力,桩体则被简化为Timoshenko梁,同时考虑了其弯曲和剪切变形,得到了单桩水平振动更为精确的解析解。通过与基于桩体被简化为Euler梁模型的理论比较,得到了均匀土层中可以将桩体近似简化为Euler梁来处理的界限桩长。在一般情况下,这个界限桩长在8倍的桩径左右,而且其值基本上不受无量纲频率及桩体刚度比的影响。同时,从分析中还可以发现,忽略桩体的剪切变形,会使实际计算值偏小,这在实际工程中是偏于不安全的。The Beam-on-Dynamic-Winkler-Foundation (BDWF) model is utilized to determine the lateral dynamic response of single pile in viscoelastic subgrade. Based on frequency-dependent stiffness and damp coefficients, and with the pile modeled as a Timoshenko beam considering both bending and shearing, a more rigorous analytical solution on lateral vibration of a single pile is developed. By comparing the presented theory and that based on Euler beam model, the critical length of pile in homogeneous soil is obtained by modeling the pile as a Euler beam. In most cases, this critical length is about 8 times diameter of pile and it is nearly independent of dimensionless frequency and the ratio of Young's modulus of the pile to that of the soil. It is also found that neglecting the shear deformation of pile will lead to a relatively smaller calculation result, which is not safe in engineering application.

关 键 词：粘弹性地基 土力学 剪切变形 TIMOSHENKO梁 水平动力响应 解析解 界限桩 

分 类 号：TU473.1[建筑科学—结构工程]