考虑土塞效应的分数阶导数描述的黏弹性饱和土中部分外露管桩扭转振动  

Torsional Vibration of Partially Exposed Pipe Piles Considered Soil-plug Effect in Viscoelastic Saturated Soil Expressed by Fractional Derivatives

作　　者：余春春 傅敏[1] YU Chunchun;FU Min(Department of Architectural Engineering,Zhejiang College of Construction,Hangzhou 311211,China)

机构地区：[1]浙江建设职业技术学院建筑工程学院,杭州311211

出　　处：《工业建筑》2022年第1期150-158,共9页Industrial Construction

基　　金：浙江省建设科研项目(2020K095)。

摘　　要：考虑管桩的土塞效应,利用分数阶导数黏弹性理论和多孔介质理论得到了以位移表示的分数阶黏弹性饱和土的扭转振动控制方程,建立了分数阶黏弹性饱和土-部分外露管桩扭转动力相互作用模型。考虑分数阶导数和贝塞尔函数的性质以及土体边界条件,得到了等效Winkler扭转弹簧-阻尼器模型的等效刚度和阻尼系数。考虑桩周和桩芯饱和土对管桩的作用,运用传递矩阵法求解了部分外露管桩的扭转振动,得到了管桩桩顶的扭转刚度因子和等效阻尼系数。以数值算例的形式讨论了管桩和土体力学性质参数和几何参数对管桩扭转振动的影响。结果表明:管桩的几何参数对分数阶黏弹性饱和土中部分外露管桩扭转振动的影响较力学性质参数的影响要大;考虑土塞效应研究分数阶黏弹性饱和土中部分外露管桩扭转振动时不能忽略土体黏滞性的影响,但桩芯与桩周饱和土性质的差异可以忽略;管桩的管壁厚度对扭转振动的影响较为敏感。Based on the viscoelastic theory expressed by fractional derivatives and the theory of porous media,the torsional dynamic control equations in the form of displacement for viscoelastic saturated soil expressed by fractional derivatives were obtained by considering the soil-plug effect of pipe piles,the torsionally dynamic interaction model to describe viscoelastic saturated soil expressed by fractional derivatives and partially exposed pipe piles was constructed.The equivalent stiffness and damping coefficients of the equivalent Winkler torsional spring-damper model were obtained by considering properties of fractional derivatives and Bessel Function,and boundary conditions of soil.Considering the effect of saturated soil around and in pipe piles,the torsional vibration of partially exposed pipe piles in saturated soil was solved by using the transfer matrix method,and the torsional stiffness factor and equivalent damping coefficient at tops pipe piles were obtained.The influences of mechanical and geometric parameters of pipe piles and soil on torsional vibration of pipe piles were discussed by numerical examples.The results showed that the effect of the geometric parameters for pipe piles on torsional vibration of partially exposed pipe piles in viscoelastic saturated soil expressed by fractional derivative was greater than that of mechanical properties for materials.When considering the soil-plug effect,the influence of soil viscosity could not be ignored on torsional vibration of partially exposed pipe piles in viscoelastic saturated soil,but the difference of properties between saturated soil around and in pipe piles could be ignored.The wall thickness of pipe piles was sensitive to the torsional vibration.

关 键 词：分数导数 部分外露管桩 土塞效应 扭转振动 饱和土 

分 类 号：TU473.1[建筑科学—结构工程]