资源描述:
《移动荷载作用下非均匀地基的动力响应分析》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第36卷第7期岩土力学Vol.36No.72015年7月RockandSoilMechanicsJul.2015DOI:10.16285/j.rsm.2015.07.026移动荷载作用下非均匀地基的动力响应分析1,211周凤玺,曹永春,赵王刚(1.兰州理工大学土木工程学院,甘肃兰州730050;2.兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050)摘要:基于线弹性动力学理论,结合坐标变换,建立了移动荷载作用下非均匀弹性半平面地基的动力控制方程,利用半解析法研究了移动荷载作用下二维非均匀地基的动力响应问题。采用傅里叶(Fourier
2、)级数展开,假设了响应函数的级数形式,通过理论推导获得了剪切模量随深度任意变化的非均匀地基在移动荷载作用下各物理量的解析表达式。考虑土体的剪切模量沿厚度方向按幂函数梯度变化,通过数值算例分析并讨论了地基非均匀参数、荷载移动速度以及地基表面的剪切模量等对地基力学响应的影响规律,并与均质地基的计算结果进行了比较。数值结果表明:地基中各点的竖向位移随着土体表面剪切模量和表征土体非均匀性的梯度因子的增大而减小,随着荷载移动速度的增大而增大。在移动荷载作用下,非均匀地基与均匀地基的动力响应有着显著的区别。关键词:非均匀地基;移动荷载;动力响应;半解析法;傅里叶级数
3、中图分类号:TU435文献标识码:A文章编号:1000-7598(2015)07-2027-07Analysisofdynamicresponseofinhomogeneoussubgradeundermovingloads1,211ZHOUFeng-xi,CAOYong-chun,ZHAOWang-gang(1.SchoolofCivilEngineering,LanzhouUniversityofTechnology,Lanzhou,Gansu730050,China;2.WesternEngineeringResearchCenterofDisas
4、terMitigationinCivilEngineeringofMinistryofEducation,LanzhouUniversityofTechnology,Lanzhou,Gansu730050,China)Abstract:Basedonthetheoryoflinearelastodynamics,andcombinedwiththecoordinatetransformation,thedynamicgoverningequationsforahalf-planeinhomogeneoussubgradearedeveloped.Thed
5、ynamicresponseofatwo-dimensionalinhomogeneoussubgradesubjectedtomovingloadsisanalyzedbasedonasemi-analyticalmethod.UsingFourierseriesexpansion,andassumingtheseriesformofresponsefunction,theanalyticalexpressionsofvariousphysicalquantitiesaredevelopedfortheinhomogeneoussubgradesubj
6、ectedtomovingloads,inwhichtheshearmoduluscanarbitrarilychangewithdepth.Assumingtheshearmodulushasanexponentialdistributionwiththethickness,aparametricstudyispresentedtoillustratetheinfluenceofthefoundationsoilinhomogeneityandloadmovingvelocityaswellasshearmodulusatsubgradesurface
7、onthedynamicalresponseoffoundationsoils.Thecalculatedresultsarecomparedwiththeresponsesofahomogeneoussubgrade,showingthattheverticaldisplacementofsoildecreaseswiththeincreaseoftheshearmodulusatthesurfaceofsubgradeandtheinhomogeneousgradientindex,andincreaseswiththeincreaseofthelo
8、admovingvelocity.Underamovingload,thedyn