有限深度Gibson地基上梁的稳定性  

THE STABILITY OF BEAMS ON ELASTIC LAYERED GIBSON FOUNDATION

作　　者：刘齐建[1] 赵跃宇[1] 马建军[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《工程力学》2009年第2期48-52,共5页Engineering Mechanics

基　　金：中国博士后科学基金项目(20060390871);湖南省自然科学基金项目(07JJ3012)

摘　　要：采用变分原理,给出了地基弹性模量呈线性变化的Gibson地基上梁稳定性的解析方法。将非均匀地基以改进Vlasov双参数模型模拟,并对地基-梁系统的最小势能取变分,得到梁稳定性计算的控制微分方程,然后建立了特征参数γ与失稳模态的相关关系。梁的失稳荷载可通过求解特征值得到,采用简单的迭代程序可求得失稳荷载与失稳模态。结果表明:地基土表层特性对地基模型的竖向弹性和连续特性影响较大,地基下部的影响有限。地基非均匀性将影响梁的失稳荷载和失稳模态,上硬下软地基上梁失稳将需要更大的失稳荷载。An analytical method for the stability analysis of beams on the layered Gibson soil is developed. The modified Vlasov model is adopted to simulate the foundation behavior. Using the variational principle, the governing equation of the beam and the relation between parameter ）, and buckling mode shape are derived. The buckling loads and the corresponding mode shapes of the beam can be determined by solving the eigenvalues of the boundary conditions of the beam. Parametric study shows that the soil properties near the surface have larger influence on the vertical elasticity and continuity of the foundation than those near the bottom. The inhomogeneity of the foundation affects the buckling loads and corresponding mode shapes greatly. The contribution of the resting foundation near the surface to the buckling load is more significant than those near the bottom.

关 键 词：GIBSON地基 梁 稳定性 改进Vlasov模型 屈曲模态 

分 类 号：TU311.2[建筑科学—结构工程]