膨胀土地基输电线杆塔基础承载力特性数值模拟

摘要

基于河南南阳膨胀土不同饱和度条件下的三轴试验结果,通过三维弹塑性有限元数值模拟,研究了大板和台阶两种典型的杆塔基础抗压和抗拔承载特性及随着土体饱和的变化规律.结果表明,随着膨胀土饱和度的增加,基础的极限抗压和抗拔承载力均明显降低,且降低速率逐渐减小.此外,在相同埋深条件下,大板基础的极限抗拔承载力要明显高于台阶基础.在不考虑膨胀土膨胀效应时,饱和度增加对两种基础抗压承载力的影响程度要明显高于对其抗拔承载力的影响程度.%Based on the results of triaxial tests of the expansive soil with different saturations in NanYang , Henan province ,China .Relationship between the saturation and compression and uplift bearing capacity of plate foundation and footing foundation is studied based on three-dimensional FEM simulations .It is concluded that the compressive and uplift bearing capacity decreases obviously with saturation increases and then tend to be stable .Besides ,the ultimate uplift ca-pacity of plate foundation is much greater than that of footing foundation obviously with the same cover depth .What's more ,influence of the increase of saturation on compressive bearing capacity is more visible than uplift capacity without consideration of dilatability of the soil .