膨胀土地区铁塔基础抗拔机理研究

在对高压输电线路的铁塔基础抗拔模型试验及原型试验的基础上，深入研究了膨胀土地基的抗拔性能，分析了土体位移、应力分布、承载能力以及破坏机理，指出了目前黏性土的抗拔理论计算中存在的缺陷，即土体的破坏不是只局限于破裂面的面破坏，而是整个土体内部的体破坏。提出了黏性土的抗拔承载力应由基础自重、基础上的土体重量、土的抗剪强度（破坏土体内部）以及应力重分布产生的地基承载力构成，并利用有限元进行了分析和验证。另外，对试验中的模型尺寸的影响也进行了分析。

Analysis and research for uplift mechanism on foundation of transmission line towers in expansive soil

On the base of the uplift model tests and prototype tests on foundation of transmission line tower, the uplift performance of expansive soil is deeply researched. The regularity of soil displacement, stress distribution, load capacity, failure mechanism were analyzed. The defect of existing uplift theory and calculation in clay is pointed out; this is that the failure of the soil is not only existing in cracking surface, but also existing entire soil body. Thus the composing of uplift bearing capacity is put forward that it is consisted of base weight, earth mass weight above the base, shear strength in the failure soil, and foundation bearing capacity caused by stress re-distribution owing to soil compressed; and then the FEM software is used for the analysis and validation. Finally, scale effect in the model tests is discussed.