根据哈密南—郑州±800 kV特高压直流输电线路的工程条件,对粗颗粒盐渍土地区掏挖基础抗拔承载性能进行数值模拟分析,研究了盐渍土层厚度、盐渍土层状态、基础深径比及水平荷载与上拔荷载比值对抗拔承载力的影响规律.结果表明:掏挖基础抗拔承载力在盐渍土层盐分结晶时随盐渍土层厚度增大而增大,盐分溶蚀时随盐渍土层厚度增大而减小.抗拔承载力随深径比增大持续增大,临界深径比约为4.5;随着深径比增大,盐渍土层状态对基础抗拔承载力的影响逐渐减弱;超过临界深径比后,结晶状态抗拔承载力与融化状态趋于一致.盐渍土层盐分结晶状态下的水平荷载影响系数高于溶蚀状态.%Based on the engineering condition of Southern Hami -Zhengzhou ± 800 kV UHVDC transmission line ,nu-merical analysis has been performed to evaluate the influence of thickness of saline soil layer ,saline state and ratio of horizontal load to uplift load on the uplift bearing capacity of digged foundation in coarse particle saline soil area .The re-sults show that the uplift bearing capacity increases obviously with the increment of thickness of saline soil layer under the condition of salt crystallization ,however ,under the condition of salt corrosion ,the uplift bearing capacity decreases with the thickness of saline soil layer increasing .Uplift bearing capacity increases with the ratio of embedment depth to belled diameter increasing and the critical ratio of embedment depth to belled diameter is about 4 .5 .With the ratio of embed-ment depth to belled diameter increasing ,the influence of saline state on uplift bearing capacity has gradually weakened . The uplift bearing capacity under condition of salt crystallization tends to be consistent with that under condition of salt corrosion .The influence coefficient of horizontal load in crystalline state of saline soil is higher than that in dissolved state of saline soil .
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