地下结构抗浮设计中抗拔桩的简化模型及其应用

Simplified Models for Uplift Piles in Anti-floating Design of Underground Structures and Their Application

抗拔桩是抗浮结构的重要组成部分。然而,地下结构进行整体设计时,为减少工作量及难度,需要采用能够比较准确表达抗拔桩行使功能的简化模型。从不同的角度出发,理论上探求了抗拔桩的两种简化模型(桩体弹簧模型和桩-土弹簧模型)及其弹簧刚度表达式。在运用Midas/gts计算出主体结构内力的基础上,桩体弹簧模型计算的底板内力与原设计计算结果进行了对比。前者在设置抗拔桩处的底板弯矩是后者的3倍左右,经讨论分析知,新的弹簧模型更能反映工程实际。

Uplift piles play an important role in anti-floating structures.However,in order to reduce the difficulty in calculations,simplified model which expresses the function of uplift piles should be used when designing underground structures.Two kinds of simplified models for uplift piles,pile spring model and pile-soil spring model,including their stiffness expressions,are deduced in theory from different angles.The internal forces of main structure are calculated by using Midas/gts.And the results of internal force using pile spring model are compared with the original design.Bottom plate moment of the former is three times greater than the latter.After the discussion and analysis,it is showed that the new spring model can reflect the engineering practice more precisely.