桩基冻土融沉过程中承载力迁移规律研究

通过青海国道G227桥涵病害普查发现，由于桩基冻土融沉而造成桥台病害及盖梁开裂的现象在冻土退化边缘带分布广泛。根据实测数据及Midas FEA仿真综合分析得知:桩侧土融沉过程中，桩基承载力从桩身中上部向桩底1/3处移动，桩位移显著增大，在不同温度下，桩下沉位移差别较大，冻土上限区域有必要通过减小摩擦的方式降低负摩阻力及冻胀力的影响。

Study on Migration Law of Bearing Capacity during Thawing Settlement of Frozen Soil in Pile Foundation

Through the general survey of the bridge and culvert diseases occurring along National Highway G227 in Qinghai, it was found that both the abutment diseases and the cracked capping beam caused by thawing settlement of frozen soil in pile foundation were widely spread in the boundary zone of permafrost degradation. According to the measured data and the comprehensive analysis of Midas FEA emulation, it is concluded that, during the thawing settlement of pile side soil, the bearing capacity of pile migrates from the top half of pile to the bottom third, and the pile displacement increases significantly; at different temperature, there existed obvious difference in the pile settlement displacement, thus in the range of permafrost table, it is necessary to reduce the impact of negative friction resistance and frozen-heave force by reducing the friction.