复合桩加固液化土桩身弯矩分析

Analysis on Pile Bending Moment of Liquefied Soil Reinforced by Composite Pile

通过对水泥土桩与钢管桩复合加固地基模型和碎石桩与钢管桩复合加固地基模型进行振动台模型试验,分析了这两组复合桩加固模型在模拟地震作用下超静孔隙水压力和桩身弯矩的变化情况,得出水泥土桩与钢管桩复合加固模型超静孔隙水压力几乎不变但桩身弯矩值下降很快,说明水体无排出,桩间土部分液化,土体承担荷载减小而桩体承担荷载增大;碎石桩与钢管桩复合加固模型超静孔隙水压力消散明显且桩身弯矩值有所降低,说明水体排出土体密实,土体承担荷载增大桩体承担荷载减小;因此,设计碎石桩与钢管桩复合加固液化土对实际工程很有意义。

The study analyzes excess pore water pressure and pile bending moment of two composite foundation models：cement-soil pile with steel pipe pile model and gravel pile with steel pipe pile model,by shaking table model test.The excess pore water pressure of the cement-soil pile with steel pipe pile composite foundation model is hardly dissipated and the pile bending moment decreases quickly,which manifests no discharged water,partly liquefied soil between piles,decreased load born by the soil,and increased load born by the piles.The excess pore water pressure of the gravel pile and steel pipe pile composite foundation model is dissipated obviously and pile bending moment decreases obviously,which manifests discharged water,compacted soil,increased load born by the soil,and decreased load born by the piles.Therefore,the design of the liquefiable sand soil reinforced by the gravel pile and steel pipe pile has certain significance in practical engineering.