南京红层桩基持力层承载力初探

The analysis of red layer about carrying capacity in NanJing

南京红层岩性复杂,桩基持力层承载力难确定。依据南京某工程勘察资料,建立南京红层泥岩、泥质粉砂岩不同互层情况的地质模型,运用FLAC3D软件分析,并与载荷板试验结果进行对比表明:桩基持力层应选择在厚度大于两倍桩径的泥质粉砂岩地层上,避免放置于泥岩地层;载荷板试验结果偏于保守,设计时可以把这部分作为安全储备。

The red layer is familiared in Nanjing. It is complex and different in physic character. It is very hard to confirm carrying capacity using the layer as pile＇ s bearing layers. This paper, on the basis of and lithology test data, using FLAC3D programme, simulated different instances using it as pile＇ s bearing layers. The simulating result compared with the result of loading examination. It indicate that the effective depth of pile＇ s end to the layers is not go over two multiple of stake＇ s diameter. The carrying capacity is very huge if using thickness hard layer as foundation. But it is limited of using soft layer. It is safe to little enhance the result of loading examination in designing because of lower numerical value.