沈阳地区砂土碎石土层抗拔桩承载力的试验研究

Experimental Study on Uplift Pile Bearing Capacity in Shenyang Sand Gravel-Qay

通过沈阳砂土地区旋挖成孔抗拔桩的现场静载试验、钢筋应力测试等试验,研究单桩抗拔承载能力、侧摩阻力的分布规律,得出以下结论：按地层年代划分土层确定侧摩阻力比按岩性名称划分更为合理;压浆前、后增强段侧阻力增强系数约在1.15～1.62之间;扩径支盘现象可以使局部摩阻力发挥较大,但也限制了其下部一定桩长范围内摩阻力的发挥.

Through static load test, inforcement stress tests and other tests on uplift pile in Shenyang sand area, study the uplift pile bearing capacity and lateral friction, and get the following conclusions： according to the soil division by strati graphic to determine the lateral friction is more reasonable than the soil division by lithology; before and after grouting, the lat eral friction enhancement factor is about 1.15 to 1.62 in the enhanced part; the effect of branches and plates can partly improve the lateral friction, but also limit the lower lateral friction in certain length range of the pile.