考虑钢护筒效应的混合桩水平承载性能分析

Lateral Load Capacity Analysis of Variable Section Hybrid Piles with Wteel Casing

深水桥梁基础施工时的钢护筒,在钻孔灌注桩施工完毕后保留,桩体实际上形成了"上大下小"的变截面混合桩。采用非线性的NL法比较了苏通大桥的钻孔灌注桩在考虑钢护筒效应和忽略钢护筒效应这两种工况下基桩位移和内力分布,结果表明考虑钢护筒效应可减少桩顶位移约50%,在准确计算水平荷载下的变形时不能忽略;制作并进行了8个构件的模型试验,表明施工泥皮厚度将显著影响水平荷载下的钢护筒和内部桩体的共同作用能力。

With the construction of deep-water bridge foundation,steel casing is left after the construction of cast-in place piles due to the dismantle difficulty.Then the pile actually forms a variable section pile which has bigger section area at upper part.Using the nonlinear NL method,the displacement and the internal force are analyzed for piles with and without casing in Sutong Bridge.It is found that the displacement of pile with casing can be reduced by 50%,and it can not be ignored for accurate calculation of displacement.8 model pile tests are carried out,which suggests that the slurry thickness can significantly affect the capability of co-working between the pile and the casing.