软土地基嵌入卵石层钻孔灌注桩后压浆技术问题研究

Some problems about post-grouting design of bored pile inserted to boulder bed in soft foundation

结合实际工程,对嵌入卵石层钻孔灌注桩后压浆设计、施工中后压浆方法的选择、注浆量的确定、后压浆桩的承载力计算、后压浆在超长桩中的应用等进行了研究。试验结果表明,采用后压浆时应选用桩底注浆,桩底后压浆的注浆量与桩径的平方成正比;后压浆桩端承载力可按预制桩的桩端承载力进行计算;后压浆对超长桩的承载力和沉降均有较大改善。

Based on actual projects, it carries out research on the choice of post-grouting method, grouting quantity and bearing capacity of bored pile, and the application of post-grouting in super-long pile. The experiments show that grouting under the bottom of the pile is preferred when using post-grouting, and the grouting quantity is in direct proportion to square of the diameter of the pile. The carrying capacity of the bottom of the post-grouting can be calculated according to the carrying capacity of the bottom of the prefab pile, and post-grouting can greatly improve the carrying capacity and settlement of the super-long pile.