扩底后注浆桩的现场试验研究与分析

Experimental research and analysis of cast-in-place piles with expanded-base and post-grouting

结合某工程的桩基现场静载荷试验和桩身应力测试,对比分析了同一场地中相同桩长的普通钻孔灌注直桩、后注浆灌注直桩、扩底灌注桩和扩底后注浆灌注桩4种桩型的承载力特性、桩身轴力和桩侧摩阻力的分布特性,阐述了扩底后注浆桩的桩身轴力传递规律和侧阻力发挥性状。研究表明:扩底后注浆桩有沉降小、单桩承载力高的特点,具有良好工程性状和经济效益。

Static vertical loading tests and stress tests of four types of piles, that is, the normal cast-in-place pile, the cast-in-place pile with post-grouting, the cast-in-place pile with expanded-base, the cast-in-place pile with expanded-base and post-grouting, are performed in the same site. Based on the field experiments, compares the bearing capacity behavior, the distribution of axial force and lateral friction of the four types of piles. And transmission rule of axial force and the action of lateral friction of the piles is analyzed. The results of researches prove that the cast-in-place piles with expanded-base and post-grouting possess the characteristics of low settlement and high bearing capacity.