后压浆钻孔灌注桩的荷载传递机理研究

后压浆技术可大幅提高钻孔灌注桩的承载力，在不同的土层条件下，后压浆的加固机理会表现出不同的形式。软土中长桩承载力的提高主要来源于摩阻力的提高。根据软土中应用后压浆技术的钻孔灌注桩的静载试验及桩身应力测试结果，考虑到土体的连续性引起的变形，对各桩段实测的摩阻力与位移关系进行了修正，并用传递函数对摩阻力与位移关系进行拟合，得出各桩段的摩阻力极限值，从而真实反映出压浆后摩阻力沿桩身的分布规律。

Mechanism study on bored cast-in-place piles with post-grouting technology

The post-grouting technology could improve the bearing capacity of bored cast-in-place piles; and the reinforcing mechanism of the post-grouting technology differs in different soil strata. In soft soils, the improvement of bearing capacity of long piles is mainly derived from increase in frictional resistance. The testing results of static loads and shaft stress are analyzed; and the relationships between frictional resistance and relative displacement are revised in consideration of deformation caused by soil continuity; and they are fitted by transfer functions. Based on transfer functions, the ultimate values of frictional resistance are calculated so as to reflect the real distribution regulations of frictional resistance along the shaft .