旋挖钻孔灌注桩低应变检测与分析

LOW STRAIN TESTING AND ANALYSIS OF ROTARY DRILLING CAST-IN-PLACE PILES

本文以水阳江特大桥的旋挖钻孔灌注桩低应变检测为例,分析了桩头浮浆及桩身扩径对低应变检测曲线的影响。桩头浮浆可以产生多次反射波或使波形畸变。桩身扩径产生扩径上界面的反相反射波和下界面的同相反射波;桩身扩径很大时,无桩底反射波及扩径下界面反射波,只有扩径上界面的多次反射波。

Taking the low-strain dynamic testing curves of rotary drilling cast-in-place piles for the Shuiyang River Bridge as example, this paper analyzed the effects of pile head laitance and pile shaft belly on the low strain dynamic testing curves. The pile head laitance may produce multi-reflection waves or make the waveform distorted. The pile shaft belly produces same-phase reflection on the lower interface and opposite-phase reflection wave on the upper interface. The bigger belly produces no reflection waves at pile toe and lower interface of the belly but multi-reflection waves at the upper interface.