软土地区超长PHC管桩承载力加固效果分析

Analysis on bearing capacity reinforcement effect of overlength PHC pipe piles in soft soil areas

在软土地区超长PHC管桩的施工过程中经常会出现挤土效应造成的“浮桩”问题和超孔隙水压力造成难以贯入度的假象,使得桩的实际承载力发挥受限。采用静载反力快速复压和不同锤击复打方式对桩进行加固处理,处理后通过高应变法和静载试验进行承载力加固效果验证,并通过动静对比分析,获得相关的复打控制参数。结果表明,液压锤击桩机复打和高应变试验专用设备复打相结合的方式可以作为软土地区超长PHC管桩承载力加固的手段。

During the construction of overlength PHC pipe piles in soft soil areas,there is often a phenomenon of"floating pile"caused by squeezing effect and the illusion of difficulty in penetration caused by excessive pore water pressure,which limits the actual bearing capacity of the piles.The pile is reinforced using static load reaction rapid repressing and different hammering redriving methods.After treatment,the bearing capacity reinforcement effect is verified through high strain method and static load test,and relevant redriving control parameters are obtained through dynamic and static comparative analysis.The results indicate that the combination of hydraulic hammer pile driver and high strain specialized equipment can be used as a means of strengthening the bearing capacity of overlength PHC pipe piles in soft soil areas.