某吹沙填海场地PHC管桩施工的难点及处理措施研究

Research on Difficulties and Treatment Measures of Phc Pipe Pile Construction in a Blowing Sand Reclamation Plant

PHC管桩施工速度快,质量易于保证,经济性好,所以越来越多的建筑地基采用高强度预应力混凝土管桩处理。但是PHC管桩施工遇到硬层沉桩困难,因总锤击数过高,易造成桩体疲劳破坏,难以保证成桩质量和施工速度,且如果场地地下水丰富,水位高,高于桩顶,在沉桩过程中采用开口型桩靴,沉桩时土和地下水会进入管桩芯内,且随沉桩深度增大而升高,当PHC预应力管桩桩芯内的土或地下水较高时,沉桩时易因"水锤效应"使桩体爆裂,易造成质量隐患,危及建筑物安全。以在某"吹沙填海"场地进行PHC管桩工程实例研究解决此类问题的措施。

PHC pile construction speed is fast,easy to ensure quality,economic,so more and more construction foundation uses prestressed high strength concrete drilled caisson.But penetration of the PHC pile drives the hard formation difficultly,and the total number of hammer is too high to generate pile body fatigue failure,difficult to ensure the quality of pile and construction speed.And if a plant has rich groundwater and a high water table that is higher than that of pile top.in the process of pile sinking with end-open pile shoe,the soil and groundwater will enter inside pipe pile core,and increasing with increment of the depth of the pile.When soil or groundwater is too high in the PHC pile core,in pile-sinking process,water hammer effect is easy to making the pile bady blowout and to causing quality hidden trouble and endangering building security.This paper resolves the problem of such research and gets measures to prevent such issue through research on the actual PHC plie-sinking project in a Blowing sand reclamation plant.