预应力高强混凝土支护桩抗弯试验研究及计算方法探讨

Experimental study and discussion on the flexural capacity of prestressed high strength concrete supporting piles

预应力高强混凝土支护桩(GZH)是为满足深基坑工程支护需要而设计制作的一种新型围护桩。与一般的PHC管桩相比,GZH桩需要承受更大的弯矩。但一般的规范、手册、教科书中都没有对GZH桩这种环形截面构件的抗弯承载力进行精确计算,只是根据环形偏心受压构件的经验公式进行简化计算,这种简化计算对于专用于承受水平荷载的GZH桩显然是粗糙的。为解决这一问题,通过24根GZH桩的抗弯承载力试验,分析其在弯矩作用下的破坏机理,提出适用于GZH桩的抗弯承载力计算公式,并与试验结果进行对比。计算结果表明,极限弯矩计算值安全可靠,与试验值吻合良好。

The prestressed high strength concrete supporting pile（GZH）,which is a new type of retaining pile,is designed to satisfy the need for deep foundation pit supporting.Compared with the general PHC pile,the GZH pile has to bear greater bending moment.The flexural capacity of GZH pile has no accurate calculation method in the current specifications,manuals and textbooks,but only has simplified calculation according to the empirical formula of ring cross section member under eccentric compression.This simplified calculation is obviously rough for GZH pile which is designed to bear the lateral load.In order to solve this problem,the flexural capacity test of 24 GZH piles was carried out,and the failure mechanism in the action of bending moment was analyzed.The flexural capacity formula for GZH pile was proposed and the calculation results of the formula were agreed well with the test results,which shows that the formula is effective.