作　　者： ; ; ;

机构地区： 中交四航工程研究院有限公司

出　　处： 《工业建筑》 2013年第6期90-94,116,共6页

摘　　要： 为研究先张法高强混凝土(PHC)管桩有效预压应力在制造、养护过程中的损失情况,对直径为1 400 mm、不同长度的两根PHC管桩进行了试验,并与理论计算结果进行对比。通过制桩过程中在桩身预应力钢棒上预埋电阻应变片,获得桩身不同截面的钢筋拉应力,继而探讨了不同阶段桩身预应力的分布及损失。试验结果表明,PHC管桩离心成型后预应力钢棒拉应力在张拉端处比锚固端大,沿管桩长度方向呈线性递减趋势;预应力钢筋有效拉应力和混凝土有效预压应力在张拉端较大、锚固端较小;两根管桩成型后预应力损失均在放张阶段最大;各截面测点的预应力分布具有一定的离散性,且随时间延长有增大趋势,而中部预应力分布最为均匀。 The effective compressive stress and prestress loss in manufacture and curing of larger-diameter prestressed high concrete （PHC） pipe piles were studied by a field experiment performanced for two pipes of PHC with l 400 mm diameter and different lengths. Pasting the strain gauges on prestresed steel bars directly was used for testing the prestress for the first time, and the designed prestress and the distribution of different section in different manufacture stage were compared with the experimental results. The results showed that tensile stress of prestressed steel bar was a linear decreasing trend form tension section to anchor section after forming by centrifugal technics; the effective tensile stress of prestressed steel bar and the effective compressive stress of concrete in two pipes were much lower than the theoretical data. The loss of prestress of PHC pipe piles was much greater during releasing tension than during other process, the prestress distribution of each section was not uniform but the midsection was much better which had a increasing trend with time growth.

关 键 词： 管桩 有效预压应力 预应力损失 电阻应变片

领　　域： [建筑科学] [建筑科学]