静压桩残余应力对桩承载性状试验研究与影响分析  

Experimental study on influence of residual stress of jacked pile on bearing behavior of piles

作　　者：寇海磊[1] 邢栋[2] 张明义[3] 

机构地区：[1]中国海洋大学工程学院,青岛266100 [2]潍坊学院建筑工程学院,潍坊261061 [3]青岛理工大学土木工程学院,青岛266033

出　　处：《建筑结构》2017年第16期94-97,共4页Building Structure

基　　金：国家自然科学基金项目(51408439);中国海洋大学青年英才工程计划项目(841712014);山东省住房和城乡建设厅科学技术项目(KY048);潍坊市科技发展计划项目(2015GX011;2015GX012)

摘　　要：静压桩残余应力对桩工作性状具有重要影响。通过黏性土地基中静压敞口高强预应力混凝土(PHC)管桩静载荷试验,阐明了沉桩结束后的残余应力分布特征,并对载荷试验过程中残余应力对荷载传递性状及承载力的影响进行了分析。结果显示,沉桩结束后静压桩残余应力较大,桩端残余应力占沉桩应力比值约为7.1%;残余应力沿桩身呈双曲线分布,于中性面处达到峰值;载荷试验过程中,残余应力对荷载传递性状的影响与桩顶荷载大小密切相关。不考虑残余应力影响将高估中性面以上桩侧极限摩阻力16.3%~19.5%,低估中性面以下桩侧极限摩阻力19.8%,残余应力对桩承载力影响不大。The residual stress of jacked pile has significant effects on pile working behavior. Static loading test was conducted on the open-ended pre-stressed high-strength concrete （PHC） pipe pile installed on clay base to study the distributive characteristics of residual stress after pile driving. The effect of residual stress on load transfer behavior and bearing capacity in loading experiment process were analyzed. The results show that jacked pile has large residual stress after pile driving and the residual stress at pile top accounts for about 7.1% of the whole driving pile stress. The residual stress along the pile body features a hyperbola distribution and achieves the peak value on the neutral surface. During the loading experiment, effects of residual stress on the load transfer behavior are closely related to load on the pile top. Without considering the influence of residual stress, the ultimate friction resistance of pile side above the neutral surface is overestimated by 16.3% - 19.5%, and the ultimate friction resistance of pile side under the neutral surface is underestimated by 19.8%. The residual stress has little effect on the bearing capacity of the pile.

关 键 词：PHC管桩 残余应力 桩侧摩阻力 桩端阻力 承载力 

分 类 号：TU442[建筑科学—岩土工程]