高应变法分析桩端性状对桩侧阻力的影响  

Effect analysis of the pile shaft resistance influenced by the pile toe behavior by high strain dynamic testing

作　　者：张添文[1] 梁曦[2] 

机构地区：[1]福建省建筑科学研究院厦门分院,福建厦门361006 [2]福建省建筑科学研究院,福州350025

出　　处：《工程勘察》2013年第8期20-24,共5页Geotechnical Investigation & Surveying

摘　　要：本文通过对某产生浮桩的工程采用了有效、可控的自由落锤复打法加固,并在加固过程中结合高应变动力手段监控,对采集的信号采用实测曲线拟合法进行分析计算后得出以下结论:在自由落锤复打加固浮桩后,桩端土刚度有了显著提高,随着桩端土刚度的提高,桩端附近的桩侧阻力也有了明显的提高。并分析阐述了桩端土性状对桩侧阻力的影响机理,在高应变自由落锤复打法中,桩端土受挤密作用与径向应力共同增强作用下,形成类球形的"桩土共同体"的直径要大于桩身直径,因此其所贡献的摩阻力大于加固初期的摩阻力。Through the analysis on a floated piles strengthening by controllable free falling hammer re- striking, high strain dynamic monitoring, the collected signals analyzing and measured curve matching, the conclusions are drawn as follows： after free falling hammer re-striking, the rigidity of soil underneath the pile improves significantly; with the improvement of the soil stiffness, the pile shaft resistance near the pile tip improves greatly. The influencing mechanism of the soil character underneath the pile to the pile friction resistance is stated. During the free falling hammer striking, a spherical pile-soil body will formed due to the effect of compaction and radial stress in the pile tip soil which diameter is greater than that of the pile shaft. Therefore, the friction resistance contributed by re-striking is greater than initial resistance.

关 键 词：高应变法 实测曲线拟合法 桩端土刚度 极限侧阻力 

分 类 号：TU473.1[建筑科学—结构工程]