考虑土塞效应时开口管桩的挤土效应分析

为了研究开口管桩贯入过程中土塞效应和挤土效应的相互作用问题,基于弹塑性力学基本原理,考虑开口管桩土塞的增长特征,得出了柱形孔扩张过程中桩周土体的应力场及位移场解析表达式.以土塞增长率(IFR)在开口管桩贯入过程中的变化为依据,提出了土塞增长的理想化模型,推导了土塞模型的解析表达式,分析了考虑土塞效应时开口管桩挤土效应的特征.利用模型试验获得桩周土体的径向位移,并与理论计算结果进行对比.结果表明,位移的计算值与实测值具有相同的变化趋势.

Analysis on squeezing effect of open-ended pipe pile with considering plugging effect

In order to study the interaction of plugging effect and squeezing effect in the penetration process of open ended pipe pile, the analytical expressions for the stress field and displacement field of the soil around the pile in the expansion process of cylindrical cavity were obtained with considering the plugging growth characteristics of open ended pipe pile and based on the basic principle of elastic plastic mechanics. On the basis of the change of incremental filling ratio （IFR） in the penetration process of open ended pipe pile, an ideal plugging model was established, and the analytical expression of plugging model was proposed. In addition, the characteristics of squeezing effect of open ended pipe pile were analyzed when the plugging effect was taken into account. The radial displacement of soil around the pile was obtained with a model experiment, and was compared with the theoretical calculation results. The results show that the calculated and measured displacement values have the same variation trend. 