灌注桩套管高频振动贯入过程中挤土效应研究

发布时间：2018-04-05 05:04

本文选题：灌注桩套管　切入点：高频振动　出处：《岩土力学》2015年11期

【摘要】：随着全套管振动取土灌注桩施工工艺的发展,灌注桩在工程中的应用越来越广泛,但关于灌注桩套管高频振动贯入机制,特别是套管贯入引起的挤土效应研究还不全面。全面介绍了套管高频振动贯入全过程的有限元-无限元耦合模型的建立过程后,对地表隆起、土体侧移及超孔隙水压力等挤土效应的变化规律进行了详细研究。研究结果表明:水平向的挤土位移随套管贯入深度的增加而增大,竖向挤土位移随着套管贯入深度的增加,浅层土表现为隆起量增大,而深层土表现为下沉量增大;最大挤土位移与套管贯入深度存在滞后效应;浅层土体的隆起为水平向应力加载引起竖向应力增加所致,且隆起分界面深度随着动力荷载幅值增大而增大,随振动频率的增大而减小;超孔隙水压力随套管贯入深度增加而增大,随径向距离增大呈指数型衰减。
[Abstract]:With the development of the construction technology of the whole set of tube-vibration earth-taking cast-in-place pile, the application of the cast-in-place pile in engineering is more and more extensive, but the research on the mechanism of high-frequency vibration penetration of the casing, especially the squeezing effect caused by the casing penetration, is not comprehensive.In this paper, the finite element coupling model of the whole process of casing high frequency vibration penetration is introduced in detail. The variation law of soil squeezing effect such as surface uplift, soil lateral displacement and excess pore water pressure is studied in detail.The results show that the horizontal displacement increases with the depth of casing penetration, the vertical displacement increases with the depth of casing penetration, the uplift of shallow soil increases and the depth of soil increases with the depth of casing penetration.The maximum soil displacement and casing penetration depth have hysteresis effect, the uplift of shallow soil is caused by the increase of vertical stress caused by horizontal stress loading, and the interface depth of uplift increases with the increase of dynamic load amplitude.With the increase of vibration frequency, the excess pore water pressure increases with the increase of casing penetration depth, and decreases exponentially with the increase of radial distance.
【作者单位】：福州大学土木工程学院;
【基金】：国家自然科学基金项目(No.41272299)~~
【分类号】：TU753.3

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