摘要
利用自行设计的可视化模型试验装置,进行分层介质中桩端刺入的宏细观试验,研究上覆软弱夹层对桩端刺入过程中桩端砂土变形的影响。试验表明,分层介质中桩端刺入存在端阻临界埋深,侧阻渐变趋势不同使得分层介质中达到极限端阻所需刺入深度小于纯砂介质。分层介质在细观上表现出桩端颗粒定向性的不同的演化规律。利用开发的三维非圆颗粒模块,对分层介质中桩端刺入的室内试验进行颗粒流数值模拟,数值模拟结果与室内试验具有良好的一致性。研究成果为进一步揭示桩刺入过程中桩端砂土的宏细观演化机制打下基础。
Using self-designed visual model devices,macro-meso tests on pile tip penetration in layered media are carried out to study the impact of upper weak layer on variation of lower sand around pile tip.It shows that the critical depth of pile tip resistance exists in layered medium.Because of different tendencies of frictional resistance,the depth of pile tip penetration in layered medium is less than that in pure sand in order to reach the ultimate pile tip resistance;the layered media present different variations of particle s directionality in meso side.Three-dimensional non-circle particle flow code numerical simulation program is developed to simulate the laboratory model tests of pile tip penetration in layered medium.The results of simulation have a better consistence with laboratory tests,building a foundation for the further study of macro-meso mechanism of soil variation around pile tip in the course of penetration.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2012年第2期375-381,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
高校博士点专项科研基金资助项目(200802470007)
关键词
桩基工程
桩端刺入
分层介质
纯砂
模型试验
颗粒流数值模拟
宏细观机制
pile foundations
pile tip penetration
layered medium, pure sand
model tests
particle flow codenumerical simulation
macro-meso mechanism
