摘要
静压沉桩过程中沉桩速率决定着桩周土体扰动程度与范围,而目前在静压沉桩中考虑沉桩速率对桩周土体变形影响的研究还较少。基于透明土相似材料和粒子图像测速技术(PIV),开展静压沉桩可视化模型试验研究,分析不同沉桩速率下桩周土体位移场及其演化过程。结果表明:不同沉桩速率下桩周土体位移模式表现出斜向下挤密扩张→侧向挤压→斜向上挤出的动态变化过程;沉桩初期和后期扰动范围发生变化的原因是高速沉桩下桩端下提前产生了高应力区;高速沉桩对桩周土体扰动范围略大于低速沉桩;桩周土体总的运动趋势为向上运动,且沉桩速率越大,距离桩体越近,土体竖向位移量越大。研究成果可为合理设计沉桩速率和保障施工质量与安全提供技术支持。
In the process of pile jacking,the rate of jacking governs the degree of the soil disturbance adjacent to the pile.But few published studies considering the effect of jacking rate on the deformation of soil adjacent to the pile.By using a transparent soil material and the Particle Image Velocimetry(PIV)method,a series of visual model tests were conducted to analyze the displacement field and its evolution process of the soil around piles at different pile jacking rates.The results indicate that the soil displacement patterns demonstrate a dynamic process of the downward extrusion to lateral extrusion and to upward extrusion at different pile jacking rates.The reason for the variation of disturbance range at the initial and later stages of pile-jacking is that the high stress zone is produced ahead of the time under the tip of high-speed pile-jacking,and the disturbance range of the high-speed pile-jacking is slightly larger than that of low-speed pile-jacking.The general motion trend of the soil around the pile is upward,and the greater the velocity of pile jacking and the closer the distance to the pile,the greater the vertical displacement of the soil.The research results can provide a technical support for a reasonable design of the pile jacking rate and assurance of the construction quality and safety.
作者
宋文军
冷先伦
何翔
陈建
王川
SONG Wenjun;LENG Xianlun;HE Xiang;CHEN Jian;WANG Chuan(School of Civil Engineering and Architecture,Wuhan Polytechnic University,Wuhan 430023;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071;University of Chinese Academy of Sciences,Beijing 100049)
出处
《土工基础》
2023年第1期152-156,共5页
Soil Engineering and Foundation
基金
国家自然科学基金(No.52079135)。
关键词
静压沉桩
透明土
沉桩速率
相似模型试验
位移场
Jacked Pile Installation
Transparent Soil
Pile Jacking Rates
Model Test
Displacement Field
