摘要
对软土地区的管桩竖向承载力试验成果进行了统计分析,研究表明:逾70%的管桩实际采用的竖向承载力不足管桩桩身强度的50%,未能充分发挥管桩桩身材料具有较高强度的优势。开发了适用于软土地区的扩孔灌浆管桩专利技术,通过在桩端设置尺寸大于桩身外径的端板,实现沉桩的同时在桩周形成大于桩身外径的空间,并利用管桩余浆等胶凝材料在此空间进行注浆形成扩孔灌浆管桩。对13根试验桩进行竖向抗压、抗拔和抗水平力足尺试验,表明该工艺可显著提高管桩桩端和桩侧土的阻力,以提高管桩的竖向承载力和抗侧移刚度,并在某重点工程中进行了应用,取得较好的社会经济效益。
Through the statistical analysis of the pipe piles＇ vertical bearing capacity tests in the soft soil area, according to the pipe pile foundation which mainly bears vertical load, we can find that more than 70% of the pipe piles＇ actually vertical bearing capacity were less than 50% of the ultimate strength; and it failed to get full use of the high material strength of the pipe pile. The purpose of this study is to improve the work process of the pipe pile, in order to improve its bearing capacity. By the method of prototype test, this paper presents a kind of enlarged grouting pipe pile patent which is suitable for soft soil area.We can set the endplate＇s diameter greater than the pile＇s diameter, which can form a space surrounding the pile larger than the pile＇s diameter while the pile was sinking, and we can use cementitious materials, such as the surplus grout, to jet grout into that space; then reaming grouting pipe pile is formed. Through thirteen test piles＇ vertical compression tests, tension tests, and horizontal force full scale tests, it is shown that this process significantly increased the resistance of the piles＇ tips and the soil surrounding the piles; and in this way the pipe piles＇ vertical bearing capacity and lateral stiffness can be improved. And this type of pile has been applied to a practical project, and good social and economic benefits are achieved.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第7期1984-1990,共7页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51078263)
关键词
扩孔灌浆管桩
承载力
灌浆
桩-土共同作用机制
pipe pile with enlarged diameter
bearing capacity
grouting
pile-soil interaction mechanism
