摘要
强夯加排水地基处理方法是近年来发展的一种地基处理技术,在吹填土地基处理方面得到了广泛应用。根据强夯能量耗散分析与土体密实机制,基于冲击荷载作用下孔隙水压力的发展模式,建立了强夯加排水地基处理的数值分析模型,并采用有限差分法进行了求解。采用编写的数值程序分析了强夯过程中超孔隙水压力的发展与土体密实效果,以及土体渗透系数、单击时间间隔以及砂井间距等对加固效果的影响,讨论了"重锤少夯"和"轻锤多夯"的差异,并与工程实例进行了比较。研究结果表明,建立的数值模型可以模拟强夯加排水地基处理的施工过程,较好地反映强夯过程中孔隙水压力的发展变化规律和加固效果。排水措施的设置有利于超孔隙水压力消散和加固深部土体,进而提高土体加固效果和缩短工期。最后,根据数值分析结果,提出了强夯加排水地基处理的合理设计建议。
Dynamic compaction （DC） plus drainage is a new technology developed in recent years, especially in improving the hydraulic fill deposits. Based on the analysis of energy dissipation, soil compaction mechanism and the model of pore water pressure generated by impact loading, a simple but effective model is developed to simulate the process of dynamic compaction. A numerical program based on the finite difference method is developed to solve the boundary value problem under the condition of DC plus drainage. Development of pore pressure and the performances of compaction during DC are studied by the numerical results and compared with field data. Some factors affecting the performances of compaction such as hydraulic conductivity, time between impacts and distance of wick drains are discussed. Different effects between number of drops and impact energy per drop are also analyzed. The simulation results indicate that the proposed numerical model can simulate the process of DC with drainage. The development of excess pore water pressure and the reinforcement effect of soil can be predicted correctly. The drainage structure introduced in the DC technique can reinforce the deep soil and shorten the construction period. Finally, a design procedure is proposed to improve the practicality of DC and drainage technique.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2013年第5期1478-1486,共9页
Rock and Soil Mechanics
基金
新世纪优秀人才资助项目(No.NCET-11-0579)
国家自然科学基金项目(No.51178044)
关键词
动力固结
排水
数值模拟
吹填土
dynamic compaction
drainage
numerical simulation
hydraulic fill deposits
