【作者】 沈祥；

【导师】 袁海庆； 郑祥斌；

【作者基本信息】 武汉理工大学 ， 结构工程， 2003， 硕士

【摘要】 目前，随着经济的发展，土木工程建设规模的扩大，对原有软弱地基的处理成为建筑设计和施工越来越被关注的环节，CFG桩复合地基法以其用材经济、施工快捷、加固效果良好等优点，在工程上得到了广泛的应用，特别是近年来CFG桩复合地基多种设计方法的提出与实践，对复合地基理论和实践的发展起到了重要的作用。 本文在现有CFG桩复合地基研究成果的基础上对CFG桩复合地基承载特性、作用机理作了系统的分析，对其多种设计方法及工程应用进行了较为全面的研究。因此，本文所作的工作主要有： (1)CFG桩复合地基设计思想的提出是基于进一步提高复合地基承载力和减少变形这一思路，本文对这一设计思想进行了分析，并探讨了其中目前存在争议的CFG桩是否为刚性桩和复合概念的问题。 (2)根据CFG桩复合地基承载力设计模式，分析比较了CFG桩复合地基承载力的若干计算方法，并探讨了承载力计算公式取值和深宽修正的问题。 (3)根据CFG桩复合地基沉降变形模式，对CFG桩复合地基沉降计算方法进行了分析与评价。 (4)提出CFG桩复合地基区域性设计的一般原则，探讨了软土地基以变形控制设计方法发展起来的悬桩设计思想和对复合地基承载力进行优化设计的褥垫层设计优化方法，结合湖北省地方标准讨论了CFG桩复合地基考虑区域差异的设计方法，并通过工程实例探讨了CFG桩一元复合地基在高层建筑地基处理中的应用。 (5)根据多元复合地基设计思想，对CFG桩-粉喷桩-石灰桩三元复合地基在软土地基中的加固机理、设计方法进行了讨论，并结合工程实例探讨了CFG桩多元复合地基在深厚软土地基中的应用。 最后，在全面总结论文工作的基础上，提出CFG桩复合地基尚待深入研究的若干问题。更多还原

【Abstract】 Nowadays, with the economic development and the extending scale of the civil engineering construction, the disposing to original foundation has been more and more taken into account as a segment in designing and working. The method of Cement Flyash Gravel piles composite foundation has been widely used due to its great advantages such as the economizing on material, the fast speed on working and the fine effect on consolidating, especially, the raising and practicing on the multiple designing methods of Cement Flyash Gravel piles composite foundation, which has been played an important role in the development of the theory and practice of composite foundation in recent years.The bearing character and working mechanism of Cement Flyash Gravel piles composite foundation are analyzed, following which the multiple designing methods and applying on projects are less comprehensively studied in this paper which are based on the available scientific achievements of Cement Flyash Gravel piles composite foundation. Therefore, the main problems are studied in this paper hereinafter:1.The designing thought of Cement Flyash Gravel piles composite foundation is provided, which is based on how to raise the bearing capacity and how to reduce the deforming of composite foundation. The designing thought is analyzed, in which the problems are disputed at present whether Cement Flyash Gravel piles are rigid piles and the conception of composition are studied in this paper.2.According to the designing pattern of bearing capacity of Cement Flyash Gravel piles composite foundation, the several calculating methods on the bearing capacity of Cement Flyash Gravel piles composite foundation are analyzed and compared, in which the data selected and the depth and width modified are studied.3.According to the deforming pattern of Cement Flyash Gravel piles composite foundation, the calculating methods on the deforming of Cement Flyash Gravel piles composite foundation are analyzed and assessed.4.The general designing regulation of Cement Flyash Gravel pilescomposite foundation is provided based on the district differences. The designing thought of suspending piles developing from the designing method controlled by deforming in feeble foundation and the optimizing method of plate designed developing from the optimizing design of the bearing capacity of composite foundation are studied, and the designing method of Cement Flyash Gravel piles composite foundation considered the district differences is discussed combined with the local criterion of Hubei province. According to the engineering project, the application of Cement Flyash Gravel single-element piles composite foundation is studied in the high-rise building.5.According to the designing thought of multi-element piles composite foundation, the consolidating mechanism and the designing method of CFG-PSA-LPS three- element piles composite foundation in feeble foundation are discussed. According to the engineering project, the application of CFG-PSA-LPS three- element piles composite foundation is studied in the deep feeble foundation.Finally, some problems of Cement Flyash Gravel piles composite foundation, which remain to be studied, are put forward on the basis of concluding the researching works in the paper.更多还原