【作者】 陈杰；

【导师】 张保印；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2003， 硕士

【摘要】 随着高层建筑越建越高，采用筏形基础或桩筏基础时，筏板的厚度也不断增大。由于工程界中对于厚筏基础缺少研究，不了解其具体的受力特性，在厚筏基础设计方面缺乏成熟的设计理论和计算方法，厚筏基础仍按常规筏基的设计方法进行设计，往往造成筏板过厚，使基础造价过高，产生很大的浪费。 本文根据高层建筑上部结构、基础和地基共同作用的基本原理，提出一种厚筏基础的计算方法，考虑了多种因素影响，比较符合基础的实际受力状况。然后，通过建立结构模型，用数值计算的方法研究了上部结构、筏板厚度、地基压缩模量、筏板悬挑宽度和筏板砼等级五个因素对基础沉降、基底反力和筏板内力的影响，分析了厚筏基础的基本受力特性。另外，通过对一超高层建筑桩(厚)筏基础进行原位实测，取得了比较完备的实测资料，分析了基础沉降的特点和桩顶反力、桩间土反力和筏板钢筋应力的分布特点和规律，同时用有限元法进行了近似计算，与实测结果基本吻合。 本文对筏形基础提出了“外弱内强”的地基方案，对桩筏基础提出了“外弱内强”的布桩方式，从理论上这两种方法可以使筏基达到优化设计的目标，直接结果使筏板可以大大减薄，降低基础造价。更多还原

【Abstract】 With the increase of height of tall buildings in our country, the thickness of raft become larger and larger when raft foundation or pile-raft foundation is adopted. Owning to lack of research on properties of thick-raft foundation, the appropriate designing principles and calculation methods are lacked in engineering field. Instead the traditional design methods that lack accuracy are used in designing thick-raft foundation. It usually results in too thick raft, and makes the cost of foundation very high.In this paper, on the base of the interactive principles of superstructure, base and soil, a computation method of thick-raft foundation is brought forward in which many factors are considered. The method corresponds to real foundation working conditions. By research done on a structural model with numerical calculation method, the effects of some factors, such as superstructure stiffness, thickness of raft, compressive modular constant of soil, suspended width of raft and raft concrete intensity, on the working behavior of thick-raft foundation are analyzed. And in coordination with data obtained from an engineering test on site, the regularities of foundation settlement and the distribution properties of pile reaction, soil reaction and steel stress in raft, of the pile-(thick)raft tested are analyzed. In the same time, the calculating results with finite element method almost correspond with measured results.And in the paper, the optimized design proposals of raft foundation and pile-raft foundation are presented, which can make the raft become thinner and the cost of foundation can decreases much more.更多还原