文档介绍：硕士学位论文I 摘要深基坑工程仍处于边实践边摸索阶段,尚缺乏成熟技术规范的指导,因此,加强对深基坑计算理论及数值模拟方法的研究,提高深基坑工程实践指导的科学性尤为重要。基坑支护结构作为临时性结构,设计中大多采用弹性设计,实际工程中的支护结构实测应力偏小,因此合理模拟深基坑工程的基本过程,利用有限元方法对深基坑支护结构进行优化设计,考虑塑性设计具有十分重要的理论意义和实用价值。本文研究目的是从经济和实用的角度提出支护结构塑性考虑,并将塑性引入实际工程中,验证其可行性。本文研究内容:首先介绍了近年来基坑开挖这一领域的发展状况并简要阐述了目前基坑支护体系的分类和构成情况;结合深基坑围护开挖的具体实践,利用理论分析、数值模拟、现场实时监测等手段,对深基坑开挖引起的支护结构的位移、应力改变等相关内容进行了全面深入的研究,取得了一些有成果。根据实际工程中支护结构实测应力偏小的现象,从理论上分析了深基坑围护开挖土与支护结构的相互作用机理及支护结构设计的计算方法,说明现行支护结构设计方法的保守性,提出在变形和环境要求不高的情况下,考虑支护结构塑性的概念。从理论上分析了支护结构计算的杆系有限元方法和实体有限元方法,说明三维实体有限元方法的更加合理性,并对基坑开挖面以下土体的作用提出了简化方法。 运用大型的有限元程软件 ANSYS 对深基坑支护结构进行了数值模拟,分析了支护结构在空间性状下的位移场与应力场的变化规律,通过数值模拟的结果与工程实测数据比较分析,验证了支护结构设计中考虑塑性的可行性。关键词:深基坑 支护结构 塑性 有限元方法硕士学位论文i ABSTRACT In absence of matured code’s guidance, the deep foundation is in the stage of practice and exploration. So the research for intensifying calculated and numerical methods and im- proving the rationality in guiding engineering of deep foundation is important. As temporary structure, the elastic designed methods are often used for retaining structure of deep structure and measured stress is pared to the designed value, therefore optimized design, simulating the basic process and considering plasticity of retaining structure have important theory meaning and practicality. The objective of this paper is putting forward the plastic method in view of economics and practicality, and then applying to the engineering. In this paper, the present status of development and the sorting of the deep foundation engineering is introduced. This bines specific practice of retaining structure. It mostly studies on the content of interaction between soil and retaining structure by means of utilizing theory analysis, numerical simulation, on-the-spot monitor in real time etc. It researches the relevant contents about retaining structure displacement, retaining structure stress change etc of deep foundation, and has obtained some achievements. This paper analyzes interaction mechanism between soil and retain