【作者】 陈骏峰；

【导师】 赵文光；

【作者基本信息】 华中科技大学 ， 结构工程， 2008， 博士

【摘要】 随着我国建设的不断发展,在建好的人防洞室等地下建筑上建造高层建筑的问题变得十分突出。传统的刚性基础假定已不能满足工程实践的需要,如不考虑上下部相互作用,计算成果将与实际情况有较大的出入。上部结构、基础与地下洞室地基作为一个统一的有机整体,三者相互联系、相互影响。上部结构、基础和洞室地基的共同作用已成为许多重大工程中一个不可回避的关键科学问题,对其开展研究具有较高的学术价值和工程应用价值。本文以实际工程项目—湖北省人防通讯大楼为背景,进行了现场监测和试验分析,并基于ANSYS建立了有效的宏观分析模型,对地表建筑与人防洞室群相互作用下的变形破坏机理及洞室稳定性等方面进行了较为系统的研究。本文主要研究内容及结论如下:1、介绍了工程概况和人防洞室群的基本情况,并通过现场勘察和原位测试,了解了建筑物范围内土体的工程性质,取得了后续计算分析所需的参数。2、分析了基坑的基本特征,并进行了支护方案比选及设计,得出了适合本基坑的支护方案。对基坑开挖过程进行了监测和三维数值模拟。3、阐明了防空洞与基坑的相互作用关系,采用弹性半空间的Mindlin应力解,导出了基坑开挖条件下防空洞回弹变形的计算公式,并通过数值计算对有、无洞室等两种情况下基坑的变形值进行了计算,探讨了地下洞室的存在对基坑稳定性的影响。4、开展了人防地下洞室群与地表建筑相互作用的三维数值计算,分析了人防洞室群地基在不同施工过程中的稳定性,揭示了人防地下洞室群与地表建筑相互作用规律。研究发现:在人防洞室群上直接建高层,洞室群局部的稳定性不能得到满足,且随着建筑楼层的加高,地下洞室群由稳定状态逐渐向不稳定状态发展,将影响到洞室和上部建筑的正常使用。5、结合工程实践,进行了方案比选,得出了符合本工程实际的人防洞室加固方案。对加固后的人防洞室及地表建筑进行了三维数值模拟,分析了地表建筑荷载作用下加固后的人防洞室群的变形规律和洞室群稳定性。计算结果表明,经加固后的人防洞室群,在地表建筑荷载作用下,变形大为减小,洞室群处于安全状态。6、对基础埋深对地下洞室稳定性影响进行了分析,探讨了随着基础埋深变大人防洞室稳定发展趋势,结果表明,随着建筑基础与地下洞室的最小安全厚度减小,人防洞室有向不稳定发展的趋势。给出了依托工程地表建筑基础与地下洞室的最小安全厚度。更多还原

【Abstract】 With the development of the construction in China, it becomes more and more obviously that building structure on the underground engineering such as making foundation and so on. If it is depended on the hypothesis of rigid base without regard to the interaction of structure and foundation with caverns, the result will be unreasonable and cause a big discrepancy between calculation and reality. Structure, base and foundation with caverns are an organic whole which connect and influence each other. The interaction of structure and base become an unavoidable key scientific question in some important projects.This dissertation is regarding one real project-the Building of communication in Hubei Province as the research example to make the spot-test of interaction, establish efficient macro analysis model and use the finite element program (ANSYS) to study the failure mechanism of interaction and stability of caverns and so on.The main contents and results are showing as following.The general situation of project and making caverns are introduced. The property of soil around the structure by the spot-test and reconnaissance is dissertated. It provides reliable parameters with continuous analysis.According to the characteristic of excavation, an optimal project is selected by analyzing different projects of excavation bracing. The process of excavation in three-dimension is simulated.The interaction of making foundation and excavation is described in this dissertation. It is gotten the deformation of making foundation under excavation by using Mindlin’s stress formula. The influence of caverns to the stability is discussed by analyzing the deformations of excavation with caverns and without caverns.The stability of caverns is analyzed by calculating the interaction of caverns and structure in three-dimension. It is shown that the stability of caverns will be affected if the structure is built on them. And the caverns become from stable condition to unstable condition with the height rise of structure. Even more it will affect the use of structure and making foundation. The project of reinforce suiting for caverns in this dissertation is gotten by selecting different projects and combining the engineering example. By calculating the interaction of caverns and structure after reinforce in three-dimension, it is indicated that the deformation of caverns reduces greatly after reinforcement and the caverns are safe.The influence of buried depth of foundation on the stability of caverns is analyzed after reinforce. And the stability of caverns is developed as buried depth of foundation increasing. It is shown that the caverns become unstable as buried depth of foundation increasing. Therefore, the minimal buried depth of foundation is gotten.更多还原