【作者】 刘玲；

【导师】 王庆华； 胡光艳；

【作者基本信息】 吉林大学 ， 建筑与土木工程， 2011， 硕士

【摘要】 基坑支护工程是当代岩土工程界研究的难点与热点问题。从远古追溯到现代,自人们开始懂得建造居所就有了建造工程,而深基坑工程就是建筑中的古老的基础工程,同时它也是综合了各学科的岩土工程。随着社会生产力发展水平的不断进步,建筑物高度不断增加,因建筑需要基础也就越做越深,其支护结构的难度也就不断加大,这就给这一古老课题提出了的新的内容和挑战。目前,在基坑设计中,我们既要满足它的安全性,同时也要考虑其经济性,而这两方面的性能通常又是比较矛盾的。由于现在还比较缺乏精确的设计计算方法和支护方案优选的方法,所以在实际工程中只能为了满足安全性,便使其支护类型的选择和设计都比较保守,这样就增加了投资,造成一些不必要的浪费;另一方面为了片面的追求经济性,从而降低了基坑的稳定性、变形性和设计安全方面的要求,造成一系列工程事故,导致了更大的经济损失。解决这一矛盾的最合理途径就是要不断深入的研究深基坑工程的优化设计。本文首先分析了基坑工程的发展历史及国内外研究现状,并介绍了各种支护形式的特点及适用范围。针对长春百脑汇基坑工程的实际条件,对可能采用的各种支护形式在技术上和经济上进行了分析比较,选用了桩锚和复合土钉墙的支护方法,分别进行了设计计算,然后用理正深基坑软件对基坑的稳定性进行了验算,最后对所选用的两种支护结构分别进行了有限元数值模拟,针对基坑开挖过程的理论和方法进行较深入细致的研究,分析基坑的初始应力场、位移场的形成,提出考虑开挖单元、节点以及支撑,适合分步开挖的计算模拟方法。结合实际工程的检测,采用GTS大型有限元程序对其进行了分析计算,与实际检测结果进行对比。确定其参数的选取以及数值模拟的正确性,为我省以后的深基坑支护设计与施工提供一个实用依据。更多还原

【Abstract】 Foundation pit support is the hot and difficult problem in geotechnical engineering nowadays. Construction appeared since people began to build, from the ancient to the present. The deep foundation pit engineering is the old foundation engineering, and it is also the geotechnical integrated each subject. As social productive force developing constantly and the height of buildings increasing, it need foundation deeper more and more to adapt to the building requires, and the difficulty of structure supporting is increasing, so there is a new content and challenge for the ancient subject. There has been such contradiction that haunts us in current foundation pit engineering design, the security and the economy. Because of lack of reliable design theory and better supporting method at present, it is often to make the supporting and design conservative for the safety in actual project. Therefore it has to increase investment and result unnecessary waste. On the other hand, sometimes it reduces the stability of foundation pit, deformation control and safety aspects of the design requirements in order to pursue economic, thereby causing the engineering accident, and resulting in greater economic losses. The way to solve this problem reasonably is to study the optimization design of deep foundation pit engineering.The content analyzes the history and research status of foundation pit engineering firstly, and describes characteristics and applicable scope of various supporting forms. Then it makes analyses and compares with the each support forms probably used on economy and technology, aiming at practical condition of Changchun Buynow pit engineering. It selects the anchor pile and composite soil nailing wall supporting method, designs and calculates respectively, then makes checking using Lizheng deep foundation pit software, finally makes finite element numerical simulation of excavation process with the structure that is employed. It starts the careful research on the theory and method of the excavation process of foundation pit, analyses the forming the initial stress field and the displacement field of the foundation pit, and puts forward considering the excavation unit, node, the support, and numerical simulation method that fits excavation. Combined with practical engineering detection, using GTS finite element program has carried on the analysis, contrast to the actual result. To determine the parameters and the accuracy of numerical simulation, for me the province after the deep foundation pit support design and construction to provide a practical basis.更多还原