【作者】 徐长磊；

【导师】 戴俊；

【作者基本信息】 西安科技大学 ， 岩土工程， 2006， 硕士

【摘要】 土钉支护作为一种新的挡土技术，因其经济可靠且施工简便快捷，已在我国得到迅速推广和应用。但目前土钉支护结构的设计方法不够完善，出现了理论远远落后与实践的情况。 本文在总结前人研究成果的基础上，考虑到土钉支护是一个边开挖边支护的过程，这是一个结构与土的相互作用的动态的过程，提出了深基坑工程中土钉支护的动态设计的概念；针对国家基坑规范方法中的土钉力的计算值与实测值有较大差别的问题，结合优势面理论，提出了基于优势面理论的土钉力增量计算方法。根据目前的土钉支护研究现状以及工程的实际需要，利用有限元软件ANSYS对土钉支护进行了三维非线性有限元分析。 本文通过理论分析及工程实例的验算，论证了基于优势面理论的土钉力增量计算方法的合理性，并且数值模拟得到的土钉力也与该方法计算得到的土钉力分布规律一致。通过对数值结果的分析模拟得到以下结论：土钉轴力沿土钉全长分布规律，土钉轴力随开挖深度变化规律，承受最大轴力的土钉的位置，各排土钉最大轴力的位置随着开挖深度的变化规律。这些结论对土钉支护的设计与施工具有一定指导意义。更多还原

【Abstract】 Soil nailing, a new retaining system in deep excavation, is more and more widely used in our country. It’s a kind of economic, reliable technology and is convenient in construction. But at present, the method of soil nail design is not perfect, and the theory lags behind the application in the engineering practice.Based on the past researches, the theory of dynamic design of deep excavation retained with soil nail is provided in this paper, in the consideration of that the soil nail retaining system is a dynamic procedure of the interaction of structure and soil. To the problem that there is a difference between the soil nail forces calculated in National code and measured in practice, using the preferred plane theory, an incremental calculation method for soil nail forces based on preferred plane theory is given.The results indicate that the soil nail forces calculated in this method can fit the engineering practice better. Taking advantage of software ANSYS, the paper analyses the soil nailing with 3D nonlinear FEM.Using theories in Soil Mechanics and results got from an engineering practice, the incremental calculation method for soil nail forces given in this paper is proved. Based on the results of numerical simulation, some conclusions are gotten: (1) the law of soil nail forces in whole-length of nails, (2) the law of soil nail forces’ varivation in different depths, (3) the position of soil nail with the largest force, (4) the position of the largest soil nail forces in different depths; and some brief explanations are given to these conclusions.更多还原