【作者】 何建勇；

【导师】 张钦喜；

【作者基本信息】 北京工业大学 ， 结构工程， 2003， 硕士

【摘要】 本文通过FLAC有限差分程序，分析了素土基坑和土钉墙体的整体性能和内在机理，研究了土钉和面层的连接变化、土钉表面性能的下降、土钉的横向抗剪抗弯作用、土钉浆体的开裂、面层的有无、基坑的开挖过程、基坑放坡角度等因素对土钉内力分布和土钉墙变形的影响。研究表明： (1)素土坡随着坡角的变化，存在两种破坏方式，破坏方式不同，土钉受力状态不同； (2)土钉和面层的连接方式决定着土钉长度方向上的轴力分布形态； (3)面层主要通过面层与土钉的连接和面层的本身刚度两个方面对土钉内力和墙体变形产生影响； (4)土钉横向抗剪抗弯作用的发挥程度和土钉钉头的连接方式有关，但作用不大，实际设计时可以忽略其影响； (5)随着坡体的开挖，第一排土钉的最大轴力变化不大，其它土钉的轴力都稳步增加。 此外，本文还使用交叉试验的设计分析方法对土钉长度、间距、倾角、土钉和面层的连接四个因素两个水平进行了数值模拟分析，研究发现土钉墙的设计参数对其变形的影响大小明显不同，在优先考虑显著因素的情况下，可有效的减少土钉墙体的变形。最后，基于不同状态下土钉最大轴力的分布形式，提出了对规范土钉设计土压力的改进方法；同时在前述研究分析的的基础之上，建立了一个实际工程的FLAC模型，并对计算的结果和实测内力变形结果进行了对比，表明本文所使用的数值模拟方法是可行的。更多还原

【Abstract】 In this thesis, analysis of whole performance and interior mechanism of plain soil slope and soil nailing wall with FLAG finite difference program has been carried out. At the same time, the impacts on the internal force distribution of soil nailing and the deformation of soil nailing wall of many factors, including the connection between face shield and soil nailing, the friction decline between soil nailing and soil, the shear force & bending moment resistance of soil nailing, the cement crack in soil nailing, face shield, excavation, the obliquity of slope, and so on are studied in this thesis. The study results reveal some laws:(1) Two failure modes exist in different obliquity slope and influence the internal force of soil nailing;(2) The connection between face shield and soil nailing determines the distribution of the axial force along length;(3) The influence of face shield involves its connection with soil nailing and its stiffness on soil nailing wall;(4) The transversal effect of soil nailing depended on the joint of nail head is little;(5) The maximum axial forces of other soil nailings except the first soil nailing increase gradually with excavation.In addition, the soil nailing wall is computed and analyzed with cross-over experiment including four factors, soil nailing’s length, interval, obliquity and connection between face shield and soil nailing, and two levels each factor. As a result, the influence of designed parameters of soil nailing is different evidently, and the deformation of soil nailing wall decreases largely when prominent factors are taken into account. In the end, according to the maximum axial force distribution curve under different conditions, a new method is put forward to improve the currentdesign and calculation methods of soil nailing. On the basis of these analyses, the numerical model of a real civil work is built by FLAC, and its results are compared with survey results in site, which indicates that the numerical simulation of this thesis is feasible.更多还原