【作者】 张艳；

【导师】 何鹏；

【作者基本信息】 四川大学 ， 岩土工程， 2005， 硕士

【摘要】 目前,成都地区采用的基坑支护中,土钉支护所占的比例越来越大,但是在设计中采用的稳定性分析方法不尽相同。土钉支护的设计计算中,稳定性分析是一个非常关键的内容。由于土体结构的复杂性,要确定出完全符合实际情况的滑动面是不可能的。因此,在设计计算中首先要确定一个比较贴近实际且容易确定其位置的滑动面,然后根据此滑动面来最终确定土钉支护的参数。本文根据成都地区常见的场地地质情况,在目前稳定分析常用的潜在滑动面类型中选取了一种较为适合本地区特点的滑动面类型。在此基础上,对土钉的内力计算进行了力和力矩的平衡分析,避开了土压力难以准确确定所带来的影响,提出了一种适合本地区的基于极限平衡分析的简化条分法。研究内容和计算成果包括以下几个方面: 1.成都地区常见的基坑开挖场地地质条件; 2.在成都地区常见的基坑开挖场地的地质条件下,确定出适合本地区的滑动面形式——对数螺旋线滑动面; 3.分别进行土钉支护体系力和力矩的稳定性分析; 4.采用三维有限元对土钉支护进行计算分析; 5.计算方法适用性比较。更多还原

【Abstract】 Now, soil nailing plays a more and more role in the deep excavation support. But, the methods of stability analysis are different from each other. The stability analysis of soil nailing is a key content in the designing calculation of soil nailing. Because of complexity of the soil structure, it is impossible to definitely find out a slip surface that totally meets the real situation. So the first thing is to ascertain a slip surface that meets the real one approximately and is easy to be located during the designing calculation. And then, the soil nailing’s designing parameters can be got with the slip surface. According to the normal geological conditions of foundation pits in Chengdu area, this paper chooses one kind of slip surfaces, which are used as potential ones in stability analysis presently, suitable for the soil structural characteristics in this area. Based on this, the force and moment balance analysis is carried on in the inner force calculation of soil nailings in order to avoid the uncertainty of the earth press. A predigested slice method based on the limit equilibrium method is also presented in this paper, which is suitable for Chengdu area. Following are the main research areas and achievements of this paper: 1.the normal engineering geologic conditions of foundation pits in Chengdu area; 2.promoting a logarithm screw line as the potential slip surface kind; 3.carrying on the force and moment balance analysis of soil nailing; 4.stability analysis of soil nailings by 3-D finite element method; 5.comparing the results of different calculating methods.更多还原