堆积层滑坡微型桩加固的数值分析

发布时间：2018-04-22 10:38

本文选题：膨胀土滑坡 + 微型桩　；参考：《西安工业大学》2017年硕士论文

【摘要】：现如今,随着人们活动范围的扩大,滑坡防治也倍受重视。由于工程地质条件越来越复杂,传统的支挡措施已难以满足滑坡治理的需要,因此治理滑坡越来越注重轻型化、小型化,于是注浆微型桩支护体系应运而生。微型桩的直径在100m～300mm之间,最开始只是被用来承受竖向荷载,之后随着微型桩加固技术的不断改进,这种情况慢慢发生改变。但是由于这是一种新兴技术,在实际工程中多用经验来进行设计,理论方面并不完善,严重制约了微型桩的发展和推广。在陕南地区,出现破坏的滑坡中很大一部分是膨胀土滑坡,这是因为膨胀土滑坡的土质具有十分特殊的性质,比如胀缩性、裂隙性等,这些特性使滑坡的破坏机理非常复杂,从而治理的难度也就增大。本文总结了前面学者的研究成果,并在此基础上,通过FLAC3D软件对微型桩加固膨胀土滑坡进行了模拟。首先以控制含水率来模拟膨胀土遇水膨胀的性质,然后对微型桩加固膨胀土滑坡的机理进行了研究,得出不同因素对微型桩的位移、弯矩和剪力的影响,为设计微型桩提供了十分有利的依据。通过分析得到:膨胀土滑坡在含水量大的情况下更容易发生破坏,尤其是坡脚和坡顶处,在治理滑坡时要对其进行重点加固。在使用梅花形分布的微型桩加固膨胀土滑坡时,可以有效地控制滑动面的位移和滑体的塑性区,达到加固的效果。同时,本文还对微型桩不同桩间距、桩排距以及锚固深度下的剪力、弯矩和位移进行分析,确定了微型桩的最佳桩间距为8d～10d;合理排间距宜取5d～10d;锚固深度的最佳取值为L/3。最后还模拟分析了微型桩桩距的极限状态,得出微型桩在极限状态下的作用机理。本文通过对微型桩治理膨胀土滑坡的研究,得到了膨胀土在水的作用下破坏机理及微型桩设计参数的最佳取值范围,为实际工程提供理论依据。
[Abstract]:Nowadays, with the expansion of the range of people's activities, the prevention and control of landslide is also paid much attention. Because the engineering geological conditions are more and more complex, the traditional support measures are difficult to meet the needs of the landslide treatment. Therefore, the treatment of landslides more and more attention to light, miniaturized, so the grouting micro pile supporting system arises at the historic moment. The diameter of the micro pile is from 100m to 30. 0mm, at the beginning, is only used to bear vertical load, and then with the continuous improvement of the micro pile strengthening technology, this situation is slowly changing. But because this is a new technology, it is not perfect in the practical engineering with more experience in practical engineering, which seriously restricts the development and popularization of micro pile. This is because the soil quality of the expansive soil landslides has very special properties, such as expansion and contraction, fracture and so on. These characteristics make the failure mechanism of the landslide very complicated and the difficulty of the treatment increases. This paper summarizes the research results of the previous scholars and on this basis, The FLAC3D software is used to simulate the expansion of expansive soil landslides with micro piles. First, the properties of the expansive soil are simulated by controlling the water content. Then the mechanism of the expansion of the expansive soil by the micro pile is studied, and the influence of different factors on the displacement, bending moment and shear force of the micro pile is obtained, which is very favorable for the design of the micro pile. According to the analysis, it is found that the expansive soil landslide is more prone to damage in the case of large water content, especially at the foot of the slope and the top of the slope. In the treatment of landslides, it is necessary to reinforce it. The displacement of the sliding surface and the plastic zone of the sliding body can be effectively controlled when the minitype pile of the plum shaped distribution is used to reinforce the expansive soil landslide. At the same time, the paper also analyzes the shear, bending moment and displacement of different piles with different pile spacing, pile spacing and anchorage depth, and determines that the best pile spacing of the micro pile is 8D ~ 10d; the reasonable spacing is suitable for 5D to 10d; the optimum value of the anchorage depth is L/3. finally, the limit state of the micro pile spacing is simulated and analyzed, and the conclusion is obtained. In this paper, the failure mechanism of expansive soil under the action of water and the optimum range of the design parameters of the micro pile are obtained by the study of the micro pile governing the expansive soil landslide, which provides the theoretical basis for the practical engineering.

【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1;P642.22

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