考虑预应力锚索的边坡三维极限分析法及应用研究

发布时间：2018-04-26 08:00

本文选题：边坡 + 预应力锚索　；参考：《北京交通大学》2015年硕士论文

【摘要】：边坡稳定分析问题是岩土工程中一个重要的研究领域。目前,对边坡稳定分析主要采用二维的刚体极限平衡法,其计算简单、物理意义明确,在工程界被广泛使用。然而实际的边坡稳定分析是一个三维问题,应采用三维稳定分析方法进行研究。另外,工程中对于安全储备偏低的边坡常采用一些加固措施,其中预应力锚索因其加固效果较明显,被广泛应用于边坡的加固特别是岩质边坡中。在加锚边坡的二维稳定分析中,对于锚索的处理主要是将其简化为一个单位宽度上的锚固力进行计算,而在实际工程中锚索的布置一般呈三维特征,因此,这种简化处理无法反应实际情况。在加锚边坡的稳定分析中,有必要研究考虑预应力锚索三维特性的三维极限分析方法。本文基于此提出了改进的考虑预应力锚索三维特性的三维极限分析方法,并进行了相关讨论和工程应用。主要工作如下： (1)回顾和总结了近年来有关学者在边坡三维极限平衡分析领域所做的工作,对各种分析方法的适用性和优缺点进行了简单的探讨； (2)介绍了课题组近年来提出的边坡三维极限分析法的基本理论及计算方法,并在此基础上进行了改进,提出了考虑预应力锚索三维特性的三维极限平衡和极限分析上限解法,并推导了相关计算公式。 (3)以小湾左岸坝前堆积体加固工程为例,设计了不同的锚索布置方案,对本文提出的考虑预应力锚索的三维极限分析法进行了验证,并讨论了预应力锚索的三维加固效应。 (4)采用二维刚体极限平衡、三维刚体极限平衡和F1ac3D有限差分法对湖南涔天河雾江滑坡在老水库正常蓄水位254m工况和水库扩建后正常蓄水位313m工况进行了综合分析,对扩建后正常蓄水位313m工况提出了采用预应力锚索的加固方案。采用考虑预应力锚索的三维极限分析法对加固方案进行了评价,同时采用F1aC3D有限差分法对加锚前后边坡的变形、稳定性做了进一步分析。结果表明,采用预应力锚索对雾江滑坡起到明显的加固作用。
[Abstract]:Slope stability analysis is an important research field in geotechnical engineering. At present, the two-dimensional rigid body limit equilibrium method is mainly used in slope stability analysis, which is widely used in engineering because of its simple calculation and clear physical meaning. However, the actual slope stability analysis is a three-dimensional problem, which should be studied by three-dimensional stability analysis method. In addition, some reinforcement measures are often adopted for the slope with low safety reserve, among which the prestressed anchor cable is widely used in the reinforcement of slope, especially in the rock slope because of its obvious reinforcement effect. In the 2-D stability analysis of anchored slope, the treatment of anchor cable is mainly to simplify the anchor force to a unit width, but the arrangement of anchor cable is generally three-dimensional in practical engineering, so, This simplified treatment does not reflect the actual situation. In the stability analysis of anchored slope, it is necessary to study the three-dimensional limit analysis method considering the three-dimensional characteristics of prestressed anchor cable. Based on this, an improved three-dimensional limit analysis method considering the three-dimensional characteristics of prestressed anchor cable is proposed, and the related discussion and engineering application are carried out. The main tasks are as follows: 1) reviewing and summarizing the work done by scholars in the field of slope three-dimensional limit equilibrium analysis in recent years, and simply discussing the applicability, advantages and disadvantages of various analytical methods; This paper introduces the basic theory and calculation method of the 3D limit analysis method of slope which was put forward by the research group in recent years, and improves on it, and puts forward the solution of the three-dimensional limit equilibrium and the upper limit analysis of the limit analysis considering the three-dimensional characteristic of the prestressed anchor cable. The related formulas are deduced. 3) taking the reinforcement project of accumulation body in front of Xiaowan left bank dam as an example, different cable arrangement schemes are designed, and the three-dimensional limit analysis method considering prestressed anchor cable is verified in this paper, and the three-dimensional reinforcement effect of prestressed anchor cable is discussed. Using two-dimensional rigid body limit equilibrium, three-dimensional rigid body limit equilibrium and F1ac3D finite difference method, the normal storage water level of 254m in the old reservoir and 313m after the expansion of the reservoir are comprehensively analyzed. The reinforcement scheme of prestressed Anchorage cable is put forward for the condition of 313m normal storage water level after expansion. Three-dimensional limit analysis method considering prestressed anchor cable is used to evaluate the reinforcement scheme and the F1aC3D finite difference method is used to analyze the deformation and stability of the slope before and after anchoring. The results show that prestressed Anchorage cable plays a significant role in reinforcing the Wujiang landslide.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU45

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