丰宁输水隧道出口高边坡稳定性分析与应用

发布时间：2019-01-02 16:55

【摘要】：工程建设中,往往会遇到大量的边坡工程。边坡工程建设过程中边坡失稳是一种全球性的地质灾害,与地震、火山同被列为全球三大地质灾害。边坡的失稳破坏事故,给人类带来了严重的生命与财产损失,因此,针对边坡工程施工过程中开挖与支护问题的探讨与研究,以及边坡的稳定性分析是工程建设中一项必不可少的任务。本文结合丰宁输水隧道出口高边坡实际地质情况和开挖支护施工情况,使用大型通用有限元软件ANSYS对边坡进行有限元数值模拟分析。结合输水隧洞出口高边坡实际工程地质条件,充分考虑现场开挖支护施工顺序,运用有限元软件ANSYS对边坡开挖及支护过程进行模拟,获得不同开挖阶段及支护下边坡的最大变形、最大应力等的分布情况。经过分析可知：边坡在天然状态下稳定；边坡开挖过程中加以锚喷支护是必要的,且锚喷支护能较好的改变边坡表面应力分布；第三阶段边坡开挖时坡脚位移变化较大,所以爆破时一定要留足保护层,防止对坡体造成大的扰动,发生边坡失稳。基于有限元强度折减系数法,依次选取折减系数,分别对原始坡体和开挖支护完成后边坡的强度参数进行折减,将折减后的参数输入进行有限元计算,根据坡体失稳判据,计算获得原始边坡和开挖支护完成后边坡的安全系数。通过分析不同折减系数下的收敛曲线、水平位移、塑性变形模拟结果得出：原始边坡的强度折减系数为F=6.31,即边坡模型的安全系数为6.31；开挖支护完成边坡的强度折减系数为F=5.0,即边坡模型的安全系数为5.0,又因为该边坡安全系数大于一级边坡安全系数1.35,所以说该边坡是稳定的。通过本文分析,结合数值模拟结果,讨论了该边坡易失稳情况,为输水隧道进洞施工防护提供参考。
[Abstract]:A large number of slope projects are often encountered in engineering construction. Slope instability is a global geological hazard in the process of slope engineering construction. It is classified as the three major geological hazards in the world along with earthquakes and volcanoes. The failure accident of slope instability has brought serious loss of life and property to human beings. Therefore, the study and research on excavation and support during the construction of slope engineering is carried out. And slope stability analysis is an indispensable task in engineering construction. Combined with the actual geological conditions of the high slope at the outlet of Fengning water conveyance tunnel and the construction of excavation and support, the finite element numerical simulation analysis of the slope is carried out by using the large and universal finite element software ANSYS. Combined with the actual engineering geological conditions of the high slope at the outlet of the water conveyance tunnel, the construction sequence of the field excavation and support is fully considered, and the excavation and support process of the slope is simulated by using the finite element software ANSYS. The distribution of maximum deformation and maximum stress of slope under different excavation stages and supporting conditions are obtained. Through the analysis, we can know that the slope is stable in the natural state, the bolting and shotcreting is necessary in the course of the slope excavation, and the bolting and shotcrete support can change the surface stress distribution of the slope. During the third stage of slope excavation, the displacement of slope foot changes greatly, so it is necessary to leave sufficient protective layer during blasting to prevent large disturbance to slope body and slope instability. Based on the finite element strength reduction coefficient method, the strength parameters of the original slope body and the slope after excavation support are reduced, and the reduced parameters are inputted into the finite element method. The safety factors of the original slope and the slope after excavation are calculated. By analyzing the convergence curve, horizontal displacement and plastic deformation of the original slope, it is concluded that the strength reduction coefficient of the original slope is F _ (6.31), that is, the safety factor of the slope model is 6.31; The strength reduction coefficient of the slope completed by excavation and support is F5.0, that is, the safety factor of the slope model is 5.0, and because the safety factor of the slope is larger than 1.35 of the first-grade slope, the slope is stable. Through the analysis of this paper, combined with the numerical simulation results, the instability of the slope is discussed, which provides a reference for the construction protection of the water conveyance tunnel.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV672;TV223

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