丽宁公路新团滑坡稳定性评价

发布时间：2018-01-07 03:10

本文关键词：丽宁公路新团滑坡稳定性评价　出处：《昆明理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着社会的发展,公路交通显得尤为重要。公路作为一种带状构造物,尤其在我国西南多山地区,难以避免的穿越斜坡地带,路堑的开挖极易导致斜坡失稳形成滑坡。滑坡病害不仅对公路工程的建设质量、投资及后期的养护产生较大影响,而且对过往人员的生命财产安全造成威胁。本文以丽宁公路新团滑坡为研究对象,在系统的野外调查的基础上,深入分析该滑坡形成的地质背景及其基本特征,采用极限平衡及flac3D数值模拟计算方法,对其稳定性进行评价,为滑坡治理及保护提供理论依据。研究结果表明：新团滑坡属于巨型-覆盖型土质滑坡,滑坡体主要为含砾粉质粘土夹碎块石、角砾土夹碎块石及部分红黏土等第四纪坡积物,滑床为主要为强风化灰白色白云质灰岩,滑动面(带)为岩土体分界面。新团滑坡的形成因素包括形成条件及诱发因素,其中形成条件主要为斜坡体固有的地质特征：地层岩性、地质构造、自重应力、岩土体力学参数及水文地质条件等；诱发因素为自然因素及人为因素主要表现在路堑边坡开挖及后期暴雨冲刷渗入等方面。极限平衡计算结果显示,天然状态下三个断面稳定性系数分别为1.375、1.062、1.057,滑坡整体处于极限平衡状态。暴雨状态下,稳定性系数分别为0.827、0.799、0.779,天然+地震条件下,稳定性系数分别为0.807、0.792、0.773,稳定性系数均小于1,滑坡处于不稳定状态。flac3D数值模拟结果显示,在重力情况下,滑坡整体表现稳定,大部分区域位移较小甚至无位移。滑坡的稳定性系数为1.19,基本稳定。暴雨情况下,滑坡稳定性系数计算结果为0.68。表明滑坡达到极其不稳定状态。对已有支护进行稳定性评价,得出暴雨状态下稳定系数K=0.851～0.8831.0,说明滑坡在暴雨工况下处于五级不稳定状态。目前状况下,滑坡具有再次滑动(持续暴雨情况下)的可能,需要及时加大抗滑支挡加固措施才能确保整个滑坡处治工程的稳定及公路长期运营安全。
[Abstract]:With the development of society, highway traffic is becoming more and more important. As a kind of belt structure, especially in the mountainous area of southwest China, it is difficult to avoid crossing the slope zone. The excavation of cutting is easy to cause slope instability to form landslide. Landslide disease not only has a great impact on the construction quality, investment and later maintenance of highway engineering. This paper takes Xintuan landslide of Lianning Highway as the research object and analyzes the geological background and basic characteristics of the landslide on the basis of systematic field investigation. The limit equilibrium and flac3D numerical simulation method are used to evaluate the stability of the landslide and to provide theoretical basis for landslide control and protection. The results show that the Xintuan landslide belongs to the mega-covered soil landslide, and the landslide is mainly composed of gravel-bearing silty clay clastic rock, breccia soil clastic rock and some red clay and other Quaternary slope deposits. The sliding bed is mainly weathered grayish-white dolomite, and the slip surface (belt) is the interface of rock and soil. The forming factors of Xintuan landslide include the forming conditions and inducing factors. The forming conditions are mainly the inherent geological characteristics of the slope body: stratigraphic lithology, geological structure, gravity stress, geotechnical physical parameters and hydrogeological conditions, etc. The induced factors are natural factors and human factors mainly in cutting slope excavation and late storm erosion infiltration and so on. The results of limit equilibrium calculation show that the stability coefficients of the three sections are 1.375U 1.062 and 1.057 respectively under natural condition, and the landslide is in the state of limit equilibrium and under the condition of torrential rain. The stability coefficients are 0.827 ~ 0.799U ~ (0.779) and 0.807 ~ 0.792n ~ (0.773) respectively under natural earthquake. The stability coefficient is less than 1, and the numerical simulation results show that the whole landslide is stable under gravity. The stability coefficient of landslide is 1.19, which is basically stable. The calculated result of landslide stability coefficient is 0.68, which indicates that landslide reaches extremely unstable state. The stability evaluation of existing support is carried out. The result shows that the coefficient of stability is 0.851g 0.8831.0, which indicates that the landslide is in a five-stage unstable state under the condition of heavy rain. At present, landslide has the possibility of sliding again (under the condition of continuous torrential rain), so it is necessary to increase the measures of anti-slide support and reinforcement in order to ensure the stability of the whole landslide treatment project and the long-term operation safety of the highway.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U418.55

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