昆明新机场西跑道北端高填方边坡稳定性研究

发布时间：2018-05-13 17:53

本文选题：昆明新机场 + 高填方边坡　；参考：《成都理工大学》2013年硕士论文

【摘要】：西南地区地形地貌复杂，地势起伏较大，而机场建设占地面积大，跨越的地质单元多，机场的建设势必会产生深挖高填。填方形成的高边坡的稳定性与否直接影响到工程的设计、施工、运行，甚至于机场建设的可行性。所以高填方边坡稳定性是西南地区机场工程建设所要解决的重点问题之一。本文以昆明新机场西跑道北端高填方边坡为研究对象。场区原始地形极其复杂，地处东西两侧山峰形成的谷底地带，谷底标高1900～2000m，四周山峰海拔高度2200～2800m，西北和东南侧是标高2100m以上、呈南北走向的连续山体，中部有东北向连续山体穿过整个场区，整个场区地势起伏较大，中部高、两端低。研究区最大填方高度达50多米，并且高填方下原地基存在相对软弱层，使高填方边坡稳定性问题更加突出。本文主要从填方体自身荷载作用下原地基软弱岩层变形影响、降雨入渗影响、地震动力影响三个诱发高填方边坡失稳的主要因素出发，深入研究高填方边坡的失稳规律。通过野外实地勘察，并结合研究区工程地质初勘和详勘资料，简要的概括和分析了研究区自然地理和工程地质条件。选取研究区高填方区域两条典型的边坡剖面从3个方面进行分析：（1）利用有限元分析填方体在自身荷载作用下边坡的变形破坏模式。（2）基于饱和-非饱和土力学理论，运用Geo-studio/seep软件建立渗流有限元模型，，考虑非饱和土边坡从雨水入渗到出现失稳的全过程，计算给定降雨条件下高填方边坡地下水位线位置的变化规律、边坡土体内孔隙水压力的分布规律等情况，探求渗流场的变化规律，同时将Geo-studio/seep计算所得水位线导入Geo-studio/slope模块计算和分析高填方边坡稳定性。（3）运用Geostudio/quake数值模拟软件，以研究区高填方边坡的地质模型为基本依据，按照有限元的建模原则，建立有限元计算模型，基于地震动力时程分析法进行地震工况下的数值模拟，模拟边坡在地震荷载作用下的应力场、形变场以及重要部位应力、变形在地震过程中随时间的演化状况，分析其在地震荷载作用下的潜在滑裂面并分析评价边坡稳定性；运用Flac3D软件分析计算边坡各重点部位在地震作用下高填方边坡的应力分布规律和变形规律，运用摩尔－库仑屈服准则，圈出边坡的塑性破坏区。最后综合分析高填方边坡的稳定性并提出相应的工程处理措施建议。
[Abstract]:The topography and geomorphology of southwest area are complicated and the topography is large, but the airport construction occupies a large area and spans many geological units, so the construction of the airport is bound to produce deep excavation and high fill. The stability of high slope formed by fill directly affects the feasibility of engineering design, construction, operation and even airport construction. So the stability of high-fill slope is one of the key problems to be solved in the airport construction in Southwest China. This paper takes the high fill slope at the north end of the west runway of Kunming New Airport as the research object. The original terrain of the field area is extremely complex. It is located in the valley bottom zone formed by the peaks on both sides of the east and west, the valley bottom elevation is 1900 ~ 2000m, the elevation of the surrounding peaks is 2200 ~ 2800m, and the northwest and southeast sides are continuous mountains with a elevation of above 2100m and a north-south trend. In the middle there is a continuous northeast mountain body passing through the whole field area, the whole field topography is large, the middle part is high, and the two ends are low. The maximum fill height of the study area is more than 50 meters, and there are relatively weak layers in the original foundation under the high fill, which makes the stability problem of the high fill slope more prominent. In this paper, the instability law of high fill slope is studied based on the three main factors, I. e., deformation of soft rock, rainfall infiltration and seismic dynamics, which induce instability of high fill slope. Based on field investigation and combined with the preliminary and detailed data of engineering geology in the study area, the natural geography and engineering geological conditions of the study area are summarized and analyzed briefly. In this paper, two typical slope sections in the high fill area of the study area are selected to analyze the slope deformation and failure mode of the embankment under its own load from three aspects. The finite element method is used to analyze the deformation and failure mode of the slope under its own load.) based on the theory of saturated-unsaturated soil mechanics, the deformation and failure mode of the slope is analyzed. The seepage finite element model is established by using Geo-studio/seep software. Considering the whole process from Rain Water infiltration to instability of unsaturated soil slope, the variation law of underground water level of high fill slope under given rainfall condition is calculated. The distribution law of pore water pressure in slope soil is studied to find out the variation law of seepage field. At the same time, the water level line calculated by Geo-studio/seep is introduced into Geo-studio/slope module to calculate and analyze the stability of high fill slope. Geostudio/quake numerical simulation software is used to calculate and analyze the stability of high fill slope. Based on the geological model of high fill slope in the study area, the finite element calculation model is established according to the principle of finite element modeling, and the numerical simulation under earthquake condition is carried out on the basis of seismic dynamic time history analysis. The stress field, deformation field and stress of important part of slope under earthquake load are simulated, and the evolution of deformation with time during earthquake is simulated. The potential slip surface under earthquake load is analyzed and the slope stability is evaluated. The stress distribution law and deformation law of high fill slope under earthquake action are analyzed and calculated by Flac3D software, and the plastic failure zone of slope is circumscribed by Mohr Coulomb yield criterion. Finally, the stability of high-fill slope is analyzed synthetically and the corresponding engineering treatment measures are put forward.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU43

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