【作者】 涂杰楠；

【导师】 樊怀仁；

【作者基本信息】 西安科技大学 ， 地质工程， 2008， 硕士

【摘要】 随着公路交通事业的迅速发展,需要在不同地质条件下修建不同级别的公路,在黄土地区修路,边坡失稳带来的许多问题严重影响了公路的正常运营。本文以陕北子靖高速公路魏家楼黄土边坡为研究对象,在充分论述了研究区地形地貌、地层岩性、水文地质等条件和人类工程活动的基础上,分析了影响边坡失稳的主要地质因素,得出坡高与坡度、坡脚开挖与连续暴雨对其稳定性的影响最大。采用GLE法对魏家楼黄土边坡的坡脚开挖、坡度和水位变化等影响因素进行定量分析表明,天然状态下,边坡坡度为45°时,稳定系数为1.26,该边坡处于稳定状态;在边坡坡度为45°,相对水位分别为4m、8m、12m、16m时,稳定系数分别为1.21、1.04、0.92、0.83,表明随着含水率的升高,边坡的稳定性不断变差,直至完全失稳,需要采取治理措施;边坡在相对水位为16m,坡度为35°时,稳定系数达到1.25,表明当坡体含水率较高时,只有减小边坡坡度,才能够达到稳定状态。运用FLAC3D软件对魏家楼黄土边坡进行应力和位移的三维数值模拟,通过对比第一、三、五、七步开挖后的位移和应力图,表明随着开挖的进行,边坡开挖面位移增大,对边坡稳定性影响较为严重;在坡脚出现应力集中使边坡处于亚稳定状态;需要对开挖面进行锚固且对坡脚进行加固以有效减小坡体位移和坡脚应力集中。采用Monte-Carlo法对该边坡的稳定性进行可靠性分析,得出在天然状态下,边坡破坏概率为0%;在相对水位为16m状态下,边坡破坏概率为100%,两种情况的稳定系数均服从正态分布,和实际相符。更多还原

【Abstract】 With the rapid development of the transportation, it’s requiring to build a lot of different grade roads in different geological conditions. In loess area, the destruction of highway always happens because of the loess slide. It often takes many severe effects to the normal management of the highroad. So this paper take the Wei Jialou loess slope in Zi Jing highway as the research object, at the basic of fully discuss the physiognomy, stratum lithology, hydrogeology and the man-made factor, analyses the main factor of effecting the stability of the loess is highness, gradient, excavation and continuous rainstorm.This paper adopts the GLE method to do the quantification analyses to the factors which are excavation of the foot of the slope, gradient and the water table. The result shows that: in the nature state, when the gradient is 45°, the Fs is 1.26, the slope at the stable state. When the gradient is 45°and the relative water table respective in 4m, 8m, 12m, 16m, the Fs is 1.21, 1.04, 0,92, 0.83, which indicates that with the w rise, the stability of slope becomes bad till to the slope completely destroyed, so the slope needs to be treated with. When the respective water table is 16m and the gradient is 45°, the Fs reach to 1.25, which indicate when the w of the slope body is high, if reduce the gradient, the slope would be in stable state. Taking the FLAC3D software does 3-D numerical simulation to analyses the stress and displacement to the Wei Jialou loess slope. After contrasting the diagram of displacement and stress of the first, third, fifth and seventh step excavations, which indicates that with excavating, the displacement of the slope is increasing, which serious affect the stability of the slope. And the diagram also shows that the stress concentration made the slope in the stable state. The diagram of stress and displacement of the slope both shows that the surface of slope need to be anchored and the foot of slope need to be reinforced to reduce the displacement of slope and the stress concentration.Through the Monte-Carlo method to analyses the reliability of the slope. The result shows, at the nature state, the destruction probability is 0%; at the saturation state, the destruction is 100%. The Fs of the two results both obedience the normal school, so the results are accordant with fact.更多还原