沿黄公路府谷段高陡岩质边坡稳定性分析

发布时间：2018-06-16 20:17

本文选题：边坡稳定性 + 高陡岩质边坡　；参考：《西安科技大学》2017年硕士论文

【摘要】：近年来,随着府谷县经济的快速发展,高等级公路建设的步伐明显加快,而由此带来的边坡灾害也层出不穷。其中沿黄公路府谷段公路建设开挖形成了陡的坡角,破坏了坡脚原有的应力分布。坡体由于受到节理面、差异性风化、降雨等因素的综合作用,边坡的中上部岩体出现了失稳掉块的现象。而随着风化程度的进一步加强,以及连续暴雨的不断侵蚀,最终可能会导致坡体的整体垮塌。迫于这种趋势,迫切需要对该区岩质边坡的稳定性开展分析研究,以便为岩质边坡的支护设计提供依据。基于以上认识,本文选取沿黄公路K1+255～K1+677段边坡作为工程实例段,对其稳定性及其支护设计方案进行分析研究。(1)分别从岩体内部因素(地层岩性、边坡外形)和外部因素(降雨、风化)两方面总结了影响岩质边坡稳定性的因素,分析了各因素对边坡稳定性的影响机理。文章采用赤平投影法定性分析边坡稳定性,离散元UDEC软件定量模拟边坡的变形破坏机理。(2)从定性分析得出,节理面破坏了岩体的整体稳定性,由于两组节理面的共同作用,坡面形成了楔形体;定量模拟在天然工况下5-1'、5-2'剖面的最大位移量为7.33cm、20.72cm,稳定性系数为1.89、1.85。饱水工况下5-1'、5-2'剖面的最大位移量为7.68cm、30.94cm,稳定性系数为1.40、1.38。风化+饱水工况下5-1'、5-2剖面的最大位移量为3.48m、5.72m,稳定性系数为0.89、0.88;渗流分析边坡后缘裂隙充水带高度在5m、10m、20m的情况下,边坡的稳定性系数分别为1.36、1.32、1.27,坡体内最大孔隙水压力从最开始的0.24Kpa增长到0.60Kpa。(3)从定性分析知道在暴雨或是持续降雨的情况下,雨水沿着节理面入渗,坡面会出现失稳掉块的现象;定量模拟分析得出在天然工况下坡体的稳定性较好。在暴雨工况下,5-2'剖面附近岩体会出现失稳掉快的现象,坡体的稳定性一般,这与定性分析的结果基本吻合。在风化+饱水工况下坡体整体会出现失稳垮塌的现象。渗流分析得出孔隙水压力随着充水带高度的升高而增大,坡体的稳定性随着充水带高度的升高而逐渐降低。(4)基于以上分析对坡体进行支护设计,支护方案一:清理滚石、危岩+刷方卸载+挂网喷混+被动防护网+主动防护网+排水工程;支护方案二:清理滚石、危岩+挂网喷混+主动防护网+被动防护网+排水工程。支护设计方案也可为该地区同类岩质高边坡的防护提供一定的借鉴作用。
[Abstract]:In recent years, with the rapid economic development of Fugu County, the pace of high-grade highway construction is obviously accelerated, and the resulting slope disasters also emerge in endlessly. The excavation along the Fugu section of the Yellow River highway forms a steep slope angle, which destroys the original stress distribution at the foot of the slope. Due to the combined action of joint plane, differential weathering and rainfall, the rock mass in the middle and upper part of the slope is unstable. With the further strengthening of weathering degree and the continuous erosion of continuous rainstorm, the slope body may collapse in the end. Because of this trend, it is urgent to analyze and study the stability of rock slope in this area in order to provide the basis for supporting design of rock slope. Based on the above understanding, this paper selects the slope of K1255K1677 along the Yellow River Highway as an engineering example section, and analyzes its stability and supporting design scheme from the internal factors of rock mass (stratigraphic lithology). The influence factors of rock slope stability are summarized from two aspects: slope shape) and external factors (rainfall, weathering), and the influence mechanism of each factor on slope stability is analyzed. In this paper, the stability of slope is qualitatively analyzed by the method of plane projection, and the deformation and failure mechanism of slope is quantitatively simulated by discrete element UDEC software. From the qualitative analysis, it is concluded that the joint plane destroys the whole stability of rock mass, because of the joint action of two groups of joints. A wedge is formed on the slope, and the maximum displacement of 5-1GV 5-2'section under natural conditions is 7.33 cm-1 (20.72 cm) and the stability coefficient is 1.89 cm (1.85 cm). The maximum displacement and stability coefficient of the 5-1D 5-2'profile are 7.68 cm / m ~ 30.94 cm and 1.40 cm ~ (-1) ~ (38) cm respectively under saturated water condition. Under the condition of weathering and saturated water, the maximum displacement and stability coefficient of the 5-1D 5-2 section are 3.48mand 5.72mrespectively, and the coefficient of stability is 0.89m0.88.The seepage analysis shows that the height of the water-filling zone in the back edge of the slope is 5m10m10m ~ 20m, and the maximum displacement of the profile is 3.48mand 5.72m. The slope stability coefficient is 1.36 / 1.32 / 1.27 and the maximum pore water pressure in the slope increases from 0.24Kpa at the beginning to 0.60Kpa.Ni3) from the qualitative analysis, it is found that under the condition of heavy rain or continuous rainfall, the Rain Water infiltration along the joint surface will lead to the instability of the slope. Quantitative simulation analysis shows that the stability of slope body is better under natural working conditions. Under heavy rain conditions, the rock mass near the 5-2 'profile will lose stability quickly, and the stability of slope body is general, which is in good agreement with the results of qualitative analysis. Under the condition of weathering and saturated water, the whole slope body will be unstable and collapse. Seepage analysis shows that the pore water pressure increases with the height of the water-filled belt, and the stability of the slope decreases gradually with the increase of the water-filled belt height.) based on the above analysis, the support design of the slope body is carried out. The drainage project of active protective net is carried out by unloading the hanging net and spraying the passive protective net; the second supporting scheme is to clean up the rolling stone, the dangerous rock hanging the net, the shotcrete mixing the active protective net and the passive protective net drainage project. The supporting design scheme can also provide some reference for the protection of the similar rock slope in this area.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.14

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