四川宁南县白水河高位牵引式滑坡变形破坏机理及其灾害链研究

发布时间：2018-12-13 15:53

【摘要】：四川省凉山州地区受地质构造、河流切割等因素影响,地形起伏较大,地形坡度陡,多呈“V”型高山峡谷地貌。受地形影响,区域内小气候特征明显,短历时的集中强降雨频发,导致凉山州区内的滑坡、泥石流灾害极易发生。2012年6月27日至6月28日,宁南县境内普降大暴雨,导致县域内发生大量的滑坡、泥石流灾害,造成了一定的人员伤亡、公路掩埋等。也造成了普格至宁南县S212省道内侧的斜坡发生滑动,约有20多万方的滑坡物质剪出后在重力作用下顺坡体沟道冲向坡脚,形成的堆积体堵断公路。2012年8月16日再次发生大规模滑动,达70余万方滑体剪出后流向坡脚河床,崩塌造成过往人员死亡2人、失踪3人,公路阻断长达600余米,堵塞黑水河河道100余米、河水位突然上涨近4米形成堰塞湖,阻断交通15天。滑坡直接威胁滑坡体上居住的179人的生命财产安全,特别是滑坡范围内的14户70余人。间接威胁黑水河下游沿岸众多厂矿、电站等资产近8亿元及近2万人人员的生命财产安全。因此,对该高位牵引式滑坡开展工程治理非常必要而紧迫。四川宁南县白水河高位牵引式滑坡位于黑水河右岸,滑坡在平面上整体呈“铲状”。该滑坡位于高陡的峡谷地貌区,滑坡地形上缓下陡,为滑坡的形成提供了临空条件；另一方面,陡缓交界的容易形成应力集中,坡脚剪应力集中超过其抗剪强度,在坡脚部位首先发生剪切破坏,且破坏将向坡体内部发展。滑坡区受到则木河断裂的影响,滑坡区岩体产状变化较大,小型构造较为发育,岩体较为破碎。根据现场调查,滑坡区域在2006年于原地形陡缓交界处开始出现拉裂变形,并出现小范围的垮塌；2012年6月28日,滑坡发生滑动垮塌,堵塞下部公路,并在滑动后缘形成新的临空面,坡体前缘裂缝进一步变形拉裂；2012年8月16日,再次沿着前缘临空面大规模发生滑动,堵塞下部公路和河道,并形成现状地形中的圈椅状滑床和陡壁,对上部滑体进一步形成良好的临空条件,坡体中拉裂缝再次变形拉裂,形成多级错坎地形。该滑坡的失稳滑动是由前缘开始垮塌滑动,并形成新的临空面导致后部岩土体继续变形破坏的牵引式滑动模式。在2013年3月应急勘查的基础上,结合勘查期间的深部位移监测及地表位移监测数据,制定了对该高位滑坡采用钢管桩的应急处理方案+后期抗滑桩的综合治理两步走的总体治理措施,经应急处理试运行期间的监测数据,该高位滑坡变形得到遏制,处于基本稳定状态。本论文对该高位滑坡的发育特征、形成条件及成因机制等进行分析,并对滑坡的稳定进行定性及定量的分析。在此基础上,对该高位滑坡滑动形成滚石、坡面泥石流、堵塞黑水河形成堰塞湖等次生灾害链进行进一步的分析论证。
[Abstract]:Affected by geological structure, river cutting and other factors, the topography of Liangshan prefecture in Sichuan Province is quite undulating and steep, most of which are "V" type high mountain gorge landforms. Under the influence of topography, the microclimate in the area is obvious, and the concentrated and intense rainfall in short duration leads to landslides and debris flow disasters in Liangshan prefecture. From June 27 to June 28, 2012, the heavy rain in Ningnan County, A large number of landslides and debris flow disasters occurred in the county, resulting in certain casualties, road burial and so on. It also caused the slope to slip on the inner side of the S212 provincial road from Puge to Ningnan County. About 200, 000 square landslide materials were cut out and rushed along the slope to the foot of the slope under the action of gravity. On August 16, 2012, another large-scale slide occurred, reaching more than 700,000 square skids and flowing to the riverbed at the foot of the slope. The collapse caused two deaths and three missing persons. The road was blocked for more than 600 meters. Blocking the Heishui River more than 100 meters, the river level suddenly rose nearly 4 meters to form a barrier lake, blocking traffic for 15 days. The landslide is a direct threat to the life and property of 179 people living on the landslide, especially more than 70 people from 14 families in the landslide area. It indirectly threatens the lives and property of many factories, mines, power stations and other assets along the lower reaches of the Heishui River, including nearly 800 million yuan and nearly 20,000 people. Therefore, it is necessary and urgent to carry out engineering treatment of the high-level traction landslide. The high position traction landslide of Baishui River in Ningnan County, Sichuan Province is located on the right bank of Heishui River. The landslide is located in the high and steep gorge geomorphology area. On the other hand, the stress concentration is easy to form at the steep and gentle junction, and the shear stress concentration at the foot of the slope exceeds its shear strength. The shear failure occurs first at the foot of the slope, and the damage will develop towards the body of the slope. The landslide area is affected by Zemuhe fault, the occurrence of rock mass in landslide area is changed greatly, the small structure is relatively developed, and the rock mass is relatively broken. According to the field investigation, the landslide area began to appear tensile crack deformation and a small scale collapse in 2006 at the steep and gentle junction of the original terrain. On June 28, 2012, the landslide occurred sliding collapse, blocking the lower highway, and forming a new empty surface at the back of the slide. The front crack of the slope body was further deformed and cracked. On August 16, 2012, there was another large-scale slide along the front edge, blocking the lower highway and river course, and forming the ring chair slide bed and steep wall in the present terrain, thus further forming good conditions for the upper slider. The tensile cracks in the slope are deformed and cracked again, resulting in multilevel staggered ridge topography. The unstable sliding of the landslide begins from the front edge and forms a new traction sliding mode which leads to the continuous deformation and failure of the backside rock and soil. Based on the emergency survey in March 2013, combined with the monitoring data of deep displacement and surface displacement during the exploration period, The overall control measures of two steps for comprehensive treatment of the anti-slide pile in the later stage of the emergency treatment scheme of the high landslide with steel pipe pile are formulated. The deformation of the high landslide is restrained by the monitoring data during the trial operation period of the emergency treatment. In a basically stable state. In this paper, the development characteristics, forming conditions and formation mechanism of the high level landslide are analyzed, and the stability of the landslide is analyzed qualitatively and quantitatively. On the basis of this, the secondary disaster chain such as rolling stone, mud-rock flow on slope and blocking of Heishui River to form barrier lake are further analyzed and demonstrated.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22

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