【作者】 张维；

【导师】 单炜；

【作者基本信息】 东北林业大学 ， 道路与铁道工程， 2013， 硕士

【摘要】 滑坡是一种山区常见的自然灾害,是影响山区公路交通运输安全的严重问题之一,在所有影响公路运输安全的自然地质灾害中,滑坡的危害性较为突出和更为常见。滑坡的发生与其所在区域的质地条件和自然环境有着直接联系,滑坡产生的机理有共性,也有不同的特殊性。随着我国高等级公路建设的快速发展,许多待建或在建的公路工程将要通过地质条件不良的区域,滑坡对公路的危害也越发明显。我国黑龙江省北部小兴安岭地区,有着低丘陵山区地貌,大陆性季风气候,属于岛状冻土退化地区,该地区古滑坡地貌明显,滑坡数量众多,形态各异,成因机理有着鲜明的区域性特性。对该地区滑坡的研究工作对于保证道路的安全和长期稳定至关重要。对此地区的滑坡形成机理和运动规律的研究和实践目前还比较少。滑坡发生的原因主要是土体在外界因素的影响下,内部的应力状态发生改变,土体的抗破坏下降所致,从这方面上来说,对滑坡发生机理的研究,就是对滑坡土体变形破坏机理的研究。以北黑高速公路K177+550滑坡路段为研究对象。通过阅读分析国内外关于滑坡现场勘查和室内土工试验的研究成果,初步掌握了国内外研究现状和对滑坡的研究方法,针对研究对象制定了具体的研究方案。采用GPS测绘技术对滑坡所在区域进行了地形地貌的测量,并绘制该地区的地形图,以掌握研究区域的地形地貌；在滑坡体和滑坡体周边地区钻孔布设监测仪器,以掌握滑坡体内部各土层物理指标变化特点和滑坡的运动规律。对滑坡体进行钻探勘察,以掌握滑坡体的地质结构和各结构层岩性；对滑坡体各结构土层进行钻探取样,通过现场试验取得滑坡体各土层的基本物理试验指标,通过室内试验对滑坡体各结构层土体的物理指标、力学指标的变化特性等方面进行了深入研究。研究的主要成果有：(1)通过室内试验测试了滑坡各结构层土体的基本试验指标、颗粒组成、稠度指标,研究发现滑坡各层结构土体,除砂岩以外均为细粒土,粒径组成缺失,级配不良；滑体和滑床土体的界限含水量相差不大,塑性区域范围较大,滑带土塑性范围较小,反应了各结构土层水稳定性的差异；(2)室内测试滑坡各结构层土体的饱和渗透系数,通过对土体在非饱和状态时基质吸力的测量,导出土体在非饱和状态下的含水率与渗透系数的理论关系曲线；结果显示滑床与其他结构层的渗透系数相差很大,就土层之间渗透系数的差异对土坡稳定性的影响给予了理论上的解释；(3)利用全自动三轴仪分别测试了滑体土、滑带土和滑床土在不同含水率下的弹性模量,不同附加荷载下的弹性模量,分析了变化规律；结果显示土体的弹性模量以塑性含水量附近某点为最大值,呈线性变化,土体的弹性模量随附加荷载增大减小；(4)通过室内直接剪切和反复直接剪切试验,得到滑坡土体各结构层在不同含水率下的抗剪强度指标,分析了变化点特。以试验结果为依据,对K177+550滑坡做了稳定性计算。通过上述研究,初步揭示了北黑高速公路K177+550滑坡土体的物理力学指标变化特征和滑坡形成机理,丰富完善了该地区的滑坡研究,为该地区此类型滑坡的分析和防治工作提供了参考和数值依据。更多还原

【Abstract】 Landslide is a kind of common natural disaster, mountain is one of serious problems affecting the safety of mountain area highway transportation, in all of geological disasters affecting the safety of road transport, the harm of the landslide is serious and more common. Following the rapid development of high-grade highway construction in China, to be built or under construction of highway will through the regional adverse geological conditions, the harm of the landslide on the highway is also increasingly clear. Landslide occurrence area with the texture of the condition and the natural environment has a direct connection, the mechanism of landslides are common, also has the particularity of different. China’s Heilongjiang province in northern area of Lesser Khingan Range, has low hilly landform, continental monsoon climate, the islands belong to the frozen soil degradation region, the region of ancient landslides landform, landslide are numerous, forms and formation mechanism has a distinct regional characteristic. Landslides in the area of research is very important to ensure road safety and long-term stability. At present, the research of landslide disasters in this region and practice are relatively less.The cause of the landslide mainly depends on the change of the internal stress state and strength of soil slope, from the graces, study on landslide mechanism, is the study of landslide soil mass deformation and failure mechanism. In this paper, relying on the heilongjiang province transportation hall of science and technology project "melting permafrost and landslides road subgrade stability technology widen the highway expansion project research", jilin to soon to heihe heihe river highway section of the highway expansion project as the research carrier, north of the black expressway K177+550landslide sections as the research object. Through reading and analyzing research on landslide field exploration and indoor soil test results, the preliminary master the research situation at home and abroad and the research methods of landslide, for the object of study made a concrete research plan. Using GPS surveying and mapping technology to the landslide area topography measurement, topographic map and map the region, to master the research area of landform; In landslide areas around borehole layout and landslide monitoring instrument, to grasp the changes among soil physical indicators of the landslide characteristics and movement regularity of landslides. Drilling was carried out on the landslide survey, in order to grasp the landslide geological structure and lithologic layers; Of landslide soil drilling sampling of each structure, through the field experiment with landslide basic physical test index of each soil layer, through the indoor test for various structural layers in the landslide, the change characteristics of soil physics, mechanics, etc were studied. The main results are as follows: (1) through the indoor experiment to test the basic test indexes of landslide soil layers, particle composition, consistency index, study landslide in each soil layer structure, are fine grained soils, except sandstone grain size composition is missing, grading is bad; Sliding body and sliding bed boundary of soil water content were similar, the plastic area is bigger, plastic range small, sliding zone reflects the structure of the differences in soil water stability;(2) the various structural layers in the indoor test of landslide, the saturated permeability coefficient of soil, soil based on the matrix suction in unsaturated state measurements, the moisture content of soil under unsaturated condition is derived with the theory of permeability coefficient curve; Results show that the permeability coefficient of sliding bed and other structural layer vary widely, and is the difference between soil permeability coefficient on slope stability influence gives theoretical explanation;(3) respectively using automatic triaxial apparatus to test the soil of the landslide mass and slide zone and slide bed soil under different moisture content of the elastic modulus, elastic modulus under different attached load, and analyzed the change rule; Results show that the elastic modulus of the soil in plastic for maximum moisture content near some point, a linear change, soil elastic modulus increases with additional load is reduced;(4) through laboratory direct shear and repeated direct shear test, get landslide under different moisture content in each layer of soil shear strength indexes, and analyzes the change point. Based on test results, do to K177+550landslide stability calculation.Through the above research, the preliminary reveals the north black expressway K177+550landslide of soil physical and mechanical indexes variation characteristics and formation mechanism of landslide and improve the region’s rich landslide research and analysis of this type of landslide in the region and the prevention and control work to provide the reference and basis.更多还原