巨厚松散层高陡斜坡的形成机理

川藏公路102滑坡群2#滑坡是发育在厚度近300 m的松散层高陡斜坡上的一个巨型滑坡体，每年滑坡体的不断解体失稳破坏及其后高近200m的松散高陡边坡的局部失稳破坏给川藏公路的正常运行造成了极大的影响。在地壳隆升强烈、风化剥蚀严重、河流急速下切等极为特殊的青藏高原这一特殊地质背景下形成了如此厚的松散堆积物，搞清这些巨厚层松散堆积物形成的地质背景、物质来源、形成过程、物质特性等对这种松散高陡斜坡以及其上发育的滑坡等灾害的失稳诱发因素、发展趋势、稳定性评价、如何防治等均具有十分重要的理论意义和实际意义。 本文在分析研究大量资料的基础上，依据青藏高原的地质背景，从高原的隆升特征、活动构造与地震特征、气候冰川特征入手，结合研究区的工程地质条件，得出了青藏高原这一特殊地质背景下巨厚松散层高陡斜坡的形成机理：即①隆升效应所产生的地形地貌变化、气候变化、冰川活动、构造及地震活动、大规模的构造热事件及熔融作用等效应极大的加剧了大陆的风化速率，从而在高原顶部及斜坡地带产生了大量的松散堆积物；②冰川、泥石流、滑坡等的发生使这些松散物集中搬运，在局部地段形成了巨厚层堆积；③河流的急剧侵蚀使这些快速堆积起来的巨厚层松散堆积物快速下切形成了高陡斜坡。 在上述分析及现场勘察研究的基础上，详细论述了发育在总厚度300余米的松散高陡斜坡上的2#滑坡的工程地质特征、诱发因素、失稳破坏特征等，并依据松散堆积物的特征，采用反分析理论并结合试验资料，确定了该地段松散堆积物的强度参数，进而采用有限元法、极限平衡法对滑坡体及其高度近200m的滑坡后壁高陡斜坡的稳定性进行了研究，并结合其变形破坏方式与公路工程的特点，提出了以预应力锚索肋板墙为主要加固工程的综合治理措施，以达到修筑高填方路堤和治理滑坡的目的。 由于松散介质与岩体介质的较大差异，文中采用二维弹塑性有限元模拟的办法，结合现场锚固试验成果，分析研究了松散介质内大吨位长锚索的应力传递及应力响应问题、因松散体强度较低导致的锚固段锚固能力问题、因松散体变形模量较小而导致的预应力衰减问题以及因松散体结构力弱而导致的群锚效应问题。得出了松散介质内预应力锚索体系失效的主要破坏形式、锚索体及锚固岩土体
电加热器
The 2# landslide of the Chuan-Zang Road 102 landslide-group is a giant landslide mass which is growing on the 300 meters thick round high-steep slope of the loose layer. Continuously unstable destruction yearly and behind it there is part of the high-steep slope unstable destruction which is about 200 meter high , cause giant influence to the Chuan-Zang Road regular operation. It is under the very special geology background ,Qinghai-tibet plateau , with the Earth’s crust rising strongly, efflorescing and eroding seriously , and the river shearing downside rapidly etc. that form such thick loose deposits, which has very important theory and practice meanings to make clear these giant and thickness loose deposits geology background, materials origin, forming process and the substance peculiarity etc. to the unstable induce factors, developing tendency, stability evaluation and how to prevent and cure etc. of this kind loose high steep slope, and the landslide etc. disasters growing on it.This article is based on analyzing and studying many materials ,according to the Qinghai-Tibet plateau geology background, starting with the rise character of the plateau, tectonic activity and earthquake character, climate and glacier characters, combining with geology engineering condition of the research area, analyzing the forming mechanism of the high-steep slope under the special geology background, Qinghai-Tibet plateau: that is①rising effect produces the change of climate, glacier behaviors, and earthquake, and large-scale tectonic hot event and melting actions etc. effects accelerate the effloresce speed of land, thereby produce large quantities of loose deposits at the top of the plateau and the slope zone; ②the happenings of glacier, mud-rock flow, and landslide etc. make those loose deposits move collectively, and form giant and thickness deposits at some areas;③the fierce erosion of river make those giant and thickness loose deposits which are piled fast shear downside and form high-steep slope.Based on the analysis above and the onsite prospect research, discussing the engineering geology character, induce factor, unstable destroy character and so on in details of the 2# landslide growing at the loose high-steep slope of 300 meters thick. Combining with the loose deposits characters, taking the way of finite element method and limit equilibrium to institute the wholly stability and the high slope behind the 200 meters round high-steep slope , combing with its deform styles and road engineering characters ,put forward a comprehensive cure measure, which take the prestressed anchored cables rib-board wall as the mainly stability engineering , so as to build high fill of earth embankment and cure slope.Because of the great difference between the loose medium and rock mass medium, two-dimensional elastic-plastic finite element method way is taken, combining with the cable holding test result on-spot, analysis and institute the large tonnage anchored cables stress force transmiting and the stress force responding question in the loose medium, the lower of the loose mass strength cause the end of the anchored ability question, for the minor loose mass deformation modulus cause the prestressed declined question and because of the weak texture force of the loose mass causes the anchored group effect question. It concludes the main destroy styles