节点文献
气候变化对甘肃黄土地区公路边坡侵蚀影响及防治技术研究
Study on the Corrosive Influence of Slope and Control Techniques Considering Gansu Loess Area of Climate Change
【作者】 武红娟;
【导师】 王选仓;
【作者基本信息】 长安大学 , 道路与铁道工程, 2010, 博士
【摘要】 许多在建的高速公路处于水土流失严重和地质灾害频发的黄土高原地区,由于黄土地区地质水文环境对气象灾害十分敏感,开展公路沿线气候变化对甘肃黄土地区公路边坡的侵蚀影响及防治技术研究,对黄土地区高速公路的建设和安全运营具有十分重要的指导意义。本文通过对甘肃省内公路黄土路堑边坡侵蚀破坏类型调查,分析了不同气象因子影响下甘肃黄土地区公路路堑边坡侵蚀破坏特征,研究了不同气候条件下黄土路堑边坡土体内部温湿变化规律;通过不同坡率黄土路堑边坡进行现场降雨试验,分析了黄土地区公路路堑边坡降雨径流及冲沟侵蚀破坏的形成过程,给出了坡面产生径流和冲沟侵蚀破坏发生的临界条件;并根据不同降雨强度下黄土边坡浅层土体湿度变化情况,提出土体粘聚力和内摩擦角随含水量变化回归公式。通过边坡冻融前后的物理力学试验,分析定西、平凉两地黄土经多次冻融循环后抗剪强度的变化情况,在冻融循环次数不变的情况下,进行了土壤抗剪强度、土体初始含水量和边坡坡率对黄土边坡稳定安全系数敏感性分析,并推导出季冻区黄土边坡坡面损伤模型公式。针对平定高速沿线区域黄土边坡侵蚀破坏特征,提出秸秆加筋土喷播防护技术、植物一柔性板护坡和多级小平台坡面防护新技术,通过现场降雨试验和数值模拟仿真计算,分析了不同防护型式的作用机理,给出三种新型防护技术的设计及施工方法,为工程实际中防护形式的选取和边坡防护体系的合理建立提供必要的技术支撑。
【Abstract】 Many highway is constructed in the Loess Plateau where serious soil erosion and geological disasters issued. As geologic and hydrological environment in loess area is very sensitive to meteorological disasters, research on highway Slope erosion damage and slope protection and control technology under conditions of climate change in Gansu loess region, which is of great significance on the loess area highway construction and safe operation.Based on the loess of Gansu province highway slope erosion damage type of investigation, analysised the erosion damage features of freeway slope in Gansu loess under the influence of different meteorological factors, studied the variation of soil temperature and humidity inside loess slope under different weather conditions;By different rates of loess slope field rainfall experiment, analysised the formation process of the loess area freeway slope runoff and gully erosion and damage. Depending on loess slope shallow soil moisture changes in different rainfall intensity, raised the regression formula on soil cohesion and internal friction angle changed with the water content.Slope before and after freezing and thawing through the physical and mechanical testing, analysised Dingxi and Pingliang’s variation of loess shear strength after repeated freeze-thaw cycle. In the same situation of freeze-thaw cycles, analysised the loess slope stability safety factor of sensitivity according to the soil shear strength, soil moisture content and slope of initial rate of change in slope,derived loess slope stability safety factor injury model in cold areas.According to the erosion characteristics of loess slope, three new board revetment slope protection type were proposed such as sowing straw reinforced soil protection technology, plant-flexible plate revetment and multi-stage small platform. Through the field rainfall testing and numerical simulation,analysised the mechanism on different slope protective types of.Given slope vegetation and plant fiber board’s design and construction of slope protection method, which is provided the necessary technical support for the selection of a reasonable style on engineering practice forms of protection and slope protection system.
【Key words】 Meteorological factors; Loess slope; Slope erosion; Slope protection;