工程堆载触发黄土滑坡研究-地质工程专业论文.docx

摘 要 在我国，黄土分布面积为 63 万 km2，约占陆地面积的 6.6%，黄土高原地区黄土 分布广泛、地层完整、沉积厚度大，使之成为黄土天然博物馆，也是世界黄土研究的 前沿高地。党的十八大提出的城镇化建设目标，在黄土高原地区，黄土重大灾害严重 制约城镇化建设，很难在该地区实现目标任务。如兰州市，黄土滑坡、崩塌、泥流等 重大黄土地质灾害几乎包围了这座城市，人们生命财产安全受到严重威胁，黄土重大 灾害严重制约了兰州城市的发展；陕北革命圣地延安市，市区主要集中狭长的斜坡地 带，共发育有大型黄土滑坡、崩塌近 80 处，黄土重大灾害严重制约了延安城市的发 展。兰州市和延安市都被迫在郊县削山填沟，兴建新城，填土场地修建新城区很难回 避由工程堆载触发的黄土滑坡灾害问题。 本论文以工程堆载触发黄土滑坡的孕育、成灾及演化机理为研究主线，对其分布 规律、孕灾模式、成因机理、演化过程等理论和技术方法进行较为深入系统研究，主 要结论如下： （1）触发黄土滑坡的主要堆载类型：面状堆载、点状堆载，其中面状堆载又可 分为条形均布荷载、矩形均布荷载和方形均布荷载以及三角形面状荷载； （2）堆载对坡体竖向应力的影响深度较大，对水平应力的影响深度约为荷载区 宽度的 2 倍，堆载引起的最大剪应力出现在荷载区边缘，这也是荷载区边缘出现剪切 裂缝的主要原因； （3）堆载触发黄土滑坡一般发育两条滑带，加载区外侧拉张裂缝区裂缝向下延 展与剪切裂缝联通形成浅层滑带，一般在坡体的中部剪出，加载区内侧拉张裂缝区裂 缝向下延展与剪切裂缝联通形成的深层滑带，一般在坡脚附近剪出； （4）结合物理模型试验、离心模型试验、数值模拟计算及边坡土体附加应力综 合分析，边坡体的塑性区首先出现在张拉破坏区下部和坡脚，并向坡体中间延展，堆 载触发黄土滑坡变形分区既滑动区、变形影响区和非影响区； （5）工程堆载触发边坡变形破坏可分为三种模式：触发老滑坡复活、触发饱水 层蠕滑变形、触发填土区边坡变形破坏；堆载触发黄土滑坡滑带的形态及形成过程与 荷载值、荷载部位及边坡坡度有关。 关键词：工程堆载，黄土滑坡，模型试验，成因机理，变形分区 I Absstract The loess distribution area in China was about 63,000 km2, which account for 6.6% of China’s land area. The wide distribution, great thickness, typical structure, and continue deposition of loess make loess plateau a loess natural museum, as well as frontier highland of loess research in the world. It is tough to achieve the urbanization construction goal proposed in the 18th Party Congress in the loess plateau, for the major disasters developed in the loess . For example, as the provincial capital city, Lanzhou was almost surrounded by the loess landslide, collapse, debris flow and other geologic hazards, which seriously threatened the safety of the city and greatly restricted the development of it. Besides, as the mecca of Chinese revolution, Yan’an was located on the long and narrow slope zone. About 80 large loess landslides and collapse developed here had already limited the development of Yan’an city. In order to build the new cities, Lanzhou and Yan’an are forced to cut slope and fill the ditch in the county. Hence, it is difficult to avoid the loess landslide disaste