滑坡灾害评 　课件.ppt

滑坡灾害评估 Landslide hazard evaluation 主要内容 1 地质灾害简介 1 地质灾害简介 1 地质灾害简介 1 地质灾害简介 1 地质灾害简介 1 地质灾害简介 1 地质灾害简介 地面沉降 2 灾情概况 2010年全国地质灾害类型构成 2010年与2009年全国地质灾害基本情况对比表 3 滑坡 The causes of landslides are usually related to instabilities in slopes. It is usually possible to identify one or more landslide causes and one landslide trigger. The difference between these two concepts is subtle but important. Causes may be considered to be factors that made the slope vulnerable to failure, that predispose the slope to becoming unstable. The trigger is the single event that finally initiated the landslide. Thus, causes combine to make a slope vulnerable to failure, and the trigger finally initiates the movement. Usually, it is relatively easy to determine the trigger after the landslide has occurred (although it is generally very difficult to determine the exact nature of landslide triggers ahead of a movement event). a. Weak or sensitive materials 软弱岩体 b. Weathered materials 风化岩体 c. Sheared, jointed, or fissured materials 剪切、节理、裂隙岩体 d. Adversely oriented discontinuity (bedding, schistosity, fault, unconformity, contact, and so forth) 逆向不连续(层面、片理、断层、不整合面、接触面等） e. Contrast in permeability and/or stiffness of materials 渗透率差异和刚度差异 a. Tectonic or volcanic uplift 构造隆起或火山隆起 b. Glacial rebound 冰川回弹 c. Fluvial, wave, or glacial erosion of slope toe or lateral margins 河流、海浪、冰河对坡脚和坡体侧缘的侵蚀 d. Subterranean erosion (solution, piping) 地下侵蚀（溶液侵蚀，管涌） e. Deposition loading slope or its crest 边坡或坡顶加载 f. Vegetation removal (by fire, drought) 植被破坏 g. Thawing 冰雪融化 h. Freeze-and-thaw weathering 冻融风化 i. Shrink-and-swell weathering 收缩膨胀风化 滑坡产生的原因 a. Intense rainfall or prolonged precipitation 强降雨或长期降雨 b. Rapid snow melt 冰雪骤融 c. Rapid drawdown 水位骤降 d. Earthquake 地震 e. Volcanic eruption 火山喷发 f. Thawing 融化 g. Freeze-thaw 冻融 h. Ground water changes 地下水变化 i. Soil pore water pressure 孔隙水压力 j. Surface runoff 地表径流 k. Seismic activity 地震活动 滑坡产生的原因