研究目的：即将开通的海南东环铁路及运营中的东线高速公路清水湾段受突发性大型泥石流冲击，泥石流漫过铁路路堤、穿过桥下净空后进一步漫过公路路面并流入南中国海; 通过记述泥石流的成灾过程，结合地质调查、航拍、勘探、测试等手段，分析流源区巨型滑坡的成因、滑坡转化为泥石流的机理、泥石流的径流和堆积特点。
研究结论：(1) 流源区巨型滑坡的发生表现出极强的突发性以及高位高速运动的特点; (2) 风化破碎的花岗岩体和不利的结构面组合是滑坡发生的基本条件; (3) 连续强降雨的饱水加载作用以及雨水沿陡倾张裂结构面的下渗软化作用，是诱发滑坡的直接原因; (4) 表现形态: 岩土体高速下滑后，迅速解体并与水体充分拌和转化为泥石流，沿途不断铲刮沟床，流体物质和含水量逐渐增大，高速流态化运动近 4 km 才逐渐停下来;(5) 海南东环铁路及东线高速公路位于堆积区的外缘，当泥石流到达时动能已大大减弱，其破坏程度受到了很大限制。
Research purposes:A large mud － stone flow suddenly happened in the Qingshuiwan section of Hainan east ring railway to be open for traffic soon and the eastern speedway． The mud － stone flow flowed over the railway embankment and passed through the space under the bridge and then flowed over the speedway surface into the South China Sea． By observing the forming process of mud － stone flow and using the various means，such as geologic survey，aerial photography，exploration and field test，the analysis of the formation cause for giant landslide，the mechanism of turning landslide into mud － stone flow and the runoffing and accumulating characteristics of the mud － stone flow was made．
Research conclusions: (1) The appearance of the giant landslide in fluidity area reflected the features of the suddenness and the high － level and high － speed movement of gaint mud － stone flow．(2) The broken weathered granite rock mass and the unfavorable structural plane were the basic condition for landslide． (3) The effects of the heavy rainfall，loading and water softening along the steep under structural plane were the direct cause for the landslide．(4) After the landslide was rapidly gliding，the landslide disintegrated quickly and turned into mud － stone flow with water．Then the mud － stone flow constantly scoured the ditch bed to cause increasement of the water content gradually and quickly moved for about 4 kilometers．(5) The Qingshuiwan section of Hainan east ring railway and the eastern speedhway were located in the outside edge of the accumulating area of the mud － stone flow．When the mud － stone flow arrived at this place，its intensity was much weakened with less destroy degree．
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