火山岩坡残积土地区暴雨滑坡泥石流的形成机理  

MECHANISM FOR RAINSTORM INDUCED SOIL SLIDE DEBRIS FLOWS IN AREA WITH VOLCANIC ROCK DERIVED SOILS

作　　者：戴福初[1,2,3] 李焯芬[1,2,3] 黄志全 王思敬[1,2,3] 

机构地区：[1]中国科学院地理研究所 [2]香港大学土木工程系 [3]中国科学院地质研究所工程地质力学开放研究实验室

出　　处：《工程地质学报》1999年第2期147-153,共7页Journal of Engineering Geology

摘　　要：暴雨条件诱发的浅层坡残积土质斜坡破坏的机理受控于土体在低有效围压条件下的应力应变特性。１９９３年１１月４～５日，香港大屿山地区特大局部性暴雨导致在１２０ｋｍ２范围内产生自然滑坡泥石流８００余处，且绝大多数发生于火山岩风化坡残积土地区。本文对火山岩风化坡残积土开展了室内偏压固结不排水剪和偏压固结常剪应力排水剪试验，揭示了该类土的应力应变特性；在此基础上。On November 4～5,1993, Lantau Island with an area of 120 km 2 which is the larg est outlying island of Hong Kong Territory experienced an extremely severe loca lized rainstorm, which resulted in over 800 soil slide debris flows on the natu ral terrain there. The majority of the soil slides debris flows occurred in are a with volcanic rock derived residual soil and colluvium. Triaxial tests, incl uding compression tests anisotropically consolidated undrained and drained, und isturbed volcanic rock derived soil specimens at constant shear stress, were pe rformed to investigate the stress strain behaviors of the soil. The test result s are interpreted to suggest that soil slide debris flow initiation occurs as a two stage process which consists of an initial dilation failure under drain co nditions followed by undrained failure as a result of strain softening.

关 键 词：火山岩坡 残积土 应力应变 暴雨 滑坡 泥石流 

分 类 号：P642.22[天文地球—工程地质学] P642.23[天文地球—地质矿产勘探]