摘要
近年来才开展研究的拱溃型顺层岩质滑坡,是一类独特的滑坡。它的滑动方向总是沿层面顺坡下滑,这属推动式滑坡。滑坡所在的斜坡岩层倾向与斜坡坡向大体一致;坡脚处岩层逐层拱起,并开裂脱层,发展成抗滑段,其与沿岩层层面发育的主滑段相贯通,由此呈现崩溃与滑动。滑坡经历蠕滑→滑动→剧滑三个阶段。
Yield-break landslide of bedding rock is the bedded sliding body with same dipping direction of rocks and slope direction; at the foot of the slope, the rock buckle towards the slope body bed by bed, and crack and slough to form the anti-slide section joining up the main slide section along rock bedding. Thus the rockfall and sliding occur. This is a special landslide. The study on it has been carried out in recent years.The basic developing conditions of this kind of landslide:1. The effective free surface is high and deep,as well as straight. The height of the slope is 200m at least. The annual gradient of the slope surface is 30°-45° and it equals or approximates the dipping angle of bedded rocks. The slope longitudinal section is straight. 2. Lithologic characters of the slope body mainly are rocks intercalated the soft and weak interbeds. 3. The structure surface (bedded surface or structure joint surface)may turn into sliding plane or the border of landslide. Besides, the groundwater (main dynamic and static pressure),flood, earthquake and man-made excavating at the foot of the slope can induce the landslide.The developing stages of this kind of landslide are: 1. creep-slide stage,the materials are from viscous rheologic to flowing state. Its duration is longer (some of them lasted to 32000a);2. the slide stage; the materials are in elastic medium state. Its duration is shorter (some of them only lasted more than la); 3. the severe-slide stage: the rock-beds fall and slip. Its duration is very short.This kind of landslide,sliding down along the slope,belongs to driving landslide. The volumes of landslides are up to 0. 1-20Mm3. The end edge is lower 50-100m than the original slope surface. This expresses that the motion distance of landslide is shorter.The accumulated body of this landslide is deep at the end part and gentle at the front part and the integrity is dispelled from the end to the front.The shear position is nearby the slope bottom. The sliding zones are divided into:1. anti-slide section is at the front part. It is more gentle(<30°)and even reverse-tilting is up to 5°;2. main slide section is at the end part. It is deep (30°-60°) and straight. The proportional values of lengths between the anti-slide section and the main slide section are 1. 0:2. 5. The materials Composited the sliding zones are soft and weak interbeds and the thickness is 0. 8-3.0m.
出处
《山地研究》
CSCD
1991年第4期231-235,共5页
关键词
滑坡
岩质
顺层
拱溃型
yield-break landslide, bedded landslide, rock landslide, driving landslide
