中国岩溶Issue(4)：490-497,8.DOI:10.11932/karst20140414
湖南宁乡大成桥地区岩溶地面塌陷分布特征及影响因素分析
Distribution characteristics and factors influencing karst collapse in Dachengqiao,Ningxiang,Hunan
陈亮晶 1孙锡良 1皮景 1王璨 1欧健1
作者信息
- 1. 湖南省地质矿产勘查开发局402 队，湖南 长沙 410014
- 折叠
摘要
Abstract
In the past few years,484 karst collapses with a total collapse area of over 300 km2 have occurred in the Dachengqiao area of Ningxiang county.They caused direct economic losses of more than 1 billion RMB and they have generally been increasing in number.Dachengqiao is located in the transition zone between the hills of Hunan and the Dongting lacustrine plain.The area’s geomorphology is mainly hills,with a few gul-lies and the Weishui alluvial plains;the local strata are mainly Permian,Cretaceous and Quaternary with scattered Carboniferous outcrops. Basic data about the collapses and their current status was obtained through data collection,field investi-gation,geophysical prospecting,drilling,pumping tests,long time observation,and groundwater level measurement.The environmental and geological conditions of the karst collapses in study area were analyzed according to the correlation theory of karst collapse.The temporal and spatial distribution of the collapses was determined and the factors influencing collapse were ascertained.Main conclusions are as follows, (1)Most collapses occurred during the rainy season.For instance,282 collapses (58% of total)took place between April and July.The number of collapses exhibited an increasing trend. (2)All of the karst collapses were located near cones of depression caused by drainage and dewatering. 428 collapses (88.43% of total)were in the intensely karstified zone.The collapse distribution density was greatest in gully areas,and higher in areas with non-karst overburden than in those without.404 collapses were caused by diluvial soil. (3)The main factors influencing karst collapse include the intensity of the karstification,the character-istics and thickness of the overburden,the double-layer soil structure widely found in gullies and on the allu-vial plain.Drainage and dewatering in mining area were the main factors inducing collapse.The uneven dis-tribution of rainfall,surface water leakage and river training also had important influence on the collapses. All of these factors accelerated the karst collapse process. (4)Karst collapse disaster prevention and control relies mainly on prevention.Construction should be a-voided in the following locations,covered karstification zone,thin overburden layer and double-layer struc-ture,areas near the groove of gully topography and areas with high collapse distribution density.关键词
岩溶地面塌陷/分布特征/影响因素/湖南宁乡Key words
karst collapse/distribution characteristics/influencing factors/Ningxiang Hunan分类
天文与地球科学引用本文复制引用
陈亮晶,孙锡良,皮景,王璨,欧健..湖南宁乡大成桥地区岩溶地面塌陷分布特征及影响因素分析[J].中国岩溶,2014,(4):490-497,8.
