摘要
中桥位于胶东半岛东部臧家庄盆地,是胶东地区典型灰岩分布区,区内岩溶较发育并已多次发生岩溶塌陷地质灾害。为查明中桥岩溶发育分布特征、发育程度及分布规律,为下一步中桥岩溶塌陷地质灾害治理提供依据,采用岩溶地质调查、地球物理勘探、地质钻探、抽水试验等综合研究,查明该地区可溶岩地层主要为蓬莱群香夼组两段灰岩,分布类型有裸露型、覆盖型和埋藏型;岩溶发育形态以开放式溶隙、溶洞为主,少部分地区发育溶孔;岩溶发育程度与地层纯度、岩溶裂隙含水岩组富水性强弱、溶隙率与溶洞率的高低呈正相关;采用层次分析法将研究区岩溶发育程度划分为发育区、较发育区、中等发育区、弱发育区和不发育区五个等级,研究结果为中桥地区岩溶塌陷地质灾害预防与治理提供地质依据。
Karst is developed in all provinces of China.In Shandong Province,karst is mainly developed in its southwest part,and is sporadically distributed in the Jiaodong area.Particularly,the typical development area is located in the Zhongqiao area of Yantai City—the eastern part of the Jiaodong Peninsula in Zangjiazhuang basin whose overall terrain is high at peripheral edge and low in the middle.There are four distinct seasons in the Zhongqiao area with the annual precipitation mainly concentrating in June and July.Three seasonal rivers—the Baiyang river,the Yandi river and the Shandong river—run through the whole area.With large areas of Quaternary,Cretaceous and Sinian strata exposed as well as fault structures developed,this area presents a simple geological condition,typically distributed with limestone.According to the different burial conditions,the karst area can be divided into three types:exposed karst area,covered karst area and buried karst area.There is a wide distribution of soluble rocks in this area,where karst is developed in three forms,namely,dissolved pores,dissolved cracks and karst caves.However,the irregular development of underground karst fractures leads to the relatively large difference in the abundance of karst underground water.Consequently,there have been many geological disasters of karst collapse usually occurring at a small scale after heavy rainfall in the history of the Zhongqiao area.These collapses caused certain losses to the local economy,though with no casualties.In order to find out the distribution,degree and law of karst development in the Zhongqiao area,we have carried out a comprehensive study on the karst collapse according to geological environment survey,geophysical exploration,geological drilling,pumping testing,etc.Results of geological survey and geological drilling show that soluble rock strata in the study area are mainly made up of two limestone sections of Xiangkuang Formation of Penglai Group.The distribution of three burial types and the characteristics of karst development have also been identified.Results of geophysical exploration and geological drilling demonstrate the distribution of karst strata in the study area.Meanwhile,the distribution range,development characteristics and changes of developmental depths of dissolved pores,caves and dissolved cracks have been investigated.It is found that this area is mainly composed of the north-east fault structure.Results of geological drilling and pumping testing indicate the groundwater flow direction and the distribution characteristics of karst underground water abundance,with the maximum water inflow per well greater than 3,000 m3·d-1.The degree of karst development is positively correlated with the variables such as the purity of karst strata,the water abundance of water bearing rock group in karst fissure,the distribution of anomalous points in geophysical exploration,and the level of dissolved crack ratio and cave ratio.From five evaluation factors including karst formation,water abundance,apparent resistivity,the ratio of borehole to karst and the ratio of borehole to cave,we used analytic hierarchy process to divide the karst degree in the 60 m zone and divided the degree into five grades,karst development zone,the zone with karst development at a relatively high level,the zone with karst development at a medium level,the zone with karst development at a low level and the zone with undeveloped karst.With the decline of these five grades of karst degree,both the purity of karst strata and the water abundance decrease successively,whereas the apparent resistivity,the ratio of borehole to karst and the ratio of borehole to cave all increase gradually.The distribution range of each karst degree is successively distributed without overlap.The probability of karst collapses is as follows,karst development area>the zone with karst development at a relatively high level>the zone with karst development at a medium level>the zone with karst development at a low level>the zone with undeveloped karst.Collapses mainly concentrate in the karst development area.The degree of karst development is the basic condition of karst collapse;therefore,finding out the distribution,degree and law of karst development in the Zhongqiao area may provide a geological basis for the prevention and control of geological disasters of karst collapse,and guarantee the normal life of local residents and effective operation of enterprises.The study result may also provide a basis for further research on the distribution,degree and law of karst development in the Jiaodong area.
作者
杨宁
史猛
殷焘
于林弘
王元峰
张杰
冯培培
YANG Ning;SHI Meng;YIN Tao;YU Linhong;WANG Yuanfeng;ZHANG Jie;FENG Peipei(Shandong Third Institute of Geology and Mineral Exploration,Yantai,Shandong 264004,China;Shandong Ludong Geological Engineering Co.,Ltd.,Yantai,Shandong 264004,China)
出处
《中国岩溶》
CAS
CSCD
北大核心
2023年第5期956-968,共13页
Carsologica Sinica
基金
栖霞市自然资源和规划局项目(栖霞政采[正平]服务2017012)
烟台市自然资源和规划局项目(SDGP370600202102000097,SDGP370600002302000134)。
关键词
胶东半岛中桥地区
岩溶塌陷
层次分析法
发育程度分区
the Zhongqiao area
karst collapse
Analytic Hierarchy Process
development level zoning
作者简介
第一作者:杨宁(1987-),女,高级工程师,主要从事水工环地质工作。E-mail:yangning@sddksd.com;通信作者:张杰(1983-),男,正高级工程师,主要从事水工环地质工作。E-mail:82650376@qq.com。
