Air pressure law of a reservoir constructed in karst sinkholes  

作　　者：YU Bo TAI Shengping ZHENG Kexun CHEN Shiwan HAN Xiao WANG Senlin ZUO Shuangying 

机构地区：[1]Power China Guiyang Engineering Corporation Limited,Guiyang 550081,China [2]College of Resources and Environmental Engineering,Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China

出　　处：《Journal of Mountain Science》2024年第3期1048-1057,共10页山地科学学报（英文）

基　　金：support from the National Natural Science Foundation of China(Grant.No.42162027);the Science and technology foundation of Guizhou Province(Grant.No.2022-212,2023-006)are greatly appreciated.

摘　　要：Karst sinkholes with natural negative landform provide favorable conditions for the pumped storage reservoir construction for less excavation work.However,the construction of the reservoir would plug the natural karst channels for water and air,which would cause remarkable air pressure in karst channels when the groundwater level fluctuates.A large laboratory simulation test was carried out to study the air pressure variation of a reservoir built on the karst sinkhole.The air pressure in the karst channel and inside the model was monitored during the groundwater rising and falling process.Result showed that the variation of air pressure in the karst channel and the surrounding rock exhibited a high degree of similarity.The air pressure increased rapidly at the initial stage of water level rising,followed by a slight decrease,then the air pressure increased sharply when the water level approached the top of the karst cave.The initial peak of air pressure and the final peak of air pressure were defined,and both air pressure peaks were linearly increasing with the water level rising rate.The negative air pressure was also analyzed during the drainage process,which was linearly correlated with the water level falling rate.The causes of air pressure variation in karst channels of a pumped storage reservoir built on the karst sinkhole were discussed.The initial rapid increase,then slight decrease and final sudden increase of air pressure were controlled by the combined effects of air compression in karst channel and air seepage into the surrounding rock.For the drainage process,the instant negative air pressure and gradual recovering of air pressure were controlled by the combined effects of negative air pressure induced by water level falling and air supply from surrounding rock.This work could provide valuable reference for the reservoir construction in karst area.

关 键 词：Simulation test Karst sinkhole Pumped storage reservoir Air pressure Flow rate 

分 类 号：TV62[水利工程—水利水电工程] TV221.2