Abstract: Ground collapse disasters occur frequently in covered karst areas and cause enormous harm.Studying the law of ground collapse and its influencing factors is a fundamental prerequisite for disaster warning and control.The laboratory simulation test of karst collapse was conducted to study the influences of karst structures opening size,groundwater-level variation amplitude and overlying soil thickness on the law of ground collapse caused by a single karst structure,and the deformation characteristics of overlying soil during ground collapse were analyzed.The joint collapse modes caused byadjacent karst structures were summarized,and the influences of the karst structures opening size and spacing on the soil caves development and the joint collapse were proposed.The experimental results indicate that the karst structures opening size and groundwater-level variation amplitude have a positive correlation with the development scale and rate of soil cave,and the increase of overlying soil thickness is beneficial for improving the stability of the soil cave and reducing the risk of karst collapse.The settlement deformation of overlying soil occurs during the soil cave development process,and the settlement amount and deformation rate are closely related to the karst structure size and overlying soil thickness.Multiple underlying karst structures are easy to induce joint collapse,the modes of which can be divided into the independent type,the weakly connected type and the strongly connected type,and the joint collapse process can be divided into the rapid development,the stable development and the joint collapse stages.As the opening size of adjacent karst structures increases,the time for adjacent soil caves to connect becomes shorter.When the spacing between karst structures is less than 40% of its diameter,the connected collapse type is easily to occur,and when the spacing between karst structures is more than 80% of its diameter,the adjacent soil caves develop independently.