Research On Grouting Sealing Technology Of Pipe-fissure Type Karst Water Runoff-Drain System Characteristics

In the south of China,karst development is strong and the hydrogeological conditions are complex and changeable.In this area,large-scale karst water gushing is often encountered in mining,deep foundation excavation and other engineering activities.The structure and physical circulation mechanism of water bearing medium in karst area are complex,and the karst water gushing water has the characteristics of high flow rate and high flow rate.Therefore,in the process of grouting plugging,it is necessary to adopt different grouting techniques,technology and grouting materials according to the characteristics of water bearing medium and karst water diameter.Taking the open mining area in Guangxi as the research object,this paper summarizes the typical pipe fracture type karst water drainage system in open mining area.Based on the methods of theoretical analysis,numerical simulation and indoor test,the grouting sealing technology and materials of the typical row system are studied,and a series of research results are obtained,which are embodied in the following aspects.(1)Several types of karst area typical disaster medium and karst drainage system are summarized and analyzed,and then the characteristics of runoff and excretion of karst water bearing system in open mining area are studied,and the risk grade of disaster causing is divided,and the model of typical karst water is studied.(2)In view of the fractured medium and fissure karst cave medium in the typical karst water drainage system,the layout method of the discontinuous curtain grouting is studied,and the location of the water rich area and the karst pipeline is determined by the comprehensive exploration method,and the layout and the parameters of the discontinuous curtain are designed and optimized.(3)In order to ensure the implementation effect of the discontinuous curtain belt and reduce the cost of filling fissure cave medium,the research of fiber modified cement base slurry is carried out through laboratory tests.By studying the addition of polypropylene fiber and clay powder sand,the slurry has long and controllable initial setting time,flexural strength and compressive strength.,good degree.(4)Based on the retention conditions of the slurry in the pipeline,the karst pipeline fracture hydraulic model is simplified,the flow control of the karst pipeline is theoretically analyzed,the calculation method of the proportion of the flow control in the karst pipeline is studied,and the influence of the local water head loss coefficient and the water level difference H on the controlled water flow is studied.(5)The technology of controlling flow and decreasing velocity of grouting in Karst pipeline is studied.Based on the Abaqus finite element software,the influence of the multi drainage tube on the displacement and stress of the grouting cushion is studied.The stress and displacement of the stress and displacement curves of the single drainage tube,the double drainage tube and the three drainage tube,the stress and displacement curves of the corresponding measuring line are extracted,and the influence of the number of the drainage tube on the stress and displacement of the grouting cushion is synthetically analyzed,and the grouting is optimized.Cushion scheme design.The technology of grouting and plugging for Karst pipeline is studied,which is coupled with grouting control and combined grouting.