Study On The Sealing Mode And Control Method Of Multi Pipe Water Gushing Grouting Diffusion In Karst Area

The geological conditions in karst area are extremely complex,and the bad geological structure is often exposed during the construction of underground engineering,which leads to water inrush disaster,especially the multi pipeline water inrush.Multi pipeline water inflow has the characteristics of multi-source supply,multi pipeline dense distribution,multi outlet discharge,large flow,high flow rate and strong disaster causing,which seriously affects the construction period,increases the construction cost and endangers the construction safety.Therefore,in the process of underground engineering construction,it is necessary to improve the understanding of multi pipeline water inrush in karst areas,and select appropriate methods for treatment.Based on the theoretical analysis and study of the hydraulic characteristics of water inrush,the numerical simulation of water inrush and grouting is carried out,and combined with the indoor grouting test,the characteristics of multi pipeline water inrush and the grouting sealing mode in the karst area are systematically analyzed,and the optimization suggestions for the treatment methods of multi pipeline water inrush grouting in the karst area are put forward,which have been successfully applied to the mining of Hejing mining area of China Resources Cement(Pingnan)Co.,Ltd Pit water control project.The main research contents and achievements are as follows:(1)Based on the analysis of the types of water inrush in karst areas,a groundwater runoff system is proposed,which is composed of four factors:water source,runoff channel,discharge space and water pressure.Considering the head loss(head loss along the way and local head loss),the hydraulic model of single pipe,two pipe and multi pipe water inrush is established,and the relationship between the velocity of pipe and the head of water source is deduced.(2)The multi pipe water inflow pipeline flow model and the two-phase flow model of grouting are established to simulate the dynamic process of multi pipe water inflow flow pattern,slurry diffusion pattern and sealing under the conditions of initial water head,outlet section opening and pipeline combination.The changes of flow field,slurry diffusion pattern and pressure field in the pipeline under different conditions areanalyzed,and the hydraulic characteristics of multi pipe water inflow and grouting diffusion law are clarified And the law of interaction among multiple pipelines.(3)The model test system of multi pipeline water inflow grouting and plugging is used to study the hydraulic characteristics of multi pipeline water inflow and grouting and plugging test.The hydraulic characteristics of water inflow,the diffusion form of slurry and the distribution law of pressure field under the influence of slurry type,initial water head,opening of outlet section,pipeline combination and grouting position are defined.The single slurry and C-S slurry of cement are revealed in the process of grouting and diffusion plugging The paper puts forward the optimization of multi pipe water gushing grouting.(4)Based on the first and second mining pit water control project of Guangxi Huarun cement(Pingnan)Co.,Ltd.,according to the characteristics of multi pipeline water inrush,combined with the results of laboratory test and numerical simulation,the paper puts forward the grouting treatment method of "water inrush point flow control and speed reduction+priority treatment of branch pipeline+joint grouting and sealing of main pipeline",which can better realize the sealing of multi pipeline water inrush in karst area and control the water inrush of multi pipeline It provides successful experience for reference.