Numerical Simulation Of The Influence Of Karst Pipeline On Hydraulic Tunnels Surrounding Rock Based On The Fluid-solid Coupling

This paper adopt the methods of numerical simulation and theory analysis, the numerical analysis model of fluid-solid interaction is established, the influence of the karst pipeline on stress, strain and displacement of the stage with excavation, operation and maintenance of surrounding rock which is around the circular hydraulic tunnels with pressure are studied systematically. The main research contents are as follows:(1) The motion law and development of underground water and the problem of hydraulic tunnel on study in karst area is summarized by consulting references of domestic and foreign, the research subject of this paper is proposed.(2) The development condition and the geographic character of karst is introduced systematically, the karst aquifer medium is divided, and based on that the karst water is divided to three kinds whose characters are introduced respectively; The underground karst water is elaborated systematically with the respects of karst water supply, runoff, discharge and the damage on engineering, then the difference of karst between north and south in China is compared.(3) Based on the basic principle of seepage, the mechanism of interaction between rock medium and underground water is fully analysised, the fully coupling of seepage field and stress field is proposed by the valuation of permeability coefficient, the mathematical model and finite element discretization model of seepage and stress coupling is established respectively by the relationship between permeability coefficient and stress, strain and porosity.(4) User subroutines were programmed by the relationship between permeability coefficient and volume strain, numercial analysis model of the influence of the karst pipeline with fluid-solid interaction on the surround rock of hydraulic tunnel is established by Abaqus finite elements analysis software, when around the tunnel without karst pipeline is calculated.(5) The influence of the pipeline angle,the internal water pressure of pipeline,the distance between pipeline and tunnel and the size of pipeline on the stress, strain and displacement of surround rock under the stage of excavation, operation and maintenance of hydraulic tunnel with pressure is studied by the numercial analysis model, then some valuable conclusions are obtained.