Research And Application Of Grouting Treatment Technology For Water Inrush Disaster In Karst Tunnel Floor

The construction of highway and railway operating tunnels in karst areas is constrained by factors such as design and construction during construction,resulting in tunnel leakage and water inrush during the operation period,which seriously affects the safe operation of the tunnel.Water surges in the tunnel floor during operation will not only cause economic losses but also cause casualties.At present,the traditional measures to deal with the inrush of the floor are to grouting the surrounding rock of the tunnel to form a fully enclosed reinforcement ring,so as to achieve the purpose of treating the inrush of the floor.There is very little research on the treatment of water inrush disease caused by the use of grouting reinforcement to form a water interception curtain.However,different parameters of the water interception curtain have different effects on the effect of water interception.In this paper,for the construction design problems of the thickness,length,angle and position of tunnel water cut curtains in karst areas,according to the theory of fluid-structure coupling,the finite element model is used to analyze the water cut reinforcement effectiveness and tunnel stability of different water cut curtain parameters And based on this,combined with the example of grouting engineering for comprehensive treatment of water inrush disasters in the floor of the Nanshibi tunnel during the operation period,the reasonable water cut curtain parameters in the karst area were studied,the optimal parameter combination was determined,and a suitable injection was proposed Slurry water blocking reinforcement method.Mainly conducted the following research:(1)The theory of tunnel seepage,the effect of grouting on the stress field and seepage field of the tunnel,and the fluid-solid coupling and other related theories are systematically analyzed to provide a basis and theoretical support for the selection of the parameters of the subsequent numerical model.(2)Research on parameter optimization of water cut curtain.Considering the angle of the water cut curtain as a parameter,the length,thickness and angle of the water cut curtain are combined to establish the working conditions of no curtain and multiple water cut curtains.The numerical simulation method is used to compare the seepage field and displacement field of different working conditions.,Stress field,plastic zone and other distribution changes,to get the best water cut curtain working conditions.It provides a basis for studying the treatment of water inrush diseases of tunnel floor in karst area and designing parameters of water cut curtain.(3)Grouting design and grouting effect evaluation of water cut curtain of typical karst tunnel.Combined with the Nanshibi floor surge water treatment project,the parameters of the water cut curtain determined by numerical simulation were used to guide the design and construction of the grouting scheme for the water cut curtain in the tunnel floor surge water disease area,and the reliability of the curtain was evaluated through the grouting effect on site,To ensure the effectiveness of curtain water interception and reinforcement,and provide an important guarantee for the treatment of tunnel diseases and safety and stability.