Research On Modeling Test Of Construction By Artificial Freezing Method Of Metro Contact Passage In Gravel Stratum With Abundant Water

The soil has the advantages of fast,improve the strength of reinforcement required for a short time,overall stability,high water resistance and good freezing method,so it is widely used in soft ground water tunnel and other underground engineering construction.In order to understand the changes of freezing method construction in water rich gravel stratum tunnel application process parameters and comprehensive effect,taking Nanning Metro Line 1?Qingchuan National University(the original Chen Cun Metro subway station)as engineering background,numerical simulation and laboratory using theory analysis,similar simulation method combining to make study.(1)first use of surface deformation caused by the stochastic medium theory of freezing method in construction process are analyzed,and use Matlab to set up the calculation program on freezing and excavation,calculate the deformation caused by the surface thawing process.(2)establish model test system,and use similarity principle to deduce similarity criterion of tunnel connection tunnel construction by freezing method.Including test temperature,displacement model test system and lining structure design has been obtained by freezing and thawing settlement distribution of temperature field of frozen wall;and the surface of frost heave,excavation freeze-thaw characteristics sinking displacement field.The displacement values are measured numerically.(3)for different freezing rate of freezing temperature field and displacement field are analyzed,the freezing rate is large,the soil temperature drop rate is bigger,the formation of frozen wall quickly,frost heave greater speed,but with the two conditions of the freezing process end,freezing rate for the final displacement of frozen wall and surface the impact is not big,the two conditions of the displacement tends to be equal.(4)the temperature field of freezing and thawing process of contact channel is simulated by using ABAQUS software,and then the final temperature variation law is studied and analyzed.(5)through theoretical analysis,model test and final numerical analysis,not only the feasibility of using freezing method in horizontal stratum is verified,but also the factors influencing the construction of freezing method are summarized.Therefore,in the construction of horizontal freezing method,this paper plays a good guiding role in the design and construction of the supporting excavation in the construction site.