Freezing Design And Actual Measurement Of Subway Communication Channel Constructed By Artificial Freezing Method

In recent years,with the rapid development of underground railway construction,the artificial freezing method has become one of the commonly used reinfor,cement methods in the construction of horizontal tunnels for subway shield tunnels in soft soil areas.In the past,the design of artificial freezing curtains was mainly based on the construction of mines However,there are great differences between urban underground engineering and mines in terms of construction depth,construction metho:ds and stress states.Therefore,artificial freezing method is needed in urban underground engineering.Related design methods are studied.Based on the engineering background of Xi'an Metro Line 4,this paper studies the parameters of the frozen channel of the communication channel through the physical and mechanical tests of artificial frozen soil,and then calculates the actual frozen wall and average temperature and checks the stability o,f the actual project.To ensure the safety and reliability of constructionFirstly,the mechanical parameters and characteristics of artificial fr,ozen soil are introduced.The general principles and design methods of frozen soil wall thickness and freezing parameter design are also described.Through the investigation of the soil quality of the project,a representative area was selected for earth borrowing.According tao the "Testing Method for Coal Frozen Soils",the uniaxial compressive strength test and triaxial shear of artificial frozen soil at-10 ? were carried out on the remolded soil.The test was carrierd out to obtain the physical and mechanical indexes of artificial frozen soil,which was applied to the artificial freezing curtain design in Xi'anSecondly,the principle of artificial freezing method and its advarntages and disadvantages aure introduced.The c.auses of frozen soil deformation are analyzed.The thickness of trozen wall and the average temperature of frozen wall arle theoretically studied.The ground surface deformation of frozen soil is explained by random medium theory,and then frozen.The scheme was designed,and the thickness and average temperature of the frozen wall of the actual engineering horizontal communication channel were calculated according to the theoretical calculation.Finally,the brine de-circulation temperature,pressure relief pore pressure,temperature measurement pore temperature and surface settlement are monitored and compared with the design values to ensure the safety and reliability of the construction.