Research On The Development Law Of The Double-sided Freezing Displacement Field Of Long Connected Aisle

The traditional connected aisle span is generally short,and the unilateral freezing mode is generally used to strengthen the stratum.However,with the emergence of a number of long connected aisles using the double side freezing mode,existing research results are difficult to fully describe the development law of its displacement field.The evolution law of the displacement field under this mode is the theoretical basis for controlling frost heave and solving the thawing after completion.At the same time,the double-sided freezing mode has the characteristics of long freezing period and large frozen volume.Therefore,it is urgent to study the development law of the double-sided freezing displacement field of the long connected aisle.This paper relies on the connected aisle of a certain section of Fuzhou Metro Line 2 as the engineering background,and uses the finite element software Ansys to conduct a three-dimensional numerical simulation of the freezing temperature field on both sides of the long connected aisle.By analyzing the long axis direction of the connected aisle and the development rules of frozen walls on different sections,Obtained the maximum thickness position and the weak position,and studied the temperature field development of the weak position,and proposed that the number of short-term freezing tubes at the opening of the communication channel can be appropriately reduced,and the length of the cross-overlap area in the middle of the communication channel is appropriately increased.Suggest and calculate the average crossing time of the frozen wall on the right side and the left side of the contact channel.Furthermore,through the thermo-mechanical coupling,the development law of the displacement field of the communication channel is studied,and it is inferred that the frozen concentrated area above the communication channel body is a strip dome structure,and the frost heaving core area of ? ? the stratum is located in the center of the structure,and its surface projection position is the communication channel In the middle,the development law of formation displacement field is analyzed with the change of frost heave coefficient.Finally,the measured data system is used to analyze the evolution law of the surface frost heave of the contact channel,and the accuracy of thefinite element model of the temperature and displacement fields is evaluated accordingly,and the key position of the frost heave of the frozen surface on both sides of the long contact channel is determined.Using Boltzmann The function and Gauss function fit the development and distribution of frost heave in key areas.The research results of this paper provide a certain reference for the construction of a long contact channel with a double-sided freezing model,which has certain value for controlling the frost heaving of key positions on the ground and verifying the correctness of the frost heaving model.