The Temperature Field Study On Cup-shaped Freezing Soil Wall Of Horizontal Freezing Reinforcement For Shield Tunneling Setting Out

It is necessary to form the high strength,good sealing cup-shaped freezing curtain in the periphery of shield machine and the scope of hole when shield tunneling is setting out for horizontal freezing reinforcement project. And good freezing curtain is closely related to the temperature field of freezing soil wall .So it is particulary important to study on temperature field for ensuring success to shield tunneling setting out.The research on this problem becomes more and more instant for the temperature field research on cup-shaped freezing soil wall is not understood in domestic.Based on horizontal freezing reinforcement project for Nanjing metro Line No.2 Yixian Bridge station, Researches on the temperature field by site monitoring,theoretical anlysis and numerical simulation were carried out in this dissertation.The major works and results of this dissertation are as follows:(1) The development characteristics of the frozen soil wall are revealed overall by analysing of actual measurement data of freezing temperature field with multi-freezing-tube cycle.In the future similar engineering, design and construction method could be improved according to these characteristics.(2) The temperature field of horizontal freezing reinforcement cup-shape freezing soil wall is a three-dimensional problem.In this paper,finite element software ADINA is applied to simulate the three-dimensinal temperature field of the horizontal freezing reinforcement project for Yixian Bridge station in Nanjing metro. The reliability of the model and calculation method is verified by comparative analysis of the measured data.This calculation method provides a new distinguishment way for beginning to chisel the door of a hole .(3) According to numerical simulation analysis of the impact parameters of temperature field , the impact regularity of these parameters are obtained.Impact parameters include brine temperature,diameter of freezing-tube,spacing of freezing-tube,and different soil layer.(4) According to the impact regularity of various parameters of temperature field ,put forward to the best value range of these parameters in similar engineering.