| With the development of our economy, the urban scale expand promptly. All kinds of transportation means has increased dramatically,and the traffic jam is already in many big cities. In order to reduce the pressure of the ground transportation, subway is required to construct. The subway construction mainly covering method, digging method, shield method and so on. The shield method in construction immune to the climate conditions such as season, wind and rain,and it has no noise,no disturbance,low labour intensity and the fast heading a high rate in the construction.So is widely used in the subway construction. Because of the complexity of the geological environments, in which the process of shield tunneling, we are usually to reinforce soil around the hole. Ground freezing method is reliable and it’s liberal for standards.international engineering community think it is the final solution when other methods are difficult to apply.This article analyze verticle freezing method strengthening technology for the metro tunnel shield hole,research on some aspects of the temparature field mathmatical model in the formation of the tunnel frozen wall,the design method of thickness of frozen wall,the3D numerical simulation of temparature field of frozen wall and thermal coupled field,and the freezing construction technology.In the study of the frozen soil temparature field and the frozen soil thaw deposit and frosting heaving, analyzed freezing temparature field the earth’s movement and deformation according to the property of frozen soil,and research on the general rule of the earth’s deformation caused by shield tunnel construction and measures taken control deformation.The freezing strengthening design of the entry of hole soil body include:the solution design of freezing strengthening,the design of thickness of freezing soil,the design of frozen hole and layout of thermometer hole,and the design of freezing construction parameter. In the aspects of numerical simulation,we use large-scale finite element software to select parameter and establish the calcution model to simulate the numerical calculation of temparature field and thermal coupled field of frozen wall,and analyze the result of numerical simulation calcution combine the measured data.The part of freezing construction is main include the drill construction,the install of freezing system and the analysis of freezing effect etc.The research achievement of this article will provide a theoretical basis for such construction projects. |
