Study On The Freezing Damage Mechanism And The Design In Cold Region Soft Rock Tunnel

Freezing damage is an common engineering disease,there are plenty of reasons cause the freezing damage,frost heaving force is the principal.Therefore,in the study of cold region rock tunnel,to avoid and reduce freezing damage,the key issue is to study the occurrence,expedience of the frost heaving force,and find out how to prevent these phenomenon.This paper have system study to frost heaving force.1.Summarize the hypothesizes of the freezing damage,and give a detailed analysis of each advantages and disadvantages.2.The governing differential equations are derived,which completely coupled the seepage field with the temperature field for phase change.3.In the governing differential equations of the seepage field,the influences of the porosity change by phase change between water and ice is investigated.â‘ Frost heaving force is enlarging with the expedience of the wind temperature of the soft rock tunnel.â‘¡The changes of temperature field and the frozen collar are studied before and after coupling seepage field.â‘¢Summarized the law of frost heaving force's distribution.Most scattered on the side of soft rock tunnel.The max power formed on the center of tunnel's flank.And this page gives examples.4.The seepage coefficient by phase change between ice and water is analyzed.The results indicate that the frozen collar get thinner after coupling seepage field than before.And the greater seepage coefficient,the thinner frozen collar.The frozen collar also gets thinning after coupling the phase change between water and ice.5.The formula of freezing force for tunnel in the cold region is proposed.Then the analytical method for plastic zone boundary and stress are listed.And a calculating case is analyzed.The results show that tremendous freezing forces come.