大型盾构出洞冻结加固融沉控制技术研究

AbstractNumerical simulation,laboratory physical simulation and field monitoring wereapplied to the research on forced thawing temperature field and grouting during forcedthawing technology in the large scale shield tunneling construction with artificial groundfreezing method.Firstly,the thermophysical parameters of soil in frozen and thawed state and theprimary factors acting on the freeze-thaw temperature field were analyzed.FEM had beencarried out to the research on the freeze-thaw temperature field.The significant factorsacting on the freeze-thaw temperature field were obtained.Regression equations of frozendays,thawed days and thawed area were presented by multivariant regression theory.Thefreeze-thaw temperature field in the Shangzhong Road large scale shield tunnelingconstruction was back analyzed as well.Secondly,the law of Shanghai soft soil freeze-thaw temperature field with multirowfreezing pipes was gotten by laboratory simulation test.The law of foced thawing in thatwork condition was found.Once more,according to the monitoring results in situ,the variation rules oftemperature,ground pressure and settlement of crane foundation and gound surface werereached in Shangzong Road large scale shield tunneling construction in which freezing andgrouting during forced thawing methods were applied.Finally,in response to the construction in situ,the design and construction of forcedthawing,mechanism of thaw settlement grouting and grout technique were discussedcombining with numerical simulation,physical simulation and field monitoring.Thescheme of thaw settlement controlling in large scale shield tunneling project with verticalfreezing method was attained.Due to the research which came from the practice in Shangzhong Road super largescale shield tunneling construction and was validated in practice,the contents and resultsof the research can be directly used in practical projects.The research production providessome valuable data for the conger projects in the future.Keyword:large scale shield,shield tunneling,freezing reinforcement,thaw settlementcontrolling,forced thawing,thaw settlement grouting