简介：Thestrainmonitoringandstressanalysisofanewtypeofpost-prestressedtunnellinerwerecarriedout.Theinstrumentationblockofthetunnelliner,withthedimensionsof12.06minlength,6500mmindiameter,and650mminthickness,waspost-prestressedwiththeunbondedtendons,eachofwhichconsistsof8piecesofdouble-loopedstrandsandtheaxialspacingofthetendonsis500mm.Concretestrainmeters,rebarmeters,loadcellandzero-stressmeterswereinstalledforthestrainmonitoring.Thetensioningloadswereappliedincrementallyinthreecycles(50%,77%and100%)attheconcreteageof28dandthetensioningworklastedfor187.1h.Strainreadingsweretakenbeforeandaftereachcycleduringtensioningperiodandatthespecifiedtimeintervalaftertensioningperiod.Itisfoundthatconcretecreepdevelopedovertensioningperiodis30%oftotalstrainand41.5%ofelasticstrainrespectively.Prestressforceintheunbondedtendonandconcretestressinthelinerwereevaluatedaccordingtotheobservedstrainvariations.Bothofthemaretime-dependent,andabout5.3%,8.3%and9.0%oftheprestresslossesareobservedattheageof1d,30dand60drespectivelyafterstressing.Thedistributionofprestressinthelinerisrelativelyuniformandmeetsthedesignrequirement.