Model Test Study on In-service Karst Highway Tunnel

摘要

Thisarticle,basedontheBaishanTunnel,optimizedtheselectionforthesimilarmaterialsofkarstcavesfiller,surroundingrockandlining,carriedoutastudyonsimilarmodeltesttoin-servicekarsthighwaytunnelwiththegeometricsimilarityratioof1/40.Then,thedistributionlawandtrendofsurroundingrockpressurewererevealed.Subsequently,themechanicalbehaviorsofthesurroundingrockwerediscussedafterendowingsometreatmenttothesecaves.Theresultsshowthat:?the?surroundingrockfromBaishanTunnelcanbeproperlysimulatedbythemixtureofbaritepowder,plasterpowderandcementwiththeproportionof1:12:2;?applyingthelowerelasticmodulusmaterial,comparedtosurroundingrock,tofillthosekarstcaves,whichwillleadtogreatercompressiondeformationunderthesameload;?whenthesecaveswerelaidnearbythespandrel,haunchandspringing,karstcaveswillcauseunsymmetricalpressuretotunnellining.Although,thosecaveshavebeenfilled,whichshouldbeattachedgreatimportanceduringthetunnelservice.