Kayan aikin Jet Grouting na tunel

Jet grouting na tunneling yana wakiltar wata hanya ta musamman ta daidaita ƙasa da gyaran ƙasa da ake amfani da ita a cikin ginin ƙasa, musamman a cikin yanayi masu iyaka inda hanyoyin tushe masu zurfi na al'ada ko hanyoyin katsewa da rufe ba su yiwu ba ko kuma ba su dace da tattalin arziki. Wannan rukuni na kayan aiki yana ƙunshe da injuna da tsarin da aka tsara don aiwatar da ayyukan jet grouting na matsi mai yawa a cikin aikin hakar tunnel, inda gyaran ƙasa mai kyau ke da mahimmanci don kula da kwanciyar hankali na fuskar, sarrafa zaɓi, da inganta dukkan halayen ƙasa kafin ko a lokaci guda da ci gaban tunnel. Ka'idar aiki ta jet grouting na tunneling tana shafar shigar da slurry na siminti ko sinadarai a ƙarƙashin matsi mai yawa—yawanci 300 zuwa 700 bar—ta hanyar na'urar kulawa ta jetting ko bindiga mai kulawa da aka sanya a kan rig na hakar. Jirgin jet mai sauri, tare da saurin fita da yawanci ya wuce 200 m/s, yana yanke da haɗa ƙasa mai kewaye, yana cire kayan a lokaci guda da kuma motsa grouting cikin gurɓataccen. Wannan tsari yana ƙirƙirar ginshiki ko hanyar haɗin gwiwa na abubuwan ƙasa da aka gyara wanda ke ƙara haɗin kai, rage permeability, da kuma daidaita fuskar tunnel. Ayyukan sun haɗa da pre-grouting a gaban fuskar injin hakar tunnel (TBM) a cikin ƙwayoyin ƙasa masu rauni, post-grouting don sarrafa zaɓi da kuma rufe gurɓataccen bayan layukan sassa, da kuma gyaran yankunan da aka shafa da kuskuren, shigar ruwa, ko abubuwan ƙasa da ba a zata ba. Tsarin kayan aiki yawanci yana ƙunshe da rig na hakar da aka shirya tare da tsarin mast na musamman da ke da ikon sarrafa jetting na tsaye da na kwance, wani shahararren shuka grouting mai matsi mai yawa tare da famfunan centrifugal da aka ƙayyade don aiki mai ci gaba a 500–700 bar, na'urorin tacewa da haɗawa, tsarin jigilar slurry, da bindiga mai kulawa ta jetting tare da nozzles da yawa (nau'in jet guda, biyu, ko uku). Tsarin tripod ko na tafiya yana ba da ikon sarrafa matsayi da kuma ba da damar sake saita sauri a cikin fadin tunnel. Tsarin sake amfani da mud ko slurry da kuma tsarin zubar da su suna da mahimmanci, yayin da jet grouting na tunneling ke haifar da babban adadin ruwan dawowa mai ɗauke da fines wanda dole ne a raba shi da sarrafa shi bisa ga ƙa'idodin muhalli. Zaɓin kayan aikin jet grouting na tunneling yana dogara da abubuwa da yawa ciki har da tsarin ƙasa na in-situ da halayen ƙarfi, yanayin ruwa, zurfin ƙasa da tsarin damuwa, diamita da tazara da ake so na ginshiki, sararin aiki da iyakokin sararin sama a cikin tunnel, da ƙayyadadden haɗin gwiwar grouting (slurry na siminti ko microfine siminti ko grouts na sinadarai). Na'urar kulawa ta jetting dole ne ta kasance da ikon juyawa na tsaye da na radial don samun madaidaicin wurin rami da kuma tabbatar da isasshen rufin tsakanin ginshikan da aka gyara don ci gaba da yankin gyara. Ayyukan jet grouting na tunnel suna ƙarƙashin ƙa'idodin Turai EN 14679 (Aiwar da ayyukan geotechnical na musamman—Jet grouting) da EN 12716 (Aiwar da ayyukan geotechnical na musamman—Grouting), da kuma ƙayyadaddun aikin da aka samo daga rahotannin binciken geotechnical. Kayan aikin dole ne su nuna bin ƙa'idodin tsarin matsi da kuma bayar da takardun shaidar ƙarfin famfuna, ƙimar matsi, da tsarin tsaro. Masu aiki suna buƙatar horo a cikin sarrafa matsi, rheology na grouting, da kimanta kwanciyar hankali na fuska don tabbatar da aiwatar da inganci da tsaro a cikin mawuyacin yanayin ƙasa.