Rijiyoyin Jet Grouting na Tunel
Kayan aikin Jet Grouting na Tunnel
Kayan aikin jet grouting na tunnel kayan aikin musamman ne da aka tsara don aiwatar da ayyukan jet grouting na matsa lamba mai yawa a cikin yanayin ƙasa, musamman don gina tunnels, tallafawa hakar, da daidaita ƙasa a cikin wuraren ƙasa masu iyaka. Waɗannan tsarin suna shigar da groud mai matsa lamba ta hanyar harsashi masu daidaito zuwa cikin ƙasa da dutsen, suna yanka da haɗa kayan cikin gida tare da siminti don ƙirƙirar ginshiƙai masu ƙarfi tare da ƙarin ƙarfin ɗaukar nauyi, rage shayarwa, da haɗin jiki. A cikin injiniyan tushe mai zurfi, kayan aikin jet grouting na tunnel suna zama kayan aiki masu mahimmanci don maganin ƙasa kafin ginin, daidaita bayan hakar, da ƙirƙirar katanga don sarrafa ruwan ƙasa ta hanyar ƙasa mai rauni ko mai shayarwa.
Ana amfani da kayan aikin jet grouting na tunnel a cikin aikace-aikace masu yawa na ƙasa. Babban amfani sun haɗa da jet grouting don daidaita fuskar tunnel da shigar da gwaji, ƙirƙirar ginshiƙai na jet grouting na tsaye da jujjuyawa don tallafawa katangar tunnel da hana rushewar rami, shigar da katanga masu hana ruwa a kusa da hakar ƙasa, inganta dutsen mara inganci da ke kewaye da sassan tunnel, da kuma katanga masu hana shayarwa a cikin ƙasa mai karfi. Waɗannan kayan aikin suna da mahimmanci a cikin hakar birni inda ya kamata a rage girgizar jiki da sauti, da kuma a cikin ƙasa mai ruwa inda hanyoyin katanga na diaphragm na gargajiya ke fuskantar ƙalubale na tsari. Aikace-aikacen suna faɗaɗa zuwa gyaran groud a ƙarƙashin gine-ginen da ke akwai yayin ci gaban tunnel da ƙarfafa ƙasa kafin ayyukan hakar na shield.
Ka'idar aiki tana dogara ne akan tsarin groud mai matsa lamba, yawanci yana ƙunshe da piston ko famfo mai jujjuyawa wanda ke iya fitar da matsa lamba na 350–800 bar, yana isar da groud ta hanyar harsashi mai jujjuyawa zuwa ga mai kulawa mai jujjuyawa wanda ke da ɗaya, biyu, ko uku na harsashin shigarwa. Harsashin hakar yana sanya jerin harsashi a cikin madaidaicin wurare a cikin tunnel, kuma ƙarfin jujjuyawa na mai kulawa yana ba da damar jujjuyawa na harsashi a kwance da tsaye don ƙirƙirar tsarin ginshiƙi. Yayin da aka janye harsashin a hankali, ruwan jujjuyawa mai sauri (yawanci 200+ m/s a lokacin fita daga harsashi) yana yanka ƙasa da dutsen da ke kewaye yayin da yake haɗawa da su tare da groud slurry, wanda ke haifar da ginshiƙi mai ƙarfi na ƙasa da siminti. Matsa lamba da saurin jujjuyawa suna sarrafa diamita na ginshiƙi, yawanci 0.8–2.5 m dangane da nau'in ƙasa da ƙirar harsashi.
Tsarin kayan aiki yana bambanta sosai bisa ga yanayin shigarwa. Tsarin harsashi guda ɗaya yana ba da daidaito don magani na musamman; tsarin harsashi biyu da uku suna hanzarta ƙirƙirar ginshiƙi da rage lokacin aiki. Harsashin hakar yawanci ana sanya su a kan kayan aikin jujjuyawa ko na tafiye-tafiye don ba da damar motsi a cikin sassan tunnel, yayin da shigarwa mai tsaye ana amfani da su inda ake buƙatar samun dama akai-akai ga wuraren magani na dindindin. Kayan aikin da aka ƙera na musamman suna da ƙira don tunnels masu ƙarancin sarari; tsarin modular suna ba da damar rarrabawa da sake haɗawa a cikin ɗakunan kaddamarwa masu iyaka. Kayan haɗa groud suna da mahimmanci, yawanci suna da haɗin gwiwa tare da masu haɗa ruwa ko na'urorin jujjuyawa masu ƙarfi don samun slurry mai ɗanɗano tare da riƙon ƙananan ƙwayoyin da kuma viskositi mai dacewa don shigar da ruwan ƙasa.
Ka'idodin zaɓin kayan aikin jet grouting na tunnel suna mai da hankali kan matsa lamba mafi girma, ƙarancin diamita na harsashi, zurfin hakar da isa a cikin tsarin tunnel, daidaito da maimaitawa na mai kulawa, daidaiton isar da groud, da kuma dacewa da yanayin ƙarancin sarari. Babban sarrafa kansa—ciki har da sarrafa matsa lamba na harsashi, daidaita saurin jujjuyawa, da sa ido kan matsa lamba—yana zama al'ada, yana ba da damar daidaitaccen tsarin ginshiƙi da takaddun shaida na aiwatar da magani. Amfanin kayan aiki a ƙarƙashin tsawon lokutan aiki da ikon dakatar da gaggawa suna da mahimmanci a cikin yanayin tunnel mai aiki.
Ka'idodin da suka dace sun haɗa da EN 12715 (aiwatar da aikin musamman na geotechnical: groud), EN ISO 13286 (kayan da ba a haɗa ba da kuma waɗanda aka haɗa da ruwa—Sashi na 3: jet grouting), da DIN 4093 (jet grouting), wanda ke ƙayyade buƙatun aiki, dacewar kayan, da hanyoyin tabbatar da inganci. Maganin ƙasa na musamman na tunnel yana ƙarƙashin EN 14679 (aiwatar da jet grouting mai zurfi) da kuma ƙa'idodin gini da hakar ƙasa na ƙasa.