Na'urar hakowa

Masu hakowa da aka tura a cikin ginin bangon ƙasa da katangar katanga suna zama muhimman kayan tallafi don fasahohin ginin tushe mai zurfi na musamman da suka haɗa da bangon diaphragm, katangar katanga, ginshiƙan secant, bangon katanga, da kuma aikin haɗa ƙasa. Waɗannan injinan suna aiki fiye da aikin hakar ƙasa na al'ada; suna ba da hakar ƙasa na injiniya, kula da zagayowar slurry, da kuma cire kayan da ke da muhimmanci don kula da daidaito a cikin yanayin ruwa da ƙasa mai ruwa. Masu hakowa a wannan rukunin yawanci suna aiki tare da injinan hakowa, tsarin kula da slurry, da hanyoyin bututun tremie, suna ƙirƙirar tsarin aiki wanda ke haɗa matsayin masu hakowa, ƙarfin kwandishan, da ƙarfin hydraulic wanda ke shafar nasarar shigar da katangar katanga da daidaita ƙasa. Ka'idar aiki tana mai da hankali kan cire ƙasa da aka hakar yayin gudanar da shigar ruwa da kuma jigilar kayan da aka makale. A cikin ginin bangon diaphragm bisa ga EN 1536, masu hakowa suna cire kayan da aka cika da bentonite daga bangon jagora da tsarin tallafin rami, suna aiki tare da injinan hakowa na bangon jagora don kafa geometrin panel na tsari zuwa ±500 mm na juriya. Don aikin katangar katanga, masu hakowa suna gudanar da cire kayan daga tashi da tsarin juyawa, wanda ke da mahimmanci don kula da daidaito na hydrostatic a cikin rami masu zurfi. A cikin rawar tallafi na jet grouting, masu hakowa suna cire ginshiƙan ƙasa-cement da aka haɗa da manyan ɓangarorin da injinan hakowa ba za su iya rushewa ba, suna hana toshewar a cikin dawo da casing da sanya panel na bangon. Aikace-aikacen haɗa ƙasa suna amfani da kwandishan masu hakowa da aka kera tare da paddles na haɗawa na musamman don shayar da ƙananan ƙasa ko kayan da aka hakar kafin sake amfani da su a cikin tituna ko tsarin slurry. Tsarin kayan aiki yana bambanta bisa ga zurfin aikace-aikace da nau'in ƙasa. Masu hakowa na al'ada (CAT 320, Komatsu PC200) suna aiki a zurfi zuwa 15 m tare da ƙarfin kwandishan na hydraulic na 0.8–1.2 m³, wanda ya dace don ginin bangon jagora da hakar panel na sama. Nau'ikan da ke da tsawo tare da tsawon boom na 11–14 m suna tallafawa panel na bangon diaphragm masu zurfi (25–50 m zurfi) ba tare da taimakon crane mai motsi ba. Masu hakowa na amphibious suna rage zaman wurin da kuma samun damar wurare masu iyaka ta hanyar tsarin trestle na wucin gadi. Kayan haɗi na musamman sun haɗa da kwandishan na hydraulic masu sauri (ISO 16028), kwandishan hakowa masu nauyi tare da tsarin hakowa da aka ƙarfafa wanda aka kimanta don ƙasa mai haɗin kai tare da ƙimar SPT N da ta wuce 50, da kuma kwandishan hakowa na slurry da aka tsara don gudanar da kayan da aka hakar a ƙarƙashin ruwa ba tare da shigar da iska ba. Ka'idodin zaɓi suna dogara ne akan zurfin hakar, diamita na rami, rarraba ƙasa (ISO 14688), buƙatun ƙarfi na slurry, da kuma ƙuntatawa na samun damar wurin. Nauyin injin da ƙarfin ɗaukar ƙasa (yawanci 60–80 kPa don matakan wucin gadi) suna tantance ko nau'ikan da aka biye ko na taya sun dace da yanayin wurin. Matsakaicin kwandishan na hydraulic na masu hakowa ya kamata ya dace da fitar da famfon ruwan jijiya na injinan hakowa don hana canje-canje na matakin slurry da suka wuce ±500 mm, bisa ga ka'idodin ISO 22476-12 don ingancin ginin tushe mai zurfi. Kwarewar mai aiki tare da daidaiton rami, rheology na slurry, da kuma gudanar da rarraba kayan suna bambanta sakamakon aiki a cikin wuraren birane masu iyaka ko kuma a cikin tsarin ƙasa mai rauni. Ka'idodin da suka dace sun haɗa da EN 1536 (aiwatar da ayyukan geotechnical na musamman—bangon diaphragm), DIN 4126 (juriya na bangon diaphragm), ISO 14688 (rarraba ƙasa don ayyukan geotechnical), ISO 22476-12 (ingancin ruwa a cikin gwajin rami), da API RP 2A (la'akari da ƙira na tushe don ɗaukar kayan aiki). Bin waɗannan ka'idodin yana tabbatar da cewa tura masu hakowa yana daidai da daidaiton ƙasa, haɗin slurry, da kuma ka'idojin zubar da kayan da aka kafa ta injiniyoyin tushe da hukumomin kula.