Ishidi elihlangene, elaziwa kakhulu njenge-duct elihlangene noma i-conduit yokuvikela, iyisistimu ekhethekile yokwenziwa kwe-polymeric efakwe ukuze ifake futhi ivikele ama-cable nezinhlaka ezithunyelwe ngaphakathi kwezinhlelo zokwakha ezimnandi nezokuxhumanisa. Ngokuvamile yenziwe ngensimbi ye-polyethylene enobukhulu obuphezulu (HDPE) noma i-polypropylene (PP), le mithi inobubanzi obuhlangene obubanzi obunikeza ukuvikeleka kwesakhiwo ngesikhathi igcina ukuguquguquka kokufaka ngaphakathi kwezimo ezihlukahlukene zamabhodo. Ubuso bangaphakathi buhlanzekile ukuvimbela ukugqokwa kwezintambo ngesikhathi sokufakwa nasekucindezelweni, kanti iprofayili ehambayo ikhulisa kakhulu ukunyakaza, ivumela ishidi ukuthi ixhume imithwalo yekhaladi nezimo zokuphenduka ezivamile kuzinhlelo zokwakha ezijulile. Le msebenzi emibili iyenza ukuba ishidi elihlangene libe ingxenye ebalulekile ezinhlelweni zanamuhla zokuxhumanisa nezimpande zomhlaba, ikakhulukazi lapho ukuzinza kwesakhiwo okuthile nokuvikelwa kokuguguleka kuyizidingo ezibalulekile. Ku-engineering ejulile nasemkhakheni wezinhlelo ze-geotechnical, ishidi elihlangene likhombisa izinhlelo ezibucayi ezihlukahlukene ngaphakathi kwezinhlelo zokuxhumanisa ezinokweluleka okukhululekile okuqhutshwa yokuma komhlaba, ukusekela udonga lokugcina, kanye nokuvikelwa kwemigqa. Umsebenzi omkhulu ukuhlela insimbi ye-prestressing enegunya eliphezulu ukuba ikhululeke emhlabathini oguguleka nezimo zamanzi, ngaleyo ndlela, lengtha impilo yokusebenza yokuhlakaza kuze kufike eminyakeni engama-50+. Ezinhlelweni ezifana nokusekelwa kokuhlikihla, ivimbela ukuhamba okukhululekile phakathi kwekhebula elicindezelweyo nomhlabathi onentshula okwakuzobangela ukuvuvukala kokuguguleka. Ishidi elihlangene likhulu kakhulu ezindaweni zokuhamba kwemifula, emhlabathini onokwakheka okwandisiwe, kanye nezindawo ezinamaminerali, lapho insimbi engavikelwanga izoba nesidumbu esisheshayo. Le sistimu ivikela izinto zokusebenza ze-prestressing emonakalweni temathiyalweni ngesikhathi sokufakwa, yehlisa ukulahleka okwenziwe endaweni yokwakha futhi iqinisekisa ukuhlanganiswa okulungile kwamandla aphakeme nezisingatha. Ishidi elihlangene ngokuvamile lilungiswa ngezikhonyane ezihambayo noma ngezinsika ezilungisiwe, ngokuhlanganiswa kwamabala okuqala ukusuka ku-25 mm kuya ku-100 mm ukuze kuxhase ama-strands ahlukaniswe, ama-cable amaningi, noma ama-rod e-prestressed. Ukufakwa kubandakanya ukugijima ishidi phezu kuka-tendon we-prestressing ngaphambi kokufakwa ebhodini, bese kudwetshwe indawo yokumbula phakathi kwe-sheath nobubanzi bebhodi usebenzisa izinhlelo eziphathelene nomhlaba we-cement-based noma i-epoxy resin. Ukuhlinzeka kahle endaweni yokwakha kudinga ukuvikelwa kokukhanyisa kwe-UV kanye nomonakalo wezinsimbi; izikhonyane kufanele zigcinwe ngaphansi kokuvikelwa futhi ziphathwe ngokuqaphela ukuze kugwemeke ukuvuvukala noma ukuchithwa. I-bore elihambayo elilungile ibalulekile ekufakweni okufanele—noma iyiphi umhlinzeko noma umonakalo uphephuka ukusebenza kwesistimu. I-sheaths ejwayelekile ihlukaniswa ngokuhlanganiswa kokugcina, ubukhulu bodonga, kanye nezinga lokwenziwa. Izinguquko ze-HDPE zithandwa kakhulu ezinhlelweni ezivamile ngenxa yokuguquguquka okunezimo ezahlukene; okokufaka kwe-PP kunikeza ukwesekwa okuyinganekwane kodwa kulahlekelwa ukusebenza ezikhathini ezinzima. Ukubhaliswa kwendaba ngokuvamile kwehla kumalungelo/ubukhulu bodonga (isb. 40/2.5, echaza ubukhulu bomlando obungama-40 mm nendaba yokuhlukumeza emijondolo enga-2.5 mm). Izinkomba zokukhethwa zihlanganisa i-pH yomhlaba ne-ion zikamasimba (ama-sulfate, ama-chloride), isikhathi sokusebenza okulindelekile sokuxhumanisa, imiphumela yokugubha noma amakhono wokukhanya, kanye nokuhambisana nezinhlelo zokugcoba. I-ishidi le-high-modulus (ubukhulu bodonga obuphakeme) likhethwa emhlabeni ongenakunwa okuthathu olwehlisa ku-arching noma ezinkambisweni ezithola ukucindezela lapho uzinze ebhodini ngesikhathi sokwakha kuhlangene. Abahloli baphinde bacabangele ukuhamba—ama-sheaths angaphansi kokuhamba kancane awavimbeli ukuvuselelwa kwamanzi futhi kuthandwa ezimweni eziphakeme. Ukuklama kwe-sheath ehambisanayo nokusebenza kufanele kuhambisane ne-EN 1537 (Ukuqedwa kwemisebenzi engajwayelekile ye-geotechnical: Ama-anchor), i-ISO 11760 (Imikhono ye-plastiki nezinye izinsiza: Ukuhlola amandla we-hydrostatic wesikhathi eside), kanye ne-ASTM D6379 (Izindlalifa nokuhlola amafabrics, ukukhomba kwe-geotextile). Ukuhambisana nalezi zinga kuqinisekisa izinga elihlangene lemikhiqizo, ukuvikelwa kokuguguleka okuhlosiwe, kanye nokuhlola okuhlanganisa isikhathi eside sokuhlanganiswa kwezinsimbi ezibalulekile.
Ishidi elihlangene, elaziwa kakhulu njenge-duct elihlangene noma i-conduit yokuvikela, iyisistimu ekhethekile yokwenziwa kwe-polymeric efakwe ukuze ifake futhi ivikele ama-cable nezinhlaka ezithunyelwe ngaphakathi kwezinhlelo zokwakha ezimnandi nezokuxhumanisa. Ngokuvamile yenziwe ngensimbi ye-polyethylene enobukhulu obuphezulu (HDPE) noma i-polypropylene (PP), le mithi inobubanzi obuhlangene obubanzi obunikeza ukuvikeleka kwesakhiwo ngesikhathi igcina ukuguquguquka kokufaka ngaphakathi kwezimo ezihlukahlukene zamabhodo. Ubuso bangaphakathi buhlanzekile ukuvimbela ukugqokwa kwezintambo ngesikhathi sokufakwa nasekucindezelweni, kanti iprofayili ehambayo ikhulisa kakhulu ukunyakaza, ivumela ishidi ukuthi ixhume imithwalo yekhaladi nezimo zokuphenduka ezivamile kuzinhlelo zokwakha ezijulile. Le msebenzi emibili iyenza ukuba ishidi elihlangene libe ingxenye ebalulekile ezinhlelweni zanamuhla zokuxhumanisa nezimpande zomhlaba, ikakhulukazi lapho ukuzinza kwesakhiwo okuthile nokuvikelwa kokuguguleka kuyizidingo ezibalulekile. Ku-engineering ejulile nasemkhakheni wezinhlelo ze-geotechnical, ishidi elihlangene likhombisa izinhlelo ezibucayi ezihlukahlukene ngaphakathi kwezinhlelo zokuxhumanisa ezinokweluleka okukhululekile okuqhutshwa yokuma komhlaba, ukusekela udonga lokugcina, kanye nokuvikelwa kwemigqa. Umsebenzi omkhulu ukuhlela insimbi ye-prestressing enegunya eliphezulu ukuba ikhululeke emhlabathini oguguleka nezimo zamanzi, ngaleyo ndlela, lengtha impilo yokusebenza yokuhlakaza kuze kufike eminyakeni engama-50+. Ezinhlelweni ezifana nokusekelwa kokuhlikihla, ivimbela ukuhamba okukhululekile phakathi kwekhebula elicindezelweyo nomhlabathi onentshula okwakuzobangela ukuvuvukala kokuguguleka. Ishidi elihlangene likhulu kakhulu ezindaweni zokuhamba kwemifula, emhlabathini onokwakheka okwandisiwe, kanye nezindawo ezinamaminerali, lapho insimbi engavikelwanga izoba nesidumbu esisheshayo. Le sistimu ivikela izinto zokusebenza ze-prestressing emonakalweni temathiyalweni ngesikhathi sokufakwa, yehlisa ukulahleka okwenziwe endaweni yokwakha futhi iqinisekisa ukuhlanganiswa okulungile kwamandla aphakeme nezisingatha. Ishidi elihlangene ngokuvamile lilungiswa ngezikhonyane ezihambayo noma ngezinsika ezilungisiwe, ngokuhlanganiswa kwamabala okuqala ukusuka ku-25 mm kuya ku-100 mm ukuze kuxhase ama-strands ahlukaniswe, ama-cable amaningi, noma ama-rod e-prestressed. Ukufakwa kubandakanya ukugijima ishidi phezu kuka-tendon we-prestressing ngaphambi kokufakwa ebhodini, bese kudwetshwe indawo yokumbula phakathi kwe-sheath nobubanzi bebhodi usebenzisa izinhlelo eziphathelene nomhlaba we-cement-based noma i-epoxy resin. Ukuhlinzeka kahle endaweni yokwakha kudinga ukuvikelwa kokukhanyisa kwe-UV kanye nomonakalo wezinsimbi; izikhonyane kufanele zigcinwe ngaphansi kokuvikelwa futhi ziphathwe ngokuqaphela ukuze kugwemeke ukuvuvukala noma ukuchithwa. I-bore elihambayo elilungile ibalulekile ekufakweni okufanele—noma iyiphi umhlinzeko noma umonakalo uphephuka ukusebenza kwesistimu. I-sheaths ejwayelekile ihlukaniswa ngokuhlanganiswa kokugcina, ubukhulu bodonga, kanye nezinga lokwenziwa. Izinguquko ze-HDPE zithandwa kakhulu ezinhlelweni ezivamile ngenxa yokuguquguquka okunezimo ezahlukene; okokufaka kwe-PP kunikeza ukwesekwa okuyinganekwane kodwa kulahlekelwa ukusebenza ezikhathini ezinzima. Ukubhaliswa kwendaba ngokuvamile kwehla kumalungelo/ubukhulu bodonga (isb. 40/2.5, echaza ubukhulu bomlando obungama-40 mm nendaba yokuhlukumeza emijondolo enga-2.5 mm). Izinkomba zokukhethwa zihlanganisa i-pH yomhlaba ne-ion zikamasimba (ama-sulfate, ama-chloride), isikhathi sokusebenza okulindelekile sokuxhumanisa, imiphumela yokugubha noma amakhono wokukhanya, kanye nokuhambisana nezinhlelo zokugcoba. I-ishidi le-high-modulus (ubukhulu bodonga obuphakeme) likhethwa emhlabeni ongenakunwa okuthathu olwehlisa ku-arching noma ezinkambisweni ezithola ukucindezela lapho uzinze ebhodini ngesikhathi sokwakha kuhlangene. Abahloli baphinde bacabangele ukuhamba—ama-sheaths angaphansi kokuhamba kancane awavimbeli ukuvuselelwa kwamanzi futhi kuthandwa ezimweni eziphakeme. Ukuklama kwe-sheath ehambisanayo nokusebenza kufanele kuhambisane ne-EN 1537 (Ukuqedwa kwemisebenzi engajwayelekile ye-geotechnical: Ama-anchor), i-ISO 11760 (Imikhono ye-plastiki nezinye izinsiza: Ukuhlola amandla we-hydrostatic wesikhathi eside), kanye ne-ASTM D6379 (Izindlalifa nokuhlola amafabrics, ukukhomba kwe-geotextile). Ukuhambisana nalezi zinga kuqinisekisa izinga elihlangene lemikhiqizo, ukuvikelwa kokuguguleka okuhlosiwe, kanye nokuhlola okuhlanganisa isikhathi eside sokuhlanganiswa kwezinsimbi ezibalulekile.