Xa kuthengwa izikhonkwane zokuphahla i-ambrella kwiiprojekthi zokwakha zaphesheya, abathengi abaninzi bagxininisa kuphela kwixabiso lemveliso kunye neenkcukacha, ukugatya ukuhambelana phakathi kwezinto eziphathekayo kunye nemozulu yendawo. Ukukhetha izinto ezingalunganga kukholisa ukukhokelela kumhlwa kwangaphambi kwexesha, ukukhulula izikhonkwane kunye nokuvuza kophahla, okuzisa iindleko ezinkulu zokulondolozwa kunye nelahleko yeprojekthi. Ukuqonda ulungelelwaniso phakathi kweempawu zemozulu kunye nezixhobo ezikhawulezayo kunokunceda abathengi behlabathi benze izigqibo zokuthengwa kwezenzululwazi kunye nokunciphisa umngcipheko wokwakha{2}
Iinketho ezintathu zezinto eziphambili zisetyenziswa ngokubanzi kwiikhonkwane zokuphahla iambrela, ezizezi zintsimbi ezithambileyo zekhabhoni, ezishushu -zediphu intsimbi kunye nentsimbi engatyiwa, ngelixa ubhedu kunye ne-aluminiyam zigcinelwe iiprojekthi ezikhethekileyo zokuhombisa uphahla. I-Q195 kunye ne-Q235 i-carbon steel emnene inexabiso eliphantsi kunye ne-ductility enhle, kulula ukubethelela ukusebenza. Nangona kunjalo, intsimbi yekhabhoni engenanto ayinakukwazi ukulwa -nomhlwa. Ingafakwa kuphela kwindawo eyomileyo yangaphakathi okanye egqunyiweyo yophahla, kwaye ayinakuvela{7}}kwimvula yexesha elide kunye nokufuma. Le mathiriyeli ayifane isetyenziselwe{9}iiprojekthi zophahla zomoya ezivulekileyo kwindawo efumileyo yetropikhi okanye yetropikhi.
Kushushu -diphu intsimbi ekhandisiweyo yeyona imathiriyeli eyamkelwa ngokubanzi kwindawo efumileyo yangaphandle. I-zinc coating engqindilili eyenziwe kukudipha eshushu inokumelana nokufuma kunye nomhlwa ophakathi. Kwiindawo zobushushu obuphezulu-, i-zinc layer isebenza njenge-anode yedini ukukhusela isiseko sentsimbi. Ixabiso layo lihlala phakathi kwentsimbi yekhabhoni engenanto kunye nentsimbi engenastainless, ilungele imimandla yemvula engaphakathi,{5}}izindlu ezakhiweyo ezisemaphandleni kunye nophahla lwefektri eqhelekileyo. Kodwa umda ucacile: i-chloride kwiindawo zenkungu yetyuwa iya kutshabalalisa i-zinc coating ngokuqhubekayo. Kwiindawo eziselunxwemeni ezinetyuwa eninzi, i-zinc layer iya kuguga ngokukhawuleza, ibangele ukurusa kwe-substrate. Ngoko ke, amanyathelo okukhusela okongeziweyo afunekayo ukuba izikhonkwane ze-galvanized zisetyenziselwa kwiindawo ezinxweme
I-304 kunye ne-316 insimbi engenastainless lukhetho oluphezulu{2}}lokufuma kunye nenkungu yetyuwa kwiindawo eziselunxwemeni. Umxholo ophezulu we-chromium wenza ifilimu ezinzileyo ye-passivation kumphezulu wesikhonkwane, ukwahlula amanzi kunye ne-chloride ion. Le ndlela yokukhusela ayizukusilela ngokulula naphantsi kokhukuliseko lwenkungu yetyuwa yexesha elide. Ubomi benkonzo ye-304 yezikhonkwane ze-ambrela zensimbi ezingenasici zinokufikelela kwiminyaka engama-20, phantse akukho kugcinwa kufunwayo. 316 insimbi engenasici inokumelana ne-chloride corrosion, esetyenziswa kwiiprojekthi ze-offshore ezinetyuwa enkulu. I-drawback ephambili yensimbi engenasici lixabiso eliphezulu lokuthenga, ngoko ke abathengi kufuneka babale iindleko ezipheleleyo zobomi endaweni yokuthelekisa kuphela ixabiso leyunithi.
Ngaphandle kokuthelekisa izinto, abathengi nabo kufuneka bathathele ingqalelo ukhetho oluchanekileyo ngokwemozulu yendawo. Kwiindawo ezinomoya, izikhonkwane eziphothiweyo zeambrela ze-shank ziyacetyiswa. Inkozo ephothiweyo yonyusa amandla okuluma ngoomatshini kunye nokumelana nokutsalwa, ukuthintela ukuwisa izikhonkwane okubangelwa kukungcangcazela komoya okuqhubekayo. Idayamitha yentloko yezikhonkwane imisela indawo yokugquma amanzi. Kwimimandla enemvula enkulu, iintloko zeambrela ezinkulu zikhethwa ukuba zigqume imingxuma yezikhonkwane kwaye zomeleze ukusebenza kobungqina bamanzi{4}. Ubude bezikhonkwane kunye nobubanzi be-shaft bukhethwa ngokuhambelana nobukhulu betayile yophahla kunye nobunzima be-substrate. Kakhulu{7}}izikhonkwane ezimfutshane azinakufumana ubunzulu obaneleyo bokuzinzisa, okukhokelela kumandla anganelanga okulungisa.
Inkcazo yokufakela isebenzisana nokulungelelaniswa kwemozulu. Kwiindawo ezinemvula, ubungakanani bokugqithelana kweethayile kunye nezithuba zezikhonkwane kufuneka ziphunyezwe ngokungqongqo. Ithayile nganye idinga izikhonkwane ezi-6-8, izithuba eziwelanayo. Ukufakela okusemgangathweni kunokunciphisa umngcipheko wokuvuza kwephahla kunye nokwandisa ukusebenza kwee-umbrella zokuphahla izikhonkwane. Iintsilelo ezininzi zeeprojekthi zaphesheya azibangelwa bubunjani bezikhonkwane, kodwa ukhetho lwemathiriyeli engafanelekanga okanye{10}}ulwakhiwo olungelulo.
Ukushwankathela, abathengi kufuneka balungise imvula yendawo, ukufuma, inqanaba lenkungu yetyuwa kunye namandla omoya phambi koku-odola izikhonkwane zokuphahla iambrela. Imozulu eyomileyo ephakathi kwelizwe inokwamkela iimveliso ezifakwe amazinki ukulawula uhlahlo lwabiwo-mali. Imimandla yenkungu yetyuwa elunxwemeni idinga i-304 okanye i-316 yentsimbi engenakutyiwa ixesha elide{4}}. Iiprojekthi ezikhethekileyo zokuhlobisa uphahla zingakhetha izikhonkwane zobhedu okanye i-aluminium eyenziwe ngokwezifiso. Ukuthelekisa izinto zenzululwazi, ukucaciswa kunye nemozulu kunceda ekwandiseni ixabiso lezinto zokubopha uphahla kunye nokunciphisa imingcipheko yokusebenza kwexesha elide{7}} kwiiprojekthi zokwakha.