Qhov chaw nyob:Cov hlau luam saum toj no tau muab tso rau saum av, thaum ntim cov tsheb tso tsheb hlau luam hauv av muaj roj av.
Kev Nyab Xeeb Kev Nyab Xeeb thiab Kev Tiv Thaiv Kev Nyab Xeeb:Cov qauv saum toj no yog cov muaj kev cuam tshuam ntau dua, muaj kev pheej hmoo ntau dua, tab sis cov dej xau yog qhov yooj yim los xyuas thiab tswj hwm; Hauv qab av muaj cov kua dej zais (uas tuaj yeem yooj yim ua rau cov av hauv corrosion, thiab muaj kev sib tw saib xyuas kev saib xyuas kev saib xyuas cov chaw.
Tus nqi thiab txij nkawm:Cov qauv saum toj no muaj qhov pib teeb tsa qis thiab cov nqi kho mob qis dua, thiab yooj yim dua; underground models have a high initial cost due the investment in pit excavation, anti-corrosion and anti-floating, and maintenance requires excavation, which is difficult.
Muaj feem cuam tshuam cov xwm txheej:Cov qauv saum toj no haum rau cov chaw nyob nrog thaj chaw txaus, chaw taws teeb, lossis kev lag luam thiab kev lag luam me me nrog lawv cov roj depots; Cov qauv hauv av yog qhov tsim nyog rau cov chaw nres tsheb hauv nroog, thaj chaw uas muaj qhov chaw txwv, thaj chaw uas muaj cov cai nruj ib puag ncig.
