Kev tsim kho uas muaj prefabricated ncaj nraim -faus PE-RT insulated piping yuav tsum nruj me ntsis raws li cov qauv xws li CJJ 28 thiab CJJ/T 81. Ua ntej kev tsim kho, cov kav dej yuav tsum tau txheeb xyuas thiab ntsuas cov kua dej kom ntseeg tau tias kev ua haujlwm tau ua tiav hauv qhov chaw qhuav. Rau ntau tshaj - excavation qhov tob ntawm 150 mm los yog tsawg dua, ib txwm siv cov av backfill (compaction Ntau dua lossis sib npaug li 90%); rau qhov tob tshaj 150 mm, graded xuab zeb thiab gravel (compaction Ntau tshaj los yog sib npaug rau 95%) yog siv. Cov kav dej yuav tsum tau qis qis dua siv cov uas tsis yog{11}}cov hlua hlau thiab muab tso rau hauv txoj kab ncaj nraim nrog txoj kab nqes tsawg kawg yog 0.002. Rau cov kav dej uas muaj lub npe sab nraud ntawm 63 mm lossis ntau dua, lub pob tw fusion vuam yog ua haujlwm ntawm qhov kub ntawm 230℃thiab 250 degree, nrog cov pob qij txha kaw ntawm - qhov chaw polyurethane foaming. Cov yeeb nkab kawg yuav tsum tau capped thaum kawg ntawm txhua hnub ua haujlwm. Backfilling yuav tsum tau ua sai sai tom qab lub raj xa dej tau kuaj xyuas; lub trench yuav tsum tsis txhob sawv ntsug dej thiab khib nyiab. Backfilling yuav tsum tau ua symmetrically nyob rau hauv cov khaubncaws sab nraud povtseg ntawm ob sab, nrog rau txhua txheej thickness tsis pub tshaj 200 hli; unilateral backfilling yog nruj me ntsis txwv tsis pub. Cov cheeb tsam txuas ntxiv los ntawm cov yeeb nkab hauv qab mus rau 0.5 m saum cov yeeb nkab yas yuav tsum tau rov qab ua manually siv nruab nrab - mus rau - cov xuab zeb lossis cov av dawb, tsis muaj pob zeb, cov av khov, lossis lwm yam khib nyiab. Compaction yuav tsum muaj raws li nram no: yeeb nkab puag Ntau tshaj los yog sib npaug rau 90%; cov yeeb nkab zoo txhawb lub kaum sab xis thiab sab ntawm cov yeeb nkab Ntau dua lossis sib npaug li 95%; thiab thaj tsam li ntawm 0.5 m saum cov yeeb nkab yas Loj dua lossis sib npaug li 90%. Mechanical compaction yog tso cai rau thaj tsam ntau tshaj 0.5 m saum cov yeeb nkab yas, nrog rau qib compaction tsis pub tsawg tshaj 90% (los yog raws li qhov yuav tsum tau ntawm qhov chaw specifications). Qhov tsawg kawg nkaus hauv av npog qhov tob yog 1.0 m nyob rau hauv txoj kev rau tsheb tsav tsheb thiab 0.6 m nyob rau hauv uas tsis yog -motorized tsheb txoj kab thiab kev taug kev; Kev tiv thaiv npog slabs yuav tsum tau nruab yog tias qhov tob no tsis tuaj yeem ntsib. Backfilling nyob ib ncig ntawm lub valve chambers yuav tsum tau ua symmetrically; unilateral backfilling yog nruj me ntsis txwv tsis pub. Cov voids sab laug tom qab rho tawm ntawm cov ntawv steel pawg yuav tsum tau ntim nrog xuab zeb thiab compacted. Cov txheej txheem kev tsim kho tau ua kom muaj kev nyab xeeb ntawm cov kav dej thiab lub sijhawm ntev - ruaj khov ntawm cov cua sov.