Tom qab kev teeb tsa ncaj qha faus insulated kav, backfilling yog cov kauj ruam kawg, tsis tau nws yog feem ntau yooj yim overlooked. Ntau lub tuam txhab tsim kho, maj nrawm kom tau raws li lub sijhawm kawg, tsuas yog shovel cov av uas tau khawb los ntawm lub trench rov qab rau hauv, tsis quav ntsej txawm tias lub pob zeb, cia nyob ib leeg compacting hauv txheej. Txawm li cas los xij, qhov zoo ntawm backfill ncaj qha txiav txim siab ntev npaum li cas cov kav dej insulated tuaj yeem ua haujlwm ruaj khov.
Yog tias cov khoom siv rov qab muaj cov pob zeb, cov cib tawg, lossis cov khoom siv pov tseg, cov yeeb nkab tiv thaiv sab nrauv yuav yog thawj qhov kev txom nyem. Thaum siab -qhov ntom ntom polyethylene cov kav dej tiv thaiv sab nraud muaj qee qhov kev cuam tshuam, lawv tsis tuaj yeem tiv taus qhov rov ua dua los ntawm cov pob zeb ntse thaum lub sijhawm rov qab thiab compaction. Thaum cov yeeb nkab tiv thaiv sab nrauv raug punctured lossis dented, cov dej hauv av yuav maj mam nkag mus rau hauv cov ntsiab lus puas. Polyurethane ua npuas ncauj yog qhov yooj yim tshaj plaws rau dej- nws cov thermal conductivity nce exponentially tom qab dej seeps hauv, txo nws cov rwb thaiv tsev nyhuv.
Tsis tas li ntawd, cov npuas dej yuav maj mam hydrolyze thiab pulverize nyob rau hauv ib puag ncig ntub, uas yuav ua tsis tau tiav nyob rau hauv ob peb xyoos. Tom qab peb mus rau tsib xyoos ntawm kev ua haujlwm, yog tias qhov kub poob qis dua los yog qhov tshwm sim, kev khawb nws feem ntau qhia tau tias cov npuas dej tau softened los ntawm dej, thiab cov phab ntsa sab hauv ntawm cov yeeb nkab tiv thaiv sab nrauv yog them nrog dej stains. Lub sijhawm ntawd, kev kho mob nyuaj.
Dhau li ntawm kev puas tsuaj rau cov yeeb nkab tiv thaiv sab nrauv, qhov tsis zoo rov qab ua rau muaj lwm qhov teeb meem: cov yeeb nkab tsis txaus. Raws li cov kev cai, ib txheej ntawm cov xuab zeb zoo, feem ntau tsawg kawg yog 200 mm tuab, yuav tsum tau muab tso rau ntawm ob sab thiab saum cov yeeb nkab kom sau qhov khoob nyob ib puag ncig nws thiab muab kev txhawb nqa zoo ib yam. Yog hais tias cov av nplaum los yog av uas muaj gravel yog siv ncaj qha rau backfilling, qhov khoob nyob ib ncig ntawm cov yeeb nkab yog ib qho nyuaj rau sau, thiab cov yeeb nkab yuav tsis tau txais kev sib txhuam txaus los tiv thaiv axial tshem tawm thaum lub sij hawm thermal expansion thiab contraction. Yog li ntawd, cov yeeb nkab arches upwards thaum rhuab, tawg txoj kev nto thiab txawm ua rau sib koom detachment thiab leaks. Tshwj xeeb tshaj yog nyob rau hauv cov ntsiab lus kev ntxhov siab xws li lub luj tshib thiab tees, kev tswj tsis txaus ua rau muaj kev pheej hmoo ntawm cov yeeb nkab tsis ua haujlwm.
Layered compaction ntawm backfill yog qhov tseem ceeb sib npaug. Cov kev cai xav kom txhua txheej txheej rov qab tsis pub tshaj 300 hli hauv thickness thiab yuav tsum tau compacted txheej los ntawm txheej. Qee qhov chaw tsim kho, kom txuag tau sijhawm, tsuas yog muab cov av pov tseg rau hauv lub trench thiab roughly compact nws nrog machinery, xav txog txoj hauj lwm ua. Qhov tshwm sim ntawm qhov no yog tsis txaus cov av compaction hauv qab lub raj xa dej, ua rau tsis sib haum xeeb tom qab lub sijhawm ua haujlwm. Qhov no tuaj yeem ua rau ntu ntawm cov raj xa dej raug tshem tawm lossis muaj kev ntxhov siab, ua rau cov welds puas thiab cov txheej tiv thaiv sab nraud.
Backfilling tej zaum yuav zoo li tsis tseem ceeb thiab pheej yig, tab sis nws qhov cuam tshuam rau lub raj xa dej yog qhov ntev -. Thaum cov kav dej insulated tau faus, khawb lawv rau kev tshuaj xyuas thiab kho yog kim dua. Ntau dua li tos xyoo rau cov teeb meem tshwm sim, nws yog qhov zoo dua los ua tib zoo saib xyuas kom meej thaum rov qab ua dua - tshem cov pob zeb, nteg ib txheej ntawm cov xuab zeb zoo, thiab muab tso rau hauv txheej. Kev saib xyuas kom zoo rau cov ntsiab lus no ua kom lub raj xa dej 30 xyoo tsim lub neej.