隨著全(quan)國城(cheng)市化進度(du)的加快，各地(di)城(cheng)市發展均具規模，原(yuan)有給水管網能力(li)已(yi)不能滿(man)足城(cheng)市工業的發展、人口數(shu)量的增加及經濟的發展，因此(ci)城(cheng)市管網改造勢(shi)在必行(xing)。

　　1、 城(cheng)(cheng)市(shi)(shi)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)改(gai)(gai)造的(de)(de)(de)(de)必要性近幾(ji)(ji)年(nian)(nian)來，我國各地城(cheng)(cheng)市(shi)(shi)發展(zhan)(zhan)(zhan)均具規(gui)模(mo)(mo)，其(qi)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)事業(ye)迅速(su)發展(zhan)(zhan)(zhan)。城(cheng)(cheng)市(shi)(shi)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)在(zai)其(qi)新建成(cheng)的(de)(de)(de)(de)一定(ding)時期內(nei)，其(qi)供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)能(neng)力可以(yi)滿(man)足(zu)一定(ding)時期的(de)(de)(de)(de)供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)要求(qiu)，隨著城(cheng)(cheng)市(shi)(shi)化(hua)進度的(de)(de)(de)(de)加快，城(cheng)(cheng)市(shi)(shi)工業(ye)的(de)(de)(de)(de)發展(zhan)(zhan)(zhan)，人口數量(liang)(liang)的(de)(de)(de)(de)不(bu)(bu)(bu)斷增加和人民生(sheng)活水(shui)(shui)(shui)(shui)(shui)(shui)平的(de)(de)(de)(de)日益提(ti)高用水(shui)(shui)(shui)(shui)(shui)(shui)指(zhi)標的(de)(de)(de)(de)加大(da)(da)，其(qi)城(cheng)(cheng)市(shi)(shi)用水(shui)(shui)(shui)(shui)(shui)(shui)量(liang)(liang)急(ji)劇增長(chang)，給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)的(de)(de)(de)(de)供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)能(neng)力逐漸不(bu)(bu)(bu)能(neng)適應用水(shui)(shui)(shui)(shui)(shui)(shui)量(liang)(liang)增長(chang)的(de)(de)(de)(de)需求(qiu)。同時，由于(yu)城(cheng)(cheng)市(shi)(shi)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)規(gui)模(mo)(mo)的(de)(de)(de)(de)不(bu)(bu)(bu)斷擴大(da)(da)，部分老城(cheng)(cheng)區有的(de)(de)(de)(de)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)已運行幾(ji)(ji)十(shi)年(nian)(nian)，管(guan)(guan)(guan)線改(gai)(gai)造、鋪設缺(que)乏統一規(gui)劃，大(da)(da)規(gui)模(mo)(mo)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)系統在(zai)管(guan)(guan)(guan)線連接、構筑物設置(zhi)等方面存在(zai)諸多不(bu)(bu)(bu)合理(li)之處，增大(da)(da)了供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)能(neng)耗，并使部分供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)區域水(shui)(shui)(shui)(shui)(shui)(shui)量(liang)(liang)欠缺(que)，低壓區不(bu)(bu)(bu)斷擴大(da)(da)、供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)安(an)全性降(jiang)低。這(zhe)一系列問題成(cheng)為阻(zu)礙各城(cheng)(cheng)市(shi)(shi)供(gong)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)擴建及優化(hua)的(de)(de)(de)(de)主要問題。城(cheng)(cheng)市(shi)(shi)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)設施屬市(shi)(shi)政基(ji)礎設施，給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)是給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)設施的(de)(de)(de)(de)主要組成(cheng)部分。老舊城(cheng)(cheng)給(gei)(gei)(gei)水(shui)(shui)(shui)(shui)(shui)(shui)管(guan)(guan)(guan)網(wang)(wang)改(gai)(gai)造對管(guan)(guan)(guan)網(wang)(wang)的(de)(de)(de)(de)安(an)全運行、適應與城(cheng)(cheng)市(shi)(shi)的(de)(de)(de)(de)經濟發展(zhan)(zhan)(zhan)至關重要。

　　2、 城市給水管網改造的原則

　　(1)城市給水(shui)(shui)管(guan)網改造(zao)(zao)既要根據舊城改造(zao)(zao)規(gui)(gui)劃(hua)(hua)所(suo)確定的(de)原則(ze)(ze)進行，還應(ying)注重其對(dui)舊城改造(zao)(zao)規(gui)(gui)劃(hua)(hua)的(de)影響。城市總用(yong)水(shui)(shui)量包(bao)括(kuo)城市居民(min)生活用(yong)水(shui)(shui)、消防(fang)用(yong)水(shui)(shui)和(he)市政(zheng)用(yong)水(shui)(shui)(如街道(dao)(dao)灑水(shui)(shui)、綠(lv)地澆水(shui)(shui)等)，而這些都(dou)與(yu)城市的(de)人口數目、工(gong)業發展(zhan)規(gui)(gui)模、建(jian)筑(zhu)層數和(he)設(she)(she)備標準等規(gui)(gui)劃(hua)(hua)內(nei)容有關。給水(shui)(shui)管(guan)線的(de)位置(zhi)和(he)走向應(ying)符合(he)城市規(gui)(gui)劃(hua)(hua)的(de)要求(qiu)，盡(jin)可能(neng)沿現有道(dao)(dao)路(lu)或規(gui)(gui)劃(hua)(hua)道(dao)(dao)路(lu)敷設(she)(she)，供水(shui)(shui)區(qu)范圍(wei)應(ying)根據規(gui)(gui)劃(hua)(hua)原則(ze)(ze)確定，并將給水(shui)(shui)管(guan)合(he)理分布于(yu)(全(quan))供水(shui)(shui)區(qu)。另一方面，道(dao)(dao)路(lu)規(gui)(gui)劃(hua)(hua)網絡和(he)道(dao)(dao)路(lu)建(jian)設(she)(she)先后均須與(yu)管(guan)線建(jian)設(she)(she)相配合(he)。

　　(2)充(chong)分(fen)發(fa)揮(hui)(hui)現有給水(shui)設施(shi)的供水(shui)能力(li)。城(cheng)市(shi)在不(bu)同的發(fa)展時(shi)(shi)期(qi)都建(jian)有相(xiang)應的給水(shui)設施(shi)，這(zhe)是(shi)因為在確定水(shui)廠建(jian)設規(gui)(gui)模時(shi)(shi)，一般是(shi)滿足城(cheng)市(shi)近(jin)、遠期(qi)規(gui)(gui)劃年(nian)限(xian)(xian)的用水(shui)量要求。給水(shui)設施(shi)具有初期(qi)投資(zi)大、財(cai)務(wu)收(shou)(shou)入有限(xian)(xian)、項目投資(zi)回收(shou)(shou)期(qi)長(chang)等特點(dian)。對(dui)于運行良好(hao)的現有給水(shui)設施(shi)，充(chong)分(fen)發(fa)揮(hui)(hui)其供水(shui)能力(li)，就(jiu)是(shi)發(fa)揮(hui)(hui)其經(jing)濟效益。

　　(3)投(tou)資(zi)(zi)造價(jia)(jia)低。給水管網在滿(man)足各(ge)用戶對(dui)水量(liang)、水壓的要求以(yi)及考慮施工(gong)維修方(fang)便的前提下，應節(jie)省造價(jia)(jia)，減少投(tou)資(zi)(zi)，而不(bu)是追求簡(jian)單(dan)的管線長(chang)度。

　　(4)切實(shi)可(ke)(ke)行。舊(jiu)城(cheng)(cheng)改(gai)(gai)造(zao)規(gui)劃常(chang)分為近期規(gui)劃年限(xian)(xian)常(chang)采用5-10年，遠期規(gui)劃年限(xian)(xian)常(chang)采用10-20年，而舊(jiu)城(cheng)(cheng)給(gei)水管網的改(gai)(gai)造(zao)設(she)計(ji)則(ze)強調(diao)逐年實(shi)施(shi)(shi)的可(ke)(ke)能(neng)性。所(suo)以(yi)改(gai)(gai)造(zao)設(she)計(ji)要依(yi)據政府部(bu)門對舊(jiu)城(cheng)(cheng)改(gai)(gai)造(zao)規(gui)劃的具體實(shi)施(shi)(shi)計(ji)劃(如(ru)路網的改(gai)(gai)造(zao)等)，確定逐年改(gai)(gai)造(zao)安排，做好經濟(ji)估算(suan)，保證管網改(gai)(gai)造(zao)落到處。

　　3、管(guan)(guan)網(wang)(wang)(wang)改(gai)造(zao)中(zhong)(zhong)可采取并(bing)網(wang)(wang)(wang)施(shi)工(gong)(gong)(gong)工(gong)(gong)(gong)藝的(de)(de)方法(fa)及(ji)需注意的(de)(de)問題(ti)。對于舊城區而言管(guan)(guan)網(wang)(wang)(wang)改(gai)造(zao)的(de)(de)途徑大(da)多數是將(jiang)舊管(guan)(guan)線(xian)拆除更換新(xin)的(de)(de)原管(guan)(guan)徑或加大(da)管(guan)(guan)徑后的(de)(de)新(xin)管(guan)(guan)道(dao)(dao)，然后在(zai)(zai)將(jiang)原有(you)(you)支(zhi)管(guan)(guan)及(ji)原有(you)(you)管(guan)(guan)道(dao)(dao)上的(de)(de)用戶與新(xin)管(guan)(guan)逐(zhu)一(yi)并(bing)網(wang)(wang)(wang)連通。這(zhe)樣在(zai)(zai)并(bing)網(wang)(wang)(wang)過程(cheng)(cheng)中(zhong)(zhong)需要在(zai)(zai)一(yi)定范圍(wei)內(nei)(nei)停(ting)水(shui)(shui)施(shi)工(gong)(gong)(gong)，這(zhe)意味著在(zai)(zai)施(shi)工(gong)(gong)(gong)過程(cheng)(cheng)中(zhong)(zhong)將(jiang)影(ying)響(xiang)部(bu)分用戶正(zheng)常用水(shui)(shui)，同時供(gong)水(shui)(shui)企業在(zai)(zai)一(yi)定時間內(nei)(nei)要減少(shao)(shao)部(bu)分供(gong)水(shui)(shui)量。從這(zhe)個意義上講，并(bing)網(wang)(wang)(wang)施(shi)工(gong)(gong)(gong)是整(zheng)個管(guan)(guan)網(wang)(wang)(wang)改(gai)造(zao)過程(cheng)(cheng)中(zhong)(zhong)最(zui)關(guan)鍵的(de)(de)一(yi)環。通過多年一(yi)來(lai)在(zai)(zai)設計及(ji)工(gong)(gong)(gong)程(cheng)(cheng)施(shi)工(gong)(gong)(gong)中(zhong)(zhong)的(de)(de)實踐我體會到，如在(zai)(zai)管(guan)(guan)網(wang)(wang)(wang)改(gai)造(zao)、新(xin)舊管(guan)(guan)網(wang)(wang)(wang)施(shi)工(gong)(gong)(gong)中(zhong)(zhong)若能統籌調度(du)、合理(li)安排、優化施(shi)工(gong)(gong)(gong)方案和先(xian)后順序，便可最(zui)大(da)限度(du)地壓縮停(ting)水(shui)(shui)時間，減少(shao)(shao)停(ting)水(shui)(shui)范圍(wei)。將(jiang)損失(shi)及(ji)投資降(jiang)到最(zui)低。同時也減少(shao)(shao)了由于停(ting)水(shui)(shui)帶來(lai)的(de)(de)社會影(ying)響(xiang)，并(bing)直(zhi)接關(guan)系到供(gong)水(shui)(shui)企業的(de)(de)經濟(ji)效益和設會效益。以下就這(zhe)個問題(ti)談幾點認識(shi)。

　　(1)新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)的(de)定(ding)位問題：新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)定(ding)位一定(ding)要(yao)摸清(qing)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)的(de)具體(ti)位置(zhi)(zhi)(zhi)，并盡量(liang)不(bu)(bu)占據(ju)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)的(de)原有位置(zhi)(zhi)(zhi)。最(zui)好能保證新(xin)(xin)(xin)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)間距(ju)不(bu)(bu)大(da)于1米(這樣新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)敷(fu)(fu)設(she)管(guan)(guan)(guan)槽可于要(yao)拆除(chu)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)段管(guan)(guan)(guan)槽同時(shi)開挖節省投資)，新(xin)(xin)(xin)設(she)管(guan)(guan)(guan)線(xian)(xian)埋深應大(da)于舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)，新(xin)(xin)(xin)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)的(de)豎(shu)向間距(ju)在0.3-0.5m左右既可。這樣在新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)的(de)敷(fu)(fu)設(she)過程(cheng)中不(bu)(bu)至于必須事(shi)先拆除(chu)平行及(ji)交叉的(de)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)，從(cong)而使舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)能正常供(gong)水，直至并網(wang)施(shi)工全部完成以后，再徹底廢(fei)除(chu)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)。(由(you)于舊(jiu)(jiu)(jiu)(jiu)城改造中地(di)下管(guan)(guan)(guan)線(xian)(xian)較(jiao)多，新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)的(de)具體(ti)部門(men)協商(shang)確(que)定(ding)。在布置(zhi)(zhi)(zhi)新(xin)(xin)(xin)管(guan)(guan)(guan)線(xian)(xian)已無其它(ta)合適(shi)位置(zhi)(zhi)(zhi)，不(bu)(bu)得不(bu)(bu)占據(ju)舊(jiu)(jiu)(jiu)(jiu)管(guan)(guan)(guan)線(xian)(xian)位置(zhi)(zhi)(zhi)時(shi)，則應采取臨時(shi)供(gong)水措(cuo)施(shi)。其另做(zuo)探討).

　　(2)并(bing)(bing)(bing)網施工過程中(zhong)盡量采(cai)取雙管(guan)(guan)同(tong)時(shi)(shi)供(gong)(gong)(gong)水(shui)方式。在新舊(jiu)管(guan)(guan)線并(bing)(bing)(bing)網施工中(zhong)由于原用戶(hu)支管(guan)(guan)一(yi)般較多，加之管(guan)(guan)徑、管(guan)(guan)材不(bu)一(yi)，各別支線位置(zhi)不(bu)詳等原因(yin)，故情況(kuang)較為(wei)復雜，并(bing)(bing)(bing)網所(suo)需時(shi)(shi)間較長(chang)。若將舊(jiu)干管(guan)(guan)廢除后(hou)統一(yi)進行并(bing)(bing)(bing)網施工，如遇特殊情況(kuang)就會造成個別用戶(hu)停水(shui)數天(tian)。這(zhe)是用戶(hu)無法接受的(de)(de)，同(tong)時(shi)(shi)對供(gong)(gong)(gong)水(shui)企業也(ye)是不(bu)小(xiao)的(de)(de)損(sun)失。如能采(cai)取新舊(jiu)干管(guan)(guan)同(tong)時(shi)(shi)供(gong)(gong)(gong)水(shui)的(de)(de)方法，以上(shang)問(wen)題便可得到妥善的(de)(de)解決。

　　(3)并(bing)(bing)(bing)(bing)網(wang)施(shi)工(gong)(gong)(gong)應遵循(xun)先(xian)大用(yong)戶(hu)，后(hou)(hou)小用(yong)戶(hu)，先(xian)重點后(hou)(hou)一般，先(xian)易(yi)后(hou)(hou)難的(de)(de)原(yuan)(yuan)則。在當(dang)地管(guan)(guan)(guan)(guan)線管(guan)(guan)(guan)(guan)理(li)部門的(de)(de)配合(he)下查清楚(chu)現狀支(zhi)管(guan)(guan)(guan)(guan)的(de)(de)位置及(ji)管(guan)(guan)(guan)(guan)徑(jing)(jing)，做好(hao)施(shi)工(gong)(gong)(gong)組織設(she)計。如(ru)我們在館(guan)陶(tao)路DN600供(gong)水(shui)(shui)(shui)管(guan)(guan)(guan)(guan)網(wang)改造施(shi)工(gong)(gong)(gong)中，依據(ju)供(gong)水(shui)(shui)(shui)規劃(hua)要(yao)求(qiu)，設(she)計將原(yuan)(yuan)管(guan)(guan)(guan)(guan)徑(jing)(jing)DN200管(guan)(guan)(guan)(guan)線改造為(wei)DN600管(guan)(guan)(guan)(guan)線，全長860米(mi)。其(qi)中原(yuan)(yuan)有交叉支(zhi)路干管(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)徑(jing)(jing)DN150至DN200管(guan)(guan)(guan)(guan)3處(chu)(chu)，原(yuan)(yuan)有用(yong)戶(hu)支(zhi)管(guan)(guan)(guan)(guan)管(guan)(guan)(guan)(guan)徑(jing)(jing)DN50至DN100管(guan)(guan)(guan)(guan)36處(chu)(chu)(見附圖).新(xin)DN600供(gong)水(shui)(shui)(shui)管(guan)(guan)(guan)(guan)道(dao)試(shi)壓、消毒、刷管(guan)(guan)(guan)(guan)敷設(she)完成(cheng)后(hou)(hou)，制定了(le)以(yi)下施(shi)工(gong)(gong)(gong)方案(an)[1]首先(xian)將Ja處(chu)(chu)連(lian)通(tong)(tong)(tong)，打(da)開(kai)閥(fa)門1使新(xin)DN600干管(guan)(guan)(guan)(guan)通(tong)(tong)(tong)水(shui)(shui)(shui)，同時保持原(yuan)(yuan)DN200舊管(guan)(guan)(guan)(guan)仍然(ran)正常供(gong)水(shui)(shui)(shui)[2]開(kai)始各用(yong)戶(hu)支(zhi)管(guan)(guan)(guan)(guan)并(bing)(bing)(bing)(bing)網(wang)施(shi)工(gong)(gong)(gong)，以(yi)Y1為(wei)例：首先(xian)關閉(bi)閥(fa)門6將Jb處(chu)(chu)斷開(kai)，在與閥(fa)門2接(jie)(jie)通(tong)(tong)(tong)，此處(chu)(chu)可(ke)采用(yong)新(xin)型(xing)管(guan)(guan)(guan)(guan)材(cai)柔性接(jie)(jie)口縮短(duan)時間(jian)，待(dai)接(jie)(jie)通(tong)(tong)(tong)后(hou)(hou)打(da)開(kai)閥(fa)門2即(ji)可(ke)恢復(fu)支(zhi)管(guan)(guan)(guan)(guan)供(gong)水(shui)(shui)(shui)。其(qi)余用(yong)戶(hu)支(zhi)管(guan)(guan)(guan)(guan)及(ji)支(zhi)干管(guan)(guan)(guan)(guan)并(bing)(bing)(bing)(bing)網(wang)施(shi)工(gong)(gong)(gong)方法與其(qi)相同。[3]待(dai)全部用(yong)戶(hu)支(zhi)管(guan)(guan)(guan)(guan)及(ji)支(zhi)干管(guan)(guan)(guan)(guan)并(bing)(bing)(bing)(bing)網(wang)完成(cheng)后(hou)(hou)，將Jc和(he)Jd處(chu)(chu)均(jun)斷開(kai)，將原(yuan)(yuan)200管(guan)(guan)(guan)(guan)道(dao)與新(xin)設(she)閥(fa)門5連(lian)通(tong)(tong)(tong)即(ji)可(ke)。至此原(yuan)(yuan)200管(guan)(guan)(guan)(guan)道(dao)全部廢除、拆(chai)除，并(bing)(bing)(bing)(bing)網(wang)施(shi)工(gong)(gong)(gong)完成(cheng)。通(tong)(tong)(tong)過采取以(yi)上方法施(shi)工(gong)(gong)(gong)，既(ji)大大縮短(duan)了(le)停(ting)水(shui)(shui)(shui)時間(jian)及(ji)施(shi)工(gong)(gong)(gong)周(zhou)期，又節省(sheng)了(le)需設(she)臨時管(guan)(guan)(guan)(guan)要(yao)占用(yong)道(dao)路，影響交通(tong)(tong)(tong)及(ji)加大工(gong)(gong)(gong)程投(tou)資的(de)(de)問題。取得(de)了(le)良好(hao)的(de)(de)社會效用(yong)和(he)經濟效益。