沉(chen)井(jing)應(ying)用(yong)范圍：埋置(zhi)較深(shen)的(de)構(gou)筑物(wu)采(cai)用(yong)沉(chen)井(jing)法施(shi)(shi)(shi)工(gong)(gong)，從經(jing)濟(ji)和技術角度來看，沉(chen)井(jing)施(shi)(shi)(shi)工(gong)(gong)，也比(bi)其他施(shi)(shi)(shi)工(gong)(gong)方法更(geng)為(wei)合理。給(gei)水(shui)排水(shui)工(gong)(gong)程的(de)地下構(gou)筑物(wu)，多采(cai)用(yong)沉(chen)井(jing)。如江心及岸邊的(de)取水(shui)構(gou)筑物(wu)、城市雨污(wu)水(shui)泵站下部結構(gou)等。沉(chen)井(jing)施(shi)(shi)(shi)工(gong)(gong)，實質上(shang)就是(shi)將一(yi)個在地面上(shang)事(shi)先澆制(zhi)(zhi)好的(de)構(gou)筑物(wu)通(tong)過挖(wa)土沉(chen)入(ru)到地下一(yi)定(ding)深(shen)度后成為(wei)地下構(gou)筑物(wu)的(de)施(shi)(shi)(shi)工(gong)(gong)過程。沉(chen)井(jing)基礎施(shi)(shi)(shi)工(gong)(gong)一(yi)般可分為(wei)早地施(shi)(shi)(shi)工(gong)(gong)、水(shui)中筑島及浮運沉(chen)井(jing)三種。施(shi)(shi)(shi)工(gong)(gong)前應(ying)詳(xiang)細了解場地的(de)地質和水(shui)文條件(jian)。水(shui)中施(shi)(shi)(shi)工(gong)(gong)應(ying)做好河流(liu)汛期、河床沖刷、通(tong)航及漂流(liu)物(wu)等調(diao)查研(yan)究(jiu)，充分利用(yong)枯水(shui)季(ji)節，制(zhi)(zhi)訂詳(xiang)細的(de)施(shi)(shi)(shi)工(gong)(gong)計(ji)劃及必要的(de)措施(shi)(shi)(shi)，確保施(shi)(shi)(shi)工(gong)(gong)安全。

沉(chen)(chen)(chen)(chen)(chen)井(jing)接(jie)高(gao)(gao)前應(ying)盡量(liang)糾正前一(yi)節(jie)的(de)傾(qing)斜，接(jie)高(gao)(gao)一(yi)節(jie)的(de)豎向中軸線(xian)應(ying)與前一(yi)節(jie)的(de)豎向中軸線(xian)重合。水上(shang)沉(chen)(chen)(chen)(chen)(chen)井(jing)接(jie)高(gao)(gao)時(shi)，井(jing)頂露出水面不(bu)應(ying)小(xiao)(xiao)于(yu)1．5m。地(di)(di)面上(shang)沉(chen)(chen)(chen)(chen)(chen)井(jing)接(jie)高(gao)(gao)時(shi)，井(jing)頂露出地(di)(di)面不(bu)應(ying)小(xiao)(xiao)于(yu)o．5m。接(jie)高(gao)(gao)前不(bu)得掏空刃腳，避免沉(chen)(chen)(chen)(chen)(chen)井(jing)傾(qing)斜。沉(chen)(chen)(chen)(chen)(chen)井(jing)應(ying)用范(fan)圍：如(ru)因場地(di)(di)狹窄，沉(chen)(chen)(chen)(chen)(chen)井(jing)施工方案，同(tong)時(shi)受(shou)附(fu)近建(jian)筑物或(huo)其他因素條件的(de)限制(zhi)，而(er)不(bu)適宜采用大開挖(wa)的(de)地(di)(di)點(dian)，可采用沉(chen)(chen)(chen)(chen)(chen)井(jing)法施工。沉(chen)(chen)(chen)(chen)(chen)井(jing)預(yu)制(zhi)完成并準(zhun)確就位(wei)后，開始(shi)抽除墊(dian)木。不(bu)論沉(chen)(chen)(chen)(chen)(chen)井(jing)大小(xiao)(xiao)，此(ci)項工作均要求在2～4h內完成。抽除墊(dian)木前，應(ying)對墊(dian)木分(fen)組編(bian)號，準(zhun)備回填用的(de)砂料(liao)，測量(liang)刃腳標高(gao)(gao)和(he)沉(chen)(chen)(chen)(chen)(chen)井(jing)中線(xian)。

沉(chen)(chen)(chen)(chen)井(jing)應(ying)(ying)用(yong)范(fan)圍(wei)：沉(chen)(chen)(chen)(chen)井(jing)可(ke)(ke)作為橋(qiao)梁墩臺的深(shen)基(ji)(ji)礎，由于(yu)平面尺寸小(xiao)，而下(xia)(xia)沉(chen)(chen)(chen)(chen)深(shen)度比(bi)較大，因此(ci)，在橋(qiao)梁工程(cheng)中(zhong)廣(guang)泛采(cai)用(yong)。大型(xing)設備基(ji)(ji)礎、地下(xia)(xia)倉庫、人防掩蔽所(suo)、盾構拼裝(zhuang)井(jing)、船塢(wu)塢(wu)首(shou)等均可(ke)(ke)采(cai)用(yong)沉(chen)(chen)(chen)(chen)井(jing)。沉(chen)(chen)(chen)(chen)井(jing)應(ying)(ying)用(yong)范(fan)圍(wei)：沉(chen)(chen)(chen)(chen)井(jing)可(ke)(ke)用(yong)作礦區的豎井(jing)，面積比(bi)較小(xiao)，沉(chen)(chen)(chen)(chen)井(jing)施工公(gong)司，一般為圓(yuan)形，直(zhi)徑在15m以內。但下(xia)(xia)沉(chen)(chen)(chen)(chen)深(shen)度卻(que)很深(shen)，一般要在100m以上，可(ke)(ke)用(yong)作上下(xia)(xia)人員、材料(liao)、產品(煤和礦石)的豎向通道(dao)(dao)，同時(shi)還可(ke)(ke)作為豎向風道(dao)(dao)之用(yong)。下(xia)(xia)沉(chen)(chen)(chen)(chen)過程(cheng)中(zhong)，應(ying)(ying)隨時(shi)掌握土層變化(hua)情況，分析和檢驗土的阻力與沉(chen)(chen)(chen)(chen)并(bing)重(zhong)力的關系，選用(yong)的下(xia)(xia)沉(chen)(chen)(chen)(chen)方(fang)法(fa)，并(bing)做好下(xia)(xia)沉(chen)(chen)(chen)(chen)觀測記(ji)錄(lu)。