應(ying)避(bi)免(mian)因井外棄土(tu)(tu)(tu)引(yin)(yin)起對(dui)沉(chen)(chen)井結(jie)構(gou)(gou)的(de)(de)偏壓。應(ying)注(zhu)意河(he)床因沖淤引(yin)(yin)起的(de)(de)土(tu)(tu)(tu)面高差，必要(yao)時可(ke)用(yong)(yong)沉(chen)(chen)井外棄土(tu)(tu)(tu)來調整。沉(chen)(chen)井應(ying)用(yong)(yong)范圍(wei)：沉(chen)(chen)井可(ke)用(yong)(yong)作(zuo)(zuo)礦(kuang)區的(de)(de)豎井，面積比較小，一般(ban)為(wei)圓形，直徑在(zai)15m以內(nei)。但下(xia)(xia)沉(chen)(chen)深(shen)度卻(que)很(hen)深(shen)，一般(ban)要(yao)在(zai)100m以上(shang)(shang)(shang)，可(ke)用(yong)(yong)作(zuo)(zuo)上(shang)(shang)(shang)下(xia)(xia)人(ren)員、材料、產品(煤(mei)和(he)礦(kuang)石(shi))的(de)(de)豎向通道(dao)，同(tong)時還可(ke)作(zuo)(zuo)為(wei)豎向風道(dao)之用(yong)(yong)。將事先在(zai)地面上(shang)(shang)(shang)用(yong)(yong)鋼筋(jin)混凝(ning)土(tu)(tu)(tu)制成的(de)(de)井筒(tong)形狀的(de)(de)結(jie)構(gou)(gou)作(zuo)(zuo)為(wei)基坑坑壁(bi)(bi)的(de)(de)支(zhi)撐(cheng)，在(zai)井壁(bi)(bi)的(de)(de)保護(hu)下(xia)(xia)，用(yong)(yong)機械(xie)和(he)人(ren)工在(zai)井內(nei)挖土(tu)(tu)(tu)，并在(zai)其自重(zhong)作(zuo)(zuo)用(yong)(yong)下(xia)(xia)沉(chen)(chen)入土(tu)(tu)(tu)中的(de)(de)結(jie)構(gou)(gou)物(wu)稱為(wei)沉(chen)(chen)井。

沉(chen)(chen)(chen)井下(xia)(xia)(xia)(xia)沉(chen)(chen)(chen)至(zhi)設計(ji)標(biao)高(gao)(gao)時，應(ying)(ying)進行沉(chen)(chen)(chen)降觀測，沉(chen)(chen)(chen)井施工(gong)價格，滿足(zu)設計(ji)要求(qiu)(qiu)后(hou)(hou)方(fang)可(ke)封底。經檢驗合格后(hou)(hou)，應(ying)(ying)及時封底。滲水(shui)量上(shang)(shang)升速度≤6mm／min時，可(ke)用(yong)(yong)澆筑普通混凝(ning)土(tu)方(fang)法(fa)封底，否則宜采用(yong)(yong)水(shui)下(xia)(xia)(xia)(xia)混凝(ning)土(tu)封底。井底下(xia)(xia)(xia)(xia)沉(chen)(chen)(chen)至(zhi)設計(ji)標(biao)高(gao)(gao)2．om以上(shang)(shang)時，應(ying)(ying)放慢下(xia)(xia)(xia)(xia)沉(chen)(chen)(chen)速度，控制井內除(chu)土(tu)量和(he)除(chu)土(tu)位置，以求(qiu)(qiu)沉(chen)(chen)(chen)井平穩下(xia)(xia)(xia)(xia)沉(chen)(chen)(chen)、正確(que)就(jiu)位。沉(chen)(chen)(chen)井應(ying)(ying)用(yong)(yong)范圍：沉(chen)(chen)(chen)井可(ke)用(yong)(yong)作礦區的(de)豎(shu)(shu)井，面積比較小，一般為圓(yuan)形，直徑(jing)在(zai)15m以內。但下(xia)(xia)(xia)(xia)沉(chen)(chen)(chen)深(shen)度卻很深(shen)，一般要在(zai)100m以上(shang)(shang)，沉(chen)(chen)(chen)井施工(gong)，可(ke)用(yong)(yong)作上(shang)(shang)下(xia)(xia)(xia)(xia)人員(yuan)、材料(liao)、產(chan)品(pin)(煤和(he)礦石)的(de)豎(shu)(shu)向通道(dao)(dao)，同(tong)時還可(ke)作為豎(shu)(shu)向風道(dao)(dao)之用(yong)(yong)。

沉(chen)井施(shi)工(gong)(gong)(gong)，實質(zhi)上就是將一個在(zai)地面上事先澆制好的構(gou)筑物通過挖(wa)土沉(chen)入到地下(xia)(xia)一定深度后成為地下(xia)(xia)構(gou)筑物的施(shi)工(gong)(gong)(gong)過程。沉(chen)井應用(yong)(yong)范圍：如因場(chang)地狹窄，同時(shi)(shi)受附近建筑物或其(qi)他因素條件的限制，而不(bu)適宜采(cai)用(yong)(yong)大開挖(wa)的地點，可采(cai)用(yong)(yong)沉(chen)井法(fa)施(shi)工(gong)(gong)(gong)。沉(chen)井下(xia)(xia)沉(chen)至設計(ji)標高時(shi)(shi)，應進(jin)行沉(chen)降觀測(ce)，沉(chen)井施(shi)工(gong)(gong)(gong)技術，滿足設計(ji)要(yao)求(qiu)后方可封(feng)底(di)。經檢驗合格(ge)后，沉(chen)井施(shi)工(gong)(gong)(gong)工(gong)(gong)(gong)法(fa)，應及時(shi)(shi)封(feng)底(di)。滲水(shui)(shui)量上升速度≤6mm／min時(shi)(shi)，可用(yong)(yong)澆筑普通混凝土方法(fa)封(feng)底(di)，否則宜采(cai)用(yong)(yong)水(shui)(shui)下(xia)(xia)混凝土封(feng)底(di)。