大慶降水公(gong)司提(ti)醒您井點降水具(ju)體流(liu)程如下:
設備要求
井(jing)點(dian)設(she)備主要包(bao)括(kuo)井(jing)點(dian)管(下端(duan)為濾管)、集水(shui)總管和抽水(shui)設(she)備等。
井(jing)(jing)點(dian)管(guan)(guan)采用(yong)Φ60×5長6.0m無(wu)縫鋼(gang)(gang)管(guan)(guan)。管(guan)(guan)下端配2.0m濾(lv)管(guan)(guan),濾(lv)管(guan)(guan)采用(yong)與井(jing)(jing)點(dian)管(guan)(guan)同直徑鋼(gang)(gang)管(guan)(guan),井(jing)(jing)點(dian)管(guan)(guan)和濾(lv)管(guan)(guan)之間連接(jie)鋼(gang)(gang)制(zhi)管(guan)(guan)箍,與集(ji)水(shui)(shui)(shui)總管(guan)(guan)連接(jie)用(yong)耐壓膠管(guan)(guan),濾(lv)管(guan)(guan)鉆梅花(hua)孔(kong),直徑5mm,距15mm,外(wai)包尼龍網(100目)五層(ceng),鋼(gang)(gang)絲網二層(ceng),外(wai)纏20#鍍鋅鐵(tie)絲,間距10mm。集(ji)水(shui)(shui)(shui)總管(guan)(guan)為內徑100—127mm的(de)無(wu)縫鋼(gang)(gang)管(guan)(guan),每節長4米,其間用(yong)橡皮(pi)套(tao)管(guan)(guan)連結,并(bing)用(yong)鋼(gang)(gang)箍接(jie)緊,以防漏水(shui)(shui)(shui),總管(guan)(guan)上裝有與井(jing)(jing)點(dian)管(guan)(guan)聯結的(de)短接(jie)頭,間距0.8米—1.2米。
每套(tao)抽水設備有真空泵(beng)(beng)一臺,離心泵(beng)(beng)一臺,水氣分離器一臺,每套(tao)井點(dian)降水設備帶70根井點(dian)降水管。
施工方案
井(jing)(jing)點(dian)的平面(mian)布置(zhi):當基坑(keng)或(huo)溝(gou)槽寬度(du)(du)小(xiao)于6m,且降水深度(du)(du)不(bu)超過6m時,可(ke)用(yong)單排(pai)(pai)線(xian)狀井(jing)(jing)點(dian),布置(zhi)在地(di)下水流(liu)的上游一(yi)(yi)側,兩端(duan)延伸長度(du)(du)以不(bu)小(xiao)于槽寬為(wei)宜(yi)。如寬度(du)(du)大于6m或(huo)土(tu)質不(bu)良(liang),則用(yong)雙排(pai)(pai)線(xian)狀井(jing)(jing)點(dian)。面(mian)積較大的基坑(keng)宜(yi)用(yong)環狀井(jing)(jing)點(dian),有時也可(ke)布置(zhi)成U形,以利于挖土(tu)機和(he)運土(tu)車輛出入(ru)基坑(keng)。井(jing)(jing)點(dian)管(guan)距(ju)離基坑(keng)壁不(bu)應小(xiao)于1.0—1.5m,以防(fang)局部漏氣。井(jing)(jing)點(dian)管(guan)間距(ju)一(yi)(yi)般為(wei)0.8m—1.6m,由計算或(huo)試驗確定。井(jing)(jing)點(dian)管(guan)在總管(guan)四角(jiao)部位應適當加密。
井點高程布置:井點的埋設(she)深(shen)度H(不包括濾管)。H≥H1+h+IL(m)
H1——井管埋設面至(zhi)基坑底的距離;
h——基坑(keng)中心處底面(mian)至降低(di)后地下水位的距離,一(yi)般(ban)為0.5—1.0m;
I——地下(xia)水(shui)降落坡度,雙(shuang)排或(huo)環狀井(jing)點(dian)1/10,單排井(jing)點(dian)為1/4~1/5;
L——井點管(guan)至(zhi)基(ji)坑中心的水平(ping)距離。
同時還應(ying)考慮井點(dian)管(guan)一般(ban)要露出(chu)面0.2m左(zuo)右,無論(lun)在(zai)任何情況下,濾管(guan)必須埋在(zai)透水層內,為了(le)充(chong)分利用抽吸能力,總(zong)(zong)管(guan)的布置(zhi)接近地下水位(wei)線,應(ying)事(shi)先挖槽,水泵軸心標(biao)高宜與(yu)(yu)總(zong)(zong)管(guan)平行或略低于總(zong)(zong)管(guan),總(zong)(zong)管(guan)應(ying)具有0.25—0.5%坡度(坡向泵層),各(ge)段總(zong)(zong)管(guan)與(yu)(yu)濾管(guan)最好分別設在(zai)同一水平面,不宜高低懸(xuan)殊。