長螺旋動力頭

（1）鉆機(ji)(ji)對位(wei)(wei)鉆機(ji)(ji)就位(wei)(wei)時(shi)，液(ye)壓支腿要落在(zai)實處，松軟(ruan)處可(ke)用枕木等(deng)物墊(dian)塞，利用液(ye)壓支腿使鉆機(ji)(ji)水平并調(diao)整鉆機(ji)(ji)立柱與(yu)水平面垂直(zhi)，垂直(zhi)偏差(cha)不大(da)于1%，對位(wei)(wei)偏差(cha)不超過(guo)20mm。

（2）鉆進成孔

鉆(zhan)(zhan)(zhan)(zhan)進成孔中(zhong)，對鉆(zhan)(zhan)(zhan)(zhan)壓、轉(zhuan)(zhuan)速和鉆(zhan)(zhan)(zhan)(zhan)進速度要根(gen)據(ju)地(di)質變化(hua)與動力頭工作電(dian)流(liu)(liu)(liu)顯示(shi)值(zhi)(zhi)(zhi)進行(xing)合理調整，正(zheng)常(chang)鉆(zhan)(zhan)(zhan)(zhan)進的(de)電(dian)流(liu)(liu)(liu)值(zhi)(zhi)(zhi)一般為100A左右。當電(dian)流(liu)(liu)(liu)值(zhi)(zhi)(zhi)大于(yu)140A的(de)額定值(zhi)(zhi)(zhi)時(shi)，應迅速進行(xing)空(kong)鉆(zhan)(zhan)(zhan)(zhan)，使緊抱鉆(zhan)(zhan)(zhan)(zhan)桿葉片(pian)上(shang)的(de)土(tu)塊甩出，待電(dian)流(liu)(liu)(liu)值(zhi)(zhi)(zhi)降到正(zheng)常(chang)范圍后(hou)方(fang)可繼(ji)續鉆(zhan)(zhan)(zhan)(zhan)進，鉆(zhan)(zhan)(zhan)(zhan)進時(shi)應采用間歇鉆(zhan)(zhan)(zhan)(zhan)進方(fang)法(即鉆(zhan)(zhan)(zhan)(zhan)進→空(kong)鉆(zhan)(zhan)(zhan)(zhan)→鉆(zhan)(zhan)(zhan)(zhan)進)，以利于(yu)被(bei)切削巖(yan)土(tu)及時(shi)排出地(di)面。當鉆(zhan)(zhan)(zhan)(zhan)至設計(ji)深度后(hou)空(kong)轉(zhuan)(zhuan)30-60s，待電(dian)流(liu)(liu)(liu)穩定后(hou)停鉆(zhan)(zhan)(zhan)(zhan)并發出信號(hao)，為泵送(song)混(hun)凝土(tu)做好準備

（3）泵壓混凝土與提升鉆(zhan)桿

混(hun)凝(ning)(ning)(ning)土可采用現場攪拌混(hun)凝(ning)(ning)(ning)土，混(hun)凝(ning)(ning)(ning)土坍落度(du)一般(ban)為(wei)150～180mm，石子(zi)粒徑通(tong)常為(wei)5～20mm，摻高(gao)效減水(shui)劑或泵(beng)送(song)劑，泵(beng)送(song)混(hun)凝(ning)(ning)(ning)土時(shi)，司(si)泵(beng)工(gong)(gong)(gong)與(yu)司(si)鉆(zhan)工(gong)(gong)(gong)要隨(sui)時(shi)聯系，保證(zheng)輸送(song)、停止輸送(song)混(hun)凝(ning)(ning)(ning)土與(yu)提(ti)升、停止提(ti)升鉆(zhan)桿(gan)的(de)工(gong)(gong)(gong)作(zuo)密切配合。鉆(zhan)桿(gan)提(ti)升要求為(wei)提(ti)升速度(du)1.5～3.5m／min，鉆(zhan)頭始終埋在混(hun)凝(ning)(ning)(ning)土下面1.0m深處；泵(beng)送(song)混(hun)凝(ning)(ning)(ning)土要求為(wei)：泵(beng)工(gong)(gong)(gong)作(zuo)壓力值一般(ban)控制在3.0-4.0MPa，并保證(zheng)提(ti)升鉆(zhan)頭時(shi)要帶壓，達到樁頂標高(gao)后超灌(guan)500mm。

（4）鋼筋籠制作安裝 氣動架柱式鉆機

鋼筋籠(long)加(jia)工質量應(ying)符合(he)設(she)計與規范要求。在泵送混凝土結束(shu)后應(ying)迅速將鉆(zhan)具移(yi)位，清理孔口，借助副卷揚機吊(diao)籠(long)入孔，并將籠(long)體(ti)振入預定深度。僅供參(can)考。