LM-200型反(fan)井(jing)(jing)鉆(zhan)機。主要由鉆(zhan)機車(che)、操作車(che)、泵車(che)、鉆(zhan)具等四部分組(zu)成,配套輔助設備為洗井(jing)(jing)泵一臺,斜井(jing)(jing)專用裝(zhuang)置一套。

廠家提供的反井鉆(zhan)機主(zhu)要技術性能如(ru)下:

        (1)導孔直徑(mm):216

        (2)導孔直徑(mm):1 400,2 000(二次擴孔)

        (3)鉆井深度(m):200,小于150 (φ2 m擴孔)

        (4)總功率(kW):82.5

        (5)主機(ji)外型尺寸(長×寬×高)

    運輸(mm):2 950×1 370×1 570

    工作(mm):3 230×1 770×3 448

        (6)主(zhu)機(ji)重量(liang)(kg):8 277

1、施工布置

1.1反井鉆(zhan)機的冷卻循環系統

    反(fan)井(jing)(jing)鉆機(ji)的冷(leng)卻(que)循(xun)環系統由(you):洗(xi)井(jing)(jing)泵(泥漿(jiang)泵)、水(shui)池(chi)(chi)、水(shui)溝組成。距(ju)反(fan)井(jing)(jing)鉆機(ji)基礎15 m處設(she)(she)置一(yi)個5 m3水(shui)池(chi)(chi),水(shui)池(chi)(chi)中間設(she)(she)一(yi)隔墻,將水(shui)池(chi)(chi)分隔成清水(shui)池(chi)(chi)和沉淀(dian)池(chi)(chi)。混(hun)凝土基礎和水(shui)池(chi)(chi)之間由(you)一(yi)水(shui)溝連接,導孔施(shi)工出現的回(hui)水(shui)、細沙沿此溝回(hui)流至(zhi)沉淀(dian)池(chi)(chi)。洗(xi)井(jing)(jing)泵設(she)(she)置在鉆機(ji)車與水(shui)池(chi)(chi)之間。具(ju)體布(bu)置見圖(tu)1。

1.2反井(jing)鉆機運(yun)輸(shu)軌道的安(an)裝

    為(wei)方(fang)便反井(jing)鉆機(ji)就位(wei)、定(ding)位(wei),在(zai)洞內卸機(ji)部(bu)位(wei)地面安裝運輸(shu)軌(gui)道,軌(gui)距60 cm,軌(gui)道為(wei)24kg/m的輕軌(gui),枕木(mu)為(wei)10 cm×10 cm方(fang)木(mu),間距為(wei)50 cm/根。

1.3反井鉆(zhan)機的(de)安裝基礎(chu)

    反(fan)井(jing)鉆機(ji)安裝在平段與斜井(jing)相(xiang)交部位,主機(ji)起(qi)(qi)鉆孔(kong)口與斜井(jing)中心線延長線吻合。操(cao)作車、泵車依(yi)次停放在擴挖過后的(de)盲洞(dong)內(nei),操(cao)作車距(ju)起(qi)(qi)鉆孔(kong)口有大(da)于1 m的(de)安全(quan)距(ju)離(li)。基(ji)礎采用C20混(hun)凝土分二期澆筑(zhu)而成,一期形成基(ji)礎并預留反(fan)井(jing)鉆機(ji)地腳螺栓坑,待機(ji)體(ti)到位并進行初校后,回填(tian)二期混(hun)凝土,以確保反(fan)井(jing)鉆機(ji)與基(ji)礎牢固銜接,不發生移位。

2、反井鉆機施(shi)工程(cheng)序

    基礎澆筑(一期含循環(huan)水池)→反井鉆(zhan)機(ji)進場安裝(包括高壓洗(xi)井泵)測量初定位φ216 mm先導孔(kong)施(shi)(shi)工→鉆(zhan)頭(tou)在(zai)預定深度出(chu)(chu)露(若未出(chu)(chu)露擴(kuo)(kuo)挖找(zhao)鉆(zhan)頭(tou))→擴(kuo)(kuo)孔(kong)鉆(zhan)頭(tou)安裝平臺施(shi)(shi)工→擴(kuo)(kuo)孔(kong)鉆(zhan)頭(tou)提(ti)升(sheng)→擴(kuo)(kuo)孔(kong)鉆(zhan)頭(tou)安裝→安裝平臺撤出(chu)(chu)→φ1 200擴(kuo)(kuo)孔(kong)施(shi)(shi)工→擴(kuo)(kuo)孔(kong)鉆(zhan)頭(tou)拆卸→反井鉆(zhan)機(ji)撤除。

3、施工過程及方法

3.1反井鉆機的安裝

    反(fan)井鉆機采用實(shi)際載重能(neng)力(li)在10 t以上的(de)平板(ban)貨車,貨箱的(de)長度(du)不宜(yi)超(chao)過5.5 m,離地(di)高(gao)度(du)不宜(yi)超(chao)過1.2 m。

3.2φ216 mm先導孔施工

    反井鉆(zhan)(zhan)(zhan)機施(shi)工(gong)(gong)(gong)的(de)(de)(de)(de)關鍵在(zai)(zai)于先(xian)導(dao)孔(kong)(kong)鉆(zhan)(zhan)(zhan)孔(kong)(kong)質量。最終導(dao)孔(kong)(kong)能否鉆(zhan)(zhan)(zhan)通(tong),鉆(zhan)(zhan)(zhan)通(tong)后(hou)(hou)的(de)(de)(de)(de)偏離誤差大(da)小(xiao)(xiao)在(zai)(zai)開鉆(zhan)(zhan)(zhan)后(hou)(hou)無法(fa)進(jin)行(xing)中間檢測(ce)和(he)控(kong)制(zhi)(zhi),只能依靠經驗,針對不(bu)同(tong)(tong)的(de)(de)(de)(de)圍巖類(lei)別(bie),實施(shi)不(bu)同(tong)(tong)的(de)(de)(de)(de)主、副(fu)泵(beng)工(gong)(gong)(gong)作壓力(li)、轉速和(he)適時(shi)(shi)裝配穩定(ding)鉆(zhan)(zhan)(zhan)桿(gan)進(jin)行(xing)控(kong)制(zhi)(zhi)。反井鉆(zhan)(zhan)(zhan)機的(de)(de)(de)(de)鉆(zhan)(zhan)(zhan)桿(gan)分為普通(tong)鉆(zhan)(zhan)(zhan)桿(gan)(1 m)和(he)穩定(ding)鉆(zhan)(zhan)(zhan)桿(gan)(0.5 m),差別(bie)在(zai)(zai)于后(hou)(hou)者比前者外周多了均勻分布的(de)(de)(de)(de)四條(tiao)3 cm厚的(de)(de)(de)(de)鋼肋(lei)板,其作用(yong)(yong)(yong)是導(dao)向(xiang),防止(zhi)鉆(zhan)(zhan)(zhan)桿(gan)隨(sui)深度的(de)(de)(de)(de)增(zeng)加旋轉產生過(guo)大(da)彎曲、過(guo)大(da)擺幅,起到穩定(ding)的(de)(de)(de)(de)作用(yong)(yong)(yong),同(tong)(tong)時(shi)(shi)保護鉆(zhan)(zhan)(zhan)桿(gan)與(yu)孔(kong)(kong)壁(bi)的(de)(de)(de)(de)接觸(chu)磨損(sun)。采(cai)用(yong)(yong)(yong)的(de)(de)(de)(de)穩定(ding)鉆(zhan)(zhan)(zhan)桿(gan)的(de)(de)(de)(de)加設方法(fa)如下:鉆(zhan)(zhan)(zhan)進(jin)2 m時(shi)(shi)必(bi)須加設1根,鉆(zhan)(zhan)(zhan)進(jin)8~10 m時(shi)(shi)再加設1根,然后(hou)(hou)每鉆(zhan)(zhan)(zhan)進(jin)20 m加設1根。上述方法(fa)較(jiao)為合(he)理(li)、穩妥。鉆(zhan)(zhan)(zhan)桿(gan)加設時(shi)(shi)一(yi)般采(cai)用(yong)(yong)(yong)副(fu)泵(beng)提(ti)供(gong)的(de)(de)(de)(de)較(jiao)小(xiao)(xiao)動力(li)運行(xing),鉆(zhan)(zhan)(zhan)桿(gan)絲扣之間力(li)度適中,過(guo)緊容(rong)易(yi)損(sun)傷絲扣,過(guo)松(song)鉆(zhan)(zhan)(zhan)桿(gan)容(rong)易(yi)脫落。為了便(bian)于拆卸鉆(zhan)(zhan)(zhan)桿(gan),可在(zai)(zai)鉆(zhan)(zhan)(zhan)桿(gan)套接前于絲扣處加設少(shao)量10號鉛絲。先(xian)導(dao)孔(kong)(kong)開始施(shi)工(gong)(gong)(gong)時(shi)(shi)一(yi)般采(cai)用(yong)(yong)(yong)副(fu)泵(beng)提(ti)供(gong)較(jiao)小(xiao)(xiao)的(de)(de)(de)(de)、均勻的(de)(de)(de)(de)動力(li),以(yi)免孔(kong)(kong)口周壁(bi)因振動過(guo)大(da)開裂而難以(yi)成型。主、副(fu)泵(beng)在(zai)(zai)不(bu)同(tong)(tong)圍巖類(lei)別(bie)、不(bu)同(tong)(tong)鉆(zhan)(zhan)(zhan)孔(kong)(kong)深度等條(tiao)件下的(de)(de)(de)(de)工(gong)(gong)(gong)作壓力(li)經驗數(shu)據(ju)見表1。

3.3φ1 200 mm擴孔施(shi)工

    擴孔(kong)開始(shi)施(shi)工(gong)時一般圍巖破(po)壞嚴重,鉆頭(tou)周圈難以均(jun)勻(yun)(yun)受(shou)力(li)。因此(ci),采用副泵提供(gong)(gong)(gong)較(jiao)小(xiao)的(de)、均(jun)勻(yun)(yun)的(de)動力(li),進尺(chi)較(jiao)慢,控制在10 cm/h,以防鉆頭(tou)偏心受(shou)力(li)過大而扭(niu)斷鉆桿(gan)。鉆進施(shi)工(gong)中要(yao)(yao)求(qiu)有(you)較(jiao)為穩定(ding)供(gong)(gong)(gong)水(shui)量,以使刀(dao)具能得(de)到水(shui)冷卻,供(gong)(gong)(gong)水(shui)量要(yao)(yao)求(qiu)不(bu)小(xiao)于(yu)7.8 m3/h。擴孔(kong)施(shi)工(gong)時,鉆桿(gan)的(de)拆卸要(yao)(yao)特別注意鉆桿(gan)卡瓦正(zheng)確擺放(fang)及(ji)自身(shen)的(de)完好程(cheng)度,以免出現卡瓦突然(ran)斷裂,造成擴孔(kong)鉆頭(tou)、鉆桿(gan)脫落。