文章來(lai)源：中國鐵路工程總公司 發布時間：2008-12-04
中(zhong)鐵一局2006年(nian)提出(chu)的“隧道(dao)仰拱施作距離掌子面(mian)30米，二次襯砌(qi)距離仰拱30米，這兩個30米‘步長’的間距控制規(gui)范，經(jing)過長達一年(nian)多時間安(an)全(quan)均(jun)衡掘進的驗(yan)證，并由業主邀請(qing)國(guo)內一流專(zhuan)家嚴格論證，已經(jing)成為國(guo)內大斷(duan)面(mian)黃土隧道(dao)施工的新規(gui)范。
中鐵一(yi)(yi)局(ju)施(shi)(shi)(shi)工(gong)(gong)(gong)的(de)(de)(de)鄭(zheng)西客運專線秦東隧(sui)道(dao)(dao)全長(chang)7684米，隧(sui)道(dao)(dao)開(kai)挖斷面(mian)(mian)比國(guo)際標準排(pai)球(qiu)場(chang)還(huan)大，是國(guo)內(nei)首座大斷面(mian)(mian)濕(shi)陷(xian)性(xing)黃土地質隧(sui)道(dao)(dao)。濕(shi)陷(xian)性(xing)黃土承載力(li)非(fei)常(chang)低，遇水就要沉落(luo)。秦東隧(sui)道(dao)(dao)掘(jue)進(jin)(jin)(jin)中黃土含水率達到20％以上(shang)(shang)，安全風險(xian)非(fei)常(chang)，隧(sui)道(dao)(dao)在(zai)(zai)施(shi)(shi)(shi)工(gong)(gong)(gong)中隨(sui)時可能發(fa)生變形坍塌，成為國(guo)內(nei)外隧(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)的(de)(de)(de)先例。中鐵一(yi)(yi)局(ju)在(zai)(zai)秦東隧(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)中“及時給隧(sui)道(dao)(dao)穿上(shang)(shang)結(jie)實的(de)(de)(de)棉襖”，用(yong)可靠的(de)(de)(de)后(hou)(hou)(hou)部(bu)(bu)(bu)工(gong)(gong)(gong)序確保前(qian)部(bu)(bu)(bu)工(gong)(gong)(gong)序的(de)(de)(de)安全推進(jin)(jin)(jin)，針(zhen)對軟弱圍(wei)(wei)巖自穩能力(li)極差的(de)(de)(de)特點，二(er)(er)次(ci)襯(chen)(chen)砌緊跟仰(yang)拱(gong)，仰(yang)拱(gong)緊跟掌子面(mian)(mian)，用(yong)二(er)(er)次(ci)襯(chen)(chen)砌穩固推進(jin)(jin)(jin)仰(yang)拱(gong)施(shi)(shi)(shi)工(gong)(gong)(gong)，用(yong)仰(yang)拱(gong)快速(su)成環穩固推進(jin)(jin)(jin)掌子面(mian)(mian)向前(qian)掘(jue)進(jin)(jin)(jin)，創造(zao)了“步長(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論(lun)(lun)。從最后(hou)(hou)(hou)一(yi)(yi)道(dao)(dao)工(gong)(gong)(gong)序通過信息流向上(shang)(shang)一(yi)(yi)道(dao)(dao)工(gong)(gong)(gong)序傳(chuan)遞信息，后(hou)(hou)(hou)部(bu)(bu)(bu)工(gong)(gong)(gong)序按(an)時按(an)量向前(qian)部(bu)(bu)(bu)工(gong)(gong)(gong)序發(fa)出生產指令。“步長(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論(lun)(lun)的(de)(de)(de)革命性(xing)意義在(zai)(zai)于徹底改變了以往隧(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)中前(qian)部(bu)(bu)(bu)開(kai)挖野馬長(chang)韁(jiang)，后(hou)(hou)(hou)部(bu)(bu)(bu)仰(yang)拱(gong)施(shi)(shi)(shi)作(zuo)、二(er)(er)次(ci)襯(chen)(chen)砌距(ju)離掌子面(mian)(mian)過長(chang)，經常(chang)導致隧(sui)道(dao)(dao)失穩坍塌的(de)(de)(de)陳舊的(de)(de)(de)隧(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)惡習，用(yong)兩個30米嚴格的(de)(de)(de)“步長(chang)”間距(ju)有(you)效(xiao)(xiao)保證了軟弱圍(wei)(wei)巖地質條(tiao)件下隧(sui)道(dao)(dao)的(de)(de)(de)安全施(shi)(shi)(shi)工(gong)(gong)(gong)。“步長(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論(lun)(lun)把廣義的(de)(de)(de)“新奧法概念”具體化，操作(zuo)簡便，經濟效(xiao)(xiao)益、社(she)會(hui)效(xiao)(xiao)益明顯，隧(sui)道(dao)(dao)已順利掘(jue)進(jin)(jin)(jin)7016米。