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　　中鐵一(yi)(yi)局(ju)2006年提(ti)出(chu)的(de)(de)(de)“隧道仰拱施(shi)作距(ju)離掌子面30米(mi)，二(er)次襯砌(qi)距(ju)離仰拱30米(mi)，這兩個30米(mi)‘步長’的(de)(de)(de)間(jian)距(ju)控制規(gui)范(fan)，經(jing)過長達一(yi)(yi)年多時(shi)間(jian)安全(quan)均衡掘進的(de)(de)(de)驗證(zheng)(zheng)，并(bing)由業主(zhu)邀請國(guo)內(nei)一(yi)(yi)流專家嚴格論證(zheng)(zheng)，已(yi)經(jing)成(cheng)為國(guo)內(nei)大斷面黃土隧道施(shi)工的(de)(de)(de)新規(gui)范(fan)。

　　中(zhong)鐵一局(ju)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)(de)鄭西客運(yun)專線秦(qin)東隧(sui)(sui)(sui)(sui)道(dao)(dao)全(quan)長(chang)(chang)7684米，隧(sui)(sui)(sui)(sui)道(dao)(dao)開挖斷面比國際標準(zhun)排球(qiu)場還大，是國內首座(zuo)大斷面濕陷性黃土(tu)(tu)地質隧(sui)(sui)(sui)(sui)道(dao)(dao)。濕陷性黃土(tu)(tu)承載力非(fei)常(chang)(chang)低，遇水就要沉(chen)落。秦(qin)東隧(sui)(sui)(sui)(sui)道(dao)(dao)掘進(jin)中(zhong)黃土(tu)(tu)含水率達到20％以上(shang)，安(an)全(quan)風險非(fei)常(chang)(chang)，隧(sui)(sui)(sui)(sui)道(dao)(dao)在(zai)(zai)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)中(zhong)隨(sui)時可(ke)能發(fa)生變形坍塌(ta)，成為國內外隧(sui)(sui)(sui)(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)的(de)(de)(de)(de)(de)先例。中(zhong)鐵一局(ju)在(zai)(zai)秦(qin)東隧(sui)(sui)(sui)(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)中(zhong)“及時給隧(sui)(sui)(sui)(sui)道(dao)(dao)穿上(shang)結實(shi)的(de)(de)(de)(de)(de)棉襖”，用可(ke)靠的(de)(de)(de)(de)(de)后部(bu)工(gong)(gong)(gong)(gong)(gong)序(xu)確保前(qian)部(bu)工(gong)(gong)(gong)(gong)(gong)序(xu)的(de)(de)(de)(de)(de)安(an)全(quan)推進(jin)，針對軟(ruan)弱(ruo)(ruo)圍巖自穩(wen)能力極(ji)差的(de)(de)(de)(de)(de)特點，二(er)(er)(er)次(ci)襯(chen)砌(qi)緊跟仰拱，仰拱緊跟掌子面，用二(er)(er)(er)次(ci)襯(chen)砌(qi)穩(wen)固(gu)推進(jin)仰拱施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)，用仰拱快速成環(huan)穩(wen)固(gu)推進(jin)掌子面向(xiang)前(qian)掘進(jin)，創(chuang)造(zao)了(le)“步(bu)長(chang)(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)理論。從最后一道(dao)(dao)工(gong)(gong)(gong)(gong)(gong)序(xu)通過信(xin)息(xi)流向(xiang)上(shang)一道(dao)(dao)工(gong)(gong)(gong)(gong)(gong)序(xu)傳遞信(xin)息(xi)，后部(bu)工(gong)(gong)(gong)(gong)(gong)序(xu)按時按量向(xiang)前(qian)部(bu)工(gong)(gong)(gong)(gong)(gong)序(xu)發(fa)出生產指令。“步(bu)長(chang)(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)理論的(de)(de)(de)(de)(de)革命性意義在(zai)(zai)于徹底改(gai)變了(le)以往隧(sui)(sui)(sui)(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)中(zhong)前(qian)部(bu)開挖野馬(ma)長(chang)(chang)韁，后部(bu)仰拱施(shi)(shi)(shi)作、二(er)(er)(er)次(ci)襯(chen)砌(qi)距離掌子面過長(chang)(chang)，經常(chang)(chang)導致隧(sui)(sui)(sui)(sui)道(dao)(dao)失(shi)穩(wen)坍塌(ta)的(de)(de)(de)(de)(de)陳舊的(de)(de)(de)(de)(de)隧(sui)(sui)(sui)(sui)道(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)惡(e)習(xi)，用兩(liang)個(ge)30米嚴格(ge)的(de)(de)(de)(de)(de)“步(bu)長(chang)(chang)”間距有效保證了(le)軟(ruan)弱(ruo)(ruo)圍巖地質條件(jian)下隧(sui)(sui)(sui)(sui)道(dao)(dao)的(de)(de)(de)(de)(de)安(an)全(quan)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)。“步(bu)長(chang)(chang)控制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)(gong)理論把廣義的(de)(de)(de)(de)(de)“新奧法(fa)概(gai)念(nian)”具體(ti)化(hua)，操作簡便，經濟(ji)效益、社會效益明顯，隧(sui)(sui)(sui)(sui)道(dao)(dao)已順利掘進(jin)7016米。