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　　中(zhong)鐵一局2006年提出的(de)(de)“隧道(dao)仰(yang)拱施作距離掌(zhang)子(zi)面(mian)30米，二次襯砌(qi)距離仰(yang)拱30米，這兩個30米‘步(bu)長’的(de)(de)間(jian)距控制(zhi)規范，經過長達一年多時間(jian)安(an)全均衡掘進的(de)(de)驗證，并由(you)業主邀請國內一流專家嚴格(ge)論(lun)證，已經成為(wei)國內大斷面(mian)黃土隧道(dao)施工的(de)(de)新規范。

　　中(zhong)(zhong)(zhong)鐵一局施(shi)(shi)(shi)工(gong)(gong)(gong)的(de)(de)鄭西客運專線秦東(dong)隧(sui)(sui)(sui)道(dao)(dao)(dao)全(quan)長(chang)7684米(mi)，隧(sui)(sui)(sui)道(dao)(dao)(dao)開挖斷面(mian)比國(guo)(guo)際標(biao)準(zhun)排球場還大(da)(da)，是國(guo)(guo)內首座大(da)(da)斷面(mian)濕陷(xian)(xian)性黃(huang)土地質隧(sui)(sui)(sui)道(dao)(dao)(dao)。濕陷(xian)(xian)性黃(huang)土承載(zai)力非(fei)(fei)常(chang)低，遇水就要沉落。秦東(dong)隧(sui)(sui)(sui)道(dao)(dao)(dao)掘(jue)進(jin)中(zhong)(zhong)(zhong)黃(huang)土含水率達(da)到20％以上，安全(quan)風險非(fei)(fei)常(chang)，隧(sui)(sui)(sui)道(dao)(dao)(dao)在施(shi)(shi)(shi)工(gong)(gong)(gong)中(zhong)(zhong)(zhong)隨時可(ke)能發生變(bian)形坍(tan)塌，成(cheng)為國(guo)(guo)內外隧(sui)(sui)(sui)道(dao)(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)的(de)(de)先例。中(zhong)(zhong)(zhong)鐵一局在秦東(dong)隧(sui)(sui)(sui)道(dao)(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)中(zhong)(zhong)(zhong)“及時給隧(sui)(sui)(sui)道(dao)(dao)(dao)穿(chuan)上結實的(de)(de)棉襖”，用(yong)可(ke)靠(kao)的(de)(de)后(hou)部(bu)工(gong)(gong)(gong)序(xu)(xu)確保前部(bu)工(gong)(gong)(gong)序(xu)(xu)的(de)(de)安全(quan)推(tui)進(jin)，針對軟(ruan)弱圍巖(yan)自穩能力極(ji)差的(de)(de)特點，二次襯砌(qi)緊(jin)跟(gen)仰(yang)(yang)拱，仰(yang)(yang)拱緊(jin)跟(gen)掌子(zi)面(mian)，用(yong)二次襯砌(qi)穩固(gu)推(tui)進(jin)仰(yang)(yang)拱施(shi)(shi)(shi)工(gong)(gong)(gong)，用(yong)仰(yang)(yang)拱快速成(cheng)環(huan)穩固(gu)推(tui)進(jin)掌子(zi)面(mian)向前掘(jue)進(jin)，創造了“步(bu)(bu)長(chang)控(kong)制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論。從最后(hou)一道(dao)(dao)(dao)工(gong)(gong)(gong)序(xu)(xu)通過信息流向上一道(dao)(dao)(dao)工(gong)(gong)(gong)序(xu)(xu)傳遞信息，后(hou)部(bu)工(gong)(gong)(gong)序(xu)(xu)按時按量(liang)向前部(bu)工(gong)(gong)(gong)序(xu)(xu)發出生產(chan)指(zhi)令。“步(bu)(bu)長(chang)控(kong)制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論的(de)(de)革命性意義在于(yu)徹底改變(bian)了以往隧(sui)(sui)(sui)道(dao)(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)中(zhong)(zhong)(zhong)前部(bu)開挖野馬長(chang)韁，后(hou)部(bu)仰(yang)(yang)拱施(shi)(shi)(shi)作、二次襯砌(qi)距離(li)掌子(zi)面(mian)過長(chang)，經常(chang)導致隧(sui)(sui)(sui)道(dao)(dao)(dao)失穩坍(tan)塌的(de)(de)陳舊的(de)(de)隧(sui)(sui)(sui)道(dao)(dao)(dao)施(shi)(shi)(shi)工(gong)(gong)(gong)惡習，用(yong)兩個30米(mi)嚴格的(de)(de)“步(bu)(bu)長(chang)”間距有效(xiao)保證了軟(ruan)弱圍巖(yan)地質條件下(xia)隧(sui)(sui)(sui)道(dao)(dao)(dao)的(de)(de)安全(quan)施(shi)(shi)(shi)工(gong)(gong)(gong)。“步(bu)(bu)長(chang)控(kong)制(zhi)”施(shi)(shi)(shi)工(gong)(gong)(gong)理論把廣義的(de)(de)“新奧法概(gai)念”具體(ti)化，操(cao)作簡便，經濟效(xiao)益、社會效(xiao)益明顯，隧(sui)(sui)(sui)道(dao)(dao)(dao)已(yi)順利掘(jue)進(jin)7016米(mi)。