隧道安全步距超標(biāo)的處理措施

隧道安全步距超標(biāo)的處理措施xx隧道是xx公路xx第x標(biāo)段內(nèi)的一座左、右分離式隧道，設(shè)巖，屬硬質(zhì)巖，抗風(fēng)化能力較強，圍巖為Ⅳ~Ⅴ級；洞身段埋深一般硬質(zhì)巖，抗風(fēng)化能力較強，圍巖為Ⅳ~Ⅴ級。類別ⅢⅢⅢⅢ里程K7+000~K7+065K7+065~K7+285K7+285~K7+480K7+480~K7+570K7+570~K7+752K7+752~K7+782K7+782~K7+824K7+824~K7+854K7+854~K7+994K7+994~K8+218K8+218~K8+260長度（m)65220904222442類別ⅢⅢⅢⅢ里程K7+000~K7+110K7+110~K7+280K7+280~K7+500K7+500~K7+592K7+592~K7+784K7+784~K7+814K7+814~K7+856K7+856~K7+886K7+886~K8+020K8+020~K8+236K8+236~K8+308長度（m)2209242216襯里程K8+141.6，距離260.2m；左線掌子面里程ZK7+878，二襯里xx隧道左、右線二襯安全步距已超過文件規(guī)定，監(jiān)理辦為此下根據(jù)目前作業(yè)隊人員和機械配備情況，結(jié)合十月、十一月份xx拱和二襯作業(yè)人員不足。由于xx地區(qū)對標(biāo)準(zhǔn)化施工要求高，造成仰進，即10.4m/3d。由于開挖、支護及二襯施工進度不均衡，開挖、3、項目部積極與業(yè)主進行了協(xié)調(diào)，第五期計量款已支付到位；4、根據(jù)目前實際情況，對現(xiàn)場二襯施工組織進行調(diào)整，以確保襯砌類型SA3SA4SA3SA4里程段落ZK7+787～ZK7+819ZK7+819～ZK7+859ZK7+859～ZK7+989ZK7+989～ZK8+213長度（m)40224圍巖類別ⅢⅣⅢⅣ里程段落ZK7+782～ZK7+824ZK7+824～ZK7+854ZK7+854～ZK7+994ZK7+994～ZK8+218長度（m)42216位，二襯跳開ZK7+937.6～ZK8+105.5段15環(huán)（其中ZK7+989~此，二襯安全距離縮短至150m，滿足標(biāo)化要求，掌子面開挖、支護素砼，二襯施工進度按照每兩天一環(huán)推進，即（10.4m)/2d；開挖施工進度按照3m/d推進。具體推進進度如下：序號掌子面里程掌子面圍巖級別二襯推進里程襯砌類型二襯安全步距（m)說明12014-12-1ZK7+798.0ⅢZK8+105.5SA4307.522014-12-3ZK7+798.0ⅢZK7+948.0SA332014-12-5ZK7+798.0ⅢZK7+937.6SA3139.6掌子面復(fù)工42014-12-7ZK7+792.0ⅢZK7+927.2SA3135.2襯砌2天/環(huán)52014-12-9ZK7+786.0ⅢZK7+916.8SA3130.8襯砌2天/環(huán)62014-12-11ZK7+780.0ⅣZK7+906.4SA3126.4襯砌2天/環(huán)72014-12-13ZK7+774.0ⅣZK7+896.0SA3襯砌2天/環(huán)82014-12-15ZK7+768.0ⅣZK7+885.6SA3117.6襯砌2天/環(huán)92014-12-17ZK7+762.0ⅣZK7+875.2SA3113.2襯砌2天/環(huán)2014-12-19ZK7+756.0ⅣZK7+864.8SA3108.8襯砌2天/環(huán)2014-12-22ZK7+747.0ⅢZK7+854.4SA4107.4襯砌3天/環(huán)2014-12-25ZK7+738.0ⅢZK7+844.0SA4襯砌3天/環(huán)2014-12-28ZK7+729.0ⅢZK7+833.6SA4104.6臺車回退里程ZK7+833.6，安全步距104.6m。此時掌子面為Ⅲ級圍巖，且襯砌類型SA3SA4SA3SA4SA4JQ里程段落K7+819~K7+851K7+851~K7+891K7+891~K8+015K8+015~K8+065K8+065~K8+110長度（m)4045圍巖類別ⅢⅣⅢⅣ里程段落K7+814～K7+856K7+856～K7+886K7+886～K8+020K8+020～K8+236長度（m)42216處就位，二襯跳開K7+948.4～K8+073.2段12環(huán)（其中K8+065~K8+073.2段襯砌類型為SA4JQ：8.2m；K8+015～K8+065段襯砌類型沉值13.17mm,下沉率93.1＞80%；位移速率為0.03mm/天＜0.15mm/二襯安全距離縮短至146.2m，滿足標(biāo)化要求，掌子面開挖、支護復(fù)二襯施工進度按照每兩天一環(huán)推進，即（10.4m)/2d；開挖施工進度按照3m/d推進。具體推進進度如下：序號掌子面里程掌子面圍巖級別二襯里程襯砌類型二襯安全步距（m)說明12014-11-28K7+802.2ⅣK8+073.2SA4JQ27122014-12-3K7+802.2ⅣK7+948.4SA3146.232014-12-5K7+796.2ⅣK7+938.0SA3141.8襯砌2天/環(huán)42014-12-7K7+790.2ⅣK7+927.6SA3137.4襯砌2天/環(huán)52014-12-9K7+784.2ⅣK7+917.2SA3襯砌2天/環(huán)62014-12-11K7+778.2ⅢK7+906.8SA3128.6襯砌2天/環(huán)72014-12-13K7+772.2ⅢK7+896.4SA3124.2襯砌2天/環(huán)82014-12-15K7+766.2ⅢK7+886.0SA3119.8襯砌2天/環(huán)92014-12-18K7+760.2ⅢK7+875.6SA4115.4襯砌3天/環(huán)2014-12-21K7+754.2ⅢK7+865.2SA4襯砌3天/環(huán)2014-12-24K7+748.2ⅢK7+854.8SA4106.6襯砌3天/環(huán)2014-12-27K7+742.2ⅢK7+844.4SA4102.2襯砌3天/環(huán)2014-12-29K7+736.2ⅢK7+834.0SA397.8臺車回退里程K7+834，安全步距97.8m。此時掌子面為Ⅲ級圍巖，且K7至此，將臺車退回至K8+062.8～K8+073.2處就位，開始施工K7+948.4～K8