隧道安全步距超标的处理措施

隧道安全步距超标的处理措施xx隧道是xx公路xx第x标段内的一座左、右分离式隧道，设岩，属硬质岩，抗风化能力较强，围岩为Ⅳ~Ⅴ级；洞身段埋深一般硬质岩，抗风化能力较强，围岩为Ⅳ~Ⅴ级。类别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长度（m)65220904222442类别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长度（m)2209242216衬里程K8+141.6，距离260.2m；左线掌子面里程ZK7+878，二衬里xx隧道左、右线二衬安全步距已超过文件规定，监理办为此下根据目前作业队人员和机械配备情况，结合十月、十一月份xx拱和二衬作业人员不足。由于xx地区对标准化施工要求高，造成仰进，即10.4m/3d。由于开挖、支护及二衬施工进度不均衡，开挖、3、项目部积极与业主进行了协调，第五期计量款已支付到位；4、根据目前实际情况，对现场二衬施工组织进行调整，以确保衬砌类型SA3SA4SA3SA4里程段落ZK7+787～ZK7+819ZK7+819～ZK7+859ZK7+859～ZK7+989ZK7+989～ZK8+213长度（m)40224围岩类别ⅢⅣⅢⅣ里程段落ZK7+782～ZK7+824ZK7+824～ZK7+854ZK7+854～ZK7+994ZK7+994～ZK8+218长度（m)42216位，二衬跳开ZK7+937.6～ZK8+105.5段15环（其中ZK7+989~此，二衬安全距离缩短至150m，满足标化要求，掌子面开挖、支护素砼，二衬施工进度按照每两天一环推进，即（10.4m)/2d；开挖施工进度按照3m/d推进。具体推进进度如下：序号掌子面里程掌子面围岩级别二衬推进里程衬砌类型二衬安全步距（m)说明12014-12-1ZK7+798.0ⅢZK8+105.5SA4307.522014-12-3ZK7+798.0ⅢZK7+948.0SA332014-12-5ZK7+798.0ⅢZK7+937.6SA3139.6掌子面复工42014-12-7ZK7+792.0ⅢZK7+927.2SA3135.2衬砌2天/环52014-12-9ZK7+786.0ⅢZK7+916.8SA3130.8衬砌2天/环62014-12-11ZK7+780.0ⅣZK7+906.4SA3126.4衬砌2天/环72014-12-13ZK7+774.0ⅣZK7+896.0SA3衬砌2天/环82014-12-15ZK7+768.0ⅣZK7+885.6SA3117.6衬砌2天/环92014-12-17ZK7+762.0ⅣZK7+875.2SA3113.2衬砌2天/环2014-12-19ZK7+756.0ⅣZK7+864.8SA3108.8衬砌2天/环2014-12-22ZK7+747.0ⅢZK7+854.4SA4107.4衬砌3天/环2014-12-25ZK7+738.0ⅢZK7+844.0SA4衬砌3天/环2014-12-28ZK7+729.0ⅢZK7+833.6SA4104.6台车回退里程ZK7+833.6，安全步距104.6m。此时掌子面为Ⅲ级围岩，且衬砌类型SA3SA4SA3SA4SA4JQ里程段落K7+819~K7+851K7+851~K7+891K7+891~K8+015K8+015~K8+065K8+065~K8+110长度（m)4045围岩类别ⅢⅣⅢⅣ里程段落K7+814～K7+856K7+856～K7+886K7+886～K8+020K8+020～K8+236长度（m)42216处就位，二衬跳开K7+948.4～K8+073.2段12环（其中K8+065~K8+073.2段衬砌类型为SA4JQ：8.2m；K8+015～K8+065段衬砌类型沉值13.17mm,下沉率93.1＞80%；位移速率为0.03mm/天＜0.15mm/二衬安全距离缩短至146.2m，满足标化要求，掌子面开挖、支护复二衬施工进度按照每两天一环推进，即（10.4m)/2d；开挖施工进度按照3m/d推进。具体推进进度如下：序号掌子面里程掌子面围岩级别二衬里程衬砌类型二衬安全步距（m)说明12014-11-28K7+802.2ⅣK8+073.2SA4JQ27122014-12-3K7+802.2ⅣK7+948.4SA3146.232014-12-5K7+796.2ⅣK7+938.0SA3141.8衬砌2天/环42014-12-7K7+790.2ⅣK7+927.6SA3137.4衬砌2天/环52014-12-9K7+784.2ⅣK7+917.2SA3衬砌2天/环62014-12-11K7+778.2ⅢK7+906.8SA3128.6衬砌2天/环72014-12-13K7+772.2ⅢK7+896.4SA3124.2衬砌2天/环82014-12-15K7+766.2ⅢK7+886.0SA3119.8衬砌2天/环92014-12-18K7+760.2ⅢK7+875.6SA4115.4衬砌3天/环2014-12-21K7+754.2ⅢK7+865.2SA4衬砌3天/环2014-12-24K7+748.2ⅢK7+854.8SA4106.6衬砌3天/环2014-12-27K7+742.2ⅢK7+844.4SA4102.2衬砌3天/环2014-12-29K7+736.2ⅢK7+834.0SA397.8台车回退里程K7+834，安全步距97.8m。此时掌子面为Ⅲ级围岩，且K7至此，将台车退回至K8+062.8～K8+073.2处就位，开始施工K7+948.4～K8