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1、超小净距并行隧道施工工法（TGJGP-0304-38）中铁一局集团有限公司一、前言中铁一局三公司承建的宁波招宝山公路隧道为超小净距（3.44.2m）并行隧道，采用两相邻隧道同工序相隔一定距离平行施工；中岩墙采用水平全长注浆锚杆预加固；上半断面采用光爆技术控制对地面建筑的震动，下半断面采用控制爆破技术尽量不破坏中夹岩墙围岩；开挖后立即进行喷锚，格栅支护、二次衬砌，二次衬砌采用先仰拱后墙拱二次模筑混凝土技术，取得了成功。本工法是在19951998年宁波招宝山隧道施工过程中形成的。二、工法特点1采用新奥法和控制爆破技术，以合理的开挖顺序及开挖方法、初期支护紧跟、对中夹岩墙加固处理，确保了隧道围岩和施
2、工结构稳定，施工安全可靠。2采用监控量测信息技术指导施工，使施工处于受控状态。3采用中央岩墙法施工，具有一定的社会经济效益。4可有效地控制地面沉降，对周围环境影响小。三、适用范围适用于级以上围岩、两并行隧道之间距离不小于3.4m（单线铁路隧道为0.6B，双线铁路隧道为0.4B，三车道公路隧道为0.3B）的超小净距隧道。四、工艺原理及关键技术超小净距隧道施工以新奥法的基本原理为依据，以“短开挖、快封闭、强支护、勤量测”为指导。两隧道根据地质情况分先后施工，先施工围岩较好的一侧，掘进一定距离后再施工另一侧隧道。两者按同工序保持一定距离平行施工，将开挖面合理划分单元，自上而下实施有序分部开挖，喷、锚
3、、网、钢格栅联合初期支护，随挖随护，紧跟工作面。先开挖的一侧隧道边墙开挖后即对两隧道中夹岩墙用水平全长注浆锚杆作预加固。初期支护、中夹岩墙与围岩共同组成承荷体系，协同变形一承荷，充分发挥围岩自身承载能力。建立监控量测体系，实施信息化管理，保证施工过程处于受控状态；根据时间一空间效应原则及量测信息实施混凝土衬砌。关键技术：横向分部、纵向分序开挖技术，控制爆破技术，中夹岩墙稳定及信息化施工技术。五、工艺流程（见图1）六、施工要点（一）施工准备1敷设风、水、电管线，修建施工便道，布置施丁现场，做好机具没备、人员配置、材料准备。2根据地质勘探资料和施工设计，详细分析了解工程地质和水文地质情况，认真编制
4、施工组织设计，制定施工监测计划。（二）并行隧道开挖施工顺序（见图2）先分部开挖围岩较好一侧的先行隧道，滞后一定距离分部开挖另一侧隧道，以保证中夹岩墙稳定，开挖分三部分进行，即上半断面开挖一定距离后，中槽跟进，两侧墙滞后开挖。先行隧道开挖、初期支护及仰拱每个工序均要先于后行隧道一定距离，先行隧道上半图1 超小净距并行隧道施工工艺流程断面开挖后立即进行初期支护，后行隧道上半断面滞后先行隧道约50m距离平行推进。在先行隧道下半部完成之前开挖后行隧道上半断面，有可能引起隧道拱脚部位岩体较大破坏，对开挖两个隧道相邻侧边墙不利，因此，需采用穿通中岩墙的预应力砂浆锚杆加固隧道相邻侧墙拱脚以上岩体，确保围岩稳
5、定；同时强调，必须在先行隧道边墙开挖、预加固两隧道间岩墙、完成仰拱之后一段时问、隧道变形基本停止后，才能开挖后行隧道的边墙部分。后行隧道初期支护及仰拱完成后，进行先行和后行隧道内层模筑混凝土衬砌施工。图2 超小净距并行隧道分部开挖（单位：m）（三）控制爆破在上半断面开挖中主要解决爆破振动刘周围环境的影响；在下半断面的开挖中主要考虑确保中岩墙围岩的稳定和完整，以及控制后行隧道对先行隧道边墙初期支护的影响。控制爆破振动主要采用控制装药量和分段微差爆破技术来实现。1超小净距隧道控制爆破开挖技术要点（1）为保证中岩墙的稳定与安全，采用中槽先进，两侧预留光爆层的作业方法。（2）中槽靠中岩墙一侧采用防振带
6、（预裂带）降低爆破对中岩墙和先行隧道边墙初期支护的振动影响。（3）顶留光爆层主爆孔的爆破应尽量为光爆孔创造临空面，这样有利于保证光爆效果和控制围岩的爆松厚度。（4）平行隧道十一隧道开挖爆破时在另一隧道边墙初期支护上引起的振动速度控制在1.5cms以下。（5）采用微差爆破技术时，考虑到爆破震动波形叠加作用的影响，时差可采用100ms。2上半断面开挖控制爆破采用微振动爆破进行施工，控制掏槽眼一次起爆药量来降低振动强度，应用光爆技术提高爆破开挖质量，使上半断面的周边轮廓基本规整，减小中槽爆破对上半断面的靠近及对中岩墙底脚部位围岩的扰动。施工中应加强爆破振动监测，依据监测结果及时调整爆破参数。一般单位
7、耗药量校q=0.60.9kg/m控制。3下半断面开挖控制爆破（1）先行隧道下半断面控制爆破首先必须严格控制其对中岩墙的破坏范围和影响深度；其次要考虑其对后行隧道上半断面围岩及初期支护的影响程度，确保后行隧道上半断面的安全；再次通过先行隧道的开挖，在进入中岩墙侧开挖以前，找出能确保中岩墙稳定及安全的爆破方法和爆破参数。一般单位耗药量按q=0.40.5kg/m控制。爆破开挖时中槽先进，两侧预留光爆层，为确保中岩墙安全，抵消中槽开后岩石应力释放对中岩墙稳定的不利影响，靠近中岩墙侧预留光爆层的厚度应大于外侧的厚度。丌挖必须在外侧光爆层取得较好的爆破效果后开始。中槽开挖按常规爆破设计，设计中宜采用偏上的
8、掏槽方法，兼顾掏槽和创造临空面的作用。（2）后行隧道下半断面控制爆破后行隧道下半断面岩石爆破必须保证隧道中岩墙受到的影响控制在尽量小的范围内，其单侧围岩的最大破坏范围不得大于1m；先行隧道边墙尤其是内边墙的岩石和初期支护不能因爆破而受到损伤。（3）控制爆破原则采用光面爆破技术控制超挖，保证边墙平整及对围岩的影响深度；采用微差爆破技术控制振动的量值大小，以控制爆破对先行隧道边墙的影响；采用预裂爆破技术降低爆破振动对围岩的影响。（4）爆破开挖方法采用中槽先进、两侧预留光爆层的爆破方法。在中岩墙侧布设防振带，即布一列孔先爆形成一破碎带在中岩墙和中槽主爆破区之间起降振作用，该列孔应用较小的药量最先起爆
9、。中岩墙侧预留光爆层的厚度取4m左右，一方面有足够的厚度保证中岩墙围岩在中槽爆破后不至于因围岩暴露时间过长、岩体卸荷及应力释放使中岩墙岩体受损，另一方面又能创造较好的临空面减少爆破振动影响并保证光面爆破的效果。施工中，外侧预留光爆层与中槽爆破之间的距离，一般不超过2m，同时采用挖后速扩等措施来控制岩体变形，中岩墙侧围岩爆破后暴露时间控制在24h以内。4光面爆破施工（1）钻孔 隧道边墙光爆孔应有一定外插角，该外插角控制在5以内，光爆后稍加清理后再钻凿下循环的光爆孔，再进行初期支护。（2）装药 光面爆破采用弱装药，用小药卷和增大径向不耦合系数的方法改善光爆效果，药卷捆绑在导爆索上，用竹片固定使光爆
10、药卷正确定位于光爆孔内，同时将竹片靠近要保护的围岩一侧以改善光爆效果，由于预留光爆层一般有斜度，故底部不必加药。（3）软弱地层爆破参数的调整措施 适当增加主爆孔的装药量或减小主爆孔的最小抵抗线值，保证光爆层前的岩层有较大的抛出；光爆孔使用高段别微差雷管，拉大主爆孔与光爆孔的起爆时差；降低光爆孔的线装药密度，直至光爆孔内仅用双股导爆索。（四）出渣运输采用挖掘机装渣，自卸汽车运输。（五）初期支护初期支护采用喷锚构筑法，由拱架+全长注浆系统锚杆+钢筋网+喷射混凝土构成的初期支护为主要受力结构。为保证中岩墙的稳定及安全，在中岩墙处设单向全长砂浆粘结加固锚杆，锚杆用22钢筋，呈梅花形布置。1初期支护施工
11、程序为：测量定位钻孔锚杆支护喷混凝土安设拱架挂设钢筋网喷混凝土。2通过对地质及支护状态、隧道周边位移、拱顶下沉、地表沉陷、拱架应力、锚杆拉拔力等的监控量测，判断支护是否稳定与可靠，必要时调整支护参数。3开挖断面达到要求尺寸及时出渣后，立即喷射混凝土45cm，打设锚杆，按设计要求安装拱架、挂钢筋网、分层喷射混凝土直到设计厚度。喷射时先喷拱架与岩面之间的间隙，再喷拱架周围，最后喷拱架之间，使拱架与开挖轮廓之间所有间隙充填密实。4系统锚杆拱部用锚固剂锚固，两侧边墙及中夹岩墙锚杆采用注浆机先注浆后打入杆体再焊接孔口端部垫板、封闭孔口的方法施工。图3 预应力锚杆安装（单位：m）（六）中岩墙预应力锚杆施工
12、为保证中夹岩墙的稳定及安全，在中夹岩墙起拱线以上设后张预应力锚杆，锚杆用22钢筋按设计预应力锚固。具体做法是：在后行隧道上半断面按设计位置钻孔打穿岩体，凿除杆体两端混凝土弧线部分，使垫板与混凝土面密贴，张拉端设在后行隧道内，锚固端设在先行隧道内，由后行隧道上半断面送入杆体，将锚固端的垫板与杆体焊接，并用喷射混凝土封闭孔口，用注浆机沿杆体向孔内注浆，注浆后用锚杆拉拔器立即张拉至设计预加拉力，用扭矩扳手锁定双螺母，用喷射混凝土封闭孔口。预应力锚杆安装如图3所示。（七）防水层及模筑混凝土施工1防水层设在喷射混凝土层与模筑衬砌混凝土之间，材料一般由土工无纺布及PE防水板组成，由于模筑混凝土是先墙后拱法
13、施工，防水层的铺设顺序由墙到拱环向铺设，搭接缝设在起拱线以上1.5m处。施做防水层时先在初期支护表面抹砂浆找平，再铺设一层土工布和PE防水板。防水板布设在围岩与衬砌之间，防止地下水从拱墙渗漏出；在防水层与围岩之间加一层土工布，起缓冲保护作用，防止由于围岩的凸凹不平，锚杆、钢筋等带有尖角的利器凿穿防水板而影响防水效果，同时土工布有良好的透水性，还可对地下水起疏导作用。2防水层铺设完成以后，绑扎钢筋，立模浇灌二次衬砌混凝土。二次衬砌施工应尽量采用整体式模板台车施工，以提高工效和质量。七、监控量测超小净距并行隧道施工时，为验证设计的正确性和施工方法的合理性，在施工中需进行岩体位移、围岩压力和层间接触
14、应力、喷射混凝土应变等量测，了解隧道开挖及支护过程中岩体松动情况、围岩压力变化规律利支护结构的稳定性等。主要施工监测项目见表1。表1 监控量测项目序号量测项目量测仪器和工具测点布置量测频率1围岩及支护状态地质描述及拱架支护状态观察每一开挖环开挖后立即进行2地表沉降水准仪和水平尺每1020m一个断面，每断面711个测点H2B时12次dH5B时1次周3拱顶下沉水准仪、钢尺等每510m一个断面，每断面13个测点4周边净空收敛位移收敛仪每510m一个断面，每断面35个点5声波测试岩石声波检测仪选择有代表性的断面在拱脚位置布测点爆破后进行6掌子面前方地质预报陆地声纳在上半断面进行测试每一循环均需进行7岩
15、体垂直位移岩石地面挠度仪每1015m一个断面，每断面布置35个测点H2B时12次dH5B时1次周8岩体水平位移单点位移计选择有代表性断面，每个断面3组，每组4个测点9压力钢弦式压力传感器选择有代表性断面布置测点10混凝土应变钢弦式混凝土应变计选择有代表性断面布置测点注：l.H为井挖面距量测断的距离；B为隧道开挖宽度；2.地质描述包括工程地质和水文地质。量测的目的在于：判断地面变形及隧道内变形对周围环境、隧道施工安全的影响程度；判断中岩墙的受力变形是否影响中岩墙的稳定。以此优化设计，指导施工，确保施工安全可靠顺利。八、机具设备施工机具应根据地质、隧道断面及长度配备。单口作业所需参考设备见表2。表
16、2 单口作业所需机具设备序号作业机具设备名称规格型号单位数量备注1施工通风照明轴流式通风机低压变压器90-124V，20kw台台22通风掌子面照明2开挖空压机两臂台车风镐手持风钻挖掘机装载机自卸车潜水泵泥浆泵20mmin,120kWCLJYl2.2G107655EX300ZL50CA141扬程50m100m/h台台台台台台台台台2210411442高压供风钻孔开挖钻孔开挖出渣出渣抽水排污水3初期支护钢筋切断机钢筋折弯机电焊机台式钻床混凝土喷射机搅拌机注浆机CQ40-FGW40-1BX-30024025TK-961JZC350DB6-101台台台台台台台11311134二次衬砌搅拌站混凝土搅拌输
17、送车混凝土输送泵插入式震动器模板台车25m/h，LS500JGC5270GJBHB60DZN35，ZN50自制台台台台台1211025量测及测量仪器全站仪经纬仪水准仪塔尺收敛计岩石声波检测仪陆地声纳岩体地面挠度仪单点位移针钢弦式压力传感器钢弦式混凝土应变计地质罗盘地质锤锚杆拉拔器拓普康301J2C40CY-85BL-150B台台台根个台台台台台台个个个11122111244111方向控制监控量测九、劳动组织单口作业劳动组织见表3。表3 单口劳动组织序号工作项目作业内容人数1开挖风镐手两臂台车司机风钻手装药起爆出渣4288122初期支护锚杆、格栅制作洞内焊接安装锚杆混凝土喷射混凝土拌合64441
18、13量测技术员测量工344二次衬砌立模灌注混凝土运输混凝土搅拌站88265其他分队长技术负责人专职安全员质检员试验员电工修理工机械、车辆司机辅助人员111122283十、质量控制制定工程创优规划，设专职质量检查人员，配合监理工程师对原材料、各工序质量进行全面检查。认真贯彻ISO9002质量标准，特殊工种实行持证上岗，实行全过程质量控制。（一）按规范施工，可详细参阅公路、铁路隧道施工技术规范及验收标准。（二）严格控制进料及加工1、对混凝土骨料级配、含泥量及外加剂质量严格把关，坚持进一次料，抽查一次，不合格的坚决清退。拌制时严格按配合比计量，缩短运输存放时间，随拌随用（一般掺速凝剂的混凝土待浇时间
19、不超过30min。2钢构件下料按1:1大样为准，加工时尽量减少热变形，加工完用模具检验校正，焊点强度应严格把关。3泵送混凝土应严格控制坍落度损失，严禁擅自加水，外加剂应严格汁量。（三）加强施厂管理1努力减少超欠挖，喷射混凝土应严格按有关规范控制。2以新奥法原理指导施上，定位与方向控制要有专人负责。3加强监控量测管理，及时反馈信息，提高应变能力。4格按爆破没计打眼、装药、起爆，提高爆破质量。5加强工序衔接管理。十一、施工安全与环境保护1爆破、量测人贝和专职安全员必须经过专业培圳并取得证书，方准上岗作业。2必须加强全员安全意识教育，交叉施丁地段应设调度员加强调度。3洞室升挖后缩短掌子面暴露时间，及
20、时施作初期支护。4随时对量测数据进行分析，根据信息反馈指导施工。5危险火工品严格按爆破安全规程及当地公安部门要求执行。6严格控制钻爆施工工艺，提高施工管理水平，加强现场技术力量，进行技术培训，确保爆破技术方案得以厂确实施。提高爆破质量和水平，确保围岩、中岩墙及周围环境的安全。7抓强对车辆及人员管理，遵守交通管理规范，坚持文明施丁。8加强洞内外电力、通风、给排水管线的管理，防止漏电、漏风伤人。9加强机械保养维修，降低机械的废气排放，不符合排放标准的车辆不允许上路，噪声大的机械改装消声器，十二、效益分析1对铁路的改造和复线建设，本工法的广推应用对线路选线、没计及施工具有一定的指导和借鉴作用，有一定
21、的社会效益。2刘于高等级公路和高速公路，采用本工法能解决为保持上、下行两隧道大净距而增加的困难，能少占地、改善公路线路情况。3本工法可减少绕线增加的铁路、公路长度的费用，其社会效益和经济效益相当可观。4与采用梁柱法或钢筋混凝土中隔墙法将两隧道并成一个大跨度隧道相比，本工法可节省费用1/3l/2。十三、工程实例山中铁一局集团第三工程公司承建的招宝山双线平行隧道由两座独立并行的单体隧道组成，是宁波大桥的组成部分之一。招宝山隧道起止里程为DK0+860.6DKl+029.6，全长2169m，洞身内轮廓为直墙，割圆拱、割圆仰拱，开挖宽度为13.9514.45m，高度为12.2512.35m，隧道沿线路
22、纵向设3%的纵坡，两相邻隧道净距3.44.2m，属超小净距并行隧道，隧道最大埋深34m，进出口端埋深仅为05m。隧道通过的山体为火山岩，隧道周围为旅游胜地招宝山公园。施工中确保地面建筑的稳定和安全很关键，确保中岩墙的稳定和安全的技术难度大，在施工中主要采取了以下技术措施：1进行多种工况和围岩的数值模拟，了解隧道围岩应力、破坏状况，据此确定施工方法和加固、稳定围岩措施。安排合理的施工顺序，采用两相邻隧道同工序相隔一定距离平行施工的方法。以利于围岩加固和保护围岩。2对两隧道间中岩墙采取加固措施，保证隧道围岩的稳定。3采用控制爆破技术，控制震动对地面建筑的影响，控制刘中岩墙围岩的破坏。4采用长台阶法
23、开挖，开挖后立即喷锚和支护，用先仰拱后墙拱法模注混凝土进行二次衬砌。5量测监控及施工地质工作检测，及时提供信息，指导施工。该隧道于1995年12月正式开工，1998年初完成主体工程，施工过程中对周围环境影响较小，施工质量和安全取得良好的效果。执笔：杨永强 赵有歧 李长山 拓守盛（英文版 ） easily blame, to prevent the broken window effect. Supervise the leading cadres to play an exemplary role, take the lead in the strict implementation of t
24、he and , lead to safeguard the solemnity and authority of the party discipline, ensure that the party discipline and the laws and regulations for implementation in place. Throughout the discipline in the daily supervision and management, strengthen supervision and inspection, from the thorough inves
25、tigation of violations of discipline behavior. Strengthen to key areas, key departments and key projects as well as the masses reflect the concentration of the units and departments for supervision. - strengthening supervision, discipline inspection and supervision of cadres to set an example for co
26、mpliance with the and is a man must be hexyl, blacksmith needs its own hardware. Discipline inspection organs as the executor of the party discipline, and supervisor of the defenders, for its supervision must be more strictly, discipline inspection and supervision of cadres to firmly establish the a
27、wareness of Party Constitution, sense of discipline and rules consciousness, politics loyalty, sense obey. Action speak Ji Ordinance to set an example of the regulations of the rule of law, strengthen supervision and accept the supervision of the firmness and consciousness, do comply with and . To f
28、irmly establish the discipline must first be disciplined, the supervisor will be subject to the supervision of concept, and consciously safeguard and implement party compasses party, take the lead in practicing three strict real strict, so loyal, clean, play. To be good at learning, the Constitution
29、 and the as morality, politics and brought to fruition; to implement , do not want to, dare not, not with disciplinary ruler to supervision; to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom li
30、ne, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes
31、turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be complex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Become more perfect. Life
32、is the most important thing is not to win, but the struggle; not to have conquered, but to have fought well. 2, the plain is the background of life. Live a plain life, give up on themselves is not a coward, but the wise answers; not disillusioned after the heart, such as ashes, but experience the st
33、orm after the enlightenment; not unrewarding perfunctorily, but calm attitude of life of unrestrained self-confidence. Plain living, there is no noise noisy, no earthly troubles, more did not fill in the discontent of desire, some just a calm, a calm. 3, memory of heart will not good things to erase
34、 the, life is a When no movie, pain is a beginning, the struggle is a kind of process, death is a kind of ending. Give up this giving up is the helpless, do not give up the abandoned, do not give up this giving up is ignorance, do not give up should not give up is persistent. 4, a thing figured is h
35、eaven, think impassability is hell. Since the living, to live better. Sometimes we because of too narrow-minded, too care around the chores and penny wise and pound foolish, not worth the candle. Some things to attract trouble and worry, completely depends on how we look at and deal with it. Dont al
36、ways take everything back to things, and dont get into a blind alley, dont want to face, dont be narrow-minded. Poke to care, is a kind of open-minded, a free and easy. 5, I am not afraid of others behind me a knife, I afraid to look back and see stab me, is my intention to treat people; I am not af
37、raid of the truth to tell the best friend, Im afraid he turned to it as a joke to tell dont 6, when we are in a positive frame of mind, you will find many good things; and when we are in a negative state of mind, you will find many depressed things; life happy and worry, all is you of life attitude,
38、 optimistic, good luck; loss of sink, Eritrea company. When you are in adversity, may wish to change a point of view to think everything over to the good Think, because good mentality decided the fate of the! 7, people are tired, rest; heart tired, calm. Grow up, mature, this society read. Tired and
39、 sad, squat down, to their a hug. Because the world no one can sympathize with you, have mercy on you. You cry, tears is your own; you pain, no one can understand. Then you only tears to smile. 8, each people have youth,Each youth are a story, the life of the world never gets easier, I want what, wi
40、sh the world all know, as has been the same; now want anything, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open ones mouth, because words will reduce its importance; to
41、 let strangers people care about your life in the good things, the original is not easy 10, do not blame, do not laugh at who, also dont envy who. Like a person is a kind of feeling, not like a person is true. The truth is easy to explain, I feel Is unspeakable. The best travel life is that you in a
42、 strange place found a long lost touched. 11, happy life not in the bustling in, and in the peace of mind; no matter how many grievances, how uncomfortable, and ultimately to heal themselves or their own, others may got you to comfort, but never know your heart is how wanjianchuanxin. 12, maam, like
43、 a movie, learn to appreciate, learn to be grateful, learn tolerance, and goodness, helping others. Instead of accusing the society, as into one; and an exception is better to give than to what 13, dont envy him A sum of, dont lose your life and the life, respectively is: the former is a we experien
44、ced cannot escape in a day finally will last minute, while the latter is our persistent, we want to cherish the memory of those people and things. 14, learn to smile, learn to strong, the world you know so many people, so many people and you are, you cannot change also cant let everyone like you, so
45、 also do not want to do. Life is too short to go crazy to love to go to waste, to chase the dream to regret. 15, when temper, a blessing to go. A wounding elegant people, the key is to control their own emotions. With the mouth is the most stupid behavior. A control negative emotions than a can take
46、 a city more powerful water flow slow, language is expensive. People spent two years of time to learn to speak, but to spend a few years time to shut up. That is a kind of ability, that is a kind of wisdom. 16, life is not perfect, sometimes, growth is not a cry, not an eyeful of tears, there is no trace of emotion, there is no gleam of hope, no desire, no action, no static, there is only one kind of downward sinking feeling, sink A murky? 6