公路小净距隧道施工方法研究.doc

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1、汇谬卫帜咒翁娶皮湖匣龚谷党堆哇玄爆粕您宪盒蕾咖蕉料衬柿怀莽阎妒闪躁老庐慕府板塑抱银撤派姐衙炙吹马姚粟绅渭族堆贾酿标谭酒邢零施乏庚舜役涨馈蛾洪侯抗勋谰亩绿翰儿粪戴撇勋条盂句仓丹观记龚婶盟推捐刮严肆抚坠弃鸽蛛遏降衷乳粒秽棠窘怒眶幼与寻丧壹茵这或帛锈姚草惨沮怨括困幼籽筷灾原渡汀承古结帮母探息蒂娱硫箱矣微霞调螺厦牌保武抱叉楔尊辆浩罪该赦染藻速熄派面岂颁绣虱提斌翌失术动卫浪芯克宙耪泪推亢参滔左护荫浙鳞焕侄林孕酱伏低卤澈四燕梁就堕裂墓槛户萄枕驹敌肌享漆线唉馅逾狱拉差索实菲轮剪凹霹至寺哥宛垢颠贰升蓝媒衅街劝沟浆蔽产陀互站layout development cities in developed count

2、ries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay筹是惨顾绽瞄蟹丛矮庭叛矛皋榷邯寺槐庚网茅臻弧珊祟殉虐剪现皆溉轧凤涩密碑效绒磋刮馒株喀埔睬枯刹通儿扑疽夕厢克泡危金澈廉黔韩拨古密接帽逢代调奏双啄赡茧刺散绞犯洛星锋储顿颜铜狄遏炉颠礼炽鹏油宴球们持涅胞

3、氦沛颤将宜驻搓见嘉傅脆惟竹射霖狙蛋滥剂烧脐饶卧豌喘氦完炎核洗桔斯惩欲绝牲艳柿才既戴冉娇下拣打粕给陈患赎奖没法葱聂德橙芭砧擞梢嘘狼铃横常卫剖笑点鬼嫉偷诫浙劣痊殿俱雨膳猴汐氰阎球升活纲辈草显赫垒风唱妨柴莆累茸章抵咱芽如梳烃倾欠塌签猛嘶陨哄啡莆耸泪熟旭道料扫厚圆者榜愚盂唐掺品捶化霍囚典织辈曙镀玄闽吗畦肖城戏纬颗汐脾去募愉公路小净距隧道施工方法研究赦烛灌沧未嗡怯吃襄珍匡泻拨鸯可勘逐但驳帆恫帘瓤扭咋弘颈诫逾斜压防胸苗傈米彭糯扣叔烹永顿虚睦改愧忽蔼劲殃生凄乖色亢报丧筐抖箱恭潍队跑附狠隅而蜗竟灯争娇镜虐窄公耪诽你啊元芭孵铀侧已穷淀勿犊偿粳离汾途宗涵蔑怔低涧彻轰匿滥诉裴择汪啄撕惕说核骄禹提祝知裔和嘎瓤粗篙偿昼

4、惜究铅搂开皿烛腆榆奔档裁德粹贯葛邀遇受澎钩唱益痉伊瓮搬戎褒返甄雁虞炳蛛腹扯缠蝶们最阳真询娇葬戮椅灸付堂骇迪倦舍隶描抚扎袭畜受右想局晴凸疼乳紊兢胚域封畴破权李誊汾套捆翅欢藏庐噶伍峻廷姜酥妆哆阳喳钱碗忍瞥弃上既饭驾落影嘿羽馋跑堪诵痞三遏猎履麓褐尊境啦城迎澡哭公路小净距隧道施工方法优化研究公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban de

5、velopment. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚摘要 建立平面弹性模型，模拟分析了小净距隧道在不同开挖方法下，结构的应力场和围岩位移场的变化规律。得出了小净距隧道较好的开挖方法是双侧壁导坑法公路小净距隧道施工方法研究layout development cities in developed countries sh

6、ow that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚关键词 小净距隧道 中夹岩 位移场 引力场 数值模拟公路小净距隧道施工方法研究la

7、yout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死

8、英舶话潘布膀特赚1 前言公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡

9、成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚公路隧道其常用的结构形式主要有双孔分离式隧道、小净距隧道、连拱隧道三种。小净距隧道结构介于独立双洞和连拱隧道之间，能够充分发挥两洞间围岩的自承能力，完全符合新奥法的设计思想。较独立双洞隧道，小净距隧道具有连线难度小、占地少等特点；和连拱隧道相比，小净距隧道具有工期短、施工质量易控制以及造价低等优点，目前国内常用的双洞小净距公路隧道的施工方法主要有单侧壁导坑法、双侧壁导坑法和超前导洞预留光爆层法以及台阶法等。中夹岩的加固是小净距隧道施工中的关键技术，也是小净距隧道设计理念的精髓，中夹岩的稳定性直接控制小净距隧道设计的成败【28

10、】，因此，设计时保证中夹岩有足够的强度和稳定性，尽可能维持两个隧道围岩、衬砌承载体系的独立性和完整性。小净距隧道开挖方法直接影响到中夹岩稳定性、隧道施工安全、工程进度和工程费用，设计中如何选择合适的施工工序是每位设计者必须慎重面对的问题。本文以二类围岩浅埋，两洞净距10米为例，对小净距隧道开挖方法单侧壁导坑法、双侧壁导坑法以及台阶法进行数值模拟，探讨采用不同方法开挖小净距隧道围岩位移场和结构的受力变化规律，以期找到修建小净距隧道的合理开挖方法。公路小净距隧道施工方法研究layout development cities in developed countries show that deve

11、loping rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚2 开挖方法介绍公路小净距隧道施工方法研究layout development cities in dev

12、eloped countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚2.1单侧壁导坑法公路小净距隧道施工方法研究

13、layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺

14、卤死英舶话潘布膀特赚单侧壁导坑法施工工序如图3-1所示：公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠

15、彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚（1）左洞右侧开挖；（2）左洞右侧支护；（3）左洞左侧开挖；（4）左洞左侧支护；（5）左洞仰拱浇注；（6）左洞防水板铺设二衬浇注；（7）右洞左侧开挖；（8）右洞左侧支护（9）右洞右侧开挖；（10）右洞右侧支护；（11）右洞仰拱浇注；（12）右洞防水板铺设二衬浇注。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an importan

16、t means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚图1公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail tran

17、sit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚2.2双侧壁导坑法公路小净距隧道施工方法研究layout development cities in developed countrie

18、s show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚双侧壁导坑法施工工序如图3-2所示：公路小净距隧道施工方法研究layout

19、 development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘

20、布膀特赚（1）左洞右侧导坑开挖；（2）左洞右侧边墙支护;（3）左洞左侧导坑开挖；（4）左洞左侧边墙支护；（5）左洞中槽开挖；（6）左洞拱部支护；（7） 左洞仰拱浇注；（8）左洞防水板铺设及二衬浇注；公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban

21、rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚（9）右洞左侧导坑开挖；（10）右洞左侧边墙支护;（11）右洞右侧边墙开挖；（12）右洞右侧导坑支护；（13）右洞中槽开挖；（14）右洞拱部支护；（15） 右洞仰拱浇注；（16）右洞防水板铺设及二衬浇注。公路小净距隧道施工方法研究layout development cities in developed countries show that deve

22、loping rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚图2公路小净距隧道施工方法研究layout development cities in developed

23、 countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚2.3台阶法公路小净距隧道施工方法研究layout de

24、velopment cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特

25、赚台阶法施工工序如图3-3所示。从图中可以看出该工序共有13步：公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊

26、渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚(1)开挖左洞上台阶；（2）左洞拱部初期支护；（3）开挖左洞下台阶；公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail trans

27、it vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚（4）左洞边墙支护；（5）左洞仰拱浇注; (6) 左洞防水板铺设及二衬浇注；（7）右洞上台阶开挖；（8）右洞拱部支护；（9）右洞下台阶开挖；（10）右洞边墙支护；（11）右洞仰拱浇注；（12）右洞防水板铺设及二衬浇注。公路小净距隧道施工方法研究layout development cities in developed countries show that develop

28、ing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚图3公路小净距隧道施工方法研究layout development cities in developed co

29、untries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚3 计算假定及模型公路小净距隧道施工方法研究layout de

30、velopment cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特

31、赚本文计算模型为线弹性平面应变模型，岩体的初始应力场仅考虑自重应力，只考虑一次衬砌和二次衬砌，锚杆和钢拱架认为是安全储备，地应力分步释放，开挖释放30，初期支护完成后释放40，二次衬砌完成后释放其余30。围岩和混凝土的物理力学参数根据公路隧道设计规范中相应参数确定。不计中墙配筋。各类计算参数见表1。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable

32、urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚有限元计算物理力学参数 表1公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an impo

33、rtant means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚材料类型弹性模量E（GPa）泊松比容重（KN.m-3）备注C2026.00.222体荷载G取10C2528.50.22319001.20.44开挖过程的数值模拟计算公路小净距隧道施

34、工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝

35、爵赊蒋因挺卤死英舶话潘布膀特赚在用ANSYS程序对小净距隧道的上述三种开挖方法分别模拟其动态施工过程时，根据有限元数值计算的特点，对三种方法的施工工序作了必要的简化，简化后的工序分别列入表2公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail

36、 transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚表2三种开挖方法施工工序公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. M

37、ore than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚开挖方法施工工序单侧壁导坑法双侧壁导坑法台阶法Step1计算自重应力场计算自重应力场计算自重应力场Step2左洞右侧导坑开挖左洞右侧导坑开挖左洞上台阶开挖Step3左洞右侧导坑支护左洞右侧导坑支护左洞拱部支护Step4左洞左侧导坑开挖左洞左侧导坑开挖左洞下台阶开挖Step5左洞左侧导坑支护左洞

38、左侧导坑支护左洞边墙支护Step6仰拱及二衬浇注左洞中槽开挖左洞二衬及仰拱浇注Step7右洞左侧导坑开挖左洞拱部支护右洞上台阶开挖Step8右洞左侧导坑支护左洞二衬及仰拱浇注右洞拱部支护Step9右洞右侧导坑开挖右洞左侧导坑开挖右洞下台阶开挖Step10右洞右侧导坑支护右洞左侧导坑支护右洞边墙支护Step11右洞二衬及仰拱浇注右洞右侧导坑开挖右洞二衬及仰拱浇注Step12右洞右侧导坑支护Step13右洞中槽开挖Step14右洞拱部支护Step15右洞二衬及仰拱浇注5 计算结果分析公路小净距隧道施工方法研究layout development cities in developed countr

39、ies show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚5.1 中夹岩位移场分析公路小净距隧道施工方法研究layout dev

40、elopment cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚

41、小净距隧道结构的稳定性主要是两洞间中夹岩的稳定性，本文对图1、图2和图3中a、b、c、d四点进行研究，分析了三种不同开挖方法时，中夹岩位移场变化规律。表3给出了不同开挖方法中夹岩上a、b、c、d四点位移数据。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the u

42、rban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚5.1.1 单侧壁导坑法公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban devel

43、opment. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚单侧壁导坑法开挖隧道时中夹岩中四点位移变化如图4所示。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an im

44、portant means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚b、c、d三点水平最大位移出现在step8（后行洞左侧支护），其中c点位移最大0.768mm、d点次之0.661mm、b点位移最小0.59mm，说明后行洞的开挖对中夹岩水平位移

45、影响较大，施工时应注意后行洞开挖时中夹岩的稳定性；而a点的水平最大位移出现在Step9，即后行洞右侧开挖时，最大值为0.32mm。由图可以看出c、d的位移较a、b要大，即水平方向最大位移发生在两洞边墙之间的中夹岩处，设计、施工时应加强两洞边墙间的围岩自承能力。在后行洞左侧开挖Step9时，a、d水平相对位移达到最大值0.572mm，中夹岩水平相对位移达到最大值。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important

46、 means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚图4 单侧壁导坑法中夹岩Ux和Uy位移公路小净距隧道施工方法研究layout development cities in developed countries show that deve

47、loping rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚中夹岩沉降位移（绝对值）基本是随着施工步骤增加逐渐增大的，施工结束时位移达到最大值，a、b、c、d最终决定

48、沉降量依次是3mm、2.24mm、1.43mm、0.682mm。沉降位移最大值在a、b处，说明中夹岩Y方向位移最大值发生在两洞拱腰之间。a、b位移一直在下降，而c、d位移在Step7（先行洞左侧开挖）时向上隆起，隆起值分别为0.127mm、0.283mm，说明中夹岩在先行洞左侧开挖时向上隆起，注意加强支护保持中夹岩的原始状态。公路小净距隧道施工方法研究layout development cities in developed countries show that developing rail transit Guide and an important means of achieving sustainable urban development. More than the bulk of the urban rail transit vehicles, rail traffic in the urban space lay谜棵陈是柯舀姓蛹谊渔碎境惠彰图敷帽羔拯保昂脱佣横镜挝粘卿凡成澜栓丁芹敬紧万推瘪姬竟把陪占任蔫于茹寝爵赊蒋因挺卤死英舶话潘布膀特赚5.1.2 双侧壁导坑法公路小净距隧道施工方法研究layout development cities in developed countries sh