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1、学校代号一一1053豆分类号一-.!1经i学号_0缸尘主主E.l夕1(J yt手硕士学位论文岩溶隧道开挖爆破对围岩及溶洞的影晌研究学位申请人姓名李波培养单位长沙理工大学导师姓名及职称吴从师教授学科专业岩土工程研究方向隧道与地下工程论文提交日期2009年5月学校代号10536 学号。61052158妖l、理工大学硕士学位论文岩溶隧道开挖爆破对围岩及溶洞的影晌研究学位申请人姓各导师姓各及职称培养单位专业各称论立提交日期论立答辩日期答辩委员会主席主-.i且主丛且盈盈盖业里主左空盘丰王盘2盟旦主主且且凶旦主2.ll盟主监盐JlI.A Study on the Influence of Surround
2、ing Rocks and the Karst Cave by Karst Tunnel Excavation Blasting by LI 80 B.E.Changsha University of Science 币1结构以及浴洞Tflf板和l侧坐在附近隧道开挖过程中的位移变化3)爆破il-:i载作用下浴洞固岩中地层波的传捕规律，并结合现场实)!O溶洞壁质点振动峰值，初步探讨附近隧道爆破开挖时浴i网服点安全振动:ili皮标准。通过数值棋拟分析及其与实测结果的对比分析，对溶洞段隧边的爆破jE动分析取得的主要成果如下:( 1) !o，l近主隧道侧的浴洞固岩和支撑地的水平位移要大于其竖向位移，淄
3、涧左侧壁的水平位移i耻大，而竖向位移在隧迫上台阶列挖过程中逐渐增大，下台阶开挖对回岩沉降影响较小。支撑地1页的沉降大约是其附近浴洞1万!板的56.3%.f1且支撑地顶承受的固岩压力较大，该处为应力集中区域。(2)浴洞隧道前段的应力和1位移比“老虎吻“处变化复杂，浴洞区隧道前段拱顶位移和l固岩应力明显要比“老虎啪“处大，而且开挖上台阶比开挖下台阶时位移增加IffJ快，当隧道开挖断而远离所泪ti断而约20m后位移趋于稳定。( 3 )救援迎i革前段开挖时在近其侧的浴洞壁质点振迷超过了爆破安全规程1:1:1交通隧道顶点振;!J速度不大于IO 20cm/ s的规定.调整爆破参数后振速基本控制在lOcm/
4、s以下，大大减小了浴洞固岩的扰动。( 4 )质点爆破血革值振速随单段最大药盐的增加l而增大或N煤源的减小而增大，应根据爆破安全振速确定最大1，1段爆破EFi茧，严格控制在其安全范围之内。即对救援通道掘进时溶洞回岩振迎峰值应不大于自cm/s.主涧爆破时也|岩的峰值振迎应不大于6cm/s.关键词浴洞叼隧边开挖爆破应力应变，质点峰值振遮ABSTRACT With devolopment of the high-grade highwuy in our country,it is inevitable that high tunnels will be constructed in karst are
5、a. Damage in surrounding rock of a tunnel and a karst cave caused by tunnel blasting is the maximal harm in the process of tunnel excavation in karst area,so as 10 make cranny peneqtrated between the sunnel and karst cave, reduce the bearing capacity ofsurrounding rock. destroy the original stress f
6、ield . and cause local stress concentration in wall rock.AII of that have negative effect 00 the stability of waJ1 rocks and tunnel construction ased 00 the process of Baixugong tunnel excavation blasting in the 84 bid section of Qing-Lian expressway in which a especial1y big limestone cave was foun
7、d,main research contents incl ude following several aspects:( 1 )stress redistribution of the surrounding rock and the reacting wall when the tunnel located at the karst cave was excavating.(2)Concrete var盯latsurroundi川n】grock of karst cave and the reactin旦、w飞vallin the process of the excavation oft
8、巾h】etunnel with a small space to an existi吨karstcave.(3)The pro叩pagatbl阳as剖tm且s臼el凶sm11山cwave I川nthe surroundi川n】grock under the blas目tl川ngJoad wa削s an、alyed.Basedon fi阳eldtest data of the peak pa盯rticalvibration velocity on the 、w叫valll rock,preliminarily discussed investigate the safe peak partica
9、l velocity on wall rock of karst cave when the tunnel was excavating with a small space to it By means of the numercalsimulation calculation on the tunnel excavation blasting and compared with test data, the main achievements attained were as follows (1 )The horizontal displacement of the karst cave
10、 surrou山川 nd】dir吨rock and reactin wall closed to the man tunnel was a l川tt川t川lelarger than the ver叫ticald副“叩placementof it.The max 川Ima剖Ihorizontal di罔splacementwas present to the lef白.tlateral wall of the karst cave.But also the vertical displacement increased gradually during the excavation of the
11、 tunnel upper bench and the excavation of the lower bench had little influence on the settlement of surrounding rock.The settlement of suppoting wall was about 56.3 percent of that of that adjacent karst cave roof.The top of supporting wall was bearing big rock pressure.lt was showed that the wall t
12、op was the stress concentratlOn reglOn (2)The stress and displacement of anterior segment of the tunnel adjacent the karst cave were complicated change and larger comparative 11 the excavation of the upper bench compared with the excavation of the lower bench,then it tended to be stable until the ex
13、cavation section was 20 meter far away from the measured section (3)When the escape trunk was blasti吨，theparticle vibration velocity on the rock face of the karst cave closed to it exceeded greatly the standard of the 可写为Kol + L.K; 1 M, = L.凡+ L.F;g + L.凡u = 1,., M) ( 2.1 ) 式中M为施工阶段数Kol为开挖i岩土体等的初始总刚
14、度矩阵，L.K;l为施工过程中岩土体和支护结构同J度的坤i211啊!减茧，用以体现土8 体单元的开挖、填筑及结构1(1元的施作或拆除M，为第1施士段开挖边界上的释放而I载的等效节点力，Ll.F;g为第1施工段新咱自军等的等效节点力守Ll.F;“ 为第1施工段增iii荷载的等效节点力。M，为第1施工段产生的节点位移增iito当土体处于非线性弹性或i;!r塑创受力状态时，女H采用吁，刚度增量i在代法;1算，对每个施工阶段wrt方程可表示为:K;oM, = IF; (i = 1,.,M;k = I,.,N) 式中N为非线怕j圭代步数。对位移、应变和应力的计算，附i且i在代公式为以= 九+叫=ID叫,
15、(=1.1;=1 乓)= e,_, + 问= IDIe, ).=1 k.1 a, = ，_， + Ia, = 。+IDIAK ;.=1 k_1 (i = 1,.,M;k = I,.,N) 式中，圳，分别为位移、应变、应力向量，。 为初始地应为 为任意施工阶段的应力增丑。敌后得到的位移、应变和应力即为数值棋拟分析的结果。2. 4溶洞段隧道爆破(2.2 ) ( 2.3 ) 钻孔爆破开挖施工法在隧道工程中被广泛应用，但运中l施工法布在着爆破引起的被传播和由此引起的振动对固岩产生危害。在岩浴地区采用钻爆法进行隧道施工，浴洞的存在对隧道爆破列挖安全有直接的影响，严重者会造成塌方、伤亡等重大事故13，28
16、1。研究表明，当溶洞与隧道处于不同的空间位直关系时，隧道rf/;敲开挖时应力将重新分布，在隧道拱1i、直恼和墙脚不同位宜会出现破坏危险区域l“，使临近浴洞与隧边之间产生裂隙贯通，降低固岩承载力，而且破坏了原有应力场，使局部图岩产 生应力集中，对施工及隧i茸的稳定产生不利影响。因此岩浴区隧道爆破开挖过程，关键就是控制爆敲开挖对临近溶洞的影响，采用合理的控制爆破技术，严格控制爆破危害。2. 4. 1岩体中的爆破地震效应(1)岩体中的爆破作用9 在工程爆破实践中，遇到的边常是不均匀与不连续性质的岩土介质，因此在岩土介质1:1:1产生的波动现象非常复杂。根据岩石爆破理论，炸药在无限大的岩体中爆炸时，企岩石内部将产生爆炸冲击波作用下的粉碎区、爆炸应力放和爆生气体共同作用下的裂隙区(中区)以及爆炸地iJ4披作用的弹性足iiJ区(
