地质环境与隧道工程的安全(卢耀如).ppt

THE EXPLORATION OF,UNDERGROUND SPACE ANDPREVENTION OF GEOLOGICAL,HAZARDS,LU YAORU，LIU QI,Chinese Academy of Geological Sciences,Tongji University,地质环境与隧道工程的安全,卢耀如 院士，刘琦,中国地质科学院,同济大学地下建筑与工程系,地质环境与地下工程的关系,隧道、地铁等地下空间的开拓与地质环境之间存在着密切的联系,地质环境的特性制约了地下工程的经济与安全,地下空间的开拓应以地质环境作为规划、设计与施工的重要基础,主要内容,对影响隧道工程建设的几种地,质环境进行探讨,分析不同地质环境中进行隧道工程建设可能诱发的工程地质问题,针对隧道等地下空间的开拓提,出了八点建议,一、中国隧道（隧洞）,工程的,历史与现状,History and,Present Situationof tunnel in China,Before 3600 years,the tunnel,system for mining mineralresources had already,reached higher level,whichsome structural wood systemare still remained in Daye,Hubei province,China.,Ancient tunnel system for mining,copper are still exited in Daye,Hubei,中国具有五千多年的文明历史，对,隧道等地下空间的开拓已有长久的,历史,在湖北的大冶地区，目前仍保留有,三千一百多年前西周时期的开矿巷,道，深度达到地下二十至六十多,米，有四百多座竖井、斜井和上千,条平巷，纵横交错，层层叠压，显,示了开凿隧道的高超技术,井巷结构示意图,湖北大冶铜绿山古代矿井和炉渣分布图,（湖北黄石市博物馆潘红耘、周百灵、周保权 供稿）（卢耀如，1986）,中国古代地下隧道的开挖还用于帝王陵墓的,建造，通过修建隧道在战争中用于攻城等。,目前，地下空间的开拓已遍及各个方面。在,水利水电建设方面，大型引水隧洞长的达,41km，大型发电隧洞长度达17km以上，埋,深达2500多m。铁道建设方面，隧道至少长,度在10km以上，已建成的有20多km，拟建,设的还有35km以上的。,中国许多城市正在大力发展地铁建设，城市,地下空间的开拓显示了其多功能性,In ancient China,the,developments of sub-surfacewere mainly for the purposesrelated to mining mineralresources,emperor tombs,war,water conservancy etc.,In present,the multi-,purposes of sub-surface,developments are related towater conservancy andhydropower,railway,expressway,storing,materials,recreation areas,etc,Urban ground,Expresswaynetwork inthe suburband exurb,Surface orundergroundParking inthe exurb,Exploration ofundergroundspace,transportationnetworkJoined bysurface andundergroundTransportation,Underground,Subway construction,networkUnderground,business district,recreation areas,Underground green spaceHuman underground living space,The sketch shows the purposes structure,of sub-surface development,连,远郊及邻区高速公路网络,地表或地下的郊区汽车停车场,地下空间开拓地下铁道建设,城市地面交通网地表与 交地 通下 网相 络,地下商业区,地下娱乐区,地 下 绿 地人类地下生存的地下空间中国城市地下空间开拓的功能示意图,In long and deeptunnels,the most,important problems arerelated to geo-,environment andgeohazards,二、主要几种地质环境对,隧道工程的影响,SEVERAL MAIN GEO-ENVIRONMENTS TOINFLUENCE TUNNELS,在长、大、深埋的隧道（隧洞）建设中，遇到的地质环境问题是多方面的,既影响到工程造价、工期，也危及隧道的施工与运行期间的安全,1SAND AND GRAVEL,FORMATION,1砂卵石层地基,砂性基岩的稳定问题,STABILITY OF SANDFOUNDATION,砂卵石层为渗流的动水压力冲刷管涌的分析,LIQUEFACTION AND PIPINGHAZARD OF SAND,FOUNDATION IN SUBWAYCONSTRUCTION,It is needed to,point out that thefeatures of threephrases flow.,三相流,THREE PHRASES FLOW,0,For the compressed gas mass:,ddt,t,+,Vx,x+,y,Vy+,z,+Vz,所以,div V=,-1 d dt,When the start velocity V0 0,then the compressed gas mass has aspeed trend.,For the un-compressed waterand rockmasses:,Vz+z,Vxx,+,Vyy,0,(density)=,ddt,0,div V 0,o,Compressed gas mass pressure Pa：,Pa a A Pof(Ra,a)dA,(8.34a),，f(Ra,a)dA气团体积变化函数；Po原始压强；o原始密度；Pa高压气团压强；a高压气团的密度。,式中，GE上面覆盖的可能破坏的岩土体重力；GR库水作用下可增加荷载重力。所以：,R,ao,A(GE+GR)f(Ra,a)dA,(8.36),产生气爆地震类型时，需要使,产生的气爆剪切破坏力a为：,-,a(a)+Fa CR(8.36),式中，Fa产生诱发地震破裂岩体的断面面积；CR破坏岩体,的凝聚力。,j=1,By multi-factors to evaluate the earthquake,to be caused by the reservoir,Ce(,n R Iii=1,mPIi/n+R Dj PDj/m)/2,(8.37),Es=EwCeKc,式中Ce对比评判系数；RIi间接因素i项的比值；PIi 间接因素i项的权重；RDJ直接因素j项的比值；PDJ间接因素j项的权重；Kc岩溶发育中差异系数；Ew地震条件方面差异系数；Es预测地震震级。,地下水等水位线图,成都市第四系潜水,砂卵石层对隧道工程的危害主要有：,（1）隧道施工排水引起周边沙层的机械管,涌与塌陷；,（2）沙层的溃入诱发大量地下水邻近河,水的溃入；,（3）不同结构的沙层地质，诱发不均匀沉,陷，影响隧道安全；,（4）沙层中夹有大块卵石对盾构施工产生,影响，甚至卡住刀片,The hydrodynamic conditions,of percolating flow in sandand gravel formation are,easily caused the liquefactionand piping,when the tunnelsto be digging to through them.,For the higher dynamic,condition and the,liquefaction feature of sand,deposit in larger river,therefore it is not suitable to,construct the tunnel by,immersed tube method.,湍急河道下砂卵石层对隧道安全分析图,长江中，水流湍急。在砂卵石层中开挖槽，建沉管法隧道砂卵石层不易保持边坡稳定河流中，砂卵石层易于蠕动使上覆卵石层厚度发生变化沉管底砂卵石层，易受流速快的砂卵石层中水流的绕流，而发生潜蚀，使沉管产生不均匀的压应力而破坏,对厚的砂层进行隧道明挖时，需要考虑三个问题：,（1）抽水初始水位下降诱发潜蚀、冲刷和地,面沉降；,（2）大量抽水后，水位下降缓慢，形成压力水头H，这时易于诱发下部的大量砂层溃入；,（3）下部有相对隔水层时，由于上部隧道抽水降低水压，下部高压水汇合；透水层隆起，产生向上大量越流补给，危及隧道的运行,For the sand formation to bedigging,the harmfulphenomena will appear inthree ways:,1.The ground water table may,decrease by pumping to appearthe piping;,2.The ground water table will contain,the water head for the much waterflow to be pumping in tunnel orfoundation pit;,3.By pumping for long time,the lower,confined,sand and gravel aquifermay happen the leakage flow tothe bottom of upper tunnel tocause more hazard.,砂层对隧道（深基坑）产生灾变危害分析图,Analysis of the sand formation to harm,the foundation pit(deep foundation),A-collapse zone of tunnel roof,B-piping zone in tunnel both sides,C-strong water-sand invasion zone,D-emerging leakage water-sand zone in tunnel bottom,2软土地基,2SOFT CLAY FORMATION,For the higher watery,feature of soft clay,the mostimportant problem is theliquefaction and creep,deformation to influence thefoundation stability.,A tunnel under the lake in softclay formation,owing to thestones about 20 cm to,influence the shield to cut thesoft clay,then the collapsewas happened,and the lakewater was invaded into thetunnel.,Shield tunneling,Analysis of the water invade induced by,the creep deformation resulted fromtunnel driving in soft clay formation,软土基础的,稳定性问题,Stability of soft soilfoundation of atunnel,The larger stone in soft soil to,influence the shield in normal,在滨海相、湖相古地质环境中：,沉积的软土多处于相对运动缓慢,或相对停滞的水环境中,颗粒细，孔隙度大，土质软弱，,含水量大,易于产生蠕变，凝聚力很小，基,本上可不计,在这种土层中修建隧道，需要考虑的工程地质问题有：,（1）土性软弱，经受隧道的荷载易于产生沉,陷，由于厚度变化，产生的不均匀沉陷对隧道内衬砌等结构造成形变；,（2）由于软土的蠕变也会对隧道的结构产生,影响，及时衬砌和支护都是非常重要的；,（3）软土经常处在地下的还原环境下，微生,物作用等易于产生甲烷气体，这些气体聚集于软土层空隙中，隧道掘进时易发生有害气体的溃入，甚至遇到火种后引起爆炸,上海地区软土层中存在甲烷气的,地质剖面图（叶为民等，2001）,对于软土，当隧道长度不长时，利用盾构易于穿越,若隧道穿越软土的长度较长时，由于软土的蠕变特性，会产生超量切削，于是在隧道盾构掘进的前方会产生蠕变凹槽,若软土层厚度不太大时，易于诱发上部海水活河水大量溃入隧道。,盾构穿越软土层，风险是必须要考虑的,For the feature of soft clay,formation,to dig the long tunnelby shield method,the,dangerous trend is to form thedepression in the soft clay andto lead the sea water or lakewater to harm the tunnel.,软土层掘进隧道产生蠕变凹槽诱发溃水灾害分析图,Other ways,the tunnel insoft clay bed,the unevenland subsidence in a veryimportant problems,whichmay cause the harm to thetunnels.,软土基础的不均匀沉降,（陈基炜和詹龙喜，2000）,Uneven land subsidence in soft clay,formation,（Chen Jiwei,Zhan Longxi,2000）,For the long tunnels underthe sea water,the activityof fault,earthquake,arealso needed to study.,海底盾构诱发海水入侵机理分析,For the long tunnels,under the sea water,theactivity of fault,earthquake,are alsoneeded to study.,3碳酸盐岩地层,3KARSTIFIED CARBONATE,ROCK FORMATIONS,Resulted by the five pairs ofspecial feactures related tokarst water:,五个对立统一特征,1.The isolated and semi-,isolated water flow and,the unified water table,It has been shown in plenty of informationin China that karst water flows in not a fewareas not only stand in isolated and semi-isolated situations but also have the sameunified ground water table.Both exist inunification under specified conditions whenthe Earths crust is stable;otherwise,theywill convert to each other.,Karst water flow under aunified ground water tableoften converter into,separate water flows due tothe uplifting of the earthcrust and the undercuttingof the river valley.On thecontrary,isolated and semi-isolated water flows may,also be converted into waterflow with unified groundwater table due to thesubsidence of the earthcrust.,2.The aquiferous andnon-aquiferous rock,bodies,Owing to the varied tectonic disturbance,inthe soluble rock body exist both aquiferousand non-aquiferous bodies which,interconvert to each other during the karstprocess.The chemical deposition anddetrital material filling during the karst,process may cause the aquiferous body totransform into non-aquiferous body.,Thus occur the following conditions;1)non-aquiferous body with nocave development;,2)non-aquiferous body with eavesbeing filled or confined(some withdead closed water locally);,3)fissure-aquiferous body with nohuge cave development;,3.The confined and,unconfined water flows,In the same aquiferous body,because of thedifference in karst development,some waterflows are unconfined and others confined,both of which can be converted into eachother during the karst process.The intensesolution may cause the confined water toconvert into the unconfined water flow,whereas the filling of the,chemical and elastic depositionmay cause the unconfined waterto convert into confined waterflow.Hence,it seems likelyunadvisable to consider theupper ground water as simplyunconfined.,4.The laminar flow and,turbulent flow in the same,bodyIn the same aquiferous body,themovement of water flow belongs either tolaminar or to turbulent.But the aquiferousbody as a whole generally belongs tolaminar flow,The average coefficient of permeability ofthe karst aquiferous body in large,dimensions is commonly less than 1 m/daywhich belongs to laminar flow.In some,sections where 5 m/day,the movement ofwater flow belongs to turbulent.The,characters of water flow movement in someareas are included in table 1.,5.The homogeneous,aquiferous body and,concentrated influent,passage-way,It is not infrequent that in a homogeneousaquiferous body with a unified ground watertable,there exists some concentrated influentpassage-way that tends to change the localmoving direction of the ground water leadingto the appearance of trough on the plan andprofile of water lever(Fig.1).,A,B,C,D,E,1,28,39,410,511,612,7,在可溶的碳酸盐岩地层分布地,区，有不同程度的喀斯特化作用：,地表有奇特山峰,发育了许多地下洞穴与通道,这些活跃在洞穴通道中的喀斯特水，有裂隙水和孔隙水，具有不同的特性。,喀斯特水的五个对立统一的特性是：,（1）孤立、半孤立的管道水流与具统一,水力联系的地下水力面和扩散流共存；,（2）含水岩体与不含水岩体共存；,（3）承压水流与非承压水流相互转化；,（4）紊流运动与层流运动共存；,（5）均质含水性与非均质含水性复杂变,化,AD,B,E,C,1,28,39,410,511,612,7,喀斯特含水岩体中五个对立统一特性分析图（卢耀如，199,The most important,problem of the tunnel to beconstruction in karstifiedcarbonate rocks is the,water-soil-sand invasion.,1.,2.,3.,4.,5.,The Conditions are usually happened:The closed water with higher pressureto harm the tunnels;,The larger karst flow to harm thetunnels;,The upper karst ground water river toharm the tunnels;,The small karst passage ways water toharm the tunnels,The larger fault water to harm thetunnels.,在喀斯特化地层上，还存在着更明显的三相流，即固体、液体和气体三相物质混合而成的三相流,三相流的一个重要特性是，固体流（泥、沙）和液体（水）是不可压缩的，而气体是可压缩的，就产生速度势，受压气体也是不断变化的,The hydrodynamic,features of solid fkloq,固体流运动力学基本特性,通常洞穴通道形态是不规则的，水流的动力状态也是多变的。,洞穴水流遇到早期沉积的颗粒时，就会产生绕流现象,当流速达到摩擦门限值时的水动力Pw，就能克服摩擦阻力Fm，对颗粒产生推动力，从而产生起始滑动，而后上举力PE使颗粒悬移运动。,水流起动临底流速与断面上平均流速有一定关系。整个过水断面上起动流速与水密度、颗粒大小、水头等有关,Pw=f(m)Pw Fm=PxPx=f(x,d,s,C1)PE=C 2 Px 0=f(d,h,K C1),（1）（2）（3）（4）（5）,0=f(g,s,d,K C 2)（6）,Hi,Si,i,洞穴通道三相流的水力特性,The hydraulic features ofthree phrases flow in karstpassages,如果洞穴通道中水流可分n段，每段(i)都有原始流速和末端实际流速，则水流速度变化为：,=0i exp(ki),对n段来讲，有：,n=01e,ak 1I1,e,aK 2 I 2,e,ak(n 1)I n 1,e,akn I n,即,nn=01 ei=1,aki Ii,由于洞穴通道断面与坡度大小的不断变化，加上固体颗粒运移时的能量消耗，因此流速是不断变化的。例如：跌水处产生重力加速度g，而获得流速：,i=0(i 1)+2gH 01,在洞穴通道中，地下瀑布、跌水冲击洞底，加上回流、涡旋和水滚等现象，又可降低水流速度,所以，随着洞穴中水流速度的变化，不断由三相流中产生固体颗粒所构成固体流的运移、沉积、再运移、再沉积的不断变化。,x,z,y,气相流的力学特性The mechanical features ofgaseous mass三相流中固体流是不断变化的，而气相流的变化更迅速。因为对液相流和固相流而言，可看作不可压缩的，应用连续性方程,表示，则：,+x y z,=0,d,t x,y,z,密度为常数时，有：d=0dt,或,div=0,对可压缩的气相流(气团)而言，则为：=+x+y+zdt,div=,1 d dt,2 2 2,x,y,z,在三相流中，被压缩产生体积变化的气体(泡或团)的起动速度可以0,计，起始压缩时存在速度势，则：,=2+2+2=div,由受压气团密度变化，产生速度势P而得到了弹性波速：,向上运移时：,ac=,s,ac,=,z,p u 2,三相流中浮移的气团，遭受浮力PB为：PB=gVa在大洞穴中，由于水位、水动能的增加，可使原先处于敞开的气体转变为处在半密闭空间的压缩气团，而相混运移，或在一定环境中，被封存成高压气团，所需压缩动能水头为：,H pa,=+2 g,10m,2,=2,三相流中气泡(团)压缩改变体积时，除了气泡自身势能以外，可引起水流流向气泡中心，作径向运动，这就改变一些水流的方向，其速度势为：,=,R dRr dt,液体向气泡中心运移的径向速度为：,L=,R 2 dRr r dt,洞穴三相流中，由于可压缩气相流的生成、弹性变形、浮移、混合与压缩等现象的发生，在总的动力条件下，不断产生局部流态的变化，也影响到化学沉积、固体径流的运移与沉积。因此，在喀斯特化地层中掘进隧道，就很容易产生向隧道突水、突泥，甚至产生大块暗河中石头的崩入，造成重大灾害,天然岩溶塌陷,Natural karst collapses,1.碳酸盐岩自身重力塌陷(1)梁状洞顶塌陷(2)穹状洞顶塌陷(3)多层洞顶塌陷,在不同的地质条件中，河流、平原、盆地、滨海地带，都有不同成因的砂卵石层沉积,受沉积时古地理地质环境影响，各地砂卵石层的结构也不尽相同,砂卵石层的颗粒级配、沉积韵律与沉积时的水动力条件密切相关,a,b,c,d,e,喀斯特化地层向隧道突水、突泥的几种情况（a）封存喀斯特水-泥土溃入隧道；（b）富水喀斯特通道突水入隧道；（c）上部暗河突水、泥-石块入隧道；（d）喀斯特水管道水多处突入隧道（e）断层带突水入隧道1.喀斯特通道；2.封闭喀斯特水泥的溶腔；3.喀斯特泉水；4.喀斯特暗河出口5.隧道；6.河水位；7.突水突泥方向,KARST COLLAPSES IN THE DEPRESSIONCAUSED BY DRAINING KARST WATER FROM,THE DAYAOSHAN RAILWAY TUNNEL,KARST COLAPSE FORMED IN THE QUATERNARY BEDAT,THE DEPRESSION ABOVE THE DAYAOSHAN TUNNEL 650 M,THE DAYAOSHAN DOUBLE TRACK TUNNEL BEEN,COVERD BY SAND,WHICH WAS EMERGINGTOHETHER WITH THE KARST WATER FROM,HIGH KARST PASSAGES,SKETCH OF EMERING KARST WATER AND CLAY-SAND INTO DAYAOSHAN RAILWAY TUNNEL,600 M,Emerging karstwater and and-clayinto tnnel,Artificial shaft,Karst depression andkarwst collapses,C11W46,槽谷及其编号洼地及其编号,S+DP22+T1,P1,P21,车心洞,小 函隧道W45W44,W46,C13,飞水涯C12C11毛家院子,W38W37,W39,W51,C10,W47,W43,W35,W36,W34,W33,C9,W40,W41,W42,W30,W29,C8,W24,W25,W26,W32,W31,W49,W22C7,W21,茨竹坝,W23,W27,W28,C6,W19,W20W18,C5,C14,毛坝,C4W17,W16,苍薄堂,W14,W15,C3,W13,W48,C2,W11,W12W50,C1黄家槽,W10W7,W9,W8,W6,W2,W3,W4,W5,衬砌台车被推移了200米,4#溶洞4#溶洞是由多个小岩溶溶隙组成的溶隙群段，该溶洞开挖施工后，受降雨影响，多次发生大规模涌水涌泥。,5#溶洞2001年7月14日，隧道突发大规模涌水突泥，最大涌水量2万m3/h。涌水涌泥持续28分钟后渐小，涌泥量1.5万m3。随后进行超前探孔时，由探孔中再次发生突水喷泥，喷射距离达40m。,装载机被推移了500米后，倾覆。,突出的巨石块达到了1立方以上,渗水流量为1立方米/秒,大瑶山突水灰岩段涌水,正洞溶洞涌泥,平导岩溶涌水,野三关隧道突水突泥,灾害情况照片,出口水流,事故发生后48小时候隧道出口流水情况,隧道出口,突泥突水的过水线,突水、突泥伴有大量泥砂块石涌出,正洞出口涌水情况,衬砌台车被推移了200米,突出的巨石块达到了1立方以上,渗水流量为1立方米/秒,三、隧道建设中几个重要的问题,SOME IMPORTMENTPROBLEMS INTUNNEL,CONSTRUCTIONS,1.地质环境对地下空间（隧道）,开拓的影响,DEVELOPMENTS OFSUB-SPACES TO BEINFLUENCED BY,GEO-ENVIRONMENTS,1.地质环境对地下空间（隧道）,开拓的影响,地下水侵蚀性及对水泥的侵蚀性；地下有害气体对地下空间的侵害；地震对地下空间的影响；,地热场对地下空间开拓的影响；构造活动性对地应力的影响；地下岩体的放射性。,2.隧道等地下空间的开拓,应当注意的方面,IMPORTMENT WAYSFOR TUNNEL,CONSTRUCTIONSMUST BE PAYUINGMORE ATTENTIIONS,2.隧道等地下空间的开拓,应当注意的方面,城市安全。地下空间开拓应以考虑大都市的安全与可持续发展为重要原则；,科学研究。地下空间开拓中应加强科学程序的协作；,防治事宜。地下空间开拓中要注意诱发灾害，防微杜渐；,风险机制。地下空间开拓中进行风险评价和风险管理。,建 议,隧道和其他地下空间的开拓，都应当要以地质环境作为规划、设计与施工的重要基础,应当依据地质环境的特性及可能诱发的有关问题进行科学地规划与设计,工程的处理措施也要考虑地质环境特征，许多实例说明，不认真研究地质生态环境，所建设的隧道等地下工程必定会带来不良的地质环境效应，反而引起环境的破坏。,SUGGESTIONS,地下空间开拓,（地铁建设类）要重视地质生态环境效应的一个建议,开拓决策,一、大都市空间开拓是发展形势所趋，,但不可草率从事、急功近利。规划基础,二、地质生态环境应是规划地下,空间开拓的重要基础,地质条件,三、地下空间开拓应是认真进行,地质环境与地质灾害的评估,综合效应,四、地下空间开拓应综合研究大都市建设的综合地质环境效应,城市安全,五、地下空间开拓应以考虑大都市的,安全与可持续发展为重要原则科学研究,六、地下空间开拓中应加强 科学程,序与协作,防治时宜,七、地下空间开拓中要注意,诱发灾害的防微杜渐,风险机制,八、地下空间开拓中进行风险评价,和风险管理,The mechanic stabilityof cave related to thetunnel is needed totake the protection.,For the tunnels,it isneeded to consider:,1.Development policy;2.Planning bases;,3.Geological condition;,4.Comprehensive impacts;,5.City(and engineering),safety;,6.Scientific research;7.Hazards prevention;8.Risk evaluation and,risk management.,